Global Fisheries for Tuna and Other Large Pelagic Species PDF

Global fisheries for tuna and other large pelagic species Dirk Zeller (Kristina Heidrich) Sea Around Us – Indian Ocean School of Biological Sciences Why should we care about tuna? 1 Historical importance of...

Global fisheries for tuna and other large pelagic species Dirk Zeller (Kristina Heidrich) Sea Around Us – Indian Ocean School of Biological Sciences Why should we care about tuna? 1 Historical importance of tuna fisheries Tuna fisheries represented in art, culture and economy – ancient Greeks/Romans Harvesting bluefin tuna in southern France (Oil on canvas, Joseph Vernet 1754) Development of the sailing and steaming tuna fishing fleets in the late 19th century 3/34 Historical development – coastal tuna fisheries, neritic & large tuna (centuries) © MSC © worldfish Historical development – industrial tuna fisheries, mainly large tuna (mainly since 1950) Historical development of tuna fisheries 1950 2018 1 https://www.seaaroundus.org/ Maritime zones EEZ (max 200 nm) Sovereign rights for exploring, exploiting, conserving and managing living and non-living resources of the water, seabed and subsoil High Seas (beyond EEZs) Common heritage of mankind, i.e., common property 1 High Seas EEZs High Seas 64% 34% 5% 9% ocean surface global surface High Seas – fishing effort But not all tuna (D & E). High seas squid fishing is prevalent in many areas as well, e.g., around Galapagos (B), off Argentina (C) and…. 1 10/34 Rodriguez et al. (2021) Science Advances 7, 9: eabe3470. High Seas – squid fishing effort In the NW Indian Ocean (unregulated – IUU), see https://www.tm- tracking.org/post/new-analysis-squid-fishing-north-west-indian-ocean-clear-as-ink 1 See also: Cappa et al. (2024) Regional Studies in Marine Science 77: 103632 Countries involved in tuna fisheries: Top 10? Indonesia Japan Papua New Guinea Not domestic-reflagged? Taiwan Spain Ecuador Korea U.S. Kiribati Not domestic-reflagged? Philippines 1 McKinney (2020). The Pew Charitable Trusts Distribution of 6 major tuna species Largely circum-global Albacore Atlantic bluefin (Thunnus alalunga) (T. thynnus) Southern bluefin Yellowfin (T. maccoyii) (T. albacares) Bigeye Skipjack (T. obesus) (Katsuwonus pelamis) www.aquamaps.org Status of tuna and tuna – like species Temperate vs tropical tunas tropical temperate Skipjack, bigeye and yellowfin Albacore, Atlantic and Southern bluefin Fast growers and shorter-lived (6-15 yrs) Slower grower and longer-lived (12-40 yrs) Suffered the slowest and least severe declines Suffered the fastest and greatest declines in in adult biomass adult biomass Lower probability of being overfished Higher probability of being overfished Status of tuna and tuna-like species Catch and biomass trends Indian Ocean Atlantic Ocean Western Pacific Ocean Eastern Pacific Ocean 1 15/34 Vulnerable bycatch species An estimated minimum of >5% of the total annual catch is discarded by global tuna fisheries  >265,000 t/year (Gilman et al. 2017) Vulnerable bycatch species Sharks Pacoureau et al. (2021) Nature 589(7843): 567-571 Management of tuna and tuna-like species: UNCLOS and UNFSA United Nations Convention on the Law of the Sea (UNCLOS) Gave coastal nations the right to 1982 manage fisheries within their Exclusive Economic Zones (EEZ) United Nations Fish Stocks Agreement (UNFSA) International treaty that set out principles 1995 Challenge: for the conservation and sustainable use How to manage highly migratory of straddling and highly migratory fish and straddling fish stocks? stocks Current Issues: Data management, IUU, subsidies, shark fishing, bycatch Highly migratory fish stocks Migrate long distances across international waters and EEZs Straddling fish stocks Migrate across or “straddle” more than one EEZ and high seas boundary Management of tunas: 5 Tuna Regional Fisheries Management Organizations  Tuna RFMOs Conservation and management FAO & Layer 3 Political/industry interference by any member country…. 20/34 Consensus decisions 1 All RFMOs: Stock assessments Stock Status Unassessed stocks Number of stocks Assessed stocks Adapted from Crespo et al. (2019) Nature Ecology & Evolution 3(9): 1273-1276. 1  Tuna RFMOs Stock Status – Kobe plot relative fishing pressure Juan-Jorda et al. 2011 Juan-Jordá et al. (2011) Proceedings of the National Academy of Sciences 108(51): 20650-20655. relative biomass Challenges Mandate vs non-mandate species non-mandate species number of species mandate species year adapted from Heidrich et al. (2022) Fish and Fisheries 23: 1264-1281 Challenges Reporting requirements Catch by year, taxon, fishing entity and gear Catch by year, taxon, fishing entity, gear and reporting area (“tuna block”) 1 adapted from Heidrich et al. (2022) Fish and Fisheries 23: 1264-1281  Challenges Taxonomic resolution (esp. elasmobranchs) higher level (“shark”) family level genus level species level 1 24/34 adapted from Heidrich et al. (2022) Fish and Fisheries 23: 1264-1281  Challenges Spatial resolution of catch reporting non – spatial Catch by year, taxon, fishing entity and gear spatial Catch by year, taxon, fishing entity, gear and reporting area (“tuna block”) 1 25/34 adapted from Heidrich et al. (2022) Fish and Fisheries 23: 1264-1281  Challenges Underrepresentation of non-target species oceanic tunas billfishes sharks neritic tunas Fewer & shorter time series available for assessments Presentist bias 1 26/34 adapted from Heidrich et al. (2022) Fish and Fisheries 23: 1264-1281  The way forward Finding the missing catch 27/34  The way forward Catch reconstruction Indian Ocean Overall 1950-2020: 30% more caught than reported 28/34 Heidrich et al. (2023) Frontiers in Marine Science 10: 1177872  The way forward Catch reconstruction Indian Ocean Recent 2000+: 20% more caught than reported 29/34 Heidrich et al. (2023) Frontiers in Marine Science 10: 1177872  The way forward Gear- & time-specific differences in reporting - IO Discards Un-reported Most under-reporting Reported Most under-reporting Most under-reporting 30/34 Heidrich et al. (2023) Frontiers in Marine Science 10: 1177872  The way forward High Seas Treaty Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ Agreement): Adopted January 2023, Chile first ratifier (May 2023) Capacity- Marine building and Environmental Area-Based genetic transfer of impact Management resources marine assessments Tools technology 31/34  The way forward Marine Protected Areas All MPAs 5.3% of global ocean 1.2% of high seas Highly Protected 2.5% of global ocean 0.8% of high seas Implemented – Highly/Fully Unimplemented – Highly/Fully Protected Protected Implemented – Other MPAs Unimplemented – Other MPAs 1 32/34  The way forward High Seas Treaty Homework: https://www.maritime-executive.com/article/high-seas-treaty-will-help-defend- small-island-nations-fisheries https://theconversation.com/we-now-have-a-treaty-governing-the-high-seas-can- it-protect-the-wild-west-of-the-oceans-201184 Andriamahefazafy M, Haas B, Campling L, Le Manach F, Goodman C, Adams TJH and Hanich Q (2024) Advancing tuna catch allocation negotiations: an analysis of sovereign rights and fisheries access arrangements. npj Ocean Sustainability 3(1): 16. https://doi.org/10.1038/s44183-024-00055-9 Andriamahefazafy M, Kull CA and Campling L (2019) Connected by sea, disconnected by tuna? Challenges to regionalism in the Southwest Indian Ocean. Journal of the Indian Ocean Region 15(1): 58-77. https://doi.org/10.1080/19480881.2018.1561240 33/34 Sea Around Us – Indian Ocean