DOI: 10.5061/dryad.dr7sqvb7t
title: The global footprint of drifting Fish Aggregating Devices

description: Tuna are among the world’s most valuable marine life and have long been
 exploited by industrial fisheries. Increasingly, tuna fishing companies
 have shifted from targeting free-swimming fish to using drifting fish
 aggregating devices (dFADs): satellite-tracked rafts that move with
 currents while accumulating fish below. Here we estimate the global
 footprint of these devices and track 30 years of progress to mitigate
 impacts. We estimate 1.41 million dFAD buoys were released between
 2007-2021, drifting across at least 134 million km2, or 37% of Earth’s
 ocean surface. Lost dFADs have stranded in 104 maritime regions,
 contributing to coastal pollution and damaging sensitive habitats.
 Regulatory progress has been made to address data quality, entanglement,
 and pollution, but concerns over unregulated dFAD deployments,
 unsustainable bycatch, and weak industry accountability persist. Our
 results demonstrate that the cumulative environmental footprint of dFADs
 reaches far beyond tuna fishing grounds and remains inadequately mitigated
 at the global scale.
description: Source data used for analysis were obtained from previously
 published peer-reviewed literature, Regional Fisheries Management
 Organization (RFMO) websites and databases, and the Marine Stewardship
 Council (MSC) website. All sources and methodology are cited in the main
 manuscript and/or Supplementary Materials.  Datasets
 provided included data aggregated from these sources and used for the
 paper analyses and visualizations.
description: # The global footprint of drifting Fish Aggregating Devices
 [https://doi.org/10.5061/dryad.dr7sqvb7t](https://doi.org/10.5061/dryad.dr7sqvb7t) ## Description of the data and file structure All data used in these analyses originated from existing peer-reviewed literature, Regional Fisheries Management Organization (RFMO) websites, and the Marine Stewardship Council (MSC) website. All individual sources as well as the methods for aggregating and analyzing these data are provided in the Supplementary Materials of the associated paper. The files provided here include only summarized data from the original sources used specifically for our analyses and to generate the figures in the associated publication. For comprehensive datasets, please refer to the sources listed.  ### Files and variables #### File: Schiller\_Fig1\_dFADTunaCatch.zip **Description:** These files enable the creation of a global map showing total reported drifting Fish Aggregating Device (dFAD) tuna catches from 2010-2020. These data are in Geographic Coordinate System using World Geodetic System 1984 and are presented at a 5° x 5° spatial scale. Any zeros in the dataset refer to no reported catch for the associated cell. The source data come from RFMO catch databases and were originally aggregated by: M. Pons, D. Kaplan, G. Moreno, L. Escalle, F. Abascal, M. Hall, V. Restrepo, R. Hilborn, Benefits, concerns, and solutions of fishing for tunas with drifting fish aggregation devices. *Fish and Fisheries* 24, 979-1002 (2023). ##### Variables (TunaData\_Apr21\*\_\*2025.dbf): * FID: Unique object identifier specifying location in the ocean * Shape: Shape associated with data point (Polygon) * c_PS*_*FA: volume of dFAD catch per location (x 1,000 metric tons) #### File: Schiller\_Fig1\_dFADPresence\_inShapefile.zip **Description:** These files enable the creation of a map showing dFAD buoy track presence and absence across the global ocean. These data are based on: 9,289 dFAD buoys used by 29 French and French-associated purse seiners in the Atlantic and Indian Oceans 2007–2011, 56,263 dFAD buoys used by the same fleets 2012-2018, 10,266 dFAD buoys deployed by 123 vessels of different nationalities fishing in the Western and Central Pacific (WCPO) in 2023, and 12,541 dFAD buoys deployed by 165 vessels in the Eastern Pacific (EPO) in 2022, totalling 88,359 individual dFAD buoys tracked between 2007-2023. Data were extracted by creating a 1° x 1° grid across the entire world. Images of buoy tracks from original sources (see below) were georeferenced, and then grid cells with dFAD buoy presence were identified. Track density data were typically binned in 1° x 1° cells in the source publications, and hence, the same resolution was used. These data refer to the trajectories of dFAD buoys, not necessarily whole devices (i.e., buoy, raft, and tail). ##### Variables (FishingGearPresenceAbsence.dbf) * FID: Unique object identifier specifying location in the ocean * Shape: Shape associated with an object (Polygon) * PresenceAb: whether a dFAD buoy track was present in the associated location (Presence) or not (Absence) Original sources: A. Maufroy, E. Chassot, R. Joo, D. M. Kaplan, Large-scale examination of spatio-temporal patterns of drifting fish aggregating devices (D-FADs) from tropical tuna fisheries of the Indian and Atlantic Oceans. *PLoS ONE* 10, e0128023 (2015). T. Imzilen, C. Lett, E. Chassot, A. Maufroy, M. Goujon, D. M. Kaplan, Recovery at sea of abandoned, lost or discarded drifting fish aggregating devices. *Nature Sustainability* 5, 593-602 (2022). Jon Lopez, Marlon H. Román, Cleridy E. Lennert‐Cody, Mark N. Maunder, Nick Vogel, Leanne M. Fuller "Floating-object fishery indicators: a 2022 report", Inter-American Tropical Tuna Commission (2022) L. Escalle, M. Hamer, "Spatial and temporal description of drifting FAD use in the WCPO derived from analyses of the FAD tracking programmes and observer data" (WCPFC-SC19-2023/EB-WP-05, The Western and Central Pacific Fisheries Commission, 2023 #### File: Schiller\_Fig1\_dFADStrandings\_inShapefile.zip **Description:** These files enable the creation of a global map showing dFAD strandings by exclusive economic zone (EEZ). Data included here were amalgamated from existing peer-reviewed articles and grey literature, which determined dFAD strandings in two ways: physical observations of the device (i.e., buoys or raft material), and inferred strandings based on dFAD tracks (buoys only). The data obtained from all sources were entered into a database binned by exclusive economic zone (EEZ) of the world’s maritime nations and territories. Strandings in nations bordering multiple oceans (USA, Mexico, Australia) were binned separately by ocean based on the stranding location provided in the source. This dataset includes the total number of strandings estimated for each location between 1999-2023. However, for most locations, the data available encompassed much shorter timeframes. While these data represent a comprehensive amalgamation of publicly available strandings data, it is likely that values presented are underestimates due to limited dFAD coverage and reporting rates over time. Zeros in the dataset refer to no reported/no recorded dFAD strandings for the associated region at the time of data collection. ##### Variables (FAD\_StrandingsbyEEZ.dbf) * FID: Unique object identifier specifying location in the ocean * Shape: Shape associated with an object (Polygon) * GEONAME: dFAD stranding location (EEZ) * Sum_*d*_FADs: total number of dFADs stranded in location Original sources: E. E. Kimak, "The Distribution, Composition, and Management of Drifting Fish Aggregating Devices (Dfads) in the North Atlantic Ocean", thesis, Nova Southeastern University, Fort Lauderdale, FL, USA (2021). SPC, "Reporting to reusing: How satellite buoys from the purse seine fishery can benefit local communities" (2024). S. D. Balderson, L. E. C. Martin, “Environmental impacts and causation of ‘beached’ Drifting Fish Aggregating Devices around Seychelles Islands: a preliminary report on data collected by Island Conservation Society [IOTC–2015–WPEB11–39]” (Mahe, Seychelles, 2015). Oceanika, “Preserving Coral Reefs: OCEANIKA’s actions to safeguard Seychelles coastal ecosystems through the retrieval of abandoned, lost, or discarded dFADs [IOTC-2023-WGFAD04-INF02]” (Mahe, Seychelles, 2023). M. Clark, C. C. Mees, “Update on the catch and bycatch composition of illegal fishing in the British Indian Ocean Territory (BIOT) and a summary of abandoned and lost fishing gear [IOTC–2015–WPEB11–48]” (London, UK, 2015). IPNLF, “Sustained systematic non-compliance of drifting fish aggregating devices (dFADs) with Resolution 19/02 ‘Procedures on a Fish Aggregating Devices (FADs) Management Plan’ [IOTC-2023-CoC20-INF01_Rev1]” (2023) L. Escalle, J. Scutt Phillips, M. Brownjohn, S. Brouwer, A. Sen Gupta, E. Van Sebille, J. Hampton, G. Pilling, Environmental versus operational drivers of drifting FAD beaching in the Western and Central Pacific Ocean. *Scientific Reports* 9, 14005 (2019). T. Imzilen, C. Lett, E. Chassot, D. M. Kaplan, Spatial management can significantly reduce dFAD beachings in Indian and Atlantic Ocean tropical tuna purse seine fisheries. *Biological Conservation* 254, 108939 (2021). R. Banks, M. Zaharia, "Characterization of the costs and benefits related to lost and/or abandoned Fish Aggregating Devices in the Western and Central Pacific Ocean" (1514-PNA/R/01/A Poseidon Aquatic Resources Management Ltd for The Pew Charitable Trusts, 2020 I. MacMillan, M. J. Attrill, T. Imzilen, C. Lett, S. Walmsley, C. Chu, D. M. Kaplan, Spatio-temporal variability in drifting Fish Aggregating Device (dFAD) beaching events in the Seychelles Archipelago. *ICES Journal of Marine Science* 79, 1687-1700 (2022) J. Mourot, L. Escalle, T. Thellier, J. Lopez, J. Wichman, S. J. Royer, L. Hood, B. Bigler, B. Jaugeon, T. R. Nicholas, K. Pollock, F. Prioul, L., M., A. Marks, M. Kutan, J. Jones, J. M. Lynch, H. Tait, P. Hamer, "Analyses of the regional database of stranded drifting Fish Aggregating Devices (dFADs) in the Pacific Ocean" (SC19-EB-WP-04, Western and Central Pacific Fishery Commission, 2023;[https://meetings.wcpfc.int/node/19394](https://meetings.wcpfc.int/node/19394)). #### File: Schiller\_Fig2\_JuvenileCatch.xlsx **Description:** This file contains the dFAD fishery catch-at-size data summarized from RFMO stock assessments and reports for skipjack (SKJ), yellowfin (YFT), and bigeye (BET). We used the following region-specific length at 50% maturity (L50) values as our indicator of maturity for each stock based on the information from each species' most recent stock assessment or other published estimate: * Atlantic bigeye (ICCAT BET): 110cm * Atlantic yellowfin (ICCAT YFT): 115cm * Atlantic skipjack (ICCAT SKJ): 42cm * Indian bigeye (IOTC BET): 110.888cm * Indian yellowfin (IOTC YFT): 75cm * Indian skipjack (IOTC SKJ): 38cm * East Pacific bigeye (IATTC BET): 107.8cm * East Pacific yellowfin (IATTC YFT): 81.6cm * East Pacific skipjack (IATTC SKJ): 52cm * West Pacific bigeye (WCPFC BET): 103cm * West Pacific yellowfin (WCPFC YFT): 104.57cm * West Pacific skipjack (WCPFC SKJ): 50.1cm The total number of fish (i.e., catch or count, see region-specific Variables below) at or exceeding these values was classified as 'mature', and those below these values were classified as 'immature' for our analyses. All zeros in the dataset refer to no fish reported at the associated size class. Original sources: ICCAT, T2SZ database - size frequencies (observed) for SKJ [2024-01-31], ICCAT Statistical Database (2024). ICCAT, T2SZ database - size frequencies (observed) for YFT [2024-01-31], ICCAT Statistical Database (2024). ICCAT, T2SZ database - size frequencies (observed) for BET [2024-01-31], ICCAT Statistical Database (2024). Pacific Community, BET 2023 Diagnostic Model [GitHub Repository] (2023). [https://github.com/PacificCommunity/ofp-sam-bet-2023-diagnostic](https://github.com/PacificCommunity/ofp-sam-bet-2023-diagnostic). Pacific Community, YFT 2023 Diagnostic Model [GitHub Repository] (2023). [https://github.com/PacificCommunity/ofp-sam-yft-2023-diagnostic](https://github.com/PacificCommunity/ofp-sam-yft-2023-diagnostic). C. Castillo Jordán, T. Teears, J. Hampton, N. Davies, J. Scutt Phillips, S. McKechnie, T. Peatman, J. Macdonald, J. Day, A. Magnusson, R. Scott, F. Scott, G. Pilling, P. Hamer, “Stock assessment of skipjack tuna in the western and central Pacific Ocean: 2022” (2022). IOTC, Standardized size frequency data available in the IOTC database for bigeye tuna [IOTC-DATASETS-2024-04-02-SF-BET-1965-2022] (2024). IOTC, Standardized size frequency data available in the IOTC database for yellowfin tuna [IOTC-DATASETS-2024-04-02-SF-YFT-1952-2022] (2024). IOTC, Standardized size frequency data available in the IOTC database for skipjack tuna [IOTC-DATASETS-2024-04-02-SF-SKJ-1982-2022] (2024). IATTC, “The tuna fishery in the eastern Pacific Ocean in 2022” (2023). ##### Variables: IOTC * rfmo: the RFMO providing the data (i.e., Indian Ocean Tuna Commission, IOTC) * stock: the tuna stock (YFT = yellowfin, BET = bigeye, SKJ = skipjack) * fleet: the fishing set type (LS = IOTC code for "log set") * year: the year of data sampling * length_cm: the size class of fish (centimetres) * n_fish: the count of fish observed in the size class ('length_cm') * source: original data source ##### Variables: ICCAT * rfmo: the RFMO providing the data (i.e., International Commission for the Conservation of Atlantic Tunas, ICCAT) * stock: the tuna stock (YFT = yellowfin, BET = bigeye, SKJ = skipjack) * fleet: the fishing set type (FAD = ICCAT code for "Fish Aggregating Device") * year: the year of data sampling * length_cm: the size class of fish (centimetres) * catch_Nr: the count of fish observed in the size class ('length_cm') - source: original data source ##### Variables: IATTC * rfmo: the RFMO providing the data (i.e., Inter-American Tropical Tuna Commission, IATTC) * stock: the tuna stock (YFT = yellowfin, BET = bigeye, SKJ = skipjack) * fleet: the name of the purse-seine fleet associated with the catch * year: the year of data sampling * length_cm: the size class of fish (centimetres) * catch_t: the catch of fish observed (tonnes) in the size class ('length_cm') - source: original data source ##### Variables: WCPFC * rfmo: the RFMO providing the data (i.e., Western and Central Pacific Fisheries Commission, WCPFC) * stock: the tuna stock (YFT = yellowfin, BET = bigeye, SKJ = skipjack) * fleet: the name of the purse-seine fleet associated with the catch * year: the year of data sampling * length_cm: the size class of fish (centimetres) * catch_samples: the number of fish observed in the size class ('length_cm') - source: original data source #### File: Schiller\_Fig2\_dFADCatch.csv **Description:** This file contains the data required to assess the composition of catch by dFADs relative to other tuna fishing gears from 1970-2020. Publicly available RFMO data were used to determine total global catch for the main tropical tunas (skipjack, yellowfin, bigeye) across all gears. There is a small area of Convention overlap in the Pacific between the Inter-American Tropical Tuna Commission (IATTC) and Western and Central Pacific Fisheries Commission (WCPFC), so to avoid double-counting in this part of the ocean, we used the data specific to the WCPO provided by WCPFC and data specific to the Eastern Pacific from IATTC rather than catch data from their entire Convention Areas. We used data from Pons et al. (2023) as the most recent estimate of total dFAD catches globally. From the global RFMO catch total, we subtracted the dFAD catch volume from Pons et al. (2023) to obtain the total tuna catch by other gears. Original sources: M. Pons, D. Kaplan, G. Moreno, L. Escalle, F. Abascal, M. Hall, V. Restrepo, R. Hilborn, Benefits, concerns, and solutions of fishing for tunas with drifting fish aggregation devices. *Fish and Fisheries* 24, 979-1002 (2023). ICCAT, Task I data [2024-01-31], Nominal Catch Information (2024). WCPFC, Annual Catch Estimates 2022 - data files, Tuna Fishery Yearbook (2024). IATTC, EPO total estimated catch by year, flag, gear, species (Sept. 2023) (2023). IOTC, Best scientific estimates of nominal catch data by IOTC species, gear, and vessel flag reporting country (IOTC-DATASETS-2024-06-11-NC-SCI_1950-2022) (2024). ##### Variables * Year: fishing year * dFAD_mt: total catch (metric tons) of tropical tunas caught with the use of dFADs * Other_mt: total catch (metric tons) of tropical tunas caught using other gears #### File: Schiller\_Fig2\_dFADDeployments.csv **Description:** This file contains the data required to assess differences between reported and estimated dFAD deployments from 2007-2021. 'Reported' dFAD deployments were extracted from RFMO databases and documents. Our approach to calculating 'Estimated' dFAD buoy deployments involved scaling deployments from reporting fleets by total fleet size (number of dFAD fishing vessels) in the Indian Ocean and by total fleet dFAD catch in the Atlantic Ocean (see 'notes' in data file for specifics). As it was impossible to discern whether there were gaps in deployment numbers reported for the Eastern Pacific, no additional estimates were made for this region. For the Western Pacific (WCPO), we used a comprehensive estimate of total deployments based on observer and tracking data available from 2016-2019 and estimated the total deployments of other years based on the average proportion of estimated WCPO deployments from this source relative to the total estimated deployments of the three other regions combined. In doing this, we assumed that the WCPO region deploys an approximately stable fraction (32 percent) of all dFAD buoys deployed worldwide. See 'notes' for cells where 'source' is blank in the dataset, which details the process of determining 'Estimated' values based on 'Reported' data and the associated Reported 'source'. Original sources: A. Maufroy, D. M. Kaplan, N. Bez, A. D. De Molina, H. Murua, L. Floch, E. Chassot, Massive increase in the use of drifting Fish Aggregating Devices (dFADs) by tropical tuna purse seine fisheries in the Atlantic and Indian oceans. *ICES Journal of Marine Science* 74, 215-225 (2017). M. Ortiz, C. Mayor, “Summary and review of the FOB/FADs deployed ST08-FADs DEP ICCAT Database 2011-2021” (Madrid, 2023). IOTC, “Review of data on fish aggregating devices [IOTC-2022-WGFAD03-03_Rev2]” (2022). IOTC, “A recent review of the large-scale purse seine fishery operating in the Indian Ocean with Drifting Fish Aggregating Devices [IOTC-2023-WGFAD05-03]” (2023). Jon Lopez, Marlon H. Román, Cleridy E. Lennert‐Cody, Mark N. Maunder, Nick Vogel, Leanne M. Fuller. "Floating-object fishery indicators: a 2022 report", Inter-American Tropical Tuna Commission (2022). L. Escalle, S. R. Hare, T. Vidal, M. Brownjohn, P. Hamer, G. Pilling, Quantifying drifting Fish Aggregating Device use by the world's largest tuna fishery. *ICES Journal of Marine Science* 78, 2432-2447 (2021). ##### Variables * year: fishing year * ocean: ocean in which dFAD deployment occurred (EPO = Eastern Pacific, WCPO = Western and Central Pacific) * dFADs_deployed: number of dFADs deployed * type: data type (whereby 'Reported' = from RFMO and 'Estimated' = reconstructed using existing information provided in 'notes' and 'source') * notes: information related to dataset gaps or reconstruction approach (ICCAT = International Commission for the Conservation of Atlantic Tunas, IATTC = Inter-American Tropical Tuna Commission, IOTC = Indian Ocean Tuna Commission, WCPFC = Western and Central Pacific Fisheries Commission, FOB = Floating Object Buoy) * source: data source #### File: Schiller\_Fig3\_Timelines.xlsx **Description:** This file contains the data required to visualize trends in dFAD publications, management recommendations, non-governmental organization (NGO) advocacy, and eco-certifications over time. To capture trends in publications related to dFADs over time, we extracted all publications with the keywords ‘FAD’, ‘DFAD’, and “Fish aggregating device” from the Open Alex database ([https://openalex.org/](https://openalex.org/)). The search was completed in May 2023 and yielded 903 papers and publications whose titles and abstracts were manually checked and categorized into papers that covered anchored (aFADs), drifting (dFADs), or other topics less relevant to this review. All papers that dealt exclusively or non-exclusively with dFADs were reviewed in detail, cataloged, and binned by year of publication.  Using published RFMO compendia, we amalgamated a time series of RFMO conservation and management measures (CMMs, also called “Resolutions” or “Recommendations”) to determine how the uptake in the number of dFAD management measures has changed over time. We included measures specific to dFADs as well as those for target tropical tuna fisheries that have specific dFAD components (see Table S6 in the Supplementary Materials of Schiller *et al.* 2025 for the document name of all CMMs included).  To understand how NGO observer attention toward dFADs has changed over time, we amalgamated NGO observer advocacy letters submitted to the four RFMOs from 2007-2023 (n=402). All of these letters were obtained from each RFMO's website under meeting documents for each year. We then coded each letter for the presence (‘1’) or absence (‘0’) of content related to dFADs. See Table S7 in the Supplementary Materials of Schiller *et al.* 2025 for a list of all 402 NGO letters analyzed. To determine the number of Marine Stewardship Council (MSC) certified dFAD fisheries in each year, we used information from the MSC website ([https://fisheries.msc.org/en/fisheries/](https://fisheries.msc.org/en/fisheries/)). We included all tuna fisheries up to June 2024 that had been certified at least once (including those now suspended or withdrawn, *n*=64) but not those currently in assessment for the first time. Any purse seine fisheries originally certified for a free-school component but that later also became certified for a dFAD component were deemed ‘free school’ until the year in which the dFAD component was included. A list of all fisheries included is provided in Table S8 in the Supplementary Materials of Schiller *et al.* 2025. Original sources (RFMO websites and compendia): ICCAT website: [https://www.iccat.int/en/meetings.asp](https://www.iccat.int/en/meetings.asp) IATTC website: [https://www.iattc.org/en-US/Event](https://www.iattc.org/en-US/Event) WCPFC website: [https://meetings.wcpfc.int/](https://meetings.wcpfc.int/) IOTC website: [https://iotc.org/meetings](https://iotc.org/meetings) ICCAT, Compendium management recommendations and resolutions adopted by ICCAT for the conservation of Atlantic tuna and tuna-like species (International Commission for the Conservation of Atlantic Tunas, Madrid, Spain, 2024). WCPFC, Conservation and Management Measures, and Resolutions (Western and Central Pacific Fisheries Commission, [https://cmm.wcpfc.int/](https://cmm.wcpfc.int/), 2024). IOTC, "Compendium of active CMMs" (IOTC-2024-WPICMM07-REF01, Indian Ocean Tuna Commission, 2024). IATTC, All active resolutions (Inter-American Tropical Tuna Commission, [https://www.iattc.org/en-US/resolution/](https://www.iattc.org/en-US/resolution/), 2024). ##### Variables (dFAD\_literature) * year: year of publication * publications_n: count of publications with dFAD content ##### Variables (dFAD\_cmms) * year: year in which the Conservation and Management Measure was adopted * iattc: number of dFAD measures adopted at the Inter-American Tropical Tuna Commission * iccat: number of dFAD measures adopted at the International Commission for the Conservation of Atlantic Tunas * iotc: number of dFAD measures adopted at the Indian Ocean Tuna Commission * wcpfc: number of dFAD measures adopted at the Western and Central Pacific Fisheries Commission ##### Variables (dFAD\_observers) * year: year in which the observer letter was presented at the annual RFMO meeting * iattc_dFADpresent_n: count of how many IATTC observer letters contained the presence of dFAD content * iccat_dFADpresent_n: count of how many ICCAT observer letters contained the presence of dFAD content * iotc_dFADpresent_n: count of how many IOTC observer letters contained the presence of dFAD content * wcpfc_dFADpresent_n: count of how many WCPFC observer letters contained the presence of dFAD content - notes: information on source documents ##### Variables (dFAD\_msc) * year: year of certification * dFAD_cert: count of dFAD purse seine tuna fisheries certified by MSC * fs_cert: count of free school purse seine tuna fisheries certified by the MSC * other_cert: count of other tuna fisheries (not free school or dFAD) certified by MSC * notes: information on source documents #### File: Schiller\_dFADAdvocacy\_ContentAnalysis.xlsx **Description:** This file contains a summary of dFAD content in NGO letters presented at RFMO meetings. We coded in detail the dFAD priorities identified in each NGO letter for early years (2007-2014) and the most recent year (2023) to assess how observer attention toward specific dFAD issues has changed over time. Since regional advocacy related to dFADs started at different times, ‘early’ letters analyzed reflect the first 2-3 years in which dFAD issues were present at a given RFMO. We analyzed a combined total of 14 ‘early’ letters for IOTC, ICCAT, and WCPFC between 2007-2014, but did not include IATTC due to the absence of letters before 2020. For ‘recent’ letters (*n*=27), we coded letters submitted to all four RFMOs in 2023. Our coding was based on topics falling under two key categories: concerns and proposed solutions (Table S18, Supplementary Materials), and we used presence/absence scoring to capture whether these topics were mentioned in each letter. Thus, a given letter could include one or more topics. ##### Variables * year: year in which the observer letter was presented at the annual RFMO meeting * RFMO: name of RFMO to which the letter was presented * Observer: name of NGO presenting the letter * Type: type of NGO (ENGO = environmental non-governmental organizations, INGO = industry non-governmental organization) * Document name: identification code of observer letter (from RFMO website) * *Columns F-V*: dFAD related content (concerns and solutions), whereby '1' indicates the topic was present in the letter and '0' indicates the topic was absent from the letter #### File: Schiller\_Fig4\_MSCConditions.xlsx **Description:** This file includes the data used to assess differences in open conditions between free school, dFAD, and other tuna fishing gears and to assess which areas of the MSC assessment have the most open conditions for dFAD fisheries. For all fisheries with at least one MSC assessment (including those suspended or withdrawn), we calculated the total number of open conditions identified during the first assessment cycle based on information in the June 2023 Conditions Log ([https://fisheries.msc.org/en/the-msc-conditions-log/)](https://fisheries.msc.org/en/the-msc-conditions-log/). ##### Variables (conditions\_all) * gear: fishing gear used (whereby PS-FAD = dFAD purse seine, PS-FS = free school purse seine, Other tuna = other gears catching tuna, Non-tuna = fisheries targeting species other than tuna) * fishery: name of MSC-certified fishery * conditions_n: number of open conditions at time of first assessment ##### Variables (conditions\_tuna) * gear: fishing gear used (whereby 'PS-FAD' = dFAD purse seine, 'PS-FS' = free school purse seine, 'Other tuna' = other gears catching tuna) * fishery: name of MSC-certified fishery * stocks_n: number of tuna stocks included in the MSC assessment * conditions_n: number of open conditions at time of first assessment ##### Variables (msc\_indicators) * msc_indicator: MSC assessment Principle Indicator name and number * dFAD_with_n: number of dFAD fisheries with open conditions related to the Principal Indicator * dFAD_without_n: number of dFAD fisheries without open conditions related to the Principal Indicator ## Code/software NA ## Access information Other publicly accessible locations of the data: please see 'Data description' and Supplementary Materials. Data was derived from the following sources: please see 'Data description' and Supplementary Materials.