TY - JOUR
T1 - Reconstructing past fisheries catches for large pelagic species in the Indian Ocean
AU - Heidrich, Kristina N.
AU - Meeuwig, Jessica J.
AU - Zeller, Dirk
N1 - Funding Information:
This research was supported by an Australian Government Research Training Program (RTP) Scholarship. KH was also supported by the Forrest Research Foundation. General Sea Around Us research is supported by the Oak Foundation, the Paul M. Angell Family Foundation, the Marisla Foundation, the David and Lucile Packard Foundation and the Bloomberg Philantropies via Rare. However, no specific or dedicated funds were provided to support this specific research.
Publisher Copyright:
Copyright © 2023 Heidrich, Meeuwig and Zeller.
PY - 2023
Y1 - 2023
N2 - Comprehensive catch data are fundamental to support the sustainable management of large pelagic fisheries. However, catch data reported by the Indian Ocean Tuna Commission (IOTC) on behalf of its member countries currently under-represent the extent of these fisheries in the Indian Ocean. We reconstructed fisheries catches of large pelagic species for the Indian Ocean from 1950 to 2020, aiming to improve the comprehensiveness of existing reported data and to provide more ecologically relevant datasets for research and management uses. We reconstructed catches for 42 countries operating five major gear groups (longline, purse seine, gillnet, pole-and-line, and other gears) in the large pelagic fisheries. Reconstructed catches were 30% higher than the data reported by the IOTC. We demonstrated that distant-water fishing fleets historically dominated large-scale industrial fishing but were gradually replaced by fleets flagged to Indian Ocean rim countries. Our results also indicated an average discard rate of ~14% over the 1950-2020 period, primarily attributable to extensive discarding practices associated with longline and gillnet vessels. Reporting over time has improved only for tunas, whereas shark catches still remain under-reported, accounting for 51% of total unreported landings and discards in 2020. We confirmed substantial taxonomic aggregation in the data reported by the IOTC on behalf of its member countries, masking important patterns and trends and further complicating the sustainable management of exploited species in the Indian Ocean. We recommend substantially increased observer coverage and far better and stronger support by all member countries to improve the fisheries statistics in the IOTC.
AB - Comprehensive catch data are fundamental to support the sustainable management of large pelagic fisheries. However, catch data reported by the Indian Ocean Tuna Commission (IOTC) on behalf of its member countries currently under-represent the extent of these fisheries in the Indian Ocean. We reconstructed fisheries catches of large pelagic species for the Indian Ocean from 1950 to 2020, aiming to improve the comprehensiveness of existing reported data and to provide more ecologically relevant datasets for research and management uses. We reconstructed catches for 42 countries operating five major gear groups (longline, purse seine, gillnet, pole-and-line, and other gears) in the large pelagic fisheries. Reconstructed catches were 30% higher than the data reported by the IOTC. We demonstrated that distant-water fishing fleets historically dominated large-scale industrial fishing but were gradually replaced by fleets flagged to Indian Ocean rim countries. Our results also indicated an average discard rate of ~14% over the 1950-2020 period, primarily attributable to extensive discarding practices associated with longline and gillnet vessels. Reporting over time has improved only for tunas, whereas shark catches still remain under-reported, accounting for 51% of total unreported landings and discards in 2020. We confirmed substantial taxonomic aggregation in the data reported by the IOTC on behalf of its member countries, masking important patterns and trends and further complicating the sustainable management of exploited species in the Indian Ocean. We recommend substantially increased observer coverage and far better and stronger support by all member countries to improve the fisheries statistics in the IOTC.
KW - bycatch
KW - discards
KW - sharks
KW - tunas
KW - unreported catches
UR - http://www.scopus.com/inward/record.url?scp=85161081643&partnerID=8YFLogxK
U2 - 10.3389/fmars.2023.1177872
DO - 10.3389/fmars.2023.1177872
M3 - Article
AN - SCOPUS:85161081643
SN - 2296-7745
VL - 10
JO - Frontiers in Marine Science
JF - Frontiers in Marine Science
M1 - 1177872
ER -