DOI: 10.14466/cefasdatahub.128
title: Occurrences of sensitive fish species in scientific trawl surveys of the Northeast Atlantic 1983-2020

description: The OSPAR ([https://www.ospar.org/convention][1]) fish biodiversity assessment concerns sensitive and often rare species in the northeast Atlantic Ocean and marginal seas. All fish species captured during fishing on scientific groundfish (otter and beam trawl) surveys are recorded but not necessarily weighed and measured for length. The biodiversity assessment for sensitive and often rare species thus makes use of the occurrences (presence and absences) of a species only.

A list of sensitive fish species was developed to guide the work for the OSPAR fish biodiversity assessment. The list was created by first collating all sensitive fish species recorded on international and national hard law lists, Regional Seas Conventions lists, International Agreement Lists, relevant IUCN Red List species (classified as EX, CR, VU or EN) and all ICES and academic work to identify sensitive fish species. From this extensive list of species, species were removed if they did not occur in the OSPAR area of the Northeast Atlantic Ocean. Remaining species were divided by region; Bay of Biscay and Iberian Coast, Celtic Seas, Greater North Sea, Norwegian Sea and parts of Macaronesia where data was available. Those species whose normal distribution was at the very edge of an OSPAR region were not assessed within the region.
Species where ICES or ICCAT quantitative stock assessments are conducted in all or part of their distribution were retained on the list, but highlighted so as to avoid duplication of work. The list was then cross-referenced with the ICES WKCOFIBYC (ICES, 2021a) and WKABSENS (ICES, 2021b) sensitive species lists and reviewed by expert members of the OSPAR Fish subgroup to ensure all sensitive species were included.

To overcome the potential for species misidentification for those that are difficult to identify beyond the genus level, some species were grouped by genus for the assessment. These include Hippocampus spp. (combining Hippocampus hippocampus with H. guttulatus), Alosa spp. (combining Alosa alosa and A. fallax), Dipturus spp. (combining Dipturus batis complex, D. batis, D. flossada and D. intermedia), Mustelus spp. (combining Mustelus mustelus and M. asterias), Sebastes spp. (combining Sebastes marinus, S. mentella and S. norvegicus), Dasyatis spp. (combining Dasyatis pastinaca and D. tortonesei), Galeus spp. (combining Galeus melastomus and G. atlanticus), Coregonus spp. (combining Coregonus maraena and Coregonus oxyrinchus), Raja brachyura (including Bathyraja brachyurops) and Deania calcea (including D. profundorum). After grouping, a total of 102 unique taxonomic groups were retained on the OSPAR sensitive fish species list for four OSPAR regions (Greater North Sea, Celtic Sea, Bay of Biscay and Wider Atlantic).

Data file names reflect the OSPAR region sampled, country conducting the sampling, fishing gear and time of years of sampling (as defined by Greenstreet and Moriarty 2017), e.g.:
BBICFraBT4 refers to Bay of Biscay and Iberian Coast data from France by a Beam Trawl survey in quarter 4 of the year and GNSIntOT3 refers to Greater North Sea data from International (multiple countries) sampling by an Otter Trawl survey in quarter 3 of the year etc.

Scientific trawl survey data are submitted to the ICES Database of Trawl Surveys (DATRAS):
[https://www.ices.dk/data/data-portals/Pages/DATRAS.aspx][2]

The DATRAS reporting format is detailed online:
[https://datras.ices.dk/Data_products/ReportingFormat.aspx][3]

The metadata relating to the ICES co-ordinated surveys are available here:
[https://www.ices.dk/data/data-portals/Pages/DATRAS-docs.aspx][4]

ICES Data Centre host the database of trawl surveys (DATRAS) for groundfish and beam trawl data. DATRAS has an integrated quality check utility. All data, before entering the database, have to pass an extensive quality check. Despite this errors and missing data arise, which are subsequently dealt with by the data submitters from the contributing countries as required. However, this screening process was implemented in 2009 for data from 2004 onwards. Since some survey time-series extend back to the 1960s, historic data (unless re-evaluated and re-submitted by contributing countries) may not have been subject to the same level of quality control as these more recent data. Furthermore, the type of information collected, the level of detail and resolution in the data, has gradually evolved over time. In order to derive a single format, quality assured monitoring programme data product covering the entire Northeast Atlantic region inconsistencies in the datasets required resolution. These corrections are detailed in ICES 2021a,b:

Biological data for trawl surveys are downloaded directly from DATRAS in raw exchange format (known as “HL data”). Ancillary data were processed by ICES 2021a,b to create the “SweptAreaAssessmentOuput” (which replaces the “HH data”) and these were downloaded from the same location:
[https://datras.ices.dk/Data_products/Download/Download_Data_public.aspx][5]

For the biodiversity assessment of sensitive species, the data are processed to create a standalone data product on species occurrence (presence and absence) and haul location. Initially, valid hauls are subset to determine the Standard Monitoring Programme (i.e. excluding hauls of duration shorter than 13 minutes or longer than 66 minutes) and these hauls are used to define the Standard Survey Area (excluding areas sampled infrequently over time) following the methods detailed in Greenstreet and Moriarty 2017). Biological data were accepted with ICES SpecVal of 1, 4, 5, 6, 7, 10 (see [http://vocab.ices.dk/][6] for further information on SpecVal categories). 

Additional QA/QC is made at this step to determine if species identification issues are present in the raw biological data.

References:
Greenstreet S P R and M Moriarty 2017. Manual for Version 3 of the Groundfish Survey Monitoring and Assessment Data Product. Scottish Marine and Freshwater Science Vol 8 No 18. Published by Marine Scotland. ISSN: 2043-7722. DOI: [10.7489/1986-1][7]

ICES. 2021a. Workshop on Fish of Conservation and Bycatch Relevance (WKCOFIBYC). ICES Scientific Reports. 3:57. 125 pp. [https://doi.org/10.17895/ices.pub.8194][8]

ICES. 2021b. Workshop on the production of abundance estimates for sensitive species (WKABSENS). ICES Scientific Reports. 3:96. 128 pp. [https://doi.org/10.17895/ices.pub.8299][9]


  [1]: https://www.ospar.org/convention
  [2]: https://www.ices.dk/data/data-portals/Pages/DATRAS.aspx
  [3]: https://datras.ices.dk/Data_products/ReportingFormat.aspx
  [4]: https://www.ices.dk/data/data-portals/Pages/DATRAS-docs.aspx
  [5]: https://datras.ices.dk/Data_products/Download/Download_Data_public.aspx
  [6]: http://vocab.ices.dk/
  [7]: https://data.marine.gov.scot/sites/default/files//SMFS%200818_0.pdf
  [8]: https://doi.org/10.17895/ices.pub.8194
  [9]: https://doi.org/10.17895/ices.pub.8299