Hidden population declines revealed by integrating long-term fisheries data with fishers’ knowledge
- 1Fisheries Stock Assessment Center Fisheries Resources Institute, Japan Fisheries Research and Education Agency, 2-12-4 Fukuura, Kanazawa
- 2Oceanic Fisheries Program, The Pacific Community (SPC), B.P. D5
Abstract
Technological creep, the gradual increase in fishing power due to technological innovation, can mask population declines and bias fisheries assessments, yet information on historical technology adoption is rarely available. Here, we integrate long-term fisheries statistics (1972–2022) with structured interviews with experienced fishers to reconstruct technological change in the Japanese pole-and-line skipjack tuna (Katsuwonus pelamis) fishery. We estimate population trajectories over five decades using a Bayesian state-space model with time-varying catchability informed by questionnaire data. Biomass estimates decline substantially when catchability increases over time, by approximately 3.5-fold over the study period, equivalent to about 2.5% annually, relative to models assuming constant catchability. The resulting biomass trajectory indicates that the stock off Japan is below levels compatible with maximum sustainable yield (MSY). Fishers’ perceptions corroborate the inferred decline in skipjack tuna abundance despite apparently stable catch rates. Our findings highlight the importance of incorporating dynamic catchability into population models and provide a scalable framework for correcting for technological creep using fishers’ knowledge.
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BibTeX
@article{nishimoto2026hidden,
title = {{Hidden population declines revealed by integrating long-term fisheries data with fishers’ knowledge}},
author = {Makoto Nishimoto and Yoshinori Aoki and Naoto Matsubara and Paul Hamer and Kyuhan Kim and Yuichi Tsuda},
journal = {Communications Sustainability},
year = {2026},
month = oct,
doi = {10.1038/s44458-026-00177-w},
url = {https://doi.org/10.1038/s44458-026-00177-w},
note = {CC BY},
}
RIS
TY - JOUR
TI - Hidden population declines revealed by integrating long-term fisheries data with fishers’ knowledge
AU - Makoto Nishimoto
AU - Yoshinori Aoki
AU - Naoto Matsubara
AU - Paul Hamer
AU - Kyuhan Kim
AU - Yuichi Tsuda
PY - 2026
DA - 2026/10/25
JO - Communications Sustainability
DO - 10.1038/s44458-026-00177-w
UR - https://doi.org/10.1038/s44458-026-00177-w
AB - Technological creep, the gradual increase in fishing power due to technological innovation, can mask population declines and bias fisheries assessments, yet information on historical technology adoption is rarely available. Here, we integrate long-term fisheries statistics (1972–2022) with structured interviews with experienced fishers to reconstruct technological change in the Japanese pole-and-line skipjack tuna (Katsuwonus pelamis) fishery. We estimate population trajectories over five decades using a Bayesian state-space model with time-varying catchability informed by questionnaire data. Biomass estimates decline substantially when catchability increases over time, by approximately 3.5-fold over the study period, equivalent to about 2.5% annually, relative to models assuming constant catchability. The resulting biomass trajectory indicates that the stock off Japan is below levels compatible with maximum sustainable yield (MSY). Fishers’ perceptions corroborate the inferred decline in skipjack tuna abundance despite apparently stable catch rates. Our findings highlight the importance of incorporating dynamic catchability into population models and provide a scalable framework for correcting for technological creep using fishers’ knowledge.
SN - 3059-4308
ER -