Implementation of indicators of marine litter impacts on sea turtles and biota in Regional Sea Conventions and Marine Strategy Framework Directive Areas : final report.
Date: 2020-04-02
Institutions: Directorate-General for Environment
Subjects: Atlantic Ocean, Baltic Sea, Mediterranean Sea, data collection, directive (EU), environmental impact, environmental indicator, environmental protection, marine ecosystem, marine environment, marine life, marine pollution, protection of animal life, reptile, research method

Implementation of indicators 
of marine litter impacts on sea 
turtles and biota

in Regional Sea Conventions and Marine Strategy 
Framework Directive Areas

Final Report

Darmon G INDICIT Consortium and Miaud C 
January 2017 - February 2019

INDICIT Consortium (alphabetical order):
Hedia Attia (INSTM), Mohamed Nedjmeddine Bradai (INSTM) , Andrea Camedda (CNR-IAMC), Françoise 
Claro (MNHN)*, Olfa Chaieb (INSTM), Gaëlle Darmon (CEFE-CNRS/EPHE)*, Giuseppe Andrea de Lucia 
(CNR-IAMC), Helen Kaberi (HCMR), Yakup Kaska (PAU DEKAMER), João Lagoa (IMAR, Portugal), Ana 
Liria Loza (ULPGC) *, Claude Miaud (CEFE-CNRS/EPHE)*, Maria Luz Paramio Martin (XX), Christopher 
Pham (IMAR, Portugal), Marco Matiddi (ISPRA)*, Juciaëlle Moussier (MNHN)*, Olga Novillo (UVEG), 
Patricia Ostiategui (ULPGC), Raffaella Piermarini (ISPRA), Ohiana Revuelta (UVEG), Yasmina Rodriguez 
(IMAR, Portugal), Cecilia Silvestri (ISPRA)*, Dogan Sozbilen (PAU DEKAMER), Jesús Tomás (UVEG), 
Catherine Tsangaris (HCMR), Maria Vale (FRCT), Frederic Vandeperre (IMAR, Portugal).
* Activity leaders

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Luxembourg: Publications Office of the European Union, 2020 

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Acknowledgements 

The  INDICIT  consortium  gratefully  acknowledges  the  following  persons  and  institutions  for  their  precious 
support in the achievement of the project objectives, thanks to their participation in the collection of data, their 
advice and their improvement of the documents and tools. 

Our heartfelt thanks to: 

-  Our collaborators, for the support in the collection of specimens and samples and for sharing  scientific 

expertise:   

France:  Florence  Dell’Amico  (CESTM  Aquarium  La  Rochelle,  France),  Delphine  Gambaiani  (CESTMED/EPHE, 
France), Jean-Baptiste Senegas (CESTMED), Sidonie Catteau (RTMMF), Jacques Sacchi (RTMMF), Cathy Cesarini 
(RTMMF), Jo Befort (Laboratoire vétérinaire du Gard), Jean-Marie Péricard, fishermen involved in recovering sea 
turtles, all volunteers of stranding networks. 

Greece: Reggina Stefanatou (ARCHELON, Τhe Sea Turtle Protection Society of Greece) 

Italy: Sandra Hochscheid (Stazione Zoologica Napoli); Cristiano Cocumelli (Istituto Zooprofilattico Sperimentale 
Lazio e Toscana); Ludovica Di Renzo (Istituto Zooprofilattico Sperimentale Abruzzo e Molise); Santo Caracappa 
(Istituto Zooprofilattico Sperimentale Sicilia), Giorgio Massaro, Roberto Brundu (Amp “Penisola del Sinis – Isola 
di Mal di Ventre), Stefania Coppa, Luca Palazzo (National Research Council - CReS – Centro di Recupero del Sinis), 
Angelo Ruiu (Istituto Zooprofilattico della Sardegna, Oristano), Paolo Briguglio (Clinica veterinaria “due mari” 
Oristano), Flavio Gagliardi (Acquario di Cala Gonone), Maria Ledda, Sergio Masala (Assessorato per la Difesa 
Ambiente della Regione Sardegna), Corpo Forestale e di Vigilanza Ambientale, Coast Guard and all the Sardinian 
Regional Network (Marine Protected Areas and National Parks), all the citizens and fishermen who contributed 
to the recover and conservation of sea turtles around Sardinian coast. 

Spain: Francesc Domènech and the members of the Marine Zoology Unit of the Cavanilles Institute (UVEG); 
Conselleria de Medio Ambiente, Agricultura, Canvio Climático y Desarrollo Rural de la Generalitat Valenciana; A. 
Casquet-Pérez  (CRAM  Foundation),  Carolina  Fernández-Maldonado  (CEGMA),  Eva  M.  Morón-Manchado 
(EQUINAC);  M.  J.  Gens-Abujas  and  Fernando  Escribano-Cánovas  (CR  El  Valle);  Gloria  Fernández  (Palma 
Aquarium); J. L. Crespo J. and V. Marco (Oceanografic Foundation); J. J. Castillo-Martín (CREMA).  

Portugal:  RACA,  Flying  Sharks,  Thomas  Dellinger  (University  of  Madeira),  Cláudia  Moreira  (University  of 

Madeira) and all voluntaries of stranding networks. 

Tunisia: Garde nationale tunisienne, Agence de protection et d'aménagement du Littoral, Centre national de 

veille zoologique, Association jeunes sciences kerkennah (Dr Sami Karaa), Association Notre Grand Bleu 

Turkey: EKODOSD (Ekosistemi Koruma ve Doğa Sevenler Derneği); AKUT Bodrum Association, Bodrum Branch 

Office. 

- 

The members of the External Advisory Board, for their advice: 

Benjamin  Guichard  (AFB,  France),  Filipe  JM Porteiro  (DRAM),  Gilberto  MP  Carreira  (DRAM),  Marco  Aurelio 
Santos (DRAM), Ana Tejedor Arceredillo (EEA), Jesus Gago (IEO), François Galgani (TG ML, IFREMER, France), 

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Marta Martínez-Gil Pardo de Vera (MAGRAMA), Isabelle Terrier (MTES, France), Oliviero Montanaro (MATTM, 
Italy),  Roberto  Giangreco  (MATTM,  Italy),  John  Mouat  (OSPAR),  Philip  Stamp  (OSPAR),  Lobna  Ben  Nakhla 
(RAC/SPA), Stefanie Werner (TG ML), Tatjana Hema (UNEP/MAP), Christos Iokeimidis (UNEP/MAP). 

-  Mr Michail Papadoyannakis (European Commission, Marine Environment and Water Industry, Directorate 
General Environment), Policy Officer, for scientific advice and recommendations for a better coherence 
with MSFD requirements, 

The  INDICIT  consortium  also  warmly  thanks  the  administrative  teams  for  their  precious  support  in  the 

coordination of the project:  

France  (CNRS) :  Richard  Joffre,  Chloé  Richard,  Elodie  Vatonne,  Mathilde  Büchler,  Marjorie  Gadéa,  Mélanie 

Dumeige 

Greece (HCMR): Roula Frangou 

Italy:  Andrea  Fabbri  (financial  manager  ISPRA)  Giuseppe  Tedesco  (ISPRA),  Lucia  Gigante  (ISPRA)  and  Emi 

Morroni head of the Department Bio (ISPRA) 

Spain: Ángeles Sanchís, Sebastián Torrijos, Pablo Aller and the staff of the OPER-UVEG 

Portugal: (FRCT): Francisco Pinto, Natividade Machado, Fábio Vieira 

European  Commission, Marine  Environment  and  Water  Industry,  Directorate  General  Environment:  Cecile 

Leroy 

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Project Full Title 

TURTLES AND BIOTA IN RSC AND MSFD AREAS  

IMPLEMENTATION  OF  THE  INDICATOR  OF  MARINE  LITTER  ON  SEA 

Project Acronym 

INDICIT 

Grant Agreement n° 

11.0661/2016/748064/SUB/ENV.C2 

Coordinator, institution 

C. MIAUD and G. Darmon EPHE-CNRS 

Start date, duration 

1st February 2017, 24 months 

Project website 

https://indicit-europa.eu   

Deliverable n° 

Status: 

Final (F) 

Draft (D) 

D1.11 

Deliverable Date 

31/03/2019 

Revised draft (RV) 

 (RV) 

Dissemination level: 

Public (PU) 

Restricted 

to  other  program 

participants (PP) 

Restricted  to  a  group  specified  by 

the consortium (RE) 

 (RE) 

Confidential,  only  for  members  of 

the consortium (CO) 

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Table of content 
Acknowledgements ............................................................................................................................................................... 4 
List of tables .......................................................................................................................................................................... 8 
List of Figures ......................................................................................................................................................................... 9 
List of acronyms ................................................................................................................................................................... 10 
Context ................................................................................................................................................................................ 12 
Introduction ......................................................................................................................................................................... 12 
The INDICIT project. ............................................................................................................................................................ 13 
1. INDICIT project: Structure and approaches ..................................................................................................................... 15 
1.1. General presentation of the project ............................................................................................................................. 15 
Coordination and internal organization ................................................................................................................ 19 
1.2. 
Communication outputs ....................................................................................................................................... 22 
1.3. 
Achievement of expected deliverables ................................................................................................................. 24 
1.4. 
2. Implementation of indicator “Litter ingested by sea turtles” ......................................................................................... 25 
2.1. A pilot study for refining the action plan ...................................................................................................................... 25 
2.2. Networking ................................................................................................................................................................... 26 
2.2.1. Situation at the beginning of the INDICIT project ............................................................................................. 26 
2.2.2. Training sessions for collecting data on litter impacts on sea turtles ............................................................... 27 
2.2.3. Listing stakeholders already or possibly in charge of monitoring and conditions for involvement ................. 27 
2.2.4. Recommendations for networking ................................................................................................................... 29 
2.3. Elaboration of a standardized protocol for monitoring litter impacts on sea turtles .................................................. 30 
2.3.1. Proposition of a common methodology ........................................................................................................... 30 
2.3.2. Dissemination of the standardized methodology for monitoring litter impacts .............................................. 32 
2.3.3. Costs and recommendations ............................................................................................................................ 33 
2.4. Data banking ................................................................................................................................................................. 33 
2.4.1. Procedures used during INDICIT project for data gathering and cleaning ....................................................... 33 
2.4.2. Summary of data collected ............................................................................................................................... 34 
2.4.3. Synergy with CleanAtlantic project for data banking ....................................................................................... 36 
2.5. Analysis of the indicator’s constraints .......................................................................................................................... 36 
2.5.1. Data on the leatherback turtle ......................................................................................................................... 37 
2.5.2. Possible discrepancies in the methodologies used to collect samples from live individuals ........................... 37 
2.5.3. Results on litter ingestion observed in necropsied individuals ........................................................................ 39 
2.5.4. GES scenarios .................................................................................................................................................... 50 
2.6. Summary of recommendations .................................................................................................................................... 55 
2.6.1. Networking ....................................................................................................................................................... 55 
2.6.2. Harmonisation of data collection ..................................................................................................................... 56 
2.6.3. Data banking and cleaning ................................................................................................................................ 57 
2.6.4. Need of further analyses to evaluate GES scenarios and indicator’s constraints more accurately ................. 57 
Feasibility studies of other marine litter impact indicators ...................................................................................... 58 
Indicator “Entanglement by biota with marine litter” .......................................................................................... 58 
Indicator “Micro-plastic ingestion in fish and sea turtle” ..................................................................................... 60 
In fish ............................................................................................................................................................ 60 
In sea turtles ................................................................................................................................................. 61 
4. From INDICIT to INDICIT-II ............................................................................................................................................... 62 
5. References ....................................................................................................................................................................... 62 
Appendix 1 – INDICIT deliverables time table ..................................................................................................................... 68 
Appendix 2 – General definitions ........................................................................................................................................ 70 
The Marine Strategy Framework Directive ......................................................................................................................... 70 
Definitions for MSFD Descriptor 10 “Marine Litter”. .......................................................................................................... 71 
Marine taxa used as bio-indicators of marine litter impacts in MSFD and RSCs ................................................................. 72 
Status of the indicator “Litter ingested by sea turtles” in the Regional Sea Conventions concerned by INDICIT project .. 73 
OSPAR ......................................................................................................................................................................... 73 
Barcelona convention ................................................................................................................................................. 73 
HELCOM ...................................................................................................................................................................... 74 
Summary of the European project INDICIT outcomes ............................................................ Error! Bookmark not defined. 

3. 
3.1. 
3.2. 

3.2.1. 
3.2.2. 

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List of tables 
Table 1: Members of INDICIT external Advisory Board (as presented in the proposal; in grey, new members added during 
the project) ............................................................................................................................................................................. 20 
Table 2. Members of INDICIT Steering Committee (as presented in the proposal; in grey, new members added during the 
project) ................................................................................................................................................................................... 20 
Table 3. INDICIT meetings ................................................................................................................................................... 21 
Table 4. Categories of litter items (from INDICIT protocol, 2018) ....................................................................................... 30 
Table 5. Number of data collected from excretions of live loggerhead turtles in each area/country ................................ 35 
Table 6. Number of data collected from necropsied loggerheads in each area/country.................................................... 35 
Table 7: Mean prevalence (%) and dry mass (grams) evaluated from excretions of live turtles in rescue centres per area 
and country (table “Faeces” of the INDICIT standard database) ........................................................................................... 38 
Table 8: Mean prevalence of litter ingestion (%) and dry mass of ingested litter (plastics, in grams) evaluated from the 
necropsies of loggerhead turtles per area and country (table “Necropsies” of the INDICIT standard database) ................. 40 
Table 9: Circumstances of discovery of the dead individuals per area and per country (all data pooled) ......................... 42 
Table 10: Stages of dead individuals sampled (all data). [Range and mean of standard curved carapace length (StCCL) and 
range and mean of minimum curved carapace length (Min CCL) in cm. Number of individuals per stage (Stage 1: 20 cm; 
Stage 2: ]20-40 cm]; Stage 3: ]40-60 cm]; Stage 4: ≥60 cm)]. ................................................................................................ 43 
Table 11: Percentage of necropsied individuals with more litter than food remains (dry mass) ....................................... 46 
Table 12: Models predicting the occurrence of litter ingestion and the dry mass of ingested litter (with log transformation) 
according  to  Area  (Atlantic/Mediterranean),  Country  and  StCCL  (Standard  Curved  Carapace  length)  for  necropsied 
loggerheads. Models are selected using Akaike's Information Criterion (AIC). ..................................................................... 47 
Table 13: Mean mass of ingested litter standard error ..................................................................................................... 48 
Table 14: Main results on necropsied loggerhead turtles from data after 2013 included to January 2019. [Means per area 
and country of: prevalence (mean percentage of turtles found with ingested litter), dry mass (mean dry mass of ingested 
plastic    standard  error),  dry  mass  per  StCCL  (x10),  and  percentage  of  turtles  having  more  plastics  than  food  remains, 
calculated at the population level. Minima are highlighted in light red. In grey, the results of the countries where the 30 
turtles proposed by INDICIT consortium as a minimum sample size are not achieved. ........................................................ 52 
Table 15: Pro and cons of the main GES scenarios discussed by INDICIT consortium. ....................................................... 53 

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List of Figures 
Figure 1. Distribution of partners represented in INDICIT consortium (FRCT, ULPGC, UVEG, MNHN, CNRS, ISPRA, INSTM, 
IAMC-CNR, HCMR, PAU-DEKAMER. FRCT subcontracted IMAR to provide scientific expertise. ........................................... 16 
Figure 2.  Inter-relationships among the five Activities ....................................................................................................... 16 
Figure 3: Boxplot (mean 1st and 3rd quartiles) of the standard curved carapace length of turtles sampled per area and 
country (all data pooled) ........................................................................................................................................................ 43 
Figure 4. Mean dry mass of ingested litter (plastics; g) (left) and prevalence of litter ingestion (%) (right) in necropsied 
loggerhead turtles over years from 1988 to present ............................................................................................................. 44 
Figure 5: Scatter diagrams of the projection of each parameter scores of the Hill and Smith method on a vector basis .. 46 
Figure 6. Temporal variations of the main plastic categories found in loggerhead turtles ................................................. 48 
Figure 7: Mean dry mass (g) of ingested litter evaluated in the population according to number of data selected randomly
 ................................................................................................................................................................................................ 49 
Figure 8: Simulations of monthly distribution of floating litter across the Mediterranean Sea, examples in January and 
August. Red tones are used for particle accumulation. Grey and blue tones show emptying areas (from Mansui et al., article 
in review; Collaboration with MedSeaLitter project). ............................................................................................................ 50 

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List of acronyms 
AFB: French Agency of Biodiversity 

CEMP: Coordinated Environmental Monitoring Programme 

CleanAtlantic project: Tackling Marine Litter in the Atlantic Area, Atlantic Area Transnational Program 2014-2020 

CNRS: French National Scientific Research Council 

DG Env: Environment Directorate General Environment of the European Commission 

DRAM: Regional directorate of Sea Affaires of Azores government (Direção Regional dos Assuntos do Mar) 

EAB: External Advisory Board 

EMODNET: European Marine Observation and Data Network  

EU: European Commission 

EPHE: French School of Higher Studies 

FOO: Natural food for sea turtles (e.g., pieces of crabs, jellyfish, algae…) 

FRCT: Regional Fund for Science and Technology 

GES: Good Environmental Status 

GTMF: Working Group Marine Turtle France 

HCMR: Hellenic Centre for Marine Research 

HELCOM: Convention on the Protection of the Marine Environment of the Baltic Sea Area (Helsinki convention) 

IAMC-CNR: Institute for the Marine Coastal Environment of the National Research Council 

ICES: International Council for the Exploration of the Sea of OSPAR 

IEO: Spanish Institute of oceanography 

IFREMER: French Research Institute for Exploitation of the Sea 

IMAR: Institute of Marine Research 

INDICIT: European project “Implementation of the indicator of marine litter on sea turtles and biota in RSC and MSFD areas 

(Indicator Impact Turtles)”. N° GA11.0661/2016/748064/SUB/ENV.C2 

INDICIT-II: European project “Implementation of the indicator of marine litter on sea turtles and biota in RSC and MSFD 

areas (Indicator Impact Taxa). No. 110661/2018/794561/SUB/ENV.C2 

IND PLA: Industrial plastic granules, usually cylindrical but also sometimes oval spherical or cubical shapes, or suspected 

industrial item, used for the tiny spheres (glassy, milky...) 

INSTM: Tunisian National Institute of Sciences and Technologies of sea 

ISPRA: Italian National Institute for Environmental Protection and Research 

ISTS: International Sea Turtle Society 

MAGRAMA: Spanish Ministry of Agriculture, Food and Environment 

MATTM: Italian Ministry of Environment  

MEDCIS: Support Mediterranean Member States towards coherent and coordinated implementation of the second phase 

of the Marine Strategy Framework Directive. 

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MEDPOL: Programme for the Assessment and Control of Pollution in the Mediterranean region of UNEP-MAP 

MedSeaLitter: Interreg  MED  Project  co-financed by the European Regional Development  Fund, for the development  of 
protocols  to  monitor  marine  litter  abundance  and  impacts  at  basin  and  local  scale  for  the  Mediterranean  Marine 
Protected Areas 

MEEM: French Ministry of Environment, Energy and Sea 

MISTIC SEAS (I & II): Macaronesia Islands standard indicator and criteria. Reaching common ground on monitoring marine 

biodiversity in Macaronesia 

MNHN: French National Natural History Museum 

MPA: Marine Protected area 

MSFD: Marine Strategy Framework Directive 

MSFD TG ML: Target Group Marine Litter of the Marine Strategy Framework Directive 

NFO: Anything natural, but which cannot be considered as normal nutritious food for sea turtle (stone, wood, pumice, etc.) 

OSPAR  convention:  Convention  for  the  Protection  of  the  Marine  Environment  of  the  North-East  Atlantic  (Oslo-Paris 

convention) 

PAU-DEKAMER: Turkish Sea Turtle Rescue Centre 

POM: Program of Measure 

RAC/SPA: Regional Activity Centre for Specially Protected Areas 

RSC: Regional Sea Convention 

ULPGC: University of Las Palmas de Gran Canaria 

UNEP-MAP: Mediterranean Action Plan of the United Nations Environment Programme 

USE FOA: All foamed plastics e.g. polystyrene foam, foamed soft rubber (as in mattress filling)… 

USE FRAG: Fragments, broken pieces of thicker type plastics, can be a bit flexible, but not like sheet like materials. 

USE POTH: Any other plastic type of plastics, including elastics, dense rubber, balloon pieces, soft air gun bullets… Specify 

in the column “Notes”. 

USE SHE: Remains of sheet, e.g. from bag, cling-foil, agricultural sheets, rubbish bags… 

USE THR: Threadlike materials, e.g. pieces of nylon wire, net-fragments, woven clothing… 

UVEG: University of Valencia 

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Context 
This report presents the outputs of the two-years INDICIT project (1st February 2017 – 31st January 2019), which 
aimed to support the Regional Sea Conventions (RSC) OSPAR, Barcelona and HELCOM and the Marine Strategy 
Framework Directive (MSFD) in the implementation of litter impact on marine fauna indicators. These indicators 
belong  to  the  Criteria  D10C3  and  D10C4,  according  to  the  New  Commission  Decision  2017/848/EC.  This 
document corresponds to the deliverable n° D1.11, the last of the project (deliverables listed in Appendix 1). 

Introduction 
Marine litter is defined as “any persistent, manufactured or processed solid material discarded, disposed of or 
abandoned in the marine and coastal environment”. Anthropogenic marine litter consists of items that have 
been made or used by people and deliberately discarded or unintentionally lost into the sea and on beaches 
including  such  materials  transported  into  the  marine  environment  from  land  by  rivers,  draining  or  sewage 
systems or winds (Commission Decision 2010/477/EU). It includes any persistent, manufactured or processed 
solid material, but does not include semi‐solid remains of for example, mineral and vegetable oils, paraffin and 
chemicals (see general definitions in Appendix 2). 

Anthropogenic marine litter, 60 to 80% of which being plastic, is an issue of global concern (Derraik, 2002). 
Ubiquitous in the marine environment (Cózar et al., 2014; Derraik, 2002; Eriksen et al., 2014), huge amounts of 
items are continuously entering the seas and oceans (Jambeck et al., 2015). Due to its semi-closed configuration, 
the Mediterranean Sea is particularly concerned (Galgani et al., 2015). More than 62 million floating litter items 
are evaluated to enter this sea (Suaria and Aliani, 2014). 

In addition to aesthetic and financial problems (Hardesty et al., 2015), litter pollution has a major ecological 
impact on marine habitats and fauna (Andrady, 2011a; Thompson et al., 2014; Vegter et al., 2014). The number 
of  species  known  to  be  impacted,  especially  because  of  the  ingestion  of  litter  or  entanglement  (Gall  and 
Thompson, 2015), increases with studies that invest on this issue: From 247 species listed in Laist’s review of 
1997, 663 species have been counted in 2014 and 690 in 2015 (Gall and Thompson, 2015; Laist, 1997; Thompson 
et al., 2014). All sea turtle species, about half of mammal species and one-fifth of sea bird species, but also fish 
and invertebrates, have been observed with impacts related to marine litter (Cole et al., 2013 ; Schuyler et al., 
2014; Thompson et al., 2014; Nelms et al. 2015), number of those concerned species being already classified as 
vulnerable or endangered on IUCN red list (e.g. sea turtle species).  

Various  reasons  may  explain  why  animals  are  entangled  in  or  ingest  litter.  They  may  confound  litter  with 
natural preys (e.g., Schuyler et al., 2014), or ingest such items by inadvertence, since litter could be mixed in the 
food  bowl  (Anastasopoulou  et  al.,  2013).  Plastic  durability  and  fragmentation  will  result  in  an  increase  of 
(secondary) micro-plastics (legacy items), defined as items below 5 mm (Barnes et al., 2009; Cole et al., 2011; 
Law and Thompson, 2014; MSFD GES TG ML, 2017; Thompson et al., 2004). This fragmentation will inevitably 
facilitate the ingestion of plastics by a greatest part of the food chain (Botterell et al., 2019; Vroom et al., 2017).  

The impacts of plastic ingestion on health are still poorly understood. Direct mortality, caused by perforation 
or  obstruction  of  the  digestive  system  seems  relatively  rare.  Sub-lethal  effects  are  more  likely,  such  as 
pathologies or changes in feeding and movement behaviours. Upon consumption of plastic items, the chemical 

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components constituting them, and the chemicals and metals they absorbed in the environment, may diffuse 
into  the  marine  organisms’  body  (Rochman,  2015;  Rochman  et  al.,  2013a,  2013b;  Tanaka  et  al.,  2013). 
Mechanistic (e.g., obstruction, lack of an essential quantity of nutrients)  and toxicological impacts related to 
plastic ingestion may lead to a decrease in body condition and may then affect individuals’ chances of survival 
and reproduction. Possible repercussions on populations and trophic chain are conceivable, but difficult to prove 
quantitatively. 

The characteristics and quantity of litter ingested by sentinel organisms can reflect the spatial and temporal 
trends of litter in the environment, and made available to organisms. Plastic ingested by the fulmar Fulmarus 
glacialis  is  a  bio-indicator  for  the  OSPAR  Regional  Sea  Convention  (RSC)  (EcoQO  3.3;  OSPAR,  2009)  and  the 
Marine  Strategy  Framework  Directive  ‘MSFD)  (indicator  10.2.1,  EC  2010,  see  Appendix  2).  A  long  term 
monitoring has shown the relevance of this indicator to assess the effectiveness of restoration measures, since 
the frequency of litter ingestion and the abundance of ingested litter in Fulmar populations varies in space and 
time with litter in the environment (van Franeker et al., 2011). Nonetheless, the absence of the Fulmar species 
in  the  Southern OSPAR areas  and in the Mediterranean  prevent  the use of this indicator outside  the OSPAR 
northern zones. 

Sea turtles show a global distribution, occupying multiple habitats throughout their life cycle  (Casale et al., 
2008) and showing a propensity to ingest debris (Schuyler et al., 2014) in particular in the OSPAR (Darmon et al., 
2014;  Pham  et  al.,  2017)  and  the  Barcelona  RSCs  (Camedda  et  al.,  2014;  Matiddi  et  al.,  2017).  These 
characteristics  make  them  a  relevant  indicator  for  MSFD  and  RSCs  (Matiddi  et  al.,  2011;  MSFD  Technical 
Subgroup on Marine Litter, 2013). They may also be relevant for monitoring impacts related to entanglement 
(Duncan et al., 2017; Nelms et al., 2015). Highly exposed to litter (Darmon et al., 2017a, and references therein), 
sea turtles can testify the spatial variations in litter abundance. Therefore, they have been proposed to evaluate 
the impact of litter according to the secondary Criteria D10C3 of Descriptor 10 “Marine Litter” of  MSFD (see 
Appendix  2).  The  loggerhead  turtle  Caretta  caretta  being  the  most  abundant  species  of  sea  turtle  in  the 
Mediterranean  and  commonly  seen  in  the  surrounding  Atlantic  waters,  is  the  target  species.  Specimens are 
regularly collected by existing rescue centres and stranding networks, which enables the collection of data useful 
for acquiring knowledge on the species’ biology and on the factors leading to litter ingestion or entanglement. 
The leatherback species Dermochelys coriacea has also been recommended especially for the OSPAR zones III, 
IV and V (Claro et al., 2014; Darmon and Miaud, 2016). 

While  sea  turtles  are  relevant  indicators  for  litter  impacts  related  to  ingestion  (D10C3),  with  litter  being 
considered superior to 1mm (Mattidi et al., 2011; MSFD Technical Subgroup on Marine Litter, 2013), a specific 
indicator should address distinctly the impacts of micro-litter items below 5 mm. Likewise, an indicator should 
also specifically concern impacts related to entanglement (D10C4). For these two new litter impact indicators, 
target taxa/species have to be identified. 

The INDICIT project. 

Among the projects funded by European Commission for supporting the implementation of MSFD, the project 
“Implementation of indicators of marine litter impacts on sea turtles and biota in Regional Sea Conventions and 
Marine Strategy Framework Directive Areas”, with acronym INDICIT for “Indicator Impact Turtle”, targeted the 
implantation of indicators of litter impacts for Descriptor 10 (Criteria D10C3 and D10C4). The project fitted into 

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three of the four marine regions covered by MSFD: Baltic Sea (HELCOM), North-east Atlantic Ocean (OSPAR) and 
Mediterranean Sea (Barcelona convention) (see Appendix 2). 

INDICIT major objectives addressed three indicators of litter impact: 

1)  The  “Litter  ingested  by  sea  turtles”  indicator,  belonging  to  D10C3  criteria  (previously  called  indicator 
“10.2.1” associated with “Trends in the amount and composition of litter ingested by marine animals”). 
This indicator concerns litter from 1 mm, thus combining the micro-items under 5 mm (here from 1 to 5 
mm) and the so-called meso-litter (from 5 to 25 mm) and macro-litter (>25 mm) (Andrady, 2011b; MSFD 
Technical Subgroup on Marine Litter, 2013). ). This currently does not respect the Definition of the New 
Decision Commission 2017/848 which entails to consider litter size > 5 mm and micro-litter size < 5 mm. . 
Indeed, INDICIT project took over from MSFD guideline which provided a first protocol for monitoring litter 
ingestion in sea turtles based on the Fulmar protocol (Matiddi et al., 2011; MSFD Guideline, 2013). The 
OSPAR ecological indicator EcoQo for Fulmar, which was produced many years before the definition of 
micro- and macro-litter, took into consideration all litter items from 1 mm. The EcoQO was adopted by the 
TG ML group for the GES definition of marine litter indicators in the Northern European countries. When 
INDICIT project started, some stakeholders already collected data in sea turtles, especially in Italy, Spain 
and  France,  generally  considering  litter  size  >1  mm.  Considering  the  difficulty  to  change  habits  and 
regarding the duration of the INDICIT project, the INDICIT consortium, together with the stakeholders in 
charge  of  specimen  and  data  collection,  have  worked  to  propose  a  standard  protocol  including  the 
differentiation of micro- and litter in data collection as an optional parameter (see §2.3). The relevance of 
a specific indicator for micro-litter ingested by sea turtles will be further assessed. The INDICIT proposal 
focused on this indicator, already candidate for both OSPAR and Barcelona RSCs, and in order to respond 
to the needs expressed by the 2010/477/EU Commission Decision for further development (see Appendix 
2).  For  this  reason,  the  specific  objectives  of  the  project  were  to  develop  tools  for  supporting  the 
harmonization of monitoring programmes across MSFD marine regions, by: 

(i) 

(ii) 
(iii) 

(iv) 

identifying, enlarging and empowering the networks for the standard collection of data in 
both OSPAR-Macaronesia and Barcelona RSCs; 
providing and disseminating protocols and tutorials for the collection of standard data;  
analysing  the  standard  data  to  define  the  indicators’  possible  biological  constraints, 
sample size and spatial and temporal units;  
evaluating  GES  and  Contracting  Parties’  distance  to  GES,  which  GES,  regarding  D10C3, 
corresponds to “the amount of litter and micro-litter ingested by marine animals that is at 
a level that does not adversely affect the health of the species concerned” (see Appendix 
2). 

2)  The “Entanglement with debris by marine biota” indicator. 

INDICIT proposal was to evaluate the feasibility of this new litter impact indicator at the levels of OSPAR, 
Barcelona and HELCOM RSCs, by assessing, thanks to a literature review and questionnaires to experts, 
the  prevalence  of  entanglement  in  several  taxa  (cetaceans,  fishes,  birds,  turtles,  invertebrates),  the 
possible target species, the network and survey methods, either already existing, or the potential for the 
implementation of a monitoring. 

3)  The “Micro-plastic ingestion in fish and sea turtles” indicator. 

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INDICIT proposal was to evaluate the feasibility of this new litter impact indicator. Sea turtles appeared 
relevant  for  a  concrete  application  of  such  an  indicator,  due  to  existing  networks  and  data,  and  the 
potential to specifically differentiate the size range 1 to 5 mm from data collected in the framework of 
indicator “Litter ingested by sea turtles”. Fish was also evaluated, because of their exposure to particles 
inferior to 5 mm, enabling to integrate HELCOM (where the indicator “sea turtle” can be used) in addition 
to OSPAR and Barcelona RSCs. A literature review and analysis of data already available were done in order 
to evaluate the target species and the existing survey methods to collect samples and data. 

The next chapter of this report presents INDICIT structure and approach. The INDICIT outputs are detailed in 
the following chapters, first the detailed results concerning the indicator “Litter ingestion in sea turtles”: tools 
for networking, tools for the collection and reporting of standard data, knowledge acquired thanks to the data 
collected and gathered by INDICIT consortium and collaborators, then the GES scenarios for the implementation 
of the indicator, with recommendations and perspectives provided for each section. The two feasibility study 
reports on Entanglement and Micro-litter ingestion indicators can be found in the INDICIT website in the section 
Documents. They are summarized in the third chapter of this report. 

1. INDICIT project: Structure and approaches 
1.1. General presentation of the project 

INDICIT project started the 1st February 2017 and finished the 31st January 2019. The total budget represented 
1 328 119 euros, considering an allocation of DG Environment of 999 955 Euros added to the 20% of partners’ 
co-funding. 

INDICIT consortium was composed by a consortium of 10 partner institutions from public sector, belonging to 
5 European countries (France, Greece, Italy, Portugal, Spain) and 2 non-European countries (Tunisia, Turkey), all 
contracting parties of Barcelona and/or OSPAR RSC (Figure 1): FRCT (Regional Fund for Science and Technology), 
ULPGC (The University of Las Palmas de Gran Canaria), UVEG (University of Valencia), MNHN (French National 
Natural History museum), CNRS (French National Centre of scientific Research) with EPHE (practical school)  of 
advanced  studies)  as  affiliated  entity,  ISPRA  (Italian  National  Institute  for  Environmental  Protection  and 
Research), INSTM (Tunisian National Institute of Sciences and Technologies of sea), IAMC-CNR (Institute for the 
Marine Coastal Environment of the National Research Council), HCMR (Hellenic Centre for Marine Research), 
PAU-DEKAMER  (Turkish  Sea  Turtle  Rescue  Centre).  FRCT  partner  subcontracted  IMAR  (Institute  of  marine 
research),  in  order  to  obtain  their  scientific  support  in  the  follow  up  of  the  project.  Both  FRCT  and  IMAR 
participated in the INDICIT internal meetings. 

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Figure 1. Distribution of partners represented in INDICIT consortium (FRCT, ULPGC, UVEG, MNHN, CNRS, ISPRA, 

INSTM, IAMC-CNR, HCMR, PAU-DEKAMER. FRCT subcontracted IMAR to provide scientific expertise. 

The project was structured in 5 inter-related “Act ivities” (Figure 2), all leaded by one partner. 

Figure 2.  Inter-relationships among the five Activities 

-  Activity 1 - Management and coordination, leaded by CNRS/EPHE (Claude Miaud, Gaëlle Darmon). 

The objective was to ensure the proper implementation and management of the project with respect to its 
objectives, time frame and budget constraints and to allow a smooth communication between the consortium 
members. This activity, involving all the members of the INDICIT Consortium, was divided in two tasks: 

1) Task 1.1. “Technical coordination of the project”, which aimed at ensuring an efficient technical coordination 

of the project, 

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2)  Task  1.2.  “Administrative,  legal  and  financial  management  of  the  project”  which  coordinated  the 
administrative,  legal  and  financial  management  of  the  project  in  accordance  with  the  articles  of  the  Grant 
Agreement and of the Consortium Agreement signed by all project partners. 

-  Activity 2 - Acquiring and using scientific knowledge to develop the indicators of litter impact at the sub-

regional and the whole MSFD spatial scale, leaded by CNRS/EPHE (Gaëlle Darmon, Claude Miaud) 

This activity aimed to fill  the  gaps of knowledge  needed to  define GES and criteria for the  indicator “Litter 
ingested by sea turtles” and to evaluate the relevance of two new impacts indicators “Entanglement with debris 
by marine biota” and “Micro-plastic ingestion by marine biota”. The objectives were: 

(i) 

(ii) 
(iii) 

to propose standard tools to collect samples and data (designed and shared by Activity 5, see below), 
which are evaluated and improved by stakeholders in charge of data collection (Activities 3 and 4); 
to gather and standardize data collected in Activities 3 and 4 (see below); 
from a literature review and statistical analyses of data, to evaluate the possible biological constraints 
of  the  Indicator  and  evaluate  GES  scenarios  for  indicator  “Litter  ingestion  by  sea  turtles”  from  a 
literature review and statistical analyses of data. 

For  the  other  two  indicators,  this  Activity  aimed  to  record  the  prevalence  of  the  considered  impact 
(entanglement / micro-plastic ingestion) per taxa/species, in order to evaluate the relevance of the indicator 
and, for proposing recommendation for the implementation of the indicator, to assess: 

(i) 
(ii) 
(iii) 

the relevant indicator taxa/species; 
the methodologies to sample individuals and collect data; 
the existing networks and datasets. 

The Activity 2 was divided into 6 tasks: 

1) Task 2.1 “Establishment of a state-of-the-art on the biological constraints which can influence the indicators’ 
criteria”, coordinated by CNRS/EPHE, ULPGC and ISPRA and which aimed to provide a literature synthesis on the 
biological constraints which can influence the criteria of the 3 indicators; 

2)  Task  2.2  “Pilot  study  for  the  indicator  “Entanglement  with  debris  by  marine  biota”  and  “Micro-plastic 
ingestion by fish and sea turtles”, which aimed to provide a feasibility study of the potential implementation of 
the 2 new impact indicators at the OSPAR, HELCOM and Barcelona RSCs levels; 

3) Task 2.3 “Improvement and standardization of the monitoring for the indicator 10DC3”, the objective being 
to develop a feasible set of procedures to collect data for the estimation of the indicator “Litter ingested by sea 
turtles”; 

4) Task 2.4 “Establishment of common databases in order to gather existing and new data for indicator “Litter 

ingested by sea turtles”, which aimed to closely work with Activities 3 and 4; 

5) Task 2.5 “Evaluation and/or revision of GES initial assessment, distance to GES and indicator criteria”, which 
aimed  to  provide/update  GES  scenarios  and  the  criteria  for  the  implementation  of  Indicator  1  (i.e.,  possible 
biological constraints, spatial and temporal units, sample size); 

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6) Task 2.6 “Evaluation of the influence of practical restoration measures implemented in pilot areas on the 
evaluated distance to the target of GES(s)”, which aimed to evaluate the changes in the indicator “Litter ingestion 
by sea turtles’ with litter management in pilot areas. 

-  Activity 3 - Implementation of the indicator “Impacts of marine litter on sea turtle and biota” in RSC 

OSPAR/Macaronesia regions, leaded by ULPGC (Ana Liria Loza), 

This activity intended to implement a perennial and sustainable monitoring programme for Indicator 1 “Litter 
ingested  by  sea  turtles”  in  OSPAR,  Macaronesia  being  included  for  more  coherence.  The  main  objectives 
consisted in: 

(i) 
(ii) 
(iii) 

networking and training stakeholders to collect standard data from the tools elaborated in Activity 2; 
collecting and gathering data with Activity 2; 
participating in the improvement of standard tools for the implementation of the indicator. 

The Activity was divided into 5 tasks: 

1) Task 3.1 “Identification of the local stakeholders to be mobilized in France, Spain and Portugal”, which aimed 
to network the stakeholders (rescue centres, stranding networks, laboratories, universities, etc.) who will be in 
charge of the collection of dead and/or live sea turtles and/or of the laboratory analyses to collect the  litter 
ingested by these individuals; 

2)  Task  3.2  “Local  training  on  the  established  protocols  for  data  collection  to  the  identified  stakeholders”, 
which aimed to improve the tools for monitoring (protocol) and empowering the stakeholders thanks to the 
local dissemination and training sessions; 

3) Task 3.3 “Sharing of already available data in the common databases”, which aimed to share stakeholders’ 
available  literature  and  data  on  litter  ingested  (micro  and macro-items)  by  dead  and  live  individuals  and  on 
entanglement in the RSC area with Activity 2; 

4) Task 3.4 “Collection of new data and uploading to the common databases”, which aimed to support the 

determination and the constraints of the indicator by collecting and gathering data; 

5) Task 3.5 “Validation and implementation of the GES (baseline or trends) and indicators’ criteria with the 
stakeholders at the RSC scale, and evaluation of each Member states/sub-regions’ distance to the target of GES” 
which aimed to validate with Activity 2, the GES produced thanks to the results of data analysis.  

-  Activity  4  -  Implementation  of  the  indicator  “Impacts  of  marine  litter  on  sea  turtle  and  biota”  in 
UNEP/MAP EcAp process (Barcelona convention), leaded by ISPRA (Marco Matiddi, Cecilia Silvestri) 

In parallel to Activity 3, this Activity aimed to implement a sustainable monitoring programme for the indicator 
“Litter ingested by sea turtles” at the Barcelona RSC level. The main objectives were the same than in Activity 3, 
but targeting MSFD Contracting Parties and countries outside EU belonging to the Barcelona convention for a 
greater  coherence  in  the  assessment  of  GES  and  harmonization  of  monitoring  for  evaluating  restoration 
measures, the dissemination at a large level being facilitated by Activity 5. The Activity 4 was divided into 5 tasks, 
with the same objectives than the tasks in Activity 3: 

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1) Task 4.1 “Identification of the local stakeholders to be mobilized in Italy, Greece, France and Spain”; 

2) Task 4.2 “Local training on the established protocols for data collection to the identified stakeholders”;  

3) Task 4.3 “Sharing of available data in the common databases”; 

4) Task 4.4 “Collection of new data and uploading them into the common databases”; 

5) Task 4.5 “Validation and implementation of the GES (baseline or trends) and indicator s’ criteria with the 
stakeholders at the RSC scale, and evaluation of each Member states/sub-regions’ distance to the target of GES”. 

-  Activity 5 – Communication and Dissemination, leaded by MNHN (Françoise Claro, Judicaëlle Moussier). 

This activity aimed to communicate about the project and its outcomes: 

(i) 

(ii) 

by providing technical tools for the implementation of a monitoring on debris impacts to stakeholders 
within or outside INDICIT partners’ area; 
by communicating about  the  project  context,  objectives  and results towards a general audience  in 
order to raise public awareness. 

This Activity was divided into 2 tasks: 

1) Task 5.1 “Dissemination of the developed tools for the monitoring of litter impacts on sea turtles”, which 
aimed to share the project’s outputs between consortium partners and to widely disseminate tools and results 
to stakeholders belonging to other countries either included in the MSFD area or other RSCs (e.g., HELCOM) or 
not (e.g., Southern Mediterranean countries); 

2) Task 5.2 “Communication activities”, which aimed to communicate about the program’s context and results 

to the large audience for awareness about litter impacts on marine ecosystems. 

One  of  the  major  goals  of  Activities  3  and  4  was  to  establish  a  network  of  stakeholders  in  charge  of  the 
sustained monitoring of litter ingestion by sea turtles, respectively in OSPAR-Macaronesia and Barcelona RSCs. 
The  close  collaboration  with  stakeholders  was  fundamental  to  achieve  INDICIT  objectives.  The  data  they 
collected was shared with Activity 2, in which the data was compiled, cleaned and analysed in order to evaluate 
the  indicator’s  possible  constraints  and  GES  assessments.  At  the  same  time,  the  protocols  produced  in  the 
framework of Activity 2 were reviewed and improved thanks to stakeholders involved in Activities 3 and 4, who 
implemented them in the field and for some of them, also in laboratory. Finally, the documents were compiled 
in the framework of Activity 5, for standard design and wide dissemination. 

1.2.  Coordination and internal organization 

The consortium greatly benefited from the advice of its Policy Officer, Mr Michail Papadoyannakis and an 
External Advisory Board composed of representatives of MSFD, RSCs and Member States (EAB, Table 1), in order 
to ensure that INDICIT outcomes will allow a harmonized and sustained monitoring of litter impacts at the MSFD 
and RSCs levels, with coherence among national and regional cooperation processes. The Steering Committee, 

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who could vote the project’s strategies, validated and completed the EAB composition during the project (Table 
2). 

Table  1: Members of INDICIT External Advisory Board (as presented in the proposal; in grey, new members 

added during the project) 

Organization 

OSPAR Commission 

EAB members 

John MOUAT, replaced in July 2018 by Philip STAMP (Deputy 
secretary, London, UK) 

HELCOM Commission 

Stefanie WERNER (UBA, German Environment Ministry) 

Barcelona convention secretary 

Tatjana HEMA, Christos Ioakeimidis 

Barcelona convention secretary  

Lobna BEN NAKHLA 

MATTM (Italian Ministry of Environment)  

Oliviero MONTANARO/ROBERTO GIANGRECO  

MEEM : French Ministry of Environment, Energy and 
Sea 

MPAs: French Marine Protected areas 

MAGRAMA (Ministry of Agriculture, Food and 
Environment) 

IEO (Spanish Institute of oceanography) 

IFREMER 

Isabelle TERRIER 

Benjamin GUICHARD 

Marta MARTÍNEZ‐GIL PARDO DE VERA  

Jesús GAGO 

François GALGANI 

DRAM, Azores government 

Gilberto MP. CARREIRA / Marco A. SANTOS 

Table 2. Members of INDICIT Steering Committee (as presented in the proposal; in grey, new members involved 
during the project) 

Institution 

Representative 

Substitute 

CNRS 

MNHN 

ISPRA 

Claude MIAUD (male) 

Gaëlle DARMON (female) 

Françoise CLARO (female) 

Judicaëlle MOUSSIER (female) 

Marco MATIDDI (male) 

Cecilia SILVESTRI (female) 

CNR‐IAMC 

Giuseppe DE LUCIA (male) 

Andrea CAMEDDA (male)  

HCMR 

UVEG 

ULPGC 

Eleni KABERI (female) 

Jesús TOMÁS (male) 

Catherine TSANGARIS (female) 

Ohiana REVUELTA (female) 

Ana LIRIA LOZA (female) 

Ricardo J. HAROUN TABRAUE (male) 

PAU‐DEKAMER 

Yakup KASKA (male) 

Dogan SOZBILEN (male)  

FRCT 

INSTM 

Maria Luz PARAMIO MARTIN (female) 

Francisco Pinto (male)  

Mohammed Nejmeddine BRADAI (male) 

Olfa CHAIEB (female) 

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CNRS  managed  the  inception  report  as  well  as  the  INDICIT  consortium  agreement  signed  by  beneficiaries, 
which  referred  to the  rules  and respective obligations among partners and towards EC.  An amendment was 
added, in order to consider the conditions asked by some stakeholders, that the data shared by them could be 
used only for evaluating the constraints and GES of litter impact indicators (see §2.1.3). CNRS also managed the 
6-month intermediate reports, compiling the outputs of each Activity sent by each Activity leaders (with ULPGC, 
ISPRA and MNHN), at each Reporting Period, as well as the financial reports. 

Regular meetings and workshops  were organized among INDICIT  consortium  (Table 3). EAB was invited  by 
CNRS/EPHE  to  the  intermediate  meeting  in  February  2018  and  by  MNHN,  HCMR  and  CNRS/EPHE  to  the 
Dissemination meeting in December 2018. The minutes of the regular meetings (Deliverables D1.2 to D1.6, see 
Appendix 1) and Dissemination meeting (Deliverable D5.12) are available in INDICIT website. 

Meanwhile, partners communicated remotely by regular emails and videoconferences, in particular Activity 
leaders as soon as a specific organizational question was raised. For the second year of the project, ULPGC and 
FRCT organized a one-month videoconference for partners involved in Activity 3. 

MNHN, regularly supported by all partners, shared news within Activity 5, which facilitated the exchange of 
news, both among partners and with EAB, by providing regular newsletter sent by email, on the website and 
INDICIT Facebook. Each partner also regularly communicated with EAB. EAB members sent several feedbacks, 
especially to comment on the news, helped in the improvement of the feasibility studies, and provided general 
and specific advice during the project meeting in Montpellier and the Dissemination meeting in Athens. 

Partners also regularly interacted with other experts and other projects in which they were actively involved; 
e.g., CNRS/EPHE, ISPRA, UVEG and HCMR involved in MedSeaLitter, HCMR and ISPRA in MEDCIS, FRCT in MISTIC 
SEAS II. As far as possible, partners participated in other meetings  to share expertise (WG GES, TG ML, RSCs 
meetings, other DG Env funded meetings, etc.). They also shared expertise and INDICIT outputs in international 
conferences (MedTurtle conference, the symposium of the International Sea Turtle Society [ISTS], etc.) in order 
to disseminate INDICIT tools and possibly enlarge the network and collect a greater dataset. In that respect, the 
INDICIT protocol was shared with international expert communities in a peer-reviewed journal (JOVE, video-
article managed by ISPRA, published) and other articles are planned. 

Table 3. Internal meetings for INDICIT partners 

Date 

Location 

Type of meeting and 
participants 

Objectives 

Month 1  Brussels (Belgium) 

Kick‐off meeting (all partners 
and DG representatives) 

Mutual presentation of partners + presentation of the 
project to DG representatives 

1st meeting (all partners + 
External Advisory Board) 

Facilitation exercises for collective decisions on the 
programme’s orientation 

Month 6 

Rome (Italy) 

Intermediate meeting n°1 
(all partners) 

Progresses presented by each Activity Leader 

Workshop n° 2 (all partners) 

Sharing technical skills + training session  

Month 
13 

Montpellier (France) 

Intermediate meeting n°2 
(all partners) 

Workshop n° 3 (all partners 
+ EAB) 

Progresses presented by each Activity Leader 

(parallel sessions on Activities 2,3,4,5) 

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Month 
20 

Sao Miguel, Azores 
(Portugal) 

Intermediate meeting n°3 
(all partners) 

Progresses presented by each Activity Leader 

Workshop n° 4 

Decisions on data classification and analyses 

Month 
24 

Brussels (Belgium) 

Final meeting 

Final results 

The  Project  Management  Team  (CNRS/EPHE)  regularly  communicated  with  the  PO  and  DG  ENV.  All  draft 
deliverables  were  submitted  to  the  PO,  who  greatly  helped  improving  the  documents  for  an  applicable 
implementation of the indicators in keeping with MSFD requirements.  

1.3.  Communication outputs 

The Communication outputs are presented in the Final report on Communication and in the Final report on 

Dissemination provided by MNHN (deliverables D5.7 and D5.9, available on INDICIT website). 

The tasks related to Communication were treated in Activity 5 and coordinated by MNHN. INDICIT consortium 
decided to limit the plastic in the activities as far as possible (e.g., preference for “useful” goodies (USB keys, 
porcelain mug, cloth bag); no paper pamphlet produced (but printable upon request online); glassware used 
during meetings, etc.). 

Several tools were elaborated to communicate within and outside INDICIT, such as: 

- 

- 
- 

Specific  email  addresses  for  coordination  managed  by  CNRS/EPHE  and  communication  managed  by 
MNHN, respectively coordination@indicit-europa.eu and communication@indicit-europa.eu; 
The logo and the graphic chart, 
The  website  https://indicit-europa.eu/  managed  by  MNHN  with  some  support  from  CNRS/EPHE  and 
regularly fed by partners, in which: 

(i) 
(ii) 
(iii) 
(iv) 

(v) 

(vi) 

(vii) 
(viii) 
(ix) 
(x) 

news was fed by each partner in the section “Latest announcements” (56 news); 
a public agenda announcing next events where INDICIT would participate in; 
general presentations of the project for general audience in the tab “About INDICIT”; 
a presentation of INDICIT consortium, EAB and collaborators (rescue centres, stranding 
networks, etc.) in the tab “Participants”. Partners’ logos were  presented on a map and 
videos elaborated by MNHN present each partner’s activities; 
a tab “Documents” for downloading the INDICIT documents (feasibility and pilot studies, 
protocols and translations, peer-reviewed publications), and other relevant peer-reviewed 
publications by other experts on marine litter impacts or sea turtles; 
other documents for monitoring litter impacts downloadable in the tab “Tools” in INDICIT 
website  (MSFD  guidance  (MSFD  Technical  Subgroup  on  Marine  Litter,  2013),  INDICIT 
protocol and a tutorial); 
documents for awareness and education (see below); 
a photo gallery on litter ingestion, entanglement in litter, and people in action; 
links of other relevant initiatives, directives and projects; 
Link  to  INDICIT  Facebook  account,  INDICIT  private  area  (see  below)  and  web  designer 
contact. 

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-  A Facebook account to share regular news on partners and stakeholders’ activities related to the project 

- 

(67 posts gathered with 280 persons); 
Templates  of  documents  (e.g.,  feasibility  reports,  protocols,  with  logo  and  graphic  chart,  managed  by 
MNHN; 

-  A private area on a Share point platform hosted and managed by CNRS, where partners having signed the 
consortium  agreement  can  share  (deposit,  download  and  modify)  working  documents,  notably  data 
collected  in  partnership  with  stakeholders.  In  accordance  with  the  Consortium  agreement  and  its 
amendment (see §1.2), such datasets cannot be shared freely.  

Activity  5  also  aimed  to  simultaneously  propose  technical  tools  to  stakeholders  who  will  be  in  charge  of 
monitoring  litter  impacts  in  RSCs/MSFD  areas,  to  favour  synergies  with  international  experts,  and  to  raise 
awareness. 

For  standard  monitoring  of  litter  ingestion  and  entanglement,  INDICIT  partners  developed  a  tool  kit  to  be 

disseminated to stakeholders. This tool kit contains: 

- 

- 

- 

a standard protocol for monitoring litter ingestion and entanglement in litter by sea turtles (available on 
INDICIT website); 
translations of the standard protocol in Arabic (leaded by INSTM), Greek (leaded by HCMR), French (leaded 
by CNRS/EPHE) and Spanish (leaded by UVEG and ULPGC) for a wider dissemination; 
a  video tutorial  (Deliverable  D5.11),  led  by ISPRA, published  in  a  peer-reviewed  journal  (Matiddi et  al., 
2019). 

For awareness, various documents were elaborated: 

-  A story of a turtle which was found entangled at sea and who excreted litter in a rescue center. This story, 
elaborated by MNHN, showed the anthropogenic threats to which turtles are at risk, in particular caused 
by litter, and the process to care for and release live individuals. The story was translated in Arabic (INSTM), 
French (MNHN), Greek (HCMR), Portuguese (FRCT) and Spanish (ULPGC); 

-  An educational activity sheet for children, proposed by CNRS/EPHE and ULPGC, possibly modified by all 

partners, in order to create a turtle from plastics; 

-  An  educational  activity  sheet  for  children,  proposed  by  MNHN,  for  fishing  litter  and  learning  on  litter 

impacts on sea turtles. 

An INDICIT challenge for the Ocean World Day and the Sea turtle World Day in June 2018, was proposed by 
CNRS/EPHE and MNHN, and realized by all partners. The challenge mobilized 697 participants. The objective 
was to raise awareness about plastic impacts on the environment, by proposing simultaneously and as wider as 
possible, various activities to children, based on the INDICIT pedagogical tools. Some partners proposed other 
activities, such as the release of a turtle at sea (PAU-DEKAMER, CNR-IAMC). This challenge was also proposed 
by ULPGC at the occasion of training sessions. 

A documentary was elaborated by ISPRA with the support of all partners. It presented the way all partners 
worked on the conservation of sea turtles  and  on  the  analysis of litter impacts, as well as how they worked 
together for supporting MSFD and RSCs in the implementation of litter impact indicators. This documentary was 
greatly appreciated, both by the general public and by the experts. It was diffused during a public conference 

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organized  by  DG  Environment  and  disseminated  on  partners’  websites  (e.g.,  official  websites,  Facebook  or 
Twitter accounts) as well as ISPRA’s Youtube channel. 

In parallel, INDICIT consortium did a big work on communication with other experts notably involved in other 
programs or in representative institution. Synergies with other programs (detailed in INDICIT communication 
report available in INDICIT website) was favored by (i) participating to other projects’ meetings where INDICIT 
approaches  and  results  were  presented,  (ii)  having  regular  remote  meetings  by  video-conferences,  (iii) 
discussing by emails. The consortium organized or participated in various events, such as: 

- 

Fourteen  training  sessions  proposed  to  stakeholders,  both  to  competent  authorities  and  biologists  in 
charge  of  the  collection  of  samples,  belonging  to  rescue  centers,  stranding  networks  or  veterinarian 
laboratories  for  example.  The  workshop  organized  by  ISPRA  in  Naples  (Month  6)  involved  UNEP/Map 
delegates of the Contracting Parties of the Barcelona Convention; 

-  A dissemination meeting (Deliverable D5.12, Minutes  available in INDICIT website), in December 2018, 
organized  by  HCMR  and MNHN  in  Athens  (Greece).  In  the  morning,  CNRS/EPHE  and  ULPGC  presented 
INDICIT results and the standard protocol for litter ingestion by sea turtles with the presentation of the 
video-tutorial. During the afternoon, two panel discussions gathering representatives from EU – DG ENV, 
MEDPOL, OSPAR / HELCOM, MSFD TGML, French National Authority (MTES), Spanish National Authority 
(MAPAMA),  Azores  Regional  competent  authority  (DRAM),  as well  as  NGOs  (MEDASSET)  discussed  the 
implementation of  INDICIT  outputs  for  national and  international  policies  and  the  possible  articulation 
among  RSCs  and  MSFD.  The  event  was  attended  by  stakeholders  from  9  countries,  47  persons  were 
present in Athens and more than 20 persons were connected on the livestreaming; 
Six international and 3 national conferences where 14 posters and 14 oral presentations were provided; 
Four  workshop  (co)-animated,  like  a  workshop  on  Marine  litter  impacts,  proposed  and  realized  by 
CNRS/EPHE,  MNHN  and  ULPGC  in  Porĕc  (Croatia)  during  the  MedTurtle  conference;  a  workshop  on 
ingested marine litter at the GTMF (Working Group Marine Turtle France) annual meeting. 

- 
- 

Various  documents  were  elaborated  from  INDICIT  outputs,  such  as  a  draft  Coordinated  Environmental 
Monitoring Programme (CEMP) guideline document for the candidate indicator “Litter ingested by sea turtle” 
for OSPAR written by CNRS/EPHE supported by MNHN and IFREMER, presented by France to OSPAR commission 
in April 2019 and which participating to change the indicator’s status to “common” (see Appendix 2). 

INDICIT  consortium  also  provided  a  consolidated  document  for  the  collection  of  standard  data  on  litter 
ingestion and entanglement in sea turtle, between the INDICIT protocol and the RAC/SPA protocol leaded by 
CNRS/EPHE for RAC/SPA (L. Ben Nakhla). This document (RAC/SPA INDICIT, in press) aimed at harmonizing the 
approaches between MSFD and as far as possible, the whole Mediterranean level.  

1.4.  Achievement of expected deliverables 

INDICIT proposed 53 deliverables (see Appendix 1). Most of them were considered as fully achieved. Only for 
Deliverables  2.7  (“Final  Report  on  set  of  procedures  for  a  standard  monitoring  using  the  Indicator  "Debris 
ingestion  by  sea  turtles"”),  D3.7  (“Final  report  on  the  validated  GES  and  clarified  indicator  criteria  for  the 
standard  monitoring  at  the  RSC  scale”)  and  D4.7  (“Final  report  on  the  validated  GES  and  clarified  indicator 

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criteria for the standard monitoring at the RSC scale”), the level of achievement was not judged at 100% but 
90%. These deliverables aimed at providing the criteria for using indicator “Litter ingested by sea turtles” thanks 
to  the  analysis  of  standard  data  (Activity  2)  and  the  discussion  of  results  among  stakeholders  and  partners 
(Activities  3  and  4).  The  “basic”  and  “optional”  data  collected  throughout  the  project  (see  §2.3.2)  enables 
assessing most of the biological constraints on litter ingestion, but they did not allow assessing the impact on 
health  accurately,  regarding  the  definition  proposed  by  the  new  Commission  Decision  (New  Commission 
Decision 2017/848/EC) for D10C3 GES (“the amount of litter and micro-litter ingested by marine animals that is 
at a level that does not adversely affect the health of the species concerned”, see Appendix 2). Nonetheless, 
several  GES  scenarios  have  been  discussed  and  2  scenarios  were  proposed  by  the  INDICIT  consortium  (see 
§2.4.4). The data collected during the INDICIT project should be further studied and completed with other data 
which  will 
2021,  No. 
110661/2018/794561/SUB/ENV.C2). To reach a 100% of achievement, new knowledge is needed to provide a 
better assessment on how litter affects the health of individuals, allowing the use of health or proxies for GES 
scenario. Moreover, INDICIT project proposed to evaluate the influence of practical restoration measures on the 
performance  of  the  indicator  (i.e.,  capacity  to  detect  changes  in  occurrence  and  quantity  in  different  litter 
categories and decrease in the distance to GES) in specific pilot areas (Task 2.6 in the framework of Activity 2). 
While this task was not completed during the project, the data already collected and the data which will be 
collected by the (now) experimented networks will enable achieving this task after the project (objectives of 
INDICIT-II project; see §4). The pilot areas will be selected by considering the risky areas evaluated from INDICIT 
results, litter accumulation areas (synergy with MEDSEALITTER programme), and the capacity of networks to 
collect samples in the field. 

2019-January 

(February 

INDICIT-II 

collected 

project 

during 

be 

2. Implementation of indicator “Litter ingested by sea turtles” 

The main goal of INDICIT project was to support the implementation of the indicator “Litter ingested by sea 
turtles” at the MSFD scale in coordination with RSCs OSPAR-Macaronesia and Barcelona. To achieve this goal, 
after performing a pilot study of the implementation of the indicator (§2.1), INDICIT consortium has identified 
and trained stakeholders (§2.2) to collect data in a harmonized way (§2.3). Common experiences and techniques 
were shared to complement and improve the INDICIT standard tools for monitoring litter ingestion in sea turtles 
(§2.3).  Data  collected  with  collaborators  were  compiled  in  a  standard  Excel  file  and  gathered  in  the  private 
platform available with login and password (§2.4). The data was analyzed in order to fill the gaps of knowledge 
necessary for the definition of the indicator’s constraints and GES (§2.5). 

2.1. A pilot study for refining the action plan 

A literature review was conducted during the first months of the INDICIT project in order to establish a strategy 
and action plan for supporting the implementation of the indicator “Litter ingested by sea turtles” (Darmon and 
INDICIT consortium (2018), available in INDICIT website). The objective was to identify: 

1) The state of knowledge on i) the prevalence of litter ingestion in sea turtles (occurrence and quantities), ii) 
the intrinsic, environmental and logistic factors that might influence litter ingestion in sea turtles, and which 
may be considered as constraints to consider during the monitoring (e.g., stage, body condition, methods), 

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2) the stakeholders who already collect or may collect specimens and/or information on impacts related to 

litter ingestion in sea turtles and their available material and human means. 

A review of published and grey literature was conducted, targeting all sea turtle species, more specifically the 
loggerhead and the leatherback turtles. The stakeholders’ contacts were found thanks to each INDICIT partner’s 
previous collaborations, advised by members of the EAB or found from the literature review. 

The  mean  observed  percentage  of  litter  ingestion,  evaluated  from  the  means  found  during  the  literature 
review weighted by the sample sizes, was of 87.1% for Dermochelys coriacea and 39.3% for Caretta caretta. The 
published data was not accurate enough to evaluate the occurrence of litter ingested per species and per marine 
regions,  nor  the  quantities  per  individual.  These  data  did  not  allow  proposing  GES  scenarios.  The  results 
published  in  literature  and  detailed  in  the  report,  were  indeed  hardly  comparable,  due  to  a  disparity  in  the 
protocols  used  by  the  authors  to  collect  the  litter  ingested  by  sea  turtles.  The  influence  of  the  methods for 
collecting specimens (e.g., stranding, bycatch, etc.), the protocols on dead and living turles and other intrinsic 
factors such as individual’s size/stage for example, appeared highly contrasted according to  studies and very 
variable among regions. Results found in the Mediterranean Sea were regularly different from those found in 
the oceans, maybe because of specific environmental processes in this smallest and almost closed area, where 
neritic resources might be more accessible to young turtle individuals compared to oceans, or because of the 
lack of studies, yet insufficient to well understand the factors leading to litter ingestion in sea turtles. This first 
study enabled to identify the lack of knowledge and local means to implement the monitoring, and to refine the 
project’s working strategy, with a need to reinforce the networks.  

2.2. Networking 

2.2.1. Situation at the beginning of the INDICIT project 
By assessing the institutions already collecting or able to collect information on litter impacts on sea turtles, 
their training level, the procedures employed, the available material and human means, the knowledge and data 
already acquired, this situational analysis enabled to plan the strategy for implementing the network. The results 
in date of July 2017 have been reported in the Pilot study (Deliverable 2.5 available in the tab “Documents” of 
the INDICIT website, Darmon et al., 2018: first report in the “Pilot and feasibility studies for the implementation 
of litter impacts indicators in the MSFD and RSCs OSPAR-Macaronesia, HELCOM and Barcelona” document – p.8-
67). 

Seventy-two institutions (32 involved in OSPAR RSC -Macaronesia and 43 in Barcelona RSC) were identified, 

some of them endorsing several roles. They were institutions aiming mainly at the collection of specimens: 

(i) 

(ii) 
(iii) 
(iv) 
(v) 

13 stranding networks, in charge of the observation and recovery of dead or live turtles and organized 
for alerting, taking the first measures and recovering specimens; 
21 rescue centers, in charge of medical care of live individuals brought back by stranding networks; 
11 transit centers, recovering individuals temporarily before rescue centers take charge of them; 
3 veterinarian laboratories, in charge of the external exams and necropsies; 
11  research  laboratories,  among  which  some  were  also  veterinarian  research  center  such  as  the 
University of Las Palmas, or also rescue centers, such as IAMC-CNR in Sardinia island in Italy or PAU-
DEKAMER in Turkey. INSTM also managed a stranding network and a rescue center in Tunisia. HCMR 

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collaborated with the only Greek rescue center managed by the NGO “ARCHELON - Τhe Sea Turtle 
Protection Society of Greece”. 

Some of these institutions, especially in Spain, Italy and France, were already engaged in the monitoring of 
litter  ingestion  of  sea  turtles,  reporting  their  information  to  local/regional/national  authorities,  in  charge  of 
linking  stakeholders  with  ministries,  MSFD  and  RSCs.  The  others  were  contacted  for  being  involved  in  the 
monitoring. 

2.2.2. Training sessions for collecting data on litter impacts on sea turtles 
INDICIT consortium has organized 14 training sessions during the project, 2 at international levels, 5 at national 
level and 7 locally. These workshops aimed to present the INDICIT protocol and put it into practice by performing 
initially  an  external  and  internal  exam  of  a  dead  loggerhead  turtle,  and  afterwards  the  extraction, 
characterization and quantification of the ingested litter. 

Training  was  especially  needed  in  the  Atlantic  area  of  the  project,  where  monitoring  of  litter  impacts  just 
started: At the beginning of the project, only the stakeholders of France and Azores shared data. Several training 
sessions were proposed by ULPGC and FRCT to local stakeholders in Spain and Portugal. In France, only one 
rescue  center  (CESTM  hosted  by  Aquarium  La  Rochelle),  which  also  manages  the  stranding  network  of  the 
French Atlantic coast (RTMAE), collected data from a long time and did not really need to be trained. CNRS/EPHE 
and CESTM collaborated and discussed how to improve the INDICIT protocol either during necropsies performed 
together, or by phone or email.  For  Spain  and Portugal, the spatial configuration  in archipelagoes  had to be 
considered for reaching people and propose training sessions. 

In order to harmonize the procedures of monitoring throughout the whole Mediterranean, an international 
training session was organized by ISPRA for INDICIT partners and the Mediterranean stakeholders in July 2017, 
in the Marine Turtle Research Centre of Anton Dohrn marine station in Portici. Thanks to UNEP MAP MedPol 
Program  and  the  RAC/SPA  (regional  activity  center  of  Barcelona  convention  Special  protected  areas), 
representatives from Egypt, Tunisia, Lebanon and Israel were included. 

2.2.3. Listing stakeholders already or possibly in charge of monitoring and conditions for involvement 
All INDICIT partners continued to make contact with stakeholders throughout the project duration, either by 
contacting them individually  (email/phone, etc.) or during specific events  such as during the 11 conferences 
where  INDICIT  was  represented  (e.g.,  ISTS  in  February  2018  in  Japan  or  XV  Portuguese-Spanish  Herpetology 
Congress and XIX Spanish Congress of Herpetology in Salamanca 2018), or thanks to the facilitation by EAB and 
national representatives. INDICIT consortium participated in 5 national and international workshops on the topic 
of Marine Litter, and co-organized some of them, e.g. ULPGC in MICRO 2018 international conference in Spain 
in November 2018.  CNRS/EPHE, MNHN  and UVEG organized a specific workshop on marine  litter  impacts  in 
synergy  with  RAC/SPA  of  Barcelona  Convention  (Lobna  Ben  Nakhla)  and  Archipelagos  Institute  of  Marine 
Conservation  during  the  6th  MEDTURTLE  conference  in  Croatia  in  October  2018.  These  events  provided  the 
opportunity  to  not  only  share  INDICIT  outputs,  in  particular  the  INDICIT  protocol,  but  also  enlarge  the 
networking, especially with southern countries. This protocol was also sent by email to various stakeholders, 
especially by FRCT for the Atlantic area. Posting it on INDICIT website also enabled to favor interactions with 
new contacts. 

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ULPGC  and  other  Activity  leaders  supported  by  partners,  listed  all  already  involved  stakeholders  (tab 
“Collaborators”  of  INDICIT  website”),  or  possibly  involved  stakeholders,  for  monitoring  and  reporting  on 
“indicator  Litter  ingested  by  sea  turtles”  (Table  4).  CNRS  and  MNHN  begun  a  Google  map,  which  should  be 
consolidated, referencing the stakeholders already involved in monitoring litter ingestion in sea turtles. This may 
show  the  spatial  distribution  of  the  networks  and  should  facilitate  contacts.  According  to  the  consortium 
agreement (see  §1.2), this list  and this map will be transmitted to DG Env. and national representatives but 
cannot be open access since they contain personal coordinates and thus cannot be shared in this report but 
they. 

At the end of the project, 106 stakeholders were contacted (some of them may be referenced twice, due to 
the double activities or activities in different areas). In the Mediterranean, 68 stakeholders were involved, 43 in 
the Atlantic and 6 in both areas. Several institutions, the first role of which was the collection of specimens, were 
already involved or interested to be involved in monitoring litter impact on sea turtles and in sharing data. From 
those who provided information, there were: 

(i) 

(ii) 

(iii) 

36 stranding networks, in charge of the observation and recovery of dead or live turtles, sometimes 
managed by a rescue center. Some institutions were structured in networks with voluntaries trained 
to carry out the specimens and do the first measures after having alerted a regional referent (e.g., 
RTMFF and RTMAE in France). Other institutions, not directly structured in a network, could report 
stranding  events,  such  as  NGOs  (e.g.  in  Turkey),  National  parks  in  Greece  or  research  and  rescue 
centers in Italy. 
28  rescue  centers,  in  charge  of  medical  care  of  live  specimens,  some  also  supervising  stranding 
networks and performing themselves the necropsies of dead individuals. Several did a considerable 
work with fishermen to collect bycaught individuals. 
10  transit  centers,  recovering  specimens  temporarily  before  rescue  centers  took  charge  of  the 
individuals. 

There were also laboratories or groups in charge of the acquisition or dissemination of knowledge: 

(i) 

(ii) 

(iii) 

3 veterinarian centers, 1 veterinary school and 1 veterinarian laboratory, in charge of the necropsies 
of dead specimens and of the evaluation of health status before death. Some research centers could 
also  be  in  charge  of  veterinarian  analyses  centers,  such  as  Istituto  Zooprofilattico  Sicilia,  Istituto 
Zooprofilattico Abruzzo/Molise and Istituto Zooprofilattico Sardegna (Oristano) in Italy. 
31 research laboratories, in charge of the collection and analysis of samples and the acquisition of 
knowledge  especially  on  sea  turtles  and  litter  impacts.  Among  them,  some  had  their  own  rescue 
center, such as IAMC-CNR in Sardinia Island in Italy, PAU-DEKAMER in Turkey. INSTM also managed a 
stranding network and a rescue center in Tunisia. 
2 institutions in charge of networking experts and of sharing information. 

The sampling capacity per stakeholder was sometimes difficult to assess because several institutions may take 
in charge different samples from the same specimens. The organization of the networks is highly variable among 
countries, with sometimes a referent at the regional and national level, sometimes not. In some countries, an 
official stranding network did not exist, but there was a local organization by research or rescue centers to be 
alerted and recovering on the field of dead individuals or live individuals needing care. Manipulations of sea 
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turtles generally required an official training for authorization (e.g., “carte verte” in France, delivered by the 
French Environment Ministry). 

The way to sustain networks was an important topic intensely discussed within the consortium as with other 
projects  and  representatives.  INDICIT  consortium  participated  in  a  discussion  launched  by  emails  by  IDEM 
project on “Finding a common strategy for stakeholders’ involvement in DG-ENV funded projects”. The challenge 
and  the  conditions  for  involving  stakeholders  were  also  highly  discussed  with  NGOs  and  representatives 
attending  the  INDICIT  Dissemination  meeting  in  December  2018  in  Athens,  since  it  was  a  high  constraint 
sometimes underestimated. 

Among the stakeholders contacted by the INDICIT consortium, some either did not reply or did not want to be 
involved in the project. The consortium reported all conditions for involvement shared by stakeholders. The co-
signing  of  sharing  agreements  stipulating  the  conditions  for  using  their  data,  especially  regarding  scientific 
publication or conservation reports, and the need for continuous and sufficient financial means for equipment 
and staff, were the two main critical needs they share. Stakeholders had also other requirements, such as: 

(i) 
(ii) 
(iii) 

to be trained for standard monitoring; 
to receive the results found locally, thanks to the data they collected; 
to participate in the research projects as partners or be invited in workshops as experts. 

An amendment into the INDICIT Consortium Agreement was signed by partners, in order to specify the rules 
for  sharing  and  using  stakeholders’  data,  and  testify  their  inclusion  as  co-authors,  collaborators,  or  in 
acknowledgement, depending on their support and its objectives.  

2.2.4. Recommendations for networking 
In  certain  areas/countries,  a  better  development  of  the  network  appears  necessary,  by  e.g. 
creating/reinforcing stranding networks and rescue centers, ensuring constant means and training referents or 
coordinators at the local/regional level. Engaging stakeholders in certain zones would be necessary to provide 
accurate assessments of litter impacts and GES. This is especially the case in the Atlantic area where data is 
missing, in particular in Portugal and Atlantic Spain’s coasts. This is also needed for a better coherence between 
the North-Western Mediterranean basin and the South-Western and Eastern basins. 

The conditions for involvement reported by INDICIT consortium could support engaging new stakeholders. Co-
organizing workshops among stakeholders, with experts and representatives, could facilitate the task.  These 
workshops  should  propose  training  sessions  and  sharing  experience  on  e.g.  methodologies  to monitor  litter 
impacts, which could still be optimized. Key-stakeholders, such as fishermen, who are essential to recover sea 
turtles  in  certain  areas,  should  be  involved.  Including  them  in  the  monitoring  of  litter  impact  on  sea  turtles 
instead of using them for recovering sea turtles as accidental bycatch, could support the collaboration. 

For a better reporting of information and data, a diagram of the networks should be built at both national and 
regional levels, considering specificities of each country. These diagrams should be disseminated to stakeholders 
in  order  to  facilitate  procedures  and  contacts.  Some  tools  may  accelerate  the  diffusion  of  information,  in 
particular when a turtle is observed at sea or found stranded or bycaught, for example blogs or web applications, 

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such as the Red PROMAR application of the Canary islands government, allowing citizen to post pictures with 
GPS locations, or ObsEnMer which offers a collaborative platform (managed by Cybelle Planete, France). 

2.3. Elaboration of a standardized protocol for monitoring litter impacts on sea turtles 

2.3.1. Proposition of a common methodology 
A first protocol for monitoring litter ingestion by sea turtles, based on the Fulmar approach, was proposed by 
Matiddi et al. (2011) and published in the MSFD guidance (MSFD Technical Subgroup on Marine Litter, 2013). It 
consisted in quantifying the litter found in the digestive tract extracted during necropsy of dead individuals. It 
also proposed the collection of the litter in the excrements  of live individuals in rescue centers. The protocol 
has been adapted (Matiddi et al., 2017), then completed by INDICIT Activity leaders with the feedback from 
other  partners  and  stakeholders  in  charge  of  collecting  specimens  and  samples.  The  INDICIT  protocol  was 
addressed to the collection of the ingested litter, either in the digestive tract of dead individuals by performing 
a necropsy, or in the excrements of the live individuals who remain at least 1 month and maximum 2 months in 
the rescue center, the digestive transit time being evaluated from 4 to 6 weeks on average (Camedda et al., 
2014; Darmon and Miaud, 2016; Valente et al., 2008). The INDICIT protocol aims to: 

(i) 

(ii) 

(iii) 

(iv) 

Target  especially  the  plastic  categories  (Table 4),  the  most  often  found  ingested  by  sea  turtles 
(Camedda et al., 2014; Pham et al., 2017). This should allow evaluating the programs of measures 
implemented in the framework of the Plastic Strategy;  
Improve  the  observation  sheet,  in  which  the  parameters  are  reported  in  the  order  of 
manipulations (see §2.2); 
Collect  basic  information  to  evaluate  the  presence  and  the  quantity  of  ingested  litter  in  the 
individual (see §2.2); 
Acquire knowledge on the factors leading to litter ingestion or entanglement, thanks to  the so-
called “optional parameters”. 

Table 4. Categories of litter items (from INDICIT protocol, 2018) 

CATEGORIES 

CODE 

DESCRIPTION 

  Industrial plastic 
R
E
T
T
I
L
C
I
T
S
A
L
P

Use threadlike 

Use sheet 

R
E
T
T
I
L

IND PLA 

Industrial plastic granules, usually cylindrical but also sometimes oval spherical 
or cubical shapes, or suspected industrial item, used for the tiny spheres (glassy, 
milky...) 

USE SHE 

Remains of sheet, e.g. from bag, cling-foil, agricultural sheets, rubbish bags… 

USE THR 

Threadlike materials, e.g. pieces of nylon wire, net-fragments, woven clothing… 

Use foam 

USE FOA 

All foamed plastics e.g. polystyrene foam, foamed soft rubber (as in mattress 
filling)… 

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Use fragment 

Other Use 
plastics 
Litter other than 
plastic 

USE 
FRAG 
USE 
POTH 

OTHER 

Fragments, broken pieces of thicker type plastics, can be a bit flexible, but not 
like sheet like materials. 
Any other plastic type of plastics, including elastics, dense rubber, balloon 
pieces, soft air gun bullets… Specify in the column “Notes”. 

All  non-plastic rubbish and pollutant 

Natural food 

FOO 

Natural food for sea turtles (e.g., pieces of crabs, jellyfish, algae…) 

Natural no food 

NFO 

Anything natural, but which cannot be considered as normal nutritious food for 
sea turtle (stone, wood, pumice, etc.) 

R
E
H
T
O

S
T
N
E
M
E
L
E

The  “basic”  parameters  correspond  to  information  fundamental  for  determining  the  GES  based  on  this 
indicator. While the  GES scenario has still to be  voted  (see  § 2.4.4), the minimum  number of parameters to 
record may change in the next future, for example if the objective is to target the evaluation of Programs of 
measures  (PoMs)  related  to  a  specific  litter  category.  As the  measurement  of the  other  parameters  is  time-
consuming, they were considered as “optional”. However, this information is also highly important since it aims 
to better understand the factors which may influence litter ingestion by sea turtles. Their analysis should help 
to specify the indicator’s possible constraints and better anticipate the risks related to litter exposure.  

The “basic” parameters were: 

- 
- 

- 

- 

- 
- 

The observer’s coordinates, in case that further precisions are needed; 
The  circumstances  of  discovery  of  the  sea  turtle  specimen,  with  a  standard  identification  code  which 
should be notified on each sample; 
The conservation status of the body of animals found dead, and for both live and dead individuals, the 
standard curved and straight carapace lengths; 
The main description of live individuals’ behavior or of the internal organs of dead individuals in order to 
globally assess the individual’s health status; 
The presence/absence of ingested litter; 
The dry mass of each litter category (as in Table 5). 

The “optional” parameters concerned a precise external and internal exam, aiming at better understanding 
the role of litter ingestion and entanglement on the health status or possible cause of death. They also aimed to 
give a first assessment of the relevance and constraints of other litter impact indicators, related to (i) micro-
plastic  ingestion  by  sea  turtles,  for  the  specific  size  category  1-5  mm  and  (ii)  entanglement of  sea  turtles  in 
marine litter. The “optional” parameters concerned: 

-  A better description on the possible cause of death, in particular the type of fishing gear in case of bycatch; 
- 
The observed impact of the entanglement, specifying the category of litter and if entanglement in litter 
was passive or rather active, which could be the consequence of active fishing; 

-  A characterization of the body condition, described thanks to fat reserves, injuries, measures of carapace 

- 

- 
- 

and plastron, and weight; 
The digestive capacity, measured from the mass and volume of each section of dead individuals’ digestive 
tract; 
The total volume of ingested plastics; 
The  differentiation  of  ingested  plastic  by  size  class  (micro:  1-5  mm,  meso:  5-25  mm,  macro:  >25  mm, 
according to (Andrady, 2011b; MSFD Technical Subgroup on Marine Litter, 2013) and color class: As color 

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might be difficult to assess, especially for multi-colored or worn and faded items, three main categories 
was proposed: white-transparent, light (light pink, light green, etc.), and dark (black, dark green, etc.). 

Several modifications were brought all along the project thanks to the experience shared among partners and 
with stakeholders. Among the major ones, the quantity in terms of number appeared to be confusing, some 
counting the number of fragments (of the same item) and other, the number of items (all fragments considered 
as coming from the same item, e.g. several fragments of white plastic coming from the same white plastic bag 
were counted as 1). The two parameters may give a useful but different information, the first enabling more to 
assess the impact of ingestion on health and being maybe less subjective, the second informing more on the 
type of litter causing impacts. Number of fragments and number of items were thus differentiated and proposed 
as optional parameters. 

Pictures showing the order of magnitude of the object were highly recommended for possible verification of 

some details or for further research, in the field as in the laboratory. 

2.3.2. Dissemination of the standardized methodology for monitoring litter impacts 
The INDICIT protocol and the “Observation sheet” in which data have to be handwritten, can be found in the 
INDICIT website (sections INDICIT documents and Tools; versions September 2018). The protocol detailed all the 
procedures, from the discovery of dead or live sea turtle, most of them being possible on all turtles, except for 
the leatherback when the individual should be moved or returned. 

Translations were done in order to favor local involvement and fill the gaps of data in certain areas: 

-  Arabic, 
-  Greek, 
- 
- 

Spanish, 
French. 

In addition to the website, the INDICIT protocol  was disseminated by email during the 14 training sessions 
given to stakeholders, and also during specific events such as the workshop on Marine litter impacts organized 
by INDICIT consortium, RAC/SPA and Archipelagos Institute during the MedTurtle conference in Porĕc (Croatia) 
in October 2018, and the INDICIT Dissemination meeting in December 2018 in Athens (see minutes in INDICIT 
website). 

INDICIT protocol was presented in several conferences and during other projects’ meetings (see Dissemination 
final report in INDICIT website). This offered the opportunity to make synergy with RAC/SPA center of Barcelona 
RSC, who also produced a standard protocol for monitoring litter impact on sea turtles. The two documents have 
been compiled in a RAC/SPA-INDICIT protocol and submitted by CNRS with support of other INDICIT partners to 
CORMON,  which  recently  approved  it  (RAC/SPA-INDICIT,  in  press).  This  synergy  should  facilitate  the 
harmonization with stakeholders involved in Barcelona RSC, especially with the Southern countries. 

A video-tutorial presenting the external and internal exam of a sea turtle is available in French (Darmon et al., 
2017b). During INDICIT project, ISPRA managed the elaboration of a video-tutorial showing all procedures from 

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the discovery of a dead specimens to the opening of a loggerhead turtle, with extraction of the digestive tract, 
the  differentiation of  the digestive  sections and  the extraction  and  quantification of  the  litter  ingested.  This 
video was published in a peer-review journal (Matiddi et al., 2019). The publication in a journal should facilitate 
the dissemination for a common procedure. 

2.3.3. Costs and recommendations 
Only authorized people can manipulate protected species and after contacting local authorities. CITES permits 
are also to be considered in case that samples have to be sent from/to countries having ratified the Washington 
convention. 

Moreover, manipulations absolutely require sanitary precautions in order to avoid zoonosis risk. This should 
be highlighted during training sessions with participation certificates. These sessions can be the opportunity to 
provide a material kit to stakeholders newly involved in the monitoring (list of materials provided in the INDICIT 
protocol). 

To better assess the impact of litter on individual’s health, “optional” parameters related to body condition 
are  encouraged  to  be  collected,  as  well  as  measuring  systematically  the  dry  mass  of  natural  food  remains 
(category FOO, Table 5; see §2.4.3.2). 

The  time  required  to  collect  samples  and  extract  marine  litter  depends  on  the  body  condition  level  (no 
manipulation  recommended  if  the  autolysis  is too  advanced).  An  average  of  5  hours  with  two manipulators 
should be considered for the collection of data from necropsied individuals, including the external and internal 
exam of the body. The cost of material can be evaluated from the list provided in INDICIT protocol.  

The cost of implementation should consider the equipment and training of each stakeholder by covering the 
widest  possible  area.  Fees  could  also  target  dedicated  specialized  teams  who  could  support  the  laboratory 
analyses.  Among  stakeholders  having  been  contacted  but  not  yet  involved  in  litter  monitoring,  some  are 
constrained by financial and human means. In certain areas, the number of turtles found dead is too important 
to  conduct  a  systematic  monitoring of  litter  impacts,  e.g.,  as  reported  by the  Israel  sea  turtle  rescue  centre 
during the workshop proposed by INDICIT during the MedTurtle conference in Croatia in October 2018. Further 
studies  are  needed  to  evaluate  if  the  monitoring  could  be  performed  in  a  part  of  the  area  considered  as 
representative for the country.  

In case of material and time/human constraints, stakeholders could be supported by specialized teams for 
manipulations in laboratory and data analyses. These stakeholders should be equipped with a minimum material 
in  order  to  conduct  the  first  measures  on  the  field,  perform  the  necropsies  and  extract  the  digestive  tract, 
including a freezer. The laboratory analyses could then be performed by specialized teams coming locally e.g. 
on a 6-months period. The travel and accommodation costs of such teams should be considered. 

2.4. Data banking 

2.4.1. Procedures used during INDICIT project for data gathering and cleaning 
Each partner was in charge of gathering and making a first cleaning of data collected locally. Then, the data 
was either sent by email to CNRS/EPHE, ULPGC and ISPRA as leaders of Activities 2, 3 (Atlantic area of the project) 
and 4 (Mediterranean area) who compiled the entire dataset, or in a private area. CNRS/EPHE indeed proposed 
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a Sharepoint platform accessible via login and password, in order to share documents such as INDICIT databases. 
As signed in the Consortium agreement (§1.2), only partners were authorized to access to data and only the 
results from this data can be shared in INDICIT reports and presentations but not the raw data. Stakeholders 
participating in data collection must be cited. CNRS completed data cleaning during data analysis. This task was 
highly  time-consuming.  To  this  purpose,  the  use  of  a  dedicated  platform  with  drop-menus,  as  managed  by 
IFREMER in the framework of the CleanAtlantic project could greatly save time. 

2.4.2. Summary of data collected 
A standard database (Excel file) for data on litter ingested by sea turtles was built (deliverables D2.8 and D2.9, 

Appendix 1), differentiating: 

(i) 
(ii) 

two tabs for necropsies and for faeces,  
basic and optional parameters. 

At the end of the INDICIT project, a total dataset of 1406 lines has been gathered (1 line per individual) (1014 
data  was  recorded  in  January  2018):  948  for  necropsies  and  458  for  faeces.  In the “Necropsy”  table, 3  data 
concerning  the  green  turtle  Chelonia  mydas  were  removed. This  species  would  be  possibly  monitored  since 
observations were regular, both in Atlantic and Mediterranean. Nevertheless, this should be clearly asked to 
stakeholders for a systematic monitoring and power analyses. Stakeholders were asked to give priority to the 
collection  of  the  loggerhead  turtle  and,  if  possible,  on  the  leatherback  turtle,  and  other  species  could  be 
considered in the future. All data from faeces concerned only loggerhead individuals, who were hosted in rescue 
centers. 

In the remaining data from necropsies, 838 were extracted from loggerheads and 107 from leatherbacks. For 
the  leatherback  database,  only  one  data  was  collected  in  Tunisia  and  all  other  in  France  Atlantic  from  the 
stakeholder CESTM-Aquarium La Rochelle. The possibility to integrate this species in future monitoring should 
be better evaluated. This would require specific training sessions for conducting a necropsy on this species, with 
specific manipulations and conditions of work due to the size of specimens. Due to the restricted number and 
distribution of data acquired at this stage, analyses could not be performed to assess the indicator’s constraints 
and GES for this species and only exploratory analyses were done (see §2.4.1). 

Table 5 and Table 6 show the number of data collected from live and dead loggerheads respectively: 

(i) 

(ii) 

(iii) 

data  collected  before  the  INDICIT  project  (not  always  standard  and  maybe  not  systematic)  were 
gathered and formatted to INDICIT standard Excel file (total number of data); 
the number of data collected on a 6-year period according to MSFD cycle, from 2013, year of the MSFD 
guidance (MSFD Technical Subgroup on Marine Litter, 2013), from which a standard methodology was 
started to be disseminated and known to stakeholders; 
the  number  of  data  acquired  during  the  two  years  of  the  INDICIT  project  in  order  to  evaluate  the 
minimum  sampling  capacity  per  partners’  country.  Nevertheless,  some  stakeholders’  data  was  not 
available  during  the  INDICIT  project  duration  or  the  duration  was  not  sufficient  to  process  all  the 
samples. This information thus represented a minimum sampling capacity at the Area level. 

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Table 5. Number of data collected from excretions of live loggerhead turtles in each area/country. 

Area 

Country 

Total number 
of turtles 

Number of turtles 
from 2013 

Min number of turtles during 
INDICIT project (2017-2018)* 

Atlantic 

France 

Portugal 

Spain 

Total 

Mediterranean 

France 

Greece 

Italy 

Spain 

Tunisia 

Turkey 

Total 

128 

0 

12 

140 

68 

3 

183 

39 

17 

8 

318 

5 

0 

2 

7 

68 

3 

93 

21 

17 

8 

0 

0 

1 

1 

25 

3 

33 

14 

17 

8 

210 

100 

Table 6. Number of data collected from necropsied loggerheads in each area/country 

Area 

Country 

Total number 
of turtles 

Number of turtles 
from 2013 

Min number of turtles during 
INDICIT project (2017-2018) 

Atlantic 

France 

Portugal 

Spain 

Total 

95 

66 

13 

174 

21 

33 

9 

45 

1 

6 

6 

13 

Area 

Country 

Total number 
of turtles 

Number of turtles 
from 2013 

Min number of turtles during 
INDICIT project (2017-2018) 

Mediterranean 

France 

Greece 

Italy 

Spain 

Tunisia 

Turkey 

Total 

81 

28 

198 

188 

75 

94 

664 

77 

28 

129 

85 

46 

94 

457 

37 

28 

54 

17 

28 

92 

256 

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2.4.3. Synergy with CleanAtlantic project for data banking 
A dedicated platform should help win time for data gathering and cleaning. Such platform is being developed 
by IFREMER in the framework of CleanAtlantic project with the support of INDICIT. his part was extracted from 
CEMP document written by CNRS, MNHN and IFREMER for OSPAR (April 2019). 

Data entry software is under development in the framework of Interreg project CleanAtlantic, in order to store 
data on litter impacts on sea turtles. The data management process provided a standardized and structured data 
with common referential, with QA/QC procedures. Data from each partner could be hidden to other partners 
and a moratorium can be applied on dataset, thus respecting stakeholders’ possible condition for using the data 
they collected. Data could also be made widely available, also compatible to existing mechanisms (e.g. MSFD, 
OSPAR/ICES databases and EMODNET).  

Two  options  were  proposed  for  the  administrative  architecture  of  the  central  database,  depending  on 
organism IT abilities (i.e. operating team, database server, Oracle License). The first was a transfer of the central 
architecture under use at IFREMER. In that case, each institution would need a trained staff, a database server 
and an Oracle License. Minor software developments should be required under this option. The second option 
should offer an adaptation of the existing architecture to use a PostgreSQL central Database. In that case, each 
institution  would  need  a  trained  staff,  an  operating  team  and  a  strong  IT  structure  using  an  open  source 
software. Advanced software development would be necessary under this option. 

2.5. Analysis of the indicator’s constraints 

In its objective of developing the indicator “Litter ingested by sea turtles”, INDICIT consortium analysed data 

gathered by each partner in order to: 

(i) 
(ii) 
(iii) 

assess the prevalence of litter ingestion in sea turtles and the quantity of ingested litter; 
identify the possible biological constraints of the indicator (e.g., individual size); 
evaluate the sample size and temporal and spatial unit. 

The data was explored in order to evaluate which factors may influence the prevalence and the quantity of 
ingested litter. In addition to a better understanding on the impact of litter by ingestion, these influencing factors 
may indeed be considered to stratify the data when applying the indicator (e.g., using only small individuals). 

Given that data collection, gathering and cleaning took  much more  time than expected while  planning the 
INDICIT project time table for submission, the expected time allocated to data analysis was too small to deeply 
explore  data  and  test  indicator’s  constraints.  Data  cleaning  was  completed  during  data  analyses  which 
highlighted  some  needs  of,  for  instance,  combining  factors  together  or  adjusting  methodologies.  Various 
explorations  were  done,  especially  to  select  the  factors  to  be  considered,  in  particular  concerning  the 
relationships between individual’s body condition or health status and litter ingestion. Data analyses brought to 
light the need to further discuss and standardize the methodologies used by stakeholders (partners included), 
either by completing the database from stored samples, or by better classifying the parameters used for the 
qualitative  variables  (see  below).  Some  analyses  are  presented  here  but  will  be  further  explored  thereafter, 

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especially in order to publish the results and highlight towards experts’ community the great harmonized work 
made by the INDICIT wide network. 

The prevalence of litter ingestion in sea turtles was calculated as the percentage of turtles found with ingested 
litter, based on the occurrence (or incidence) reported as presence or absence. The quantity of ingested litter 
was measured as a dry mass (grams), a total volume (mL) and a number of items or fragments (see below). The 
precision of the measurements was 2 decimals (up to 0.01). For really small but non-zero quantities, the value 
of 0.001 g (or 0.001 mL) was noted. Calculations were then based on arithmetic averages with standard errors 
(hereafter noted “SE”, calculated as the ratio of the population’s standard deviation on the squared root of the 
sample size). Averages of quantities are calculated over all available individuals, including those that contained 
no  litter (“population averages”), and compared  with quantities assessed on  only  those  found with  ingested 
litter. When sample  sizes are small, arithmetic means  may be  influenced by local variations  and outliers. An 
alternative could be to apply logarithmic (adding a small value to avoid zeros) and normal transformation of 
data,  which  can  reduce  the  role  of  the  higher  values  (ln(x)).  The  factors  influencing  the  prevalence  of  litter 
ingestion and the quantity of ingested litter were first explored with simple analyses (e.g., Student t test for 
comparison  the  means,  analysis  of  variances  (ANOVA))  and  then  a  global  approach  evaluating  the  possible 
interaction among factors (e.g., linear generalized models and multivariate analyses).  

The analysis of data was done with Excel and R (version 3.4.1; (R Core Team, 2017) software.  

2.5.1. Data on the leatherback turtle 
From the 106 individuals sampled in the Atlantic France and the only individual from Tunisia (standard straight 
carapace length ranged from 96 to 203 cm (143.4 1.53 cm; N = 94)), the occurrence of litter ingestion was really 
high: 52.83% from 1988 to present (52.38% in Atlantic France) and 53.84% when considering only the last 6 
years (data from 2013,  N =  13  individuals  all from France).  The  dry mass of ingested litter was  noted for 63 
individuals in France Atlantic: On average, 7.67 2.82 g of plastics were found ingested among turtles having 
ingested debris (N=13), which represents 1.7 0.73 g on average at the population level (i.e., when considering 
all sampled individuals for which the information was filled; N=63)).  

The data on litter ingested by the leatherback turtle (data only from necropsies) were insufficient at this stage 
to enable the development of the indicator from this species. An evaluation of the sampling capacity from this 
species should be done with a greater number of stakeholders. 

2.5.2. Possible discrepancies in the methodologies used to collect samples from live individuals 
Only  the  data  collected  from  living  loggerheads  who  remained  at  least  1  month  in  the  rescue  center  was 
considered. For these turtles, the data were gathered from all faeces collected daily from their arrival until 2 
months later.  

A total of 458 living loggerheads was sampled, from which 445 were found with ingested litter (Table 7). The 
individuals’ size ranged from 16 to 77 cm (Standard curved carapace length, mean 51.8  0.05 cm, N = 254). The 
occurrence of litter in the faeces was recorded in 445 of them, the average being 31.68% (all data from 1988 to 
present) and 57.94 % (N = 217 for the last 6 years). The dry mass of ingested plastics, noted for 396 individuals 

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since 1988, was 0.59 0.21 g on average at the population level, and of 1.06  0.44 g on a 6 year-cycle (N = 185 
from 2013; Table 7). Among those who had ingested litter, the mean dry mass of plastics was 1.93 0.69 g since 
1988 (N = 120) and 1.84 0.76 g since 2013 (N = 107). 

Considering  the  discrepancies  among  stakeholders  in  the  methodology  of  collecting  samples,  INDICIT 
consortium decided not to include data coming from living turtles for the elaboration of the indicator at this 
stage (minutes of INDICIT 4th meeting in Azores available in INDICIT website, Summer 2018). Some partners used 
a dip net to collect floating faeces on the  surface  and in the water column, scraping the possible remaining 
materials at the bottom when emptying the water and cleaning the tank. Others used filters on both incoming 
waters  (thus  avoiding  a  possible  contamination  with  micro-plastics)  and  the  water  discharge  system,  then 
collecting  the  excreted  elements  directly  on  this  last  filter.  This  second  methodology  was  probably  more 
appropriate  for  collecting  samples  in  a  standardized  way.  This  difference  underlined  the  need  for  specific 
training sessions to stakeholders working with living turtles in rescue centres. 

In the light of the high occurrence found on living loggerheads (57,94%), the collection of samples from living 
individuals  is  highly  recommended.  On  the  one  hand,  this  will  allow  a  better  understanding  of  the  factors 
influencing  litter  ingestion  and  the  consequences  on  individual’s  health,  and  to  assess  the  possible  under-
evaluation of litter ingestion from the examination of faeces compared to the examination of the entire digestive 
tract. On the other hand, thanks to the great number of rescue centres involved in the area (§2.1.3), the analysis 
of a dataset should enable the comparison with the results from necropsies, and either combine data from the 
two protocols, or propose a specific GES for living turtles.  

Table 7: Mean prevalence (%) and dry mass (grams) evaluated from excretions of living loggerhead turtles in 

rescue centres per area and country (table “Faeces” of the INDICIT standard database) 

Area 

Country 

Prevalence (N) 

Dry mass 
meanse (N) 

Prevalence (N) 

Dry mass meanse (N) 

All data 

Data from 2013 

France 

2.34 (128) 

0 (125) 

Atlantic 

Portugal 

- 

Spain 

18.18 (11) 

- 

(0) 

20 (5) 

- 

50 (2) 

0 (4) 

- 

0 

Global 

3.6 (139) 

0 (N=125) 

28.57 (7) 

0 (4) 

Mediterranean 

France 

48.53 (68) 

0.21  0.06 (60) 

48.53 (68) 

0.21  0.06 (60) 

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Greece 

100 (3) 

0.03  0.02(3) 

100 (3) 

0.03  0.02 (3) 

Italy 

Spain 

39.9 (183) 

1.06  0.45 (183) 

64.52 (93) 

1.71  0.87 (93) 

62.96 (11) 

2.36  1.31(10) 

88.89 (18) 

2.36  1.31 (10) 

Tunisia 

47.06 (27) 

0.2  0.07 (8) 

47.06 (17) 

0.2  0.07 (8) 

Turkey 

25 (8) 

(1.4 x 10-4; 7) 

25 (8) 

(1.4x10-4; 7) 

Global 

44.44 (306) 

0.86  0.31 (271) 

58.94 (207) 

1.09   0.38 (181) 

2.5.3. Results on litter ingestion observed in necropsied individuals 
Partners gathered data collected prior to INDICIT project. We suppose that loggerhead and leatherback turtles 
found dead were systematically necropsied at least after the publication of the MSFD guidance in 2013. Before 
this date, we could not verify if all turtles were systematically analyzed, or more specifically if individuals in poor 
body condition, or who presented an injury or a sign of presence of litter, were more prone to be examined. 
However, all data collected before INDICIT project were standardized according to INDICIT database and were 
thus comparable to the data collected during the INDICIT project. At the end of the project, 838 turtles were 
recorded, ranging from 1990 to 2018 (last turtle found the 26th November 2018). 

Each partner cleaned the data and a second cleaning was made by CNRS with the great support of all partners 
during data analysis. Data was classified and standardized, e.g. to minimize the number of factors for qualitative 
parameters (e.g., circumstances of discovery or causes of death, see below). Missing data was either filled by 
partners or when possible, deduced by CNRS. The phase of cleaning dataset was highly time-consuming and 
probably  under-estimated at  the  beginning of the  project. The use of a platform with drop menus and data 
control would certainly enable to gain time. 

2.5.3.1. Evaluation of metrics of measurements 
- Description of the prevalence of litter ingestion and the quantities of ingested litter 

Among  the  838  necropsied  loggerhead  turtles  from  1988  to  the  end  of  INDICIT  project  (standard  curved 
carapace length ranging from 9.4 to 89 cm with a mean of 53.45 0.03 cm), 57.62 % of the turtles have been 
found  with  ingested  litter  in  their  digestive  tract  (N  =  833  for  which  the  occurrence  was  clearly  notified). 
Considering  data  from  2013  (data  from  Portugal  was  attributed  to  the  year  2016),  the  prevalence  of  litter 
ingestion was really high with 63.03% of 522 turtles found with ingested litter (standard curved carapace length 
ranging from 10 to 89 cm with a mean of 56.32 0.04 cm). 

The total dry mass of ingested plastics was 0.75  0.08 g (N = 768). This represented 0.120.01 g of plastics / 
10 cm of turtle carapace (Standard curved carapace length). After 2013, the dry mass was evaluated to 0.78 
0.11 g (N= 480) at the population level (all sampled turtles considered), representing 0.120.02 g/10 cm. When 
considering only the individuals for which a presence of litter was found (occurrence= 1), the dry mass was 1.35 
0.13 g (N = 425) on average since 1990 (0.23 0.03 g plastics/10 cm carapace lengths), and 1.27 0.17 g since 

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2013 (N = 294; that is 0.21 0.03 g/10 cm). The mean occurrence of litter ingestion and quantities of ingested 
plastics in necropsied turtles per area (Atlantic/Mediterranean) and country found both on all data and data 
after 2013 are presented in Table 8. 

Table 8: Mean prevalence of litter ingestion (%) and dry mass of ingested litter (plastics, in grams) evaluated 
from  the  necropsies  of  loggerhead  turtles  per  area  and  country  (table  “Necropsies”  of  the  INDICIT  standard 
database) 

Area 

Country 

Prevalence (N) 

Dry mass meanse 
(N) 

Prevalence (N) 

Dry mass meanse 
(N) 

All turtles 

Turtles from 2013 

Atlantic 

France 

26.32 (95) 

0.07  0.04 (79) 

45 (20) 

0.28  0.16 (18) 

Portugal 

87.88 (66) 

1.31  0.23 (66) 

81.82 (33) 

1.13  0.35 (33) 

Spain 

84.61 (13) 

0.16  0.07 (8) 

88.89 (9) 

0.16  0.07 (8) 

Global 

54.02 (174) 

0.61  0.11 (153) 

70.97 (62) 

0.74  0.21 (59) 

France 

79.75 (81) 

1.15  0.26 (79) 

82.43 (76) 

1.23  0.27 (70) 

Greece 

64.28 (28) 

0.13  0.06 (28) 

64.28 (28) 

0.13  0.06 (28) 

Italy 

53.53 (198) 

0.74  0.13 (198) 

62.01 (129) 

0.92  0.19 (129) 

Mediterranean 

Spain 

72.43 (188) 

1.05  0.17 (168) 

80.49 (85) 

0.89  0.27 (70) 

Tunisia 

45.33 (75) 

0.63  0.41 (52) 

52.17 (46) 

0.84  0.71 (29) 

Turkey 

32.98 (94) 

0.36  0.28 (94) 

33.33 (93) 

0.37  0.29 (93) 

Global 

58.57 (664) 

0.78  0.09 (615) 

61.95 (457) 

0.78  0.12 (419) 

-  Assessing the quantity of ingested litter as a volume: complexity for providing accurate assessments 

The mean volume of plastics ingested by sea turtles was evaluated to 0.33  0.09 ml on average (N = 276), 0.05 
 0.03 ml in Atlantic area of the project (N = 78 available records) and 0.44  0.03 ml in the Mediterranean area 
of the project (N = 198), respectively when considering all data. On the last 6-year cycle, from 2013 onward, the 
mean volume was 0.48  0.01 (N=191), 0.23  0.15 ml (N=16) in the Atlantic and 0.51  0.14 ml (N=173) in the 
Mediterranean, respectively. The volume was regularly reported by partners and collaborators to be difficult to 
measure, especially for the very light plastics which are floating on the surface. Therefore, this metric was not 
retained for proposing a GES. However, the volume may inform on the impact of plastic ingestion on health, for 
example by comparing it to the digestive capacity, measured by some partners as the volume of each digestive 
full and emptied section (oesophagus, stomach and intestines:  optional parameters, N = 58  individuals  from 
France and Atlantic Spain).  

-  Assessing the quantity of ingested litter as a number of litter items: can be confusing 

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During  the  4th  INDICIT  meeting  in  September  2018  (minutes  available  in  INDICIT  website),  while  sharing 
experience on the methodologies to evaluate the quantity of ingested litter, the consortium recognized that 
partners and collaborators did not use the same approach to evaluate the number: Some evaluated the number 
of fragments by counting all pieces of litter found (as done on the Fulmar indicator), other evaluated the number 
of items by gathering all fragments of a same item and counting all supposed items. Partners and collaborators 
have then specified the methodology they used in order to differentiate the total number of plastic fragments 
and the total number of plastic items. We found a mean number of  12.11  1.12 fragments and 4.71  0.71 
items on average from the total database, and a mean number of 11.46  1.37 fragments and 5.83  0.98 items 
per individual on average from 2013. 

The information provided by these metrics could probably be more significant and eloquent for the general 
public. The two metrics did not provide the same information, the number of fragments being probably more 
related to the impact on health, the number of items informing more on the type of litter in the environment 
being possibly more related to the specific measurements associated to them. Whereas the INDICIT protocol 
proposed to record the number per litter category (Table 4) and each digestive section (oesophagus, stomach 
and intestines), this information could not be used to develop the indicator since we could not certify that the 
measurement was assessed in a harmonized way on the whole area. However, as most of samples were stored, 
data could be completed to distinguish both items and fragments, but this would require time to complete the 
database. The number of fragments and items were still asked as “optional parameters” in the INDICIT protocol 
(an update has to be done for specifying the definition and the methodology). A decision to keep or remove 
these parameters should be taken. 

2.5.3.2. Factors influencing litter ingestion (indicator’s units and constraints) 
Some factors may influence the sampling strategy and the probability to find turtles having ingested litter. To 
represent as best as possible the litter abundance and impacts, sampling ideally should be performed randomly, 
with a sufficient number of specimens to detect changes in occurrence and quantity of ingested litter. However, 
certain factors might expose turtles to litter more than others, e.g. smaller individuals may be less experienced 
and less selective or may use different marine habitats compared to larger ones. If sampling principally target 
these individuals more/differently prone to ingest litter than the others, there would be a risk to over/under-
estimate litter abundance and impacts. Nevertheless, if all individuals show same spatial and temporal variations 
in litter ingestion, all individuals could be combined in a same dataset for assessing an overall impact of litter at 
the MS or regional scale. In this way, even if young fulmars have been found to eat more plastics than older 
fulmars, as the mean mass of ingested plastics shows the same temporal fluctuations for adult and non-adult 
individuals, the two groups are combined to employ the OSPAR indicator by considering age as co-factor (van 
Franeker et al., 2011). This verification should be done for the Turtle indicator. The need for stratifying data 
according to environmental and biological factors was thus be tested. The objective was to specify the possible 
biological constraints, especially related to the circumstances of discovery and the causes of death, which may 
influence the sampling strategy, and the individual’s size that may influence turtles’ exposure to litter.  

The  INDICIT  standard  dataset  contained  a  large  number  of  basic  and  optional  parameters,  in  particular  to 
describe individual circumstances of discovery and body condition (26 parameters), some of them having been 
combined for analyses. The analyzed database contained 122 columns. A high number of combinations could 
thus be tested to assess which factors may influence litter ingestion. This part thus shows preliminary analyses 
which should be deepen in the future. 

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- Description of sampled specimens 

Circumstances of discovery. Specimens were mostly found bycaught, supposedly recovered by fishermen, or 
stranded (Table 9). However, turtles found dead stranded, floating at sea or dead later in the rescue centre after 
recovery, may have been bycaught before (Table 9). The information on the probable cause of death enabled to 
add 21 turtles as bycaught (total known as 209 bycaught turtles). 

For turtles  found bycaught,  the type of  engine involved was reported for 105 cases  but the differentiation 
remained unclear: Generally, they were longliners (22 cases), nets (30), trawls (27) and straight threads (24). 
The distance to the coast, the depth and the target species were not specified, and it was thus not possible at 
this stage, to test if litter found in bycaught individuals varied with the type of engine or the marine compartment 
in which they were captured. This information should be further detailed. 

Table 9: Circumstances of discovery of the dead individuals recorded per area and per country (all data pooled) 

Area 

Country 

Found at sea 

Bycatch 

Dead in rescue center 

Stranding 

Total 

22 

188 

20 

519 

Atlantic 

Mediterranean 

France 

Portugal 

Spain 

Global 

France 

Greece 

Italy 

Spain 

Tunisia 

Turkey 

Global 

2 

3 

2 

7 

2 

0 

5 

2 

0 

6 

12 

30 

0 

42 

40 

0 

16 

87 

3 

0 

15 

146 

0 

0 

4 

4 

1 

0 

3 

0 

0 

12 

16 

80 

18 

7 

105 

16 

28 

174 

95 

25 

76 

414 

Probable causes of death. The external and internal exams of sea turtles  aimed at identifying the probable 
cause of death. The information was recorded for 189 individuals on the entire dataset. Bycatch was the main 
cause of death (114 cases) followed by anthropogenic trauma, e.g. collision with boats (32 cases), entanglement, 
which in fact regularly appeared to be active fishing (bycatch) in set nets (20 cases) or in ghost fishing gear, and 
natural causes, e.g. disease (14 cases). Litter ingestion was identified as a direct cause of the death with certainty 
for only 4 individuals. Bycatch is supposed to sample both healthy individuals and individuals in bad condition, 
as found in our samples: For the individuals for which body condition was recorded, 13 loggerhead turtles were 
considered  as  in  fair  condition,  10  in  good  and  14  considered  in  poor  condition  or  with  injuries.  All  body 
(recorded)  conditions  were  equitably  found  among  stranded  turtles  (28  fair,  31  good,  31  injured,  24  poor). 
Bycatch and stranded seem thus a good way to sample specimen randomly according to body condition. 

Individual’s size. Several measures were taken to describe individuals’ stage and body condition. Generally, 
stakeholders  collected  the  standard  curved  carapace  length  (here  after  StCCL)  and/or  the  minimum  curved 
carapace length (hereafter MinCCL), thus not necessarily the two measures on the same individuals (Table 10). 
Moreover, it was regularly uncertain to know which measure was taken, as a standard or a minimum curved 

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carapace  length  (see  below).  Generally,  individuals  were  found  larger  in  the  Mediterranean  compared  to 
individuals sampled in the Atlantic area of the project (significant differences with Student t test, p-value<<0.001 
for both StCCL and Min CCL), with differences among countries in the Mediterranean area (Figure 3). 

Table 10: Stages of dead individuals sampled (all data). [Range and mean of standard curved carapace length 
(StCCL) and range and mean of minimum curved carapace length (Min CCL) in cm. Number of individuals per 
stage (Stage 1: 20 cm; Stage 2: ]20-40 cm]; Stage 3: ]40-60 cm]; Stage 4: ≥60 cm)].  

Area 

Country 

StCCL 

Min CCL 

Total 

9.4-89; 53.45 0.03 

12-81; 51.2 0.03 

Atlantic 

France 

14.4-68; 28.56  1.69 

21.2-66.1; 36.46  8.16  

Portugal 

9.4-71; 41.95  2.22 

12-69.5; 46.15  2.17 

Spain 

Global 

France 

34.4-72.5; 47.86  4.6 

30-71; 48.62  4.38 

9.4-72.5; 36.76 1.51 

12-71; 45.73 1.91 

31.5-82; 50.99  2.69 

27-80; 51.09  1.8 

Greece 

22.5-89; 59.59  2.95 

21-82.7; 57.15  0.93 

22-67.5; 47.43  6.52 
- 

Mediterranean 

Italy 

Spain 

Tunisia 

Turkey 

Global 

23-80; 45  8.52 

29-81; 57.5  11.22 

43-71; 58.06  1.85 

21-77; 57.41  1.84 

26.8-83; 67.19  0.91 

- 

21-89; 59.07 0.69 

21-81; 53.66 1.32 

1 

35 

21 

12 

0 

33 

0 

0 

0 

2 

0 

0 

2 

2 

3 

4 

184 

313 

284 

57 

16 

4 

77 

25 

4 

22 

51 

4 

1 

11 

29 

6 

46 

25 

9 

94 

81 

41 

17 

3 

9 

3 

15 

22 

15 

81 

51 

30 

70 

107 

267 

269 

Figure 3: Boxplot (mean 1st and 3rd quartiles) of the standard curved carapace length of turtles sampled per 

area and country (all data pooled) 

- 

Evaluation of spatial and temporal units 

Spatial  variations  in  litter  ingestion.  We  detected  no  significant  differences  neither  in  the  frequency  of 
occurrence of litter ingestion in sea turtles nor in the dry mass of ingested litter between the Atlantic and the 
Mediterranean areas of the project, both when considering data from 1988 to present and data from the last 6 
years: Prevalence of 54.02% and 61.95% (Student t test: t = -1.07, df = 268.62, p-value = 0.28) for all data, and 
70.91% and 61.95% for data after 2013 (t = 1.44, df = 81.077, p-value = 0.15); Mean dry mass of 0.61  0.11 g 
and 0.78  0.09 g (t = -1.2, df = 368.46, p-value = 0.23) for all data and, 0.74  0.21 g and 0.78  0.12 g after 2013 

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(t = -0.19, df = 101.1, p-value = 0.85). Nevertheless, there were differences among countries in each of the two 
areas: Higher prevalence and higher ingested quantities in Portugal compared to France and Spain in the Atlantic 
area (p<<0.01), and e.g. differences between Greece and Turkey compared to other countries in terms of mass 
(Table 8). 

Spatial variations in occurrence and dry mass have been regularly tested during the course of the project with 
updated  database.  The  results  changed  regularly,  underlying  a  possible  effect  of  sampling  size  (see  below), 
especially  in  areas  where  sampling  just  started  (e.g.  Atlantic  Spain,  East  Mediterranean).  The  absence  of 
differences  found  with  the  final  database  should  be  verified  later  with  a  larger  database  and  other 
countries/sub-regions  thanks  to  the  involvement  of  other  stakeholders.  Meanwhile,  the  INDICIT  consortium 
voted to differentiate data from Atlantic and Mediterranean and to propose 2 distinct GES (Minutes of INDICIT 
Intermediate meeting in INDICIT website, see §2.4.4).  

Temporal trends in litter ingestion. We found almost no temporal trend (in fact a significant but really slight 
increase)  in  the  prevalence  of  litter  ingestion  over  the  years  from  the  1990’s  till  today  (predicted  slope  of 
occurrence over years with a generalized linear model with family Binomial of 0.009 (0.003), p-value <<0.01), 
but  a  significant  slight  decrease  when  considering  data  after  2013  (slope  of  -0.06  (0.01),  p-value  <<0.01). 
However,  we  found  no  significant  temporal  trend  for  dry  mass  neither  by considering  all  data  (slope  -0.006 
(0.01,  p-value=0.62)  nor  only  data  after  2013  (slope  -0.13  (0.07,  p-value=0.06).  Nevertheless,  both, 
occurrence  and  mass  varied  a  lot  over  time  (Figure  4),  due  to  several  possible  factors  as  the  availability  of 
samples in the different involved country. 

Although  the  data  collected  before  the  INDICIT  consortium  was  standardized  for  the  INDICIT  database, 
stakeholders  should  be  contacted  to  verify  that  necropsies  were  indeed  performed  systematically  and  in  a 
standardized way. Supposing that the dissemination of the MSFD Guideline in 2013 (MSFD Technical Subgroup 
on Marine Litter, 2013) encouraged stakeholders to collect data on litter impacts with a standard methodology, 
the INDICIT consortium decided to use data from 2013 for proposing a GES, which also complies with the MSFD 
6-year  cycle  (Minutes  of  INDICIT  Intermediate  meeting  available  in  INDICIT  website).  Meanwhile,  the  whole 
dataset can be considered to better understand the biological factors influencing litter ingestion. Moreover, the 
temporal trends should be tested by differentiating litter categories (see preliminary analyses below). 

Figure 4. Mean dry mass of ingested litter (plastics; g) (left) and prevalence of litter ingestion (%) (right) in 
necropsied loggerhead turtles over years from 1988 to present 

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- 

Evaluation of the biological constraints 

Evaluating  the  relationship  between  litter  ingestion  and  individual’s  health  status.  Testing  the  possible 
relationship between litter ingestion and turtle’s body condition is important both to evaluate if data should be 
stratified (in case of different probability to ingest litter depending on individual’s body condition, size or health 
status) and to better understand the impact of litter ingestion on health. INDICIT partners and collaborators 
collected a large number of parameters to describe individuals’ body condition (see INDICIT protocol for more 
details). There were: 

(i) 

(ii) 
(iii) 

(iv) 

The size (proxy of development stage), measured by 12 carapace lengths (standard, minimum and 
maximum curved and straight carapace length, plastron curved and straight carapace length) as 
well as the body mass. Individuals were also attributed to a class of stage, according to 4 classes 
(Stage 1: 20 cm; Stage 2: ]20-40 cm]; Stage 3: ]40-60 cm]; Stage 4: ≥60 cm; Table 10). The stage 
was  assessed  first  with the  standard  CCL  if  recorded,  and  if  not,  with  other  available  carapace 
length measures. 
The circumstances of discovery, 
The body condition evaluated by the possible cause of death, the health status, the description of 
injuries (types and affected body parts) and the fat reserves, 
The  digestive  capacity  evaluated  by  the  volume  and  wet  mass  of  each  digestive  section 
(esophagus, stomach, intestines) both full and emptied. 

Defining  the  impact of  litter  ingestion on  health  was  quite  hard  at  this  stage. The mean  digestive  capacity 
(evaluated from the volumes of the 3 digestive full sections) was evaluated to 1554.86  59.65 ml. On average, 
plastics represented 0.06  0.006% of the entire digestive tract, but this did not necessarily feature impact on 
health. Identifying the causes of death was recognized by most partners and collaborators to be highly difficult. 
Death was attributed to litter ingestion for sure in only 4 individuals due to perforation or obstruction of the 
digestive tract (out of 189 cases identified). The mean length (StCCL) of individuals having ingested litter was 
54.03 cm, almost equivalent to those with no litter (52.19 cm; t-value=-0.79; p-value = 0.42).  

Identifying a parameter for better evaluating body condition. A first work was made to assess which parameter 
could  be  considered  to  evaluate  health.  Various  combinations  were  evaluated  to  assess  individual’s  body 
condition.  New  parameters  were  calculated  for  exploring  the  data  such  as  a  Body  Condition  Index  (BCI) 
evaluated thanks to the ratio [weight (kg)/straight carapace length (cm3)] X 10.000 (Barrios-Garrido et al., 2015; 
Bjorndal  et  al.,  2000).  The  BCI  calculated  from  INDICIT  data  was  evaluated  to  0.21    0.04  for  individuals 
considered as fat, 0.36  0.04 for individuals in good condition and 0.76    0.12 for thin individuals, with no 
significant difference among the 3 conditions (F=1.23; p-value=0.3). The BCI formula was evaluated from the 
green turtle Chelonia mydas (Bjorndal et al., 2000). This formula is maybe not adapted for the loggerhead and 
should be adjusted for this species. 

It was not possible to compare all parameters in a single analysis because, the individuals have been described 
by some but not all the parameters proposed in INDICIT protocol, a complete database would have 0 line. Using 
library ade4 in R (Dray et al., 2018), we performed a multivariate analysis with mixed quantitative variables and 

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trauma/At  Sea/Bycatch/Entanglement/Euthanasy/Litter 

factors (Hill and Smith method) (Hill and Smith, 1976) on Area (Atlantic/Mediterranean), Country, Month, Year, 
a  variable  “CircumstancesDeath”  combined  both  the  Circumstances  of  discovery  and  the  Cause  of  death 
(Anthrop. 
ingestion/Natural/Several/Stranding), 
Condition  (Fair/Good/        Injured/Poor),  StCCL,  Stage3  (1/2/3/4),  Occurrence,  Total  dry  mass  (TotDMass), 
logarithm of total dry mass (logMass). As revealed in Figure 5, the Hill and Smith analysis showed only one axis 
(see histogram of eigenvalues), which explained only 17.92% of the total variance. Although in 2 dimensions, 
the graph in Figure 5 should thus be interpreted only on the first axis. This first axis is led by Portugal (score 
2.09), Atlantic area (1.72) and Stage 1 (1.72), thus possibly interpreting the differences of turtles’ stages between 
the Atlantic (smaller) and the Mediterranean area of the project. However, this analysis could not allow the use 
of the scores on this first axis as a parameter to interpret a combination of variables. 

Figure 5: Scatter diagrams of the projection of each parameter scores of the Hill and Smith method on a 
vector basis 

These preliminary analyses underlined the need to standardize the information on individual body condition 
in order to better evaluate the impact of litter on health and better assess if inversely the body condition may 
affect  the  probability  to  ingest  litter.  The  numerous  optional  parameters  collected  by  several  stakeholders 
should enable further studies to better define and assess litter impacts on individual’s health. 

The percentage of turtles with more litter than food remains as a proxy of individual’s health. The use of the 
comparison of ingested litter (total dry mass) to food remains (FOO, Table 4) was discussed by INDICIT partners 
as  a  proxy  of  individual  health.  Possible  bias  due  to  specific  life  stage  conditions,  has  been  solved  with  the 
assumption that sea turtles who do not feed (e.g., adult individual during reproduction period), should also not 
ingest litter. Considering the entire INDICIT dataset, 14.51 % of sea turtles had ingested more litter than food, 
which represents 16.76 % on the 6-year cycle from 2013. Data on food remains was not always collected, but 
some could be post-evaluated on stored samples, in order to provide more accurate assessments at the country 
level (Table 11). 

Table 11: Percentage of necropsied individuals with more litter than food remains (dry mass) 

Area 

Country 

All data 

Data ≥2013 

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Total 

Atlantic 

Mediterranean 

France 

Portugal 

Spain 

Global 

France 

Greece 

Italy 

Spain 

Tunisia 

Turkey 

Global 

14.51 

21.43 

0 

- 

18.75 

11.59 

3.7 

26.26 

6.52 

9.09 

0 

16.76 

11.11 

- 

0 

9.09 

12.12 

3.7 

30.23 

16 

9.09 

0 

14.37 

17.01 

Evaluating the influence of intrinsic factors on litter ingestion. We evaluated the factors that may influence 
occurrence and dry mass using generalized linear models with a Binomial and Normal distributions respectively. 
The distribution of data on litter mass was skewed towards zero. A logarithmic transformation of mass data was 
better although it did not significantly help to normalize the distribution. A transformation would be necessary 
to analyse correctly the factors affecting the dry mass of litter and should be further explored. The following 
exploratory analyses were done with a log transformation of the mass, which gave better results. 

Effects of Area and Country have been evaluated above. The detection of a possible influence of body condition 
or size varied with the data collected during the project and in particular with the parameter chosen. We choose 
here  the  standard  curved  carapace  length  (StCCL)  since  was  recorded  most  often.  StCCL  had  no  significant 
influence on occurrence neither when considering all data (t-value =0.8 and p-value = 0.42) or only data after 
2013  (t-value  =  -1.19  and  p-value  =  0.23),  and  no  on  the  total  ingested  dry  mass  (log-transformed  +1) 
(respectively t-value= 1.72 and p-value = 0.08 with all data, and t-value = 0.519 and p-value = 0.6).  

We studied models with one, two or all of the 3 additive or interactive parameters Area, Country and StCCL 
(the  measure  mainly  recorded  to  describe  individuals’  body  condition).  We  selected  the  model  based  on 
parsimony and considering a difference in Akaike's Information Criterion (AIC) of ≥ 2 as equivalent models. The 
model  selected  for  explaining  the  occurrence  of  litter  ingestion  contained  the  additive  effects  of  the  3 
parameters (AIC= 583.81). The same model was selected for the dry mass (AIC = 701.32), but the model Country 
x StCCL was almost equivalent (AIC = 702.57; Table 11). 

Table  12:  Models  predicting  the  occurrence  of  litter  ingestion  and  the  dry  mass  of  ingested  litter  (with  log 
transformation)  according  to  Area  (Atlantic/Mediterranean),  Country  and  StCCL  (Standard  Curved  Carapace 
length) for necropsied loggerheads. Models are selected using Akaike's Information Criterion (AIC). 

Model 

1 

Area 

Country 

StCCL 

Area + Country 

Area x Country 

Area + StCCL 

Area x StCCL 

Country x StCCL 

Occurrence 

Log(Dry Mass)+1 

AIC 

1137.34 

1138.18 

1066.5 

689.14 

1033.32 

1017.41 

682.13 

663.87 

598.82 

AIC 

1304.52 

1306.08 

1263.62 

765.09 

1236.66 

1238.2 

754.77 

741.35 

702.57 

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Country + StCCL 

Area + Country + StCCL 

Area x Country + StCCL 

Area + Country x StCCL 

Area x StCCL + Country 

Area x StCCL x Country 

600.61 

583.81 

585.81 

590.02 

583.79 

596.02 

704.75 

701.32 

701.32 

702.77 

700.45 

702.99 

According to available data and these first exploratory results, data were not stratified (all individuals pooled) 

but GES will be differentiated for the 2 areas (see above). 

-  Categories of litter 

Ingested litter was differentiated in 7 categories in addition to food remain and natural no food remain (see 

Table 4). 

Table 13: Mean mass of ingested litter (standard error). Litter categories represent industrial plastics (IND), 
sheet  like  plastics  (SHE),  threadlike  plastics  (THR),  foam  (FOA),  fragments  (FRA)  and  other  types  of  plastics 
(POTH), as well as non-plastic items, food remains (FOO) and natural items not considered as natural food (NFO) 

Litter category 

All data 

≥2013 

IND 

SHE 

THR 

FOA 

FRA 

POTH 

0.001 0.0005  0.001 0.0007 

0.23 0.03 

0.2 0.03 

0.15 0.05 

0.19 0.07 

0.18 0.13 

0.26 0.04 

0.05 0.01 

0.24 0.2 

0.21 0.04 

0.03 0.01 

Non plastic 

0.58 0.46 

0.78 0.68 

FOO 

NFO 

78.35 11.8 

96.87 15.21 

2.75 0.78 

3.68 1.16 

Figure  6.  Temporal  variations  of  the  main  plastic 

categories found in loggerhead turtles 

All  categories  of  “USE”  plastic  litter  (see  Table  4)  was  found  in  necropsied  loggerheads’  digestive  tract, 
especially fragments (FRA), sheet like (SHE), threadlike (THR), with different variations over time (slope for FRAG: 
-0.03   0.006 (p-value <<0.01); SHE:  -0.02   0.005 (p<<0.01); THR: 0.008   0.009 (p=0.36); FOA: 0.01    0.02 
(p=0.54); Table 13, Figure 6). Inter-annual variations should be further studied. 

- 

Sample size 

The evaluation of occurrence and dry mass of ingested litter varied with the number of data considered. Figure 
7 shows an example of result (dry mass in this case) according to a random selection of data, from 1 to the entire 
dataset. Sample size should correspond to the number of data from which adding new data should not change 
the results. 

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Figure 7: Mean dry mass (g) of ingested litter evaluated in the population according to number of data 
selected randomly 

A power test was done in R with library pwr  (Champely et al., 2018). It aims to determine the sample size 
required to detect an effect of a given size with a given degree of confidence. Four factors were evaluated: (i) 
size of the response to detect, (ii) the variance of the response, (iii) the significance level and (iv) the power. A 
significance of 0.05 (Type I error, that is the probability to reject the null hypothesis when it is true) and a power 
of 0.90 (1 – Type II error, that is the probability to not reject the null hypothesis when it is true, in other words 
to not detect an effect when it is present) were considered. The analysis took into consideration the effect size 
that combines the minimal relevant difference and the variability into one measurement Δ/σ, based on current 
evaluations. Our results showed that, for detecting a change of 10 % in dry mass, a sample of 236 (N = 235.8) 
would be required for the whole INDICIT area. 

Further analyses should be conducted to better assess sampling size, and by separating data for the Atlantic 

and the Mediterranean areas in order to provide accurate evaluations. 

2.5.3.3. Synergies and perspectives 
More statistical analyses will be done while collecting more standard data. This will aim specially to perform 
more  powerful  tests  to  assess  the  indicator’s  possible  biological  constraints.  The  analyses  should  also 
differentiate the litter categories in order to better evaluate specific Programs of Measures, as well as to litter 
size in order to plan how supporting the stakeholders to collect data separately on micro (1-5 mm) and macro-
litter (>5 mm) according to the GES definition. 

 Moreover,  the  knowledge  learnt  from  INDICIT  database  could  be  used  for  other  projects  and  MSFD 
Descriptors, such as related for example to biodiversity (Descriptor 1), food webs (Descriptor 4), reduction of 
bycatch, or more generally for conservation of sea turtles. The INDICIT consortium agreement does not allow 
partners to share raw data, some of which belonging to stakeholders who gathered the data only for INDICIT 
project’s purpose. Only results (analyzed data) could be shared. A set of biological questions could be defined 
with other experts involved in such projects/Descriptors in order to provide the results of these specific analyses. 

INDICIT  partners  collaborated  with  other  projects.  For  example,  a  small  number  of  data  was  shared  with 
CleanAtlantic project (partner IFREMER) to start building a platform for data banking (see §2.3.3). This platform 
should  facilitate  and  possibly  accelerate  the  standardization  of  data  by  avoiding  the  phase  of  data cleaning. 
INDICIT also collaborated with MedSeaLitter, an Interreg project which, targeting the Mediterranean level, aims 

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establish  standardized  approaches  for  monitoring  litter  abundance  and  impacts  and  support  networking, 
cooperation and harmonized approaches among Marine Protected Areas. The two projects interacted in order 
to share protocols (INDICIT protocol) and data on ingested litter in necropsied loggerheads. 

As almost no empirical standard data on litter was available at the Mediterranean level, an evaluation thanks 
to simulations would help assessing indicator’s units. Therefore, maps of floating litter distribution across the 
Mediterranean was set up in the framework of MedSeaLitter in collaboration with INDICIT in order to 1) assess 
high risk areas where sea turtles may be exposed to litter and 2) test the correlation between litter distribution 
and litter ingestion in sea turtles. These maps represented the mean monthly distribution of litter calculated 
from 10 years of simulations (Mansui et al., in revision (MedSeaLitter project); Figure 8). While a diffusion of 
litter  at  the  whole basin  scale  was  shown at the  year level, thus with no clear pattern of distribution, some 
accumulation areas appeared at the trimester level with seasonal variations (Figure 8). An analysis of the mean 
monthly litter distribution (study in review) showed fluxes of litter, with litter spread over all the Mediterranean 
on Winter, while litter concentrate in the Western basin in Summer. These maps may help interpreting INDICIT 
results. A perspective would be to test the spatial constraints of the indicator “Litter ingested by sea turtles” and 
if 2 (or more) thresholds for GES corresponding to different hydro-ecological sub-regions, should be proposed 
for the Mediterranean area.  

Figure  8:  Simulations  of  monthly  distribution  of  floating  litter  across  the  Mediterranean  Sea,  examples  in 
January and August. Red tones are used for particle accumulation. Grey and blue tones show emptying areas 
(from Mansui et al., article in review; Collaboration with MedSeaLitter project). 

2.5.4. GES scenarios 
GES is expected to determine a threshold value (TV) and the extent to which this TV has to be achieved (Art. 
9(1) of MSFD 2008/56/EC, see Appendix 2). TV should represent agreed level(s) of pollution above which GES is 
approved  to  have  been  achieved.  TV  should  be  evaluated  thanks  to  a  value,  a  range  of  values  or  a  trend 
reduction. TV should reflect the significance of an adverse effect and should be compared against a reference 
condition (MSFD Commission Decision 2017/848/EU). It should be set on the precautionary principle, reflecting 
the potential risks of pollution to the marine environment consider the dynamic nature of marine ecosystems 
and their elements and possible future risks. The definition of GES for D10C3 according to MSFD 2017/848/EU 
corresponds to the amount of litter and micro-litter ingested by marine animals (i.e. sea turtles) that is at a level 
that does not adversely affect the health of the species concerned. 

Various  approaches  have  been  proposed  to  establish  TV,  e.g.  based  on  the  study  of  the  dose-effect 
relationship, defined as “the dose of the toxicant below which no adverse effects will occur” (Rosenthal and et 

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al., 1997). However, information collected until now, does not allow determining the relationship between litter 
ingestion and death for loggerhead turtles. At this stage, INDICIT data did not enable to assess individual’s health 
status  with  certainty.  From  data on  necropsies  in  Australia,  Wilcox  et  al. (2018)  estimated  that  14  pieces  of 
plastics in turtles’ digestive tract should lead to a 50% probability of mortality. However, INDICIT consortium 
agreed that this approach could not be employable as baseline for a GES, since 1) at this stage, the number of 
fragments is a confusing parameter and would need further analyses to be used as a parameter, and 2) only 4 
deaths caused by plastic ingestion were identified with certainty among the 189 individuals for who the cause 
of death was possible to evaluate (but with degree of certainty not asked to experts). Wilcox et al. (2018)’s study 
was discussed within INDICIT consortium, as well as with EAB and external experts such as Jan Van Franeker who 
shared his experience in the development of the Fulmar indicator for the OSPAR RSC (van Franeker et al., 2011). 
With some questionings regarding Wilcox et al. (2018)’s methodology, it was also recognized that evaluating the 
impact of litter ingestion on the cause of death would require an objective statement. Moreover, this would 
need  a  larger  number  of  data  associated  to  quantities  of  plastics  to  make  power  models.  All  parameters 
describing body condition collected within INDICIT project would not be usable for testing such an approach for 
now, but this information, in partnership with all experts identified during the project, would make possible to 
propose  an  objective  judgment  of  impact  of  litter  ingestion  on  body  condition  and  health.  Nevertheless,  TV 
should be based on more ambitious thresholds, based on impacts on health before reaching death. An approach 
comparing litter ingestion and body condition assessed either from external exam or evaluation of toxins in 
blood or tissues should be tested. 

Considering  MSFD  definitions  and  requirements  (see  Appendix  2),  INDICIT  data  and  current  results  (main 

results reported in Table 14), INDICIT consortium took several decisions: 

-  Reference: It was not possible to (i) find an existing control area (without pressures) neither in the current 
environmental situation nor (ii) by defining it a posteriori, due to the lack of past data to reconstruct past 
events. In the future, INDICIT data could be used with modelling on litter distribution, coupled with expert 
judgement  in  order  to  defined  a  reference  area  (Borja  et  al.,  2013).  For  now,  the  INDICIT  consortium 
decided  to  define  the  reference  condition  to  which  TV  should  be  compared,  as  the  minimum  of  litter 
impact observed in the studied area. Further studies could test other approaches, e.g., use of the median. 

- 

Spatial  unit:  As  underlined  by  the  New  Commission  Decision  2017/848/EC,  TV  needs  to  be  set  at 
appropriate geographical scales, taking into account the biotic and abiotic characteristics of regions, sub-
regions  and  subdivisions.  INDICIT  consortium  decided  to  propose  two  different  GES  scenarios,  for  the 
Atlantic, and for the Mediterranean areas of the project, in order to consider their specificities although 
the INDICIT results with data collected until January 2019 showed no significant difference in prevalence 
of  litter  ingestion  and  ingested  dry  mass  (§2.4.3.2).  Due  to  the  differences  between  the  Eastern  and 
Western basins of the Mediterranean, with a high prevalence of litter ingestion in the Western compared 
to  the  Eastern  basins,  suggest  that  1  separate  GES  should  be  proposed  for  each  of  the  two  basins,  as 
confirmed by the simulations of litter distribution (Figure 8). 

- 

Temporal  unit:  An  evaluation  and  revision  on  a  6-year  cycle  appeared  relevant  regarding  INDICIT  data 
(§2.4.3.2). 

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- 

- 

Stratification of data: No biological constraint was considered, such as individual’s size or circumstances of 
discovery (i.e., capture mode) which was either not significant or further standard data should be collected 
for power analyses (§2.4.3.2). 

Sample size. Thirty individuals per country was considered as a minimum for allowing parametric tests. A 
first  evaluation  of  236  turtles  was  found  for  assessing  GES  for  the  area.  This  is  reached  for  the 
Mediterranean  but  not  yet  in  the  Atlantic.  The  INDICIT  consortium  suggested  a  minimum  of  50-100 
samples per country. A minimum of 30, as generally required for parametric statistical analyses, could be 
tested, since it could allow reaching 236 turtles for a 6-year period. This is not yet reached for all countries 
(Table 14), but this would be possible now that a network has been implemented. 

Table 14: Main results on necropsied loggerhead turtles from data from 2013 included to January 2019. [Means 
per area and country of: prevalence (mean percentage of turtles found with ingested litter), dry mass (mean dry 
mass  of  ingested  plastic   standard error),  dry mass  per  StCCL  (x10),  and  percentage  of turtles  having more 
plastics than food remains, calculated at the population level. Minima are highlighted in light red. In grey, the 
results of the countries where the 30 turtles proposed by INDICIT consortium as a minimum sample size are not 
achieved. 

Area 

Country 

Number of 
necropsies 

Prevalence 
(%) 

Dry mass 
mean (g) 

Dry mass x 10 
per StCCL 

% turtles with 
Litter>FOO 

Atlantic 

Mediterranean 

France 

Portugal 

Spain 

Global 

France 

Greece 

Italy 

Spain 

Tunisia 

Turkey 

Global 

21 

33 

9 

45 

77 

28 

129 

85 

46 

94 

457 

45 

81.82 

88.89 

70.97 

82.43 

64.28 

62.01 

80.49 

52.17 

33.33 

61.95 

0.28  0.16 

0.07  0.05 

11.11 

1.13  0.35 

0.23  0.07 

0.16  0.07 

0.04  0.02 

0.74  0.21 

0.16  0.04 

1.23  0.27 

0.21  0.06 

0.13  0.06 

0.02  0.01 

0.92  0.19 

0.16  0.03 

0.89  0.27 

- 

0.84  0.71 

0.03  0.03 

0.37  0.29 

0.05  0.04 

0.78  0.12 

0.11  0.02 

- 

0 

9.09 

12.12 

3.7 

30.23 

16 

9.09 

0 

17.01 

Several scenarios have been discussed by INDICIT consortium considering that GES should aim to appreciate 
the environmental situation and support Member States to easily refer to it. Two scenarios were retained for 
further analyses but are still being discussed: 

- 

The first scenario was based on baselines (see Appendix 2), as for the Fulmar approach. For this, three 
approaches are possible: 1) based on the minimum prevalence, 2) based on the minimum dry  mass of 
ingested litter, which could be reported to the individual’s carapace length (see Table 14), or 3) on both 

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- 

the  minimum  prevalence  and  the  minimum  dry  mass,  this  third  option  being  retained  by  INDICIT 
consortium (Table 15). 
The second scenario aimed to consider the impact on health, as required by the new Commission Decision 
(Definition of  MSFD  2017/848/EU  considering  “a  level  that  does  not  adversely  affect  the  health  of  the 
species concerned”),  and which  is  not  considered  in  the  previous  scenario.  Nonetheless,  the  notion of 
“Health of the species” should be further specified. Health could indeed be evaluated at the population 
level,  which  would  make  sense  for  establishing  species  conservation  measures  or  measures  aiming  to 
restore/maintain ecosystem equilibrium. However, this may be difficult to evaluate because this would 
require a long term spatial and temporal monitoring of population structure (age and sex distribution) and 
an evaluation of survival and reproduction rates. Although some evaluations have been made thanks to 
analyses of bycatch (Casale, 2011), this is highly challenging for long-lived and late reproductive species. 
Assessing  the  impact  of  litter  ingestion  on  health  at  the  level  of  individual  appears  more  relevant, 
supposing that a decrease in survival or reproduction would have consequences on population dynamics. 
However, the health of sea turtle individuals was difficult to evaluate, especially on necropsied individuals 
(§2.4.3.2).  The  INDICIT  consortium  hence  proposed  to  evaluate  the  percentage  of  turtles  with  more 
plastics than food remains as a proxy of individual’s health (§2.4.3.2; Table 15).  

The  approach  of  these  two  scenarios  was  presented  to  EAB  especially  during  the  INDICIT  Final  meeting 
(Minutes of the Dissemination meeting available in INDICIT website) and generated debates. Other approaches 
were envisaged, such as adding trends to highlight efforts, e.g. a target of 10% to 30% reduction in prevalence, 
dry mass or percentage of turtles having ingested more plastics than natural food. Finally, the GES should be 
evaluated for the plastic categories mostly observed in sea turtles (FRAG, SHE, THR, see §2.4.3.2). 

Table  15:  Pro  and  cons  of  the  main  GES  scenarios  discussed  by  INDICIT  consortium  (*  3.7  %  the  following 

minimum percentage). In blue, the two scenarios retained by INDICIT consortium for further discussion. 

Scenario 

Atlantic* 

Mediterranean 

Pro 

Cons 

Prevalence 

Dry mass 

1  Baseline 

Prevalence 
and dry 
mass 

“There should 
be less than 45 
% of turtles 
with ingested 
plastics” 

“There should 
be less than 
0.13 g of 
plastics 
ingested by sea 
turtles on 
average” 

“There should 
be less than 45 
% of turtles 
with more 0.13 
g of ingested 
plastics on 
average” 

“There should be less 
than 33 % of turtles 
with ingested 
plastics” 

“There should be less 
than 0.37 g (0.13 
g?*) of plastics 
ingested by sea 
turtles on average” 

“There should be less 
than 33 % of turtles 
with more 0.37 g of 
ingested plastics on 
average” 

Easy and useful 
for assessing the 
environmental 
situation 

The impact on health is 
not assessed 

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2 

Target towards a 
threshold (impact on 
health) 

“There should 
be less than 
11.11 % of 
turtles with 
more plastics 
than food 
remains” 

“There should be 0 % 
(be less than 3.7 %*) 
of turtles with more 
plastics than food 
remains” 

Best proxy of 
health possible 
currently 

Might be constrained by 
environmental 
availability or biological 
constraints (to be 
further studied); FOO 
not considered in official 
definition. 

The second scenario proposed by INDICIT consortium, raised questions both because the “quantity of food 
remains” does not clearly appear in the D10C3 definition, and because it may depend on individual’s location 
(i.e., availability of natural resources) and stage (feeding capacity and selectivity). The notion of “health” remains 
highly  discussed  within  INDICIT  consortium  and  the  definition  of  Criteria  D10C3  referring  to  the  “health  of 
species  concerned”  has  led  to  debates  within  the  consortium.  We  considered  that  the  health  should  be 
measured at the individual level, while we should refer to “viability” for the population or the species. Therefore, 
INDICIT  consortium  focused  on  the  evaluation  of  health  at  the  individual  level,  and  tried  to  assess  the 
contribution of the individual to the population ideally thanks to parameters related to reproduction and survival 
(i.e., fitness). INDICIT consortium considered that as long as a turtle has ingested litter, this could have an impact 
on its health. Litter ingestion should be confronted to morbidity or mortality, which was not possible with the 
data  collected  during  the  project.  Some  EAB  members  suggested  considering  the  relationship  between  the 
number of ingested litter items and the direct mortality caused by litter ingestion (a dose effect). It would indeed 
enable to propose a simple scenario corresponding to the D10C3 definition. However, INDICIT consortium has 
discussed this approach which was  proposed in  Wilcox  et  al. (2018)’s study  (the probability of death due to 
ingested plastic increases with the amount of plastic in their gut). This approach allows proposing threshold and 
one result was that a load of 14 items corresponds to a probability of mortality of 50% (Wilcox et al. 2018). The 
INDICIT consortium was very skeptical about this work, especially on the way to evaluate the cause of mortality 
during necropsies. According to experts’ own experiences, the number of items cannot be the only cause of 
death, but the type and shape of plastic items would have to be taken into account. During the INDICIT project, 
a death caused by litter ingestion was indeed found in only 4 among the 189 cases where the information was 
filled out. Moreover, the methodology to assess the number of items/fragments appeared to be confusing (see 
§2.3). The relation between the probability of death and the amount of ingested plastic cannot be use with the 
currently available data. . Therefore, the second GES scenario was considered as the best approach regarding 
health we could have at this time.  

Various proxies of body condition and health, and the relationship with the dry mass of ingested litter, have 
been tested and no clear and simple link appeared with the quantity of (optional) data acquired at this stage 
(§2.5.3).  The  necessity  to  prove  an  impact  on  the  health  of  the  individual  was  highly  debated,  some  of  the 
partners considering that the impact of litter is proved by the high percentage of turtles found with ingested 
litter (population level effect). Proposing a threshold based on the effective mortality (individual effect) would 
be not enough ambitious, as it would be better not observing turtle mortality caused by marine litter.  

INDICIT consortium discussed if the sea turtle’s feeding behavior could give information on its health status. A 
turtle in good health should be able to feed on natural items, and be more selective when exposed to both 
natural items and marine litter. Stage is important to take into account, as adults during the reproductive period 
(summer months) may no feed, but in this period, they should have ingested neither natural food nor litter. This 
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hypothesis which leads to the second scenario, was also highly debated. While considered as a good proxy of 
individual’s  health,  the  partners  recognized  that  the  threshold-ratio  Litter/Food  remains  should  be  analyzed 
more accurately, and recommended to acquire more data on the FOO category.  

For the two scenarios and whatever the proxy of health (mortality, body condition index, ratio FOO/litter…) 
and the statistical approach considered, the evaluation of the threshold raised the question of what could be 
judged “acceptable” and “enough ambitious”. A reference to 0 (e.g. pristine and un-impacted area) had been 
judged unrealistic. Searching for a compromise (e.g. a reachable target and a positive effect on the species) will 
be more realistic. INDICIT consortium concluded that further research is needed to collect more data, especially 
to  acquire knowledge  on  the  evaluation of  health  in  Sea  turtle  and  the  impact  of  litter  ingestion  on  health. 
Research is also needed to better assess the ratio food remains/litter, considering spatial and inter-individual 
variations and digestibility of items. 

Thresholds are commonly evaluated in human health (e.g., exposure to lead poisoning), for example through 
physical symptoms and cognitive capacities to a more or less long term (Needleman, 2004). Other approaches 
are based on experimentations or inter-species comparisons, not possible on sea turtles due to their protection 
status.  Other  studies  rest  on  the  study  of  the  correlations  between  symptoms  and  concentrations.  Such 
toxicological  study  have  been  initiated  for  example  on  marine  mammals  (Desforges  et  al.,  2016)  and  are 
suggested for a better assessment of GES (Fossi et al., 2018). Using such methodology for sea turtles, considering 
gradient of pollution and ideally a control area or control individuals, are also further discussed. 

2.6. Summary of recommendations 

2.6.1. Networking 
The organization of networks in charge of collecting and manipulating specimens in the field is highly variable 
among countries, and sometimes the local networks may not be reached easily. Elaborating a diagram of existing 
local organizations, considering the role of each stakeholders and the contact of possible referent(s), for each 
country or region would facilitate the speed of procedures locally. Moreover, it could inspire the organization of 
new networks in other countries where monitoring is being set up.  

The perpetuation of the networks should be ensured for a sustainable standard monitoring and data reporting. 
For  this,  institutions  reported  needs  and  conditions  of  implication,  reported  by  INDICIT  consortium  (Table 
provided to the EU and EAB). Institutions generally asked for more human and material needs that have to be 
addressed, considering that the protocol for data collection, from the discovery and handling of the specimen 
to the extraction and classification of ingested litter, would require a minimum of 5 hours for one individual, 
without considering data reporting and analyses. It is also recommended to consider providing and maintaining 
the skills for collecting specimens and extracting/classifying the litter ingested, thanks to regular workshops and 
training sessions, which should help promoting the collaborations. Other tools like mobile or web applications 
and  blogs  should  facilitate  discussions  and  mutual  support  in  case  of  misunderstanding  of  the  protocol  or 
difficulties for identifying items found ingested by the turtle. 

The lack of data in some regions prevents to assess the situation in a global and consistent way. Developing 
the networks in these areas appears as a priority. This is especially the case in the OSPAR zone as well as in the 
South  Mediterranean  Sea.  Our  results  showed  that  the  impacts  of  litter  were  found  to  be  minimum  in  the 
Eastern  Mediterranean  basin  (minimum  occurrence  of  ingestion  and  minimum  ingested  litter  quantities). 

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However, data collection is just beginning in this area and a more global view (in time and space) could strongly 
change the evaluation. It is therefore necessary to reinforce the networks and collect more data in this area in 
order  to  better  understand  the  processes  and  provide  results  that  are  more  accurate.  This  is  particularly 
important as the region where the impact (occurrence and quantity of ingested litter) is evaluated as minimum 
can be used as reference for the GES. 

2.6.2. Harmonisation of data collection  
The INDICIT protocol with a video-tutorial has been highly shared. Pursuing the dissemination of the INDICIT 
protocol  would  enable  collecting  more  information  and  data,  and  engaging  more  stakeholders.  The  INDICIT 
protocol has been merged with the RAC/SPA protocol and is being disseminated to Southern Med Countries. 

The protocol proposes basic and optional parameters. “Optional” parameters, especially those related to body 
condition are encouraged to be collected, as well as measuring the dry mass of natural food remains. This was 
highly difficult to assess accurately the impacts on individual’s health with the data collected at this stage, while 
it is required in the definition of the criteria D10C3. More data on the size of the items found ingested, also 
asked as an optional parameter, should help differentiating micro-items (1-5 mm) to macro-items (>5 mm) and 
further progress on the feasibility of the implementation of the indicator “Micro-plastics ingested by sea turtles” 
(see §3). 

The collection of more data will enable refining some parts of the protocol, such as the method to count the 
items, which seems to vary among stakeholders.  The  GES scenarios have been proposed from data on  dead 
turtles (necropsies). However, thanks to the number of data that can be collected from living individuals (faeces), 
and the high occurrence of litter found in faeces, pursuing the collection of these samples from living individuals 
is highly recommended. Nevertheless, there are discrepancies in the methodologies used among stakeholders 
to collect samples and training sessions and workshops could be proposed specifically for rescue centres on this 
topic. This should allow a better understanding of the consequences of litter ingestion on individual’s health, 
and to assess the possibility of comparing results from the two protocols on dead and on living turtles.   

An average of 5 hours with two manipulators should be considered for the collection of data from necropsied 
individuals, although the time required to collect data depends on the body condition level and the quantity and 
variety  of  ingested  litter.  The  cost  of  implementation  should  consider  the  equipment  and  training  of  each 
stakeholder.  Training  sessions  should  consider  providing  a  tool  kit  to  support  the  stakeholders  who  will  be 
authorized to manipulate the specimens to handle the turtle, perform the necropsies and extract and analyse 
the litter. 

The intervention of professional teams of 2 or 3 persons specialized to extract/classify litter from digestive 
tracts and faeces in laboratory and competent to report and analyse the data may also be considered. These 
teams could support stakeholders, especially when they are too busy with other tasks, especially during the 
nesting period or after stranding events for examples. In this case, stakeholders would be asked to perform the 
first measures on the field, to do the necropsies, to collect the digestive tracts, and store them in a freezer as 
recommended in the standard protocol.  

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2.6.3. Data banking and cleaning 
Raw data cleaning required a very long time and had led to lose time for data analyses. A dedicated platform 
should help for this task, from data gathering and cleaning, with a specific pipeline in order to homogenize data. 
Such platform is being developed by IFREMER in the framework of CleanAtlantic project. 

2.6.4. Need of further analyses to evaluate GES scenarios and indicator’s constraints more accurately 

Evaluating individual’s health. The INDICIT consortium selected two major GES scenarios, the first being based 
on the Fulmar approach and the second proposing an approximate of impact on individuals’ health. The notion 
of health was difficult to assess with the data collected during the INDICIT project. The INDICIT consortium had 
difficulty to agree on the way to respond to the definition of Criteria D10C3 as currently written, since the “heath 
of the species concerned” may be confusing. Discussing the health of individuals in regards to the viability of 
populations and species, the consortium decided to further work on the “health of the individual” by collecting 
“optional” data on injuries and body condition. Further studies should be performed to better assess the impact 
on health, especially considering parameters related to individuals’ chances of reproduction and survival, which 
may be related to population dynamics and viability. 

Acquiring more data on natural food remains. The second scenario considers the quantity of natural food 
remains in relation to the quantity of ingested litter. The ratio food/litter should be further studied, considering 
possible  differences  in  individuals’  characteristics  related  to  stages  or  reproductive  period  for  example,  and 
comparing the transit digestibility between natural and plastics items. Considering that natural food can consist 
in large and hard shells, the transit digestibility could be comparable. For the moment, the second scenario was 
therefore retained as the best approach with the current state of knowledge. For this reason, and to further 
acquire more knowledge to verify the relevance of the scenario, INDICIT consortium recommends collecting the 
dry mass of natural food retained in filters of 1 mm and 5 mm.  

Testing the biological constraints more accurately. The  constraints related to intrinsic and methodological 
factors which may influence the observed occurrence and quantity of ingested litter should be further analysed. 
None of the factors that we tested had a clear influence on litter ingestion. Different parameters were used to 
test the influence of individual’s size, and the results vary according to the parameter considered. Measures 
should be standardized among stakeholders. We recommend the measurement of the standard curved carapace 
length, as it is the most commonly body size measurement used in sea turtle, in order to get enough data for 
more  powerful  statistical  tests.  Body  condition  indices,  currently  developed  for  the  green  turtle,  should  be 
tested and evaluated for the loggerhead species. In addition, the circumstances of discovery should be specified 
to test e.g., if stranding and bycaught  turtles would have  the  same  risk of litter ingestion. Nevertheless,  the 
typology should be revised, since stranded individuals may have been bycaught before. 

Verifying the units. More data is necessary to better assess the spatial and temporal units of GES reference 
and target. Our results and the collaboration with the programme MedSeaLitter suggested no difference in litter 
ingestion (occurrence and quantities) between the Atlantic and the Mediterranean. Further data will enable for 
more powerful tests and more accurate assessments. 

Perspectives for further studies. The results obtained by the INDICIT consortium and collaborators enabled 
defining the modalities of use of the indicator (the spatial unit i.e. Atlantic versus Mediterranean; the temporal 

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unit, i.e., a 6 years-cycle), the biological constraints; i.e., none at this stage) and a proposal of GES scenarios. At 
this stage, it appeared necessary to collect more data, and start evaluating the indicator in pilot areas, where 
the response to relevant programs of measures could be evaluated, e.g. related to the ban of plastic bags, which 
corresponds to the category USE SHE, a category most often found ingested by sea turtles. 

3. Feasibility studies of other marine litter impact indicators 

The INDICIT consortium discussed the relevance and feasibility of two indicators for monitoring other impacts 
of marine litter on marine wildlife, related to entanglement and to the ingestion of micro-plastics (< 5 mm). Two 
feasibility studies were carried out during the first 6 months of the project. The reports on the Entanglement 
indicator (Claro and INDICIT consortium, 2018) and on the Micro-plastic ingestion in fish and sea turtles (Silvestri 
and INDICIT consortium, 2018) with detailed results, are available in a compiled document ("Pilot and feasibility 
studies for the implementation of litter impacts indicators in the MSFD and RSCs OSPAR-Macaronesia, HELCOM 
and  Barcelona",  INDICIT  consortium,  2018)  on  the  project  website  (https://indicit-europa.eu/indicit-
documents/). The summaries are provided in the two following paragraphs. 

3.1. 

Indicator “Entanglement by biota with marine litter” 

This indicator belongs to the Criteria D10C4 “the number of individuals of each species which are adversely 
affected due to litter, such as by entanglement, other types of injury or mortality, or health effects” with a unit 
of measurement being “the number of individuals affected (lethal; sub-lethal) per species”. Our feasibility report 
focused on a review of available grey and published literature and the responses of a questionnaire disseminated 
to experts in sea turtles, marine mammals, marine birds, fish or marine litter. The objectives were to: 

i) assess the state of knowledge on entanglement in these taxa (prevalence per taxa/species, types of litter, 

type of injuries, etc.), 

ii) evaluate the constraints (methodologies, species biology, etc.), 

iii) identify and analyse the available data. 

It was also to identify the networks and skills necessary to implement the monitoring of entanglements. All 
taxa  were  assessed  in  order  to  identify  which  of  them  and  which  species  could  be  relevant  as  indicators 
especially  in  the  OSPAR-Macaronesia  areas,  HELCOM  and  Barcelona  RSCs  and  of  MSFD.  All  marine 
compartments were considered, from the surface to the bottom. The analysis of the literature and of the 21 
responses received to the questionnaire was carried out by taxon and region. 

Few data on entanglement reported in literature. The literature review showed that marine mammals, birds, 
fish and reptiles  have  been recorded to suffer from entanglement.  Individuals found  entangled were mainly 
Megafauna observed at sea or stranded and invertebrates on the sea floor.  For all taxa, the observations of 
entanglement seemed to have increased over time. Intrinsic factors such as behaviour or age, for example in 
mammals, played a significant role in the probability to be entangled in litter, and some debris may be more 
attractive  than  others.  However,  the  partial  or  opportunistic  data  found  did  not  allow  to  make  statistical 
analyses. We did not find any standard protocol and no standardized typology of the types and sizes of marine 
litter that cause entanglement. 

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Types of litter. The litter causing entanglement came from various sources, but the fragments of abandoned 
fishing gears and human product packages are the most frequently type of litter found. For litter from fishing 
activities, the distinction between passive (e.g., ghost nets) and active (e.g., animals escaped with a part of the 
gear after an accidental capture) entanglement was highly difficult to differentiate with certainty, although ghost 
gears may cause more entanglement than active bycatch. Few data were already available to better describe 
the  entanglement,  and  its  consequences  on  individuals’  body  condition,  health  or  behaviour  were  rarely 
reported. 

Methods.  The  methods  used  for  collecting  individuals  or  acquiring  information  on  entanglement  varied 
according  to  taxa.  The  observations  were  generally  made  by  NGOs,  rescue  centres,  fishermen  or  scientists. 
Entangled individuals were generally observed stranded, either opportunistically or during regular surveys, and 
more occasionally during observation campaigns, on the sea surface or in the water columns. The involvement 
of a larger audience (e.g. yachting activities) can contribute to this data collection. On the sea bed, photographic 
sampling  performed  during  sea  campaigns  and  diving  explorations  with  Remotely  Operated  Vehicles  or 
submarines  could  be  a  good  way  to  collect 
entanglement. 

information  on 

Taxa  and  species.  In  mammals,  despite  some  constraints,  e.g. 
related to their migration, harbour or grey seals appeared as relevant 
indicator  species  due  to  their  number,  the  prevalence  of 
entanglement  (Figure  9)  and  the  existence  of  a  network  for  the 
observation  and  the  rescue  of  these  species.  These  characteristics 
were also true for sea turtles. The presence of large network trained 
to collectively collect data on litter ingested by the loggerhead turtle 
(§2.2) and the standard protocol established and disseminated for 
the  indicator “Litter  ingested  by  sea  turtles”  (§2)  should  confer  a 
direct  benefit  for  the  development  of  this  new  indicator  on 
entanglement. In birds, the European shag Phalacrocorax aristotelis), 
the  Scopoli’s  Shearwater  Calonectris  diomedea  and  the  northern 
Gannet  Morus  bassanus  appeared  as  suitable  indicator  species. 
Observations appeared most often during nest surveys or  fisheries 
observer campaigns. In fish, the large distribution of the blue shark Prionace glauca was considered as a good 
species,  regularly observed during  fishery observer  programs. In invertebrates, corals and sponges  were the 
more affected, and gorgonians, black corals, scleractinians.  

Figure 10. Injuries 
caused by 
entanglement on a 
sea turtle. From 
HCMR 

Figure 9. Entanglement of a seal in fishing 
litter. Picture from Picardie Nature 

Networks. Entanglement was observed in a wide range of depths. The structures producing data in the project 
area were heterogeneous in their target and their governance, and generally, they did not benefit from stable 
human/financial  resources,  which  may  ensure  a  constant  data  flow  on  entanglement  for  each  taxon.  Skills, 
human  and  logistical  resources,  exist  at  some  level  but  the  majority  of  the  existing  data  was  collected  by 
volunteers (NGOs, rescue centres) and thanks to public and private fund raising, the other part by professional 
scientific oceanography/fishery monitoring networks, or by national entities responsible for the protection of 
the  environment.  Our  results  in  listing  all  the  stakeholders  who  collect/may  collect  data  of  interest  were 
significant but incomplete. More time would be requested to identify and contact stakeholders, and especially 
generate confidence and sign agreements for sharing information. 

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Recommendations. A better knowledge on entanglement impacts on individual’s health and the type of litter 
causing  entanglement  is  necessary.  Pursuing  data  collection  is  thus  necessary,  e.g.,  thanks  to  the  INDICIT 
protocol, which proposes to gather data on entanglement on sea turtles as optional parameters. Therefore, the 
feasibility  report  recommended  to  carry  out:  i)  a  survey  of  available  databanks  owned  by  oceanographic 
institutions/projects; ii) a study aiming to design a protocol proposal for monitoring entanglement/smothering 
of epibenthic invertebrate using ROV; and iii) to collect data and perform pilot tests. 

3.2. 

Indicator “Micro-plastic ingestion in fish and sea turtle”  

This indicator belongs to the criteria D10C3 of MSFD Descriptor 10. The aim is to assess the feasibility of an 
indicator distinguishing ingestion of plastic litter < 5 mm in size (diameter), considered as primary microplastics, 
entering  the  environment  as  particles  already  <  5mm,  or  secondary  microplastics,  i.e.  coming  from  the 
fragmentation of larger items. They may have been ingested directly in the environment, or by trophic transfer 
(first ingested by the preys) or both. This feasibility study focused on sea turtles and fish. Indeed, this fraction of 
litter size is not differentiated in the monitoring of indicator “Litter ingested by sea turtles”. As the network was 
constituted  for  sea  turtles,  it  seemed  interesting  to  evaluate  the  feasibility  of  this  indicator  for  this  taxon. 
Nevertheless, the occurrence of ingestion of micro-particles of plastics in fish is important, and their use could 
cover a wider area than indicator “Litter ingested by sea turtles”, notably by being used in the HELCOM zone. A 
review of the literature on micro-debris ingested by these two taxa has been conducted, in order to assess the 
prevalence,  sampling  techniques  and laboratory  procedures according to species,  their functional group and 
their geographical location. 

3.2.1.  In fish 

The feasibility study consisted in a literature review. The aim was to discuss the choice of a good indicator 
species, considering its habitat, trophic level, sensitivity to litter, abundance, spatial distribution and commercial 
importance.  The  sampling  techniques  were  also  evaluated.  A  wide  distribution  may  enable  to  include  the 
monitoring of litter  impacts  in the  HELCOM  RSCs, which is not  possible with the  Turtle indicator. Moreover, 
working on fish would enable targeting items with size below 1 mm.  

A total of 159 fish species has been evaluated. The ingestion of micro-plastics appeared very variable with the 
geographical  location,  the  species’  functional  groups,  size  and  feeding  behaviour,  as  well  as  the  capture 
methods.  

Differentiation of the micro-plastics from natural items. Micro-plastics were generally differentiated by visual 
inspection, density separation by buoyancy tests or in hyper-saturated saline solution, or thanks to a previous 
desiccation  in  oven.  Several  authors  proceeded  to  the  digestion  of  the  biotic  material  thanks  to  different 
methods, mostly using potassium hydroxide (KOH, 10%), sodium hydroxide (NaOH), oxidizing agents such as 
hydrogen peroxide (H2O2), at different temperatures depending on the studies. Each digestion method would 
have its advantages and inconvenient depending on the objective. 

Characterization of plastic items. The authors verified rarely the nature of items. Applying a hot metal tip on 
the particle would enable to differentiate plastics and natural item in case of doubt. Some authors proposed to 
identify the polymers thanks to micro-spectroscopy, such as the Fourier transform infrared (FT-IR) or the Raman 
spectroscopy. 

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Number and size of items. The minimum value of ingested litter found in literature was 0.03 ± 0.18 and the 
maximum  3.8  items.  More  than  80  %  of  the  fish  with  plastic  contained  only  a  single  particle.  However,  the 
number of items found ingested highly depends on the mesh size. The high variability of lower sizes tested by 
authors prevented comparing the studies. 

Types of plastics. Fibres were the prevalent type of plastic found ingested. This can be related to contamination 
during sampling in the field and analyses in the laboratory, or to waste management strategies on land which 
vary among countries. The nylon fragments from fishery activities were also highly represented, and might also 
be due to contamination. “Fragments” was also an important category. 

Avoidance  of  the  contamination.  Micro-fibres  are  ubiquitous.  Easily  transported  by  the  air,  they  can 
contaminate the samples during all the stages of the procedure, from field sampling to laboratory manipulations, 
e.g. originating from the examiner’s clothing and/or already present in the laboratory room. The MSFD TG ML 
with the “Guidance on Monitoring of Marine Litter in European Seas” suggested that the contamination should 
be  less  than  10%  of  the  average  values  of  micro-plastic  items  determined  in  the  samples.  To  limit  such 
contamination, Petri dishes should be rinsed, dried with compressed air and checked under a microscope for 
any plastic contaminants. The use of a pre-filtered deionized water and a hypersaline solution for the material 
should be done, under a clean airflow cabinet for example. The use of blank samples during all the stages of the 
procedure,  from  the  dissection of  the  animal  until  the  litter  detection  under  the  microscope.  Some  authors 
performed the filtration under a pyramid glove box, with incorporated gloves permitted sample handling with 
no interference from the external environment. The contamination in the field cannot be controlled, especially 
when buying fish from markets. The caught should be done using polymer nets and all the equipment should be 
cleaned before sampling. Trawling net with long hauls should be avoided, since when scraping the bottom, the 
net  creates  and  re-suspends  micro-plastic  particles.  Lastly,  it  is  recommended to minimize  the  stress  during 
handling, because fish can regurgitate their stomach content due to stress, stomach compression or stomach 
inversion. 

Selection of relevant indicator species. Several species have been proposed according to habitat and with the 
selection  criteria  (habitat,  trophic  level,  sensitivity  to  litter,  abundance,  spatial  distribution  and  commercial 
importance): Sardina pilchardus and Scomber sp. (pelagic), Boops boops, Mullus sp. and Mugil sp. (demersal), 
Scyliorhinus canicula (elasmobranchs), Raia clavata. 

3.2.2.  In sea turtles 

Given their propensity to ingest litter, their wide distribution, the large range of habitats used during their life 
and the networks trained to collect litter impacts (>1 mm; §2), the loggerhead species may be proposed as a 
possible indicator. 

The literature review showed few papers on the topic, since most studies concerned macro-litter (> 5 mm) or 

were based on the indicator “Litter ingested by sea turtles” who combined both micro and macro-litter.  

Differentiation of plastic items. The differentiation of plastics from natural food items were generally made 
thanks to visual identification and more exceptionally using chemical or enzymatic digestion of the digestive 
tract content or of the faeces (KOH or H2O2). The micro-plastics found ingested were generally hard fragments, 
fragments of sheets and industrial pellets. 

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To collect the specific fraction of 1 to 5 mm, a filter of 1 mm mesh could be easily affixed on the 5 mm mesh 
filter, which may allow working from data collected for the indicator “Litter ingested by sea turtles”. The same 
networks  of  stakeholders  could  be  involved  in  this  monitoring,  considering  the  additional  time  this  would 
require.  

Avoidance of contamination. The possibility of contamination depends on the manipulations in the laboratory 
or in the rescue centre, where filters should be affixed in incoming water in the tank. The digestive tract of dead 
individuals  should  be  washed  intensively  before  opening  to  extract  gut  content,  as  well  as  all  working 
instruments (scissors, sieves, etc.) before use. Working on an airflow cabinet or laminar flow hood may help 
reducing the contamination risks when identifying and classifying the micro-debris. For living turtles, intensive 
lavages of the individual and filtering systems in the water circuit before entering into the tank is recommended. 
Fish used as food would also be eviscerated before being given to the turtles. Lastly, water samples in empty 
tanks should be taken in order to evaluate possible air contamination.  

4. From INDICIT to INDICIT-II 

The INDICIT-II project (2019-2021) is a follow-up of the INDICIT project (2017-19). The project aims to: 

1)  Capitalize  the  INDICIT  results  concerning  the  networking,  the  elaboration  of  standard  guidelines,  the 
collection of large standard data set and the evaluation of GES scenario for the indicator “Litter ingested by sea 
turtles”.  Specifically,  the  new  project  will  evaluate  the  indicator’s  response  in  regards  to  the  effect  of  the 
Programmes of Measures (PoMs) in pilot areas (e.g. the quantity of USE SHE category ingested by sea turtles 
where the ban of plastic bags or of single use plastics have be implemented), to fill the gaps of data collection 
identified in the areas (e.g. Macaronesia and continental Portugal), and promote harmonization with Eastern 
and Southern countries in the Mediterranean area. 

2) Identify key elements for the implementation of two other indicators for the monitoring of litter impacts 
“Entanglement of sea turtles, birds, cetaceans in floating debris” and “Micro-debris ingestion by fish and sea 
turtles”.  

For all these indicators, GES scenarios will be tested and propose according to different spatial and temporal 
scales. Following the New Decision Commission 2017/848, these indicators will be developed considering the 
potential effect on health. For this task, analysis in ecotoxicology for evaluating the pollutant exposure will be 
tested on sea turtle biological samples. A specific attention will be devoted on the use of these 3 indicators in 
pilot areas identified thanks to a set of criteria (availability of means for sampling, pollutant sources, etc.) and 
especially the implementation of PoMs. 

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Appendix 1 – INDICIT deliverables time table 

This table presents the percentage of execution for each expected deliverable. Colours represent the degree 
of  execution,  with  red,  orange  or  green  from  bad  to  full  satisfaction.  All  tasks  have  been  completed. 
Nevertheless,  the  standard  “basic”  data  (see  §2.2.  and  §2.3.2)  collected  throughout  the  INDICIT  project  in 
collaboration  with  stakeholders  (see  §2.1.3),  did  not  enable  to  fully  assess  the  impact  of  litter  ingestion  on 
health, as defined by the New Commission Decision 2017/848/EC (see Appendix 2). While GES scenarios are 
proposed regarding the results obtained from analyses of available data (see §2.4.4), further studies are needed 
to better assess individual health and the relationship with ingested litter, a perspective of INDICIT-II project. 

Number 

Title 

Leader 

D1.1 

D1.2 

D1.3 

D1.4 

D1.5 

D1.6 

D1.7 

D1.8 

D1.9 

D1.10 

D1.11 

D2.1 

D2.1 

D2.2 

D2.3 

D2.4 

D2.5 

D2.6 

D2.7 

D2.8 

D2.9 

D3.1 

D3.2 

D3.3 

D3.4 

D3.5 

D3.6 

D3.7 

D3.8 

D3.9 

Consortium Agreement 

Minutes of project meeting 1 

Minutes of project meeting 2 

Minutes of project meeting 3 

Minutes of project meeting 4 

Minutes of final meeting 

Inception Report 

Progress Report 1 

Progress Report 2 

Progress Report 3 

Final Report 

Inception Report on Activity 2 

Short progress Report 1 on Activity 2 

Short progress Report 2 on Activity 2 

Short progress Report 3 on Activity 2 

Short progress Report 4 on Activity 2 

Reports on pilot studies 
Report on set of procedures for a standard monitoring 
using the Indicator "Debris ingestion by sea turtles" 
Final Report on set of procedures for a standard monitoring 
using the Indicator "Debris ingestion by sea turtles" 
Establishment of common databases 

Final common databases 

Inception Report on Activity 3 

Short progress Report 1 on Activity 3 

Short progress Report 2 on Activity 3 

Short progress Report 3 on Activity 3 

Short progress Report 4 on Activity 3 
Report on the validated GES and clarified indicator criteria 
for the standard monitoring at the RSC scale 
Final report on the validated GES and clarified indicator 
criteria for the standard monitoring at the RSC scale 
List of identified stakeholders 

Final list of identified stakeholders 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

CNRS 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

ISPRA 

Date 

Month 3 

Month 1 

Month 6 

Month 13 

Month 20 

Month 24 

Month 1 

15 days after M6 
15 days after 
M13 
15 days after 
M20 
60 days after 
M24 
Month 1 

Month 6 

Month 13 

Month 20 

Month 24 

Month 8 

Month 15 

Month 24 

Month 13 

Month 24 

Month 1 

Month 6 

Month 13 

Month 20 

Month 24 

Month 15 

Month 24 

Month 15 

Month 24 

% of execution 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

90% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

90% 

100% 

100% 

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Number 

D3.10 

D4.1 

D4.2 

D4.3 

D4.4 

D4.5 

D4.6 

D4.7 

D4.8 

D4.9 

D4.10 

D5.1 

D5.2 

D5.3 

D5.4 

D5.5 

D5.6 

D5.7 

D5.8 

D5.9 

D5.10 

D5.11 

D5.12 

Title 
List of evaluation indicators of the implementation of the 
monitoring program 
Inception Report on Activity 4 

Short progress Report 1 on Activity 4 

Short progress Report 2 on Activity 4 

Short progress Report 3 on Activity 4 

Short progress Report 4 on Activity 4 
Report on the validated GES and clarified indicator criteria 
for the standard monitoring at the RSC scale 
Final report on the validated GES and clarified indicator 
criteria for the standard monitoring at the RSC scale 
List of identified stakeholders 

Final list of identified stakeholders 
List of evaluation indicators of the implementation of the 
monitoring program 
Inception Report on Activity 5 

Short progress Report 1 on Activity 5 

Short progress Report 2 on Activity 5 

Short progress Report 3 on Activity 5 

Short progress Report 4 on Activity 5 

Plan for dissemination 

Final report on dissemination 

Plan for communication 

Final report on communication 

Website + intranet 
Tool kit for standardized monitoring of debris impacts on 
marine fauna 
Dissemination meeting in Greece 

Leader 

Date 

% of execution 

ISPRA 

Month 24 

ULPGC 

ULPGC 

ULPGC 

ULPGC 

ULPGC 

Month 1 

Month 6 

Month 13 

Month 20 

Month 24 

ULPGC 

Month 15 

ULPGC 

Month 24 

ULPGC 

ULPGC 

ULPGC 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

MNHN 

Month 15 

Month 24 

Month 24 

Month 1 

Month 6 

Month 13 

Month 20 

Month 24 

Month 1 

Month 24 

Month 1 

Month 24 

Month 3 

MNHN 

Month 22 

MNHN 

Month 22 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

90% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

100% 

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Appendix 2 – General definitions 
The Marine Strategy Framework Directive  

Urgent efforts for reducing litter in the marine environment and stopping the trends in environmental impacts 
are needed. The European Commission makes the struggle against marine litter one of its priorities to recover 
the  Good  Environmental  Status  (GES)  of  marine  waters,  by  restoring  clean,  healthy  and  productive  marine 
ecosystems and protecting marine biodiversity and resources. Indeed “Marine Litter” constitutes the 10th of the 
11  Descriptors  of  state  and  pressure  for  the  European  Marine  Strategy  Framework  Directive  (MSFD, 
2008/56/EC). MSFD consists in an adaptive management approach based on the assessment of anthropogenic 
pressures and impacts on the marine environment, kept up-to-date and reviewed every 6 years. 

The European Commission considers a set of detailed criteria and methodological standards to help Member 
States (MS) to implement the MSFD thanks to Programs of Measures (POMs). For this and for each of the 11 
Descriptors, MSFD should be based on: 

- an initial assessment of the current environmental status of national marine waters, 

- the determination of GES signification, 

- the establishment of environmental targets to achieve GES by 2020, associated to indicators, 

- the establishment of a monitoring programme,  

- the development of a programme of measures aiming to achieve or maintain GES by 2020. 

In the 2014 report providing the first stage of MS reporting, the EC revealed a number of weaknesses and 
requirements in particular for the updates of the determination of GES and environmental targets. For greater 
benefits  to  the  next  cycle  of  implementation  of  MSFD,  the  report  concluded  that  the  2010  “GES  Decision” 
needed  to  be  revised,  strengthened  and  improved.  Repealing  Decision  2010/477/EU,  the  New  Commission 
Decision  2017/848/EC  (Commission  Decision  (EU)  2017/848  of  17  May  2017)  lays  down  criteria  and 
methodological  standards  on  GES,  and  gives  specifications  and  standardised  methods  for  monitoring  and 
assessment. 

GES implies a condition which has been or can be compared against an anthropogenically altered state (Borja 
et al., 2012). Therefore, assessing the current environmental status requires the comparison with a reference 
condition. GES is expected to determine threshold values (TVs) and the extent to which TV have to be achieved 
(Art. 9(1) of MSFD 2008/56/EC). According to MSFD Commission Decision 2017/848/EU,  TV should underline, 
where appropriate, the quality level that reflects the significance of an adverse effect for a criterion according 
to the reference condition. TV should correspond to levels of pollutions above which GES is approved to have 
been achieved. They must be set through union, regional or sub-regional cooperation ideally at EU level, in order 
to achieve equal protections. Commission Decision 2017/848/EC Art. 2 defines TV as a value or a range of values 
that allows an assessment of the quality level achieved for a particular criterion, thereby contributing to the 
assessment of the extent to which the GES has been achieved. Trend reduction can be used as a basis to set a 
TV, in order to achieve a given operational threshold. Commission Decision 2017/848/EC specifies that TV should 
be  set on  the  basis  of  the  precautionary  principle,  reflecting  the  potential  risks  to  the marine  environment. 

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Moreover, they should accommodate the dynamic nature of marine ecosystems and their elements. TV and 
baseline have to be proposed/updated for each Criteria of Descriptor. 

Borja et al. (2013) proposed four ways to determine the Reference condition by: 

(i) 
(ii) 
(iii) 
(iv) 

finding a control area, similar to the one under study but without the pressures; 
defining it a posteriori considering the time before the pressures had exerted an influence; 
modelling a non-impacted condition numerically; 
by using expert judgement, if none of these are possible. 

The notion of Threshold Value is more debated. WG GES reminds the definitions from  Oxford dictionary as 
“the magnitude or intensity that must be exceeded for a certain reaction, phenomenon, result, or condition to 
occur or be manifested”. The one proposed by Groffman et al. (2006) is “the point at which there is an abrupt 
change in an ecosystem quality, property or phenomenon, or where small changes in an environmental driver 
produce large responses in the ecosystem”. Lastly, there is the definition proposed by Rosenthal et al. (1997) as 
“the dose of the toxicant below which no adverse effects will occur” (Minutes of the 20th WG GES). TV should 
be based on baselines where possible.  

The New Commission Decision 2017/848/EC underlines that TVs need to be set at appropriate geographical 
scales, taking into account the biotic and abiotic characteristics of regions, sub-regions and subdivisions. For this, 
MSFD attempts to work in close partnership with the Regional Sea Conventions (RSC), which also are committed 
to  develop  strategies  in  full  synergy  with  MSFD,  including  the  implementation  of  an  integrated  monitoring 
program based on indicators and reduction measures. In this way, RSCs and MSFD harmonise their approaches, 
favouring MS to coordinate their actions in order to ensure coherence of approaches and possibility to better 
analyse  the  efficiency  of  restoration  measures,  thanks  to  spatial  analyses  and  adaptive  management.  RSCs 
deploy a set of criteria and indicators, with similar objectives to those of the MSFD, thus allowing spatial and 
legal articulations between regional conventions and the European directive. In addition, MS have to determine 
the mechanisms to evaluate the  effectiveness of their PoMs to achieve TV and assess their distance to GES, 
thanks to the indicators applicable at (sub)regional levels.  

Definitions for MSFD Descriptor 10 “Marine Litter”. 

Under  MSFD  Descriptor  10  “Marine  Litter”  (D10),  GES  is  supposed  to  be  achieved  when  "Properties  and 
quantities of marine litter do not cause harm to the coastal and marine environment".  A set of primary and 
secondary criteria are given: 

- 

Primary Criteria D10C1 and D10C2 (New Commission Decision 2017/848/EC): 

GES for D10C1 represents “the composition, amount and spatial distribution of litter on the coastline, 
in the surface layer of the water column, and on the seabed, are at levels that do not cause harm to the 
coastal and marine environment”. The element concerned is “Litter”, excluding micro-litter, classified 
as the categories artificial polymer materials, rubber, cloth/textile, paper/cardboard, processed/worked 
wood, metal, glass/ceramics, chemicals, undefined, and food waste. D10C2 is specific for micro-litter, 
defined as particles < 5mm, classified in the categories ‘artificial polymer materials’ and ‘other’. 

- 

Secondary Criteria D10C3 and D10C4: 

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GES regarding D10C3 corresponds to “the amount of litter and micro-litter ingested by marine animals 
that is at a level that does not adversely affect the health of the species concerned”. For D10C4, it is “the 
number  of  individuals  of  each  species  which  are  adversely  affected  due  to  litter,  such  as  by 
entanglement, other types of injury or mortality, or health effects”. Where appropriate, the outcomes 
of criterion D10C3 and D10C4 shall also contribute to assessments under Descriptor 1 (Biodiversity). 

The New Commission Decision 2017/848/EC specifies that the use of criteria shall be agreed at Union level. 
The methodological standards are also defined, such as the scales of GES assessment. For D10C1, D10C2 and 
D10C3, they shall correspond to the subdivisions of the region or sub-region, divided where needed, by national 
boundaries.  For  D10C4,  they  should  correspond  to  those  used  for  assessment  of  the  species  group  under 
Descriptor 1 (“Biodiversity”). 

The units of measurement are: 

i) 
ii) 

iii) 

for criteria D10C1 and D10C2: “the amount of litter or micro-litter per category”;  
for D10C3: “the amount of litter/micro-litter in grams (g) and number of items per individual for 
each species in relation to size (weight or length, as appropriate) of the individual sampled”;  
for D10C4: “the number of individuals affected (lethal; sub-lethal) per species”. 

The standardised methods for monitoring and assessment regarding the secondary criteria should be based 
on  incidental occurrences  (e.g.  strandings of  dead  animals, entangled animals in  breeding  colonies,  affected 
individuals per survey). 

In 2014, European Commission reported that the implementation of indicators, associated to Marine Litter in 
particular, needs to be further advanced, thanks to the improvement of the knowledge for defining the GES 
baselines and indicators’ characteristics, and of the network capacity for a standard monitoring. The Task Group 
Marine Litter (TG ML), which, co-chaired with the Joint Research Centre (JRC), supports the implementation of 
MSFD for D10, has developed a Guidance for monitoring marine litter in the European Seas  (MSFD Technical 
Subgroup on Marine Litter, 2013). WG GES discussed the way to propose GES scenarios for D10 Criteria (Minutes 
of 20th WG GES). The reference situation, according to WG GES, can be based on an expected, a usual, a normal 
or a pristine area. Set on the basis of precautionary principle, cut-off values could be defined as proportion or 
percentile in relation to litter baselines, averages or maximum concentrations. The lower concentrations, which 
already exist in certain areas, could be a target for other areas. This could be supported by the requirement of 
an equal level of protection in different areas and seas. 

Marine taxa used as bio-indicators of marine litter impacts in MSFD and RSCs 

Plastic ingested by the fulmar Fulmarus glacialis is a bio-indicator for trends in marine litter for OSPAR (EcoQO 
3.3; OSPAR, 2009) and an “impact on biota” indicator for MSFD (indicator 10.2.1, EC 2010). Individuals found 
dead on beaches, especially after storms, are necropsied in order to determine the type and quantity of litter in 
their stomach (MSFD Technical Subgroup on Marine Litter, 2013). The GES, represented for OSPAR by EcoQO 
(“Ecological  Objective”),  relates  to  almost  pristine  conditions.  Therefore,  the  target  level  for  EcoQO  3.3  is  a 
baseline level, which currently does not exist in relatively clean artic environments: “There should be less than 
10% of northern fulmars (Fulmarus glacialis) having more than 0.1 g plastic particles in the stomach in samples 

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of 50 to 100 beach-washed fulmars from each of 4 to 5 areas of the North Sea over a period of at least five years” 
(OSPAR, 2009; van Franeker et al., 2011).   

Sea turtles are relevant indicator for monitoring litter impact through ingestion in MSFD (Criteria D10C3) and 
RSCs Barcelona and OSPAR-Macaronesia areas (Matiddi et al., 2011; MSFD Technical Subgroup on Marine Litter, 
2013), and possibly  for impacts  related to entanglement (Criteria D10C4)  (Duncan et al., 2017; Nelms et  al., 
2015). “Litter ingested by sea turtles” was proposed by France in 2015 and 2016 at EIHA meetings, then retained 
as a candidate indicator for measuring impact on biota for OSPAR in 2016 (OSPAR- EIHA 16/5/13, 2016). INDICIT 
results reported in CEMP document (2019) participated in changing the status of the indicator from candidate 
to common for the OSPAR southern zones. 

The trends in the amount of litter ingested by or entangling sea turtles is also a candidate indicator for the 
Barcelona Convention, as part of the 10th Ecological Objectives (EO10) of the Integrated Monitoring Assessment 
Programme (IMAP, Candidate indicator CI24) belonging to the Regional Plan on Marine Litter Management in 
the  Mediterranean  (RPML),  adopted  in  2013  during  the  COP18  and  came  into  force  in  2014.  The  sea  turtle 
indicator  EI  18  was  also  proposed  within  MedPol  Marine  Litter  Action  Plan  to  monitor  litter  impact  at  the 
Mediterranean scale. The loggerhead turtle Caretta caretta being the most abundant species of sea turtle in the 
Mediterranean  and  commonly  seen  in  the  surrounding  Atlantic  waters,  is  the  target  species.  Specimens are 
regularly collected by existing rescue centres and stranding networks, which enables the collection of data useful 
for acquiring knowledge on the species’ biology and on the factors leading to litter ingestion or entanglement. 
The leatherback species Dermochelys coriacea was also recommended especially for the OSPAR zones III, IV and 
V (Claro et al., 2014; Darmon and Miaud, 2016). 

Status of the indicator “Litter ingested by sea turtles” in the Regional Sea Conventions 

concerned by INDICIT project 

OSPAR 
The OSPAR Convention for the Protection of the Marine Environment in the North-East Atlantic. Litter ingested 
by sea turtle is a candidate indicator for OSPAR (10.2.1 of the 10th Ecological Quality Objectives (EcoQO)), which, 
as  other  relevant  impact  indicator  (e.g.  entanglement  of  biota  in  marine  litter),  should  be  discussed  and 
validated by the Environmental Impact of Human Activities Committee (EIHA), within the Regional Action Plan 
for Marine Litter executed over the period 2014-2021 and supervised by the marine litter group (ICG-ML). 

Barcelona convention 
The Barcelona Convention (UNEP-MAP) for the Protection of Marine Environment and the Coastal Region of 
the  Mediterranean,  which  Med  Action  Plan  (MAP)  is  an  ecosystem-based  approach  for  the  management  of 
human activities (EcAp), established on 11 Mediterranean Ecological Objectives, the 10th concerning the marine 
litter.  Turtles  are  considered  as  an  indicator  for  ingestion  and  entanglement.  The  Specially  Protected  Areas 
Regional Activity Centre (SPA/RAC) assists to the Contracting Parties for their implementation. The loggerhead 
species  is  one  of  the  target  species  for  the  Integrated  Program  for  Monitoring  and  Assessment  of  the 
Mediterranean Sea and Coasts (IMAP) signed by Contracting Parties under the Regional Plan on Marine Litter 
Management (RPML) (Candidate Indicator 24 (CI24) of the 10th Ecological Objectives (EO10)). 

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HELCOM 
The Helsinki Convention (HELCOM) for the Protection of the Marine Environment in the Baltic Sea Area, which 

regional action plan on marine litter plans to establish indicator of litter impacts. 

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Summary of the outcomes of the European project INDICIT  

Implementation of the “Impacts of marine litter on sea turtles and biota” indicator in RSC and MSFD 
areas (1 February 2017 – 31 January 2019) 

Marine litter, a major concern 

Anthropogenic marine litter is having an alarming impact on marine fauna: more than 700 species have been 
shown to be affected by litter, primarily by ingestion and entanglement: among these a number are classified 
as vulnerable or endangered on the IUCN Red List. Urgent efforts to reduce litter in the marine environment and 
stop  these  harmful  environmental  trends  are  required.  The  European  Commission’s  Marine  Strategy 
Framework Directive (MSFD, 2008/56/EC) makes the combat against marine litter a priority in recovering the 
Good Environmental Status (GES) of marine waters. The MSFD sets out a list of 11 descriptors of environmental 
status, of which ‘Marine litter’ is number 10.  

The quantity and characteristics of litter ingested by sentinel species can reflect the spatial and temporal trends 
of litter in the environment that organisms are exposed to. Sea turtles have been proposed as an indicator of 
the impact of litter by ingestion in the framework of the MSFD (for Criteria D10C3) and the OSPAR (indicator 
10.2.1)  and  Barcelona  (CI  24  IMAP)  Regional  Sea  Conventions  (RSCs).  Sea  turtles  may  also  be  relevant  for 
monitoring  impacts  related  to  entanglement.  The  loggerhead  turtle  Caretta  caretta  is  considered  a  target 
species due to its wide distribution, its use of various marine habitats and its propensity to ingest litter. The 
leatherback  turtle  Dermochelys  coriacea  has  also  been  recommended  as  an  indicator  species,  especially  for 
OSPAR (Atlantic) zones III, IV and V, where it is regularly observed. For litter impacts related to entanglement or 
ingestion of micro-particles inferior to 5 mm, target taxa/species remain to be defined. 

The INDICIT project 

The INDICIT project started on 1 February 2017 and ended on 31 January 2019. The total budget was 1,328,119 
euros,  of  which  999,955  euros  was  allocated  by  the  EC’s  Directorate-General  for  the  Environment,  and  the 
remaining 20% was co-funded by the other partners. 

The  INDICIT  consortium  was  composed  of  10  institutional  public-sector  partners  from  five  European 
countries (France, Greece, Italy, Portugal and Spain) and two non-European countries (Tunisia and Turkey). The 
consortium  was  advised  by  a  Policy  Officer  and  an  External  Advisory  Board  (EAB)  composed  of  experts  and 
representatives from the MSFD, RSCs and the seven member states.  

The INDICIT project focused on three litter impact indicators: ‘Litter ingested by sea turtles’, ‘Entanglement 
with debris by marine biota’ and ‘Micro-plastic ingestion in fish and sea turtles’. The main goal was to allow 
litter impact indicators to be implemented in a standardized way in the framework of the MSFD and the OSPAR 
(Atlantic), Barcelona (Mediterranean) and HELCOM (Baltic) RSCs, using sea turtles as a bioindicator. The specific 
objectives were to develop a common approach for monitoring litter ingested by sea turtles by 1) developing a 

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set of standardized tools, 2) creating a network and providing training sessions to stakeholders, 3) collecting and 
analysing  data  on  living  and  dead  turtles,  3)  analysing  the  indicator’s  spatial  and  temporal  limits,  biological 
constraints  and  GES  criteria.  Contrary  to  the  GES  Decision  which  establishes  the  5  mm  threshold  for 
distinguishing micro- from macro-plastics, litter was defined as items >1 mm, including both. This is a provisional 
solution, taking into account available historic data and the time and resources’ limitations of the project.  A 
further objective was to assess the relevance and feasibility of two other litter impact indicators: one related to 
entanglement (MSFD Criteria D10C4),  for which all taxa were evaluated, and one related to the ingestion of 
micro-plastics (litter items <1mm) (MSFD Criteria D10C3) by fish and sea turtles. 

The project consisted of five interrelated activities: 

•  Activity 1: Management and coordination led by the French National Centre for Scientific Research and 

the École Pratique des Hautes Études (CNRS/EPHE) and involving all the members of the INDICIT 
consortium, to ensure the proper implementation and management of the project. 

•  Activity 2: Acquisition and use of scientific knowledge to develop the litter impact indicators at a sub-
regional and global MSFD spatial scale, led by the CNRS/EPHE and involving all the members of the 
INDICIT consortium, with the aim of 1) addressing knowledge gaps by collecting and analysing 
standardized data for defining GES, constraints and units for the indicator ‘Litter ingested by sea turtles’, 
and 2) evaluating the relevance of two new impact indicators ‘Entanglement with debris by marine biota’ 
and ‘Micro-plastic ingestion by marine biota’ through feasibility studies based on a literature review and 
a questionnaire. 

•  Activity 3: Implementation of the indicator ‘Impacts of marine litter on sea turtle and biota’ in RSC 
OSPAR/Macaronesia regions, led by the University of Las Palmas Gran Canaria (ULPGC), involving 
CNRS/EPHE, the French National Museum of Natural History (MNHN) and the Regional Fund for Science 
and Technology of the Azores (FRCT), with the aim of implementing a perennial and sustainable 
monitoring programme for Indicator 1 ‘Litter ingested by sea turtles’ in OSPAR-Macaronesia through 
creating a network, training engaged stakeholders and improving the tools by considering feasibility and 
relevance in the field. 

•  Activity 4: Implementation of the indicator ‘Impacts of marine litter on sea turtle and biota’ in the 
Ecosystem Approach (EcAp) of the UNEP/MAP Barcelona convention, led by the Italian National 
Institute for Environmental Protection and Research (ISPRA), involving the CNRS/EPHE, MNHN, the 
Italian Institute for Coastal Marine Environment (CNR-IAMC), Spain’s University of Valencia (UVEG), the 
Hellenic Centre for Marine Research (HCMR), Tunisia’s National Institute of Marine Science and 
Technology (INSTM) and Turkey’s Sea Turtle Research and Rehabilitation Centre (PAU-DEKAMER), with 
the same objectives as Activity 3 but targeting the Barcelona RSC. 

•  Activity 5: Communication and knowledge sharing, led by the MNHN, involving all the members of the 
INDICIT consortium, with the aim of providing information about the project and its outcomes and 
disseminating the technical tools.  

INDICIT main results 

1. 

‘Litter ingested by sea turtles’ indicator 

Pilot study A pilot study was performed during the first months of the project in order to evaluate the state of 
knowledge  about  potential  constraints  to  consider  when  using  the  indicator,  and  to  define  the  means  for 
monitoring in existing networks (Darmon and INDICIT consortium in INDICIT consortium, 2018). 

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Networking  The  INDICIT  consortium  gathered  together  106  stakeholders,  principally  from  rescue  centres, 
stranding networks and veterinarian and research laboratories: 68 work in the Mediterranean, 43 in the Atlantic 
and 6 in both areas. Fourteen training sessions, including two international sessions, were held to train these 
stakeholders  to  collect  in  a  standardized  way  the  litter  found  in  the  digestive  tracts  of  necropsied  dead 
individuals and in the faeces excreted by living turtles. The stakeholders’ contact information and locations were 
recorded  in  a  Google  map  and  an  Excel  table,  which  was  kept  private  to  protect  potentially  sensitive 
information. The table contains both stakeholders currently involved in monitoring and the preconditions for 
involvement for other stakeholders contacted (e.g. need for material or human resources). 

Technical tools Several tools were developed in order to assist the collection of standard data on litter ingested 
by sea turtles. A protocol with an observation sheet, now available in five languages (English, Arabic, French, 
Greek and Spanish),  and a  video-tutorial have  been created. The protocol improves on the MSFD guidelines 
published by the MSFD Marine Litter Task Group in 2013, integrating stakeholder feedback and details on all 
stages of handling, from the discovery of a specimen to the extraction and analysis of the litter ingested by a 
living or dead sea turtle. It recommends ‘basic’ parameters, i.e. information essential to determining GES, and 
‘optional’ parameters, which are more time-consuming to collect, but provide valuable information for better 
understanding the factors that may influence litter ingestion by sea turtles and impact individual health.  

Data bank A standard database was built to share data, hosted in a private area accessible only to partners 
who signed the Consortium Agreement specifying the sharing guidelines (some stakeholders asked that their 
raw data be used only in the framework of the INDICIT project). The information was collected in an Excel file, 
with data corresponding to each individual turtle recorded on its own line, under either a tab for necropsies or 
a tab for faeces. INDICIT supports the development of a dedicated platform in synergy with the CleanAtlantic 
project. 

Data  gathered  A  total  of  1406  individuals  were  recorded  in  the  INDICIT  database,  948  necropsies  (841 
loggerhead and 107 leatherback) and 458 observations of faeces. Past data (from 1988), collected before the 
INDICIT project, was insufficient to accurately assess the temporal trend in litter ingestion in sea turtles. In data 
obtained from the last 6 years (from 2013 to December 2018), findings showed that 53.84% of leatherbacks 
had ingested litter, with an average of 1.7 0.73 g per individual at the population level (N = 13 individuals, all 
from France’s Atlantic waters); 57.94% of living loggerheads excreted litter (N=254; 1.06  0.44 g with N = 185); 
and 63.03% of dead loggerheads (N = 522) were found with litter, with a mean of 0.78 0.11 g (N = 480) at the 
population level. 

Main findings 

Area 

Atlantic 

Mediterr-
anean 

Country 
France 
Portugal 
Spain 
Global 
France 
Greece 
Italy 
Spain 
Tunisia 
Turkey 
Global 

Number of necropsies 
21 
33 
9 
45 
77 
28 
129 
85 
46 
94 
457 

Litter prevalence (%)  Dry mass (g)  % turtles litter > food 
0.28  0.16 
1.13  0.35 
0.16  0.07 
0.74  0.21 
1.23  0.27 
0.13  0.06 
0.92  0.19 
0.89  0.27 
0.84  0.71 
0.37  0.29 
0.78  0.12 

11.11 
- 
0 
9.09 
12.12 
3.7 
30.23 
16 
9.09 
0 
17.01 

45 
81.82 
88.89 
70.97 
82.43 
64.28 
62.01 
80.49 
52.17 
33.33 
61.95 

Main results obtained from necropsies of dead loggerhead turtles collected during a 6-year period (2013 to 2018) per 
area (Atlantic/Mediterranean) and per country. Litter prevalence: percentage of turtles having ingested litter; Dry mass: 

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mean dry mass of ingested litter; % turtles litter > food: percentage of turtles having ingested more litter than food 
(measured in terms of food remains). 

Indicator  assessment  criteria  and  constraints  Due  to the  small  amount  of  data on  the  leatherback  and the 
possible discrepancies in methodologies used by different stakeholders to collect litter from living turtle faeces, 
the indicator criteria were tested only on the data from necropsied loggerheads. The GES was evaluated from 
individuals with conservation status 2 (fresh death) and 3 (relatively fresh, early stage of decomposition). Various 
measures were considered to assess the quantity of ingested litter, such as the volume or the number of items 
or fragments. It was decided to adopt dry mass (to 2 decimals) as this appeared to be the most trustworthy 
parameter  in terms of  the  use  of  a  common methodology  between  stakeholders.  Then  all  biological  factors 
(collected as ‘basic’ or ‘optional’ parameters) were tested individually or in combination in order to assess the 
possible  constraints.  We  found  contrasting  results  when  evaluating  the  factors  influencing  litter  ingestion 
according to the parameter chosen, but no significant or major difference in: 

i)  the circumstances of discovery, especially between the most common way to collect specimens, from 

stranding and bycatch, which may be due to the low amount of data or by confounding factors related to 
typology or type of gear causing bycatch (e.g. depth, distance to the coast and turtle life stage) 

ii)  the individual’s size, evaluated with 12 measurements of carapace length and classified in 4 categories 
(20 cm; 20–40 cm; 40–60 cm; ≥60 cm), and the individual’s life stage classified in juvenile or adult.   
iii) the body condition, which indicated health status, evaluated by body weight, fat reserves, injuries and 

the possible cause of death. 

We also evaluated whether a ‘Body condition’ index could be used, based on indices used for the green turtle 
Chelonia  mydas,  but  further  research  is  needed  to  adapt  an  index  for  the  loggerhead  species.  Lastly,  we 
considered the dry mass of food remains compared to the total dry mass of litter as a proxy of individual health, 
with  the  assumption  that  individuals  that  did  not  consume  natural  items  did  not  ingest  litter  and  that  the 
digestibility of food and litter items is comparable. From 2013, over the entire area (Atlantic and Mediterranean 
Sea), an average of 16.76% of the necropsied loggerheads were found with more litter than food remains (9% 
in the Atlantic and 17% in the Mediterranean). These results (obtained from all the data collected during the 
INDICIT  project)  indicate  that  more  standard  data  would  be  necessary  to  perform  more  powerful  tests. 
However, the INDICIT consortium recommended not to stratify the dataset and to consider all data without 
constraint. 

Indicator units The project also evaluated temporal and spatial units for the indicator. Highly variable between 
countries, no significant temporal trend was found, but this should be further evaluated with a higher sample 
size. The INDICIT consortium recommended evaluating GES over a  6-year period in order to better ensure a 
standardized methodology for collecting data and to correspond to the MSFD cycle. The data obtained between 
2013 and January 2018 showed no significant differences in litter prevalence between the Atlantic (70.91%) and 
the Mediterranean (61.95%) areas of the project, although differences between countries in each of these areas 
appeared. The INDICIT consortium voted to define two distinct GES for the Atlantic and the Mediterranean, 
because of the possible differences in ecological processes between the two areas. It also highlighted the need 
for further studies in the Atlantic area to collect more data. Moreover, simulations of the monthly distribution 
of floating litter made in partnership with the MEDSEALITTER project revealed at least two distinct processes 
between the Eastern and the Western Mediterranean basins, suggesting that two distinct GES could also be 
proposed for the two basins. 

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Sample size An initial evaluation indicated that data from almost 200 individuals would be needed during a 6-
year period to detect change in the mean dry mass of litter evaluated at the population level. Based on the 
available samples, the INDICIT consortium suggested a minimum of 50 individuals per country and per year for 
evaluating the GES. 

Categories  of  litter  Further  evaluations  could  be  made  considering  litter  categories  based  on  the  MSFD’s 
‘Programmes of Measures’, especially for evaluating indicator responses to USE SHE (plastic sheets), USE FRA 
(hard plastic fragments), USE THR (threadlike plastics) and USE FOA (foam), the categories most often found 
ingested by the loggerheads. 

GES scenarios Two GES proposals were retained by the INDICIT consortium. The first is: “There should be less 
than X% of turtles with more than Y g of ingested plastics”, based on the ‘Fulmar’ scenario used in OSPAR, with 
X and Y being the minimum occurrence and dry mass of ingested litter found in the concerned area (X = 45% in 
the Atlantic and 33% in the Mediterranean, and Y = 0.13 and 0.37 respectively). However, according to the new 
Commission  Decision  2017/848/EC,  the  definition  of  Criteria  D10C3  should  refer  to  the  “health  of  species 
concerned”. As the cause of death could not be used to propose a threshold (only four deaths were attributed 
to litter ingestion of the 189 known cases), mortality could not be used to recommend GES. Thus, the ratio of 
dry  mass  of  ingested  litter  to  food  remains  was  recommended  as  the  best  proxy  of  ‘individual  health’  with 
available data on body condition, assuming that healthy individuals with no food remains did not ingest litter 
either.  The  second  GES  proposal  is: “There should  be  less  than  Z%  of  turtles with more  plastics  than  food 
remains”, Z being the minimum occurrence, which was 11.11% for the Atlantic and 3.7% for the Mediterranean. 
Collecting further data should help better assess which litter/food remains ratio should be considered and the 
ecological factors that may influence it. 

Main recommendations In the aim of allowing more accurate assessments and refining GES guidelines, the 

INDICIT consortium recommends the following actions: 

i)  Enlarge the network of stakeholders involved in monitoring litter ingestion, especially in the OSPAR and 
Mediterranean areas where no or little data is available, and consider the preconditions for involvement 
required by stakeholders who were contacted but are not yet involved (especially material and human 
means, considering that an average of five hours with two handlers is required per dead turtle from 
handling in the field to analysing the litter ingested). The professionalization of a specialized team in 
support of some stakeholders could be envisaged. 

ii)  Extend the dissemination of the INDICIT protocol and the video-tutorial. 
iii) Propose regular training sessions, with a kit offering the essential equipment for turtle handling  and litter 
analysis, envisage the development of tools to allow stakeholders to share their skills, and recommend 
workshops with expert biologists (rescue centres, stranding networks, veterinarians, researchers, etc.) 
and MSFD, RSC and member state representatives. 

iv) Plan data gathering in a dedicated platform and consider how to integrate stakeholders’ private data in 

order to pursue the statistical analyses. 

v)  Encourage the collection of the ‘optional’ parameters in the INDICIT protocol in order to acquire more 

knowledge about the impacts on individual health and define a simple way to evaluate this.  

vi) Continue reflection with experts from multi-disciplinary approaches in order to recommend GES in line 

with Criteria D10C3 and the notion of “health of the species concerned”. 

vii) Encourage the collection of data on food remains in order to advance work on the second GES proposal 
regarding the percentage of turtles with more litter than food remains as a proxy of individual health. 

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2. 

‘Entanglement by biota with marine litter’ indicator 

The feasibility study of this Criteria D10C4 indicator was based on a review of available grey and published 
literature and the responses to a questionnaire disseminated to experts in sea turtles, marine mammals, marine 
birds, fish or marine litter. The report, available on the INDICIT website, provides the detailed results per taxa. 
At this stage, information is often partial or based on opportunistic data, making an accurate  assessment of 
entanglement impossible. The constraints, relative to methodology for the collection of specimens and intrinsic 
factors such as behaviour or age, are analysed. Several relevant species are proposed, but no standard protocol 
exists at this time. The INDICIT consortium highly recommends defining a standardized typology of the types of 
marine litter causing entanglement, particularly to differentiate passive entanglement due to litter and active 
entanglement due to bycatch. Relevant networks have started to be identified. A survey of available databanks 
should  be  conducted,  and  initial  standard  data  collected  in  pilot  tests.  The  INDICIT  protocol  recommends 
collecting data on sea turtle entanglement as an optional parameter. This information could be further refined 
using the first collected data. 

3. 

‘Micro-plastic ingestion in fish and sea turtle’ indicator 

The feasibility of this Criteria D10C3 indicator, which distinguishes micro-plastics < 5 mm in size, was evaluated 
through a literature review on (i) fish, in order to enlarge the proposed area, including the HELCOM RSC, and (ii) 
on sea turtles. For the latter, the feasibility was further evaluated in the laboratory with involved stakeholders. 
The review highlighted the strong discrepancies between studies in terms of extracting the litter (e.g. digestion 
techniques), differentiating plastic particles from natural items, and avoiding contamination in the field and the 
laboratory. A selection of relevant species was proposed for fish. For sea turtles, a simple method for collecting 
data when monitoring the indicator ‘Litter ingested by sea turtles’ was proposed. A complete protocol should 
be developed for these two taxa; the collection of further standard data would allow the assessments to be 
refined. 

4.  Sharing the knowledge 

The  INDICIT  project  targeted  a  large  audience:  scientists  and  laboratories,  decisional  stakeholders,  RSC 
secretaries, national focal points and fishery management organizations, experts and technical groups, specific 
networks  (e.g.  stranding  networks  or  discussion  lists),  local  groups  and  sea  users,  non-governmental 
organizations,  as  well  as  the  general  public.  To  communicate  its  findings  and  recommendations,  INDICIT 
participated  in or  organized  international  and  national  conferences,  expert  workshops, training  sessions  and 
dissemination meetings. Several technical and awareness-raising tools have been built, and INDICIT collaborated 
with  11  research  projects.  A  28’  documentary  was  produced  during  the  project1.  These  actions  reached  an 
audience of more than 12,730 people. 

Perspectives: from INDICIT to INDICIT II 

The  INDICIT  II  project  started  in  February  2019  and  will  continue  for  two  years.  The  new  project  aims  to 
capitalize  on  the  outcomes  of  INDICIT  in order  to 1)  collect  further  data  to  refine  the  GES  proposed  for the 
indicator  ‘Litter  ingested  by  sea  turtles’,  and  test  it  in  pilot  areas  where  ‘Programmes  of  Measures’  are 
implemented in regards to specific litter categories (e.g. evaluation of a decrease in ingested fragments of plastic 
sheets where plastic bags have been banned); 2) develop the two other litter impact indicators related to i) 

1 https://indicit-europa.eu/documentary/ 

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entanglement, especially for marine taxa that spend time at the ocean surface (turtles, mammals, birds) and ii) 
micro-plastic ingestion in fish and sea turtles. For these two new indicators, new standard methodologies will 
be developed in parallel to networking initiatives and training of new stakeholders. The collected standard data 
would enable the evaluation of the constraints and inform possible GES proposal. INDICIT II also aims to better 
evaluate the impacts of litter (ingestion and entanglement) on the health of individuals, especially through eco-
toxicological approaches. 

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Open data from the EU 
The EU Open Data Portal (http://data.europa.eu/euodp/en) provides access to datasets 
from the EU. Data can be downloaded and reused for free, for both commercial and non-
commercial purposes.