2023 Fiscal Year Research-status Report
Identifying tipping points and safe operating spaces in sustainable fisheries management under future climate change
| Project/Area Number |
22K21333
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| Research Institution | Okinawa Institute of Science and Technology Graduate University |
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Principal Investigator |
DIECKMANN Ulf 沖縄科学技術大学院大学, 複雑性科学と進化ユニット, 教授 (00961187)
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| Project Period (FY) |
2022-08-31 – 2025-03-31
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| Keywords | Sustainable management / fish stocks / climate change / tipping points / safe operating spaces |
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| Outline of Annual Research Achievements |
Research achievements have been accomplished in both components of this research project.
First, the analysis of tipping points in 40+ fish stocks is revealing how sensitive the dynamics associated with the processes of recruitment, growth, maturation, and natural and fishing mortality in these stocks are to variations in life-history parameters. Sensitivities are being quantified in terms of responses of ecological stock characteristics. On this basis, climate-impact scenarios are being examined through which rising temperatures affect life-history parameters. In this way, particularly vulnerable stocks are being identified, and the causes of their vulnerability are being understood.
Second, the analysis of the safe operating space for the Northeast Arctic cod fishery is revealing how sensitive this stock’s life-history dynamics involving recruitment, growth, maturation, and natural and fishing mortality are to variations in temperature. Sensitivities are being quantified in terms of responses of ecological and socio-economic stock characteristics. On this basis, a two-dimensional continuum of management strategies is being evaluated by varying the regulated total allowable catch and minimum-size limit, in conjunction with a continuum of future climate trends. In this way, an expected future expansion of the safe operating space for this fishery is identified, and the causes of this expansion are being understood.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Research efforts during this fiscal year have focused on perfecting the parametrizations of the biological models.
For the analyses of tipping points in 40+ fish stocks, we have enhanced the quality of each stock’s life-history model by consolidating age definitions between stock assessments and our stock models, accounting for the timing of fishing relative to that of the other life-history events, accounting for initial lengths, and using observed maturation data. Moreover, we have developed dynamic stock simulations, incorporated harvest control rules, adopted a scaling interface between each stock’s spawner-recruit model and its life-history model, and conducted viability tests based on the production of spawning-stock biomass per recruit.
For the analyses of safe operating spaces in Northeast Arctic cod, we have consolidated the age definition between stock assessments and our stock model, calibrated the size and temperature dependences of natural mortality, upgraded the modeling of the spawning-ground fishery, and developed the software named ‘libpspm’, a feature-rich numerical package for solving physiologically structured population models.
All model refinements are improving the match between observations and predictions.
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| Strategy for Future Research Activity |
tentativeFor the analyses of tipping points in 40+ fish stocks, two papers are in preparation: (1) on a methodologically unified estimation of stock-recruitment relations and (2) on elasticities characterizing how vulnerable biological stock characteristics are to changes in life-history parameters and how vulnerable these life-history parameters are to changes in ocean temperature.
For the analyses of safe operating spaces in Northeast Arctic cod, three papers are in preparation: (3) on the R/C++ package developed for the combined analysis of life-history dynamics and socio-economic dynamics, (4) on how vulnerable biological stock characteristics are to changes in ocean temperature, and (5) on how vulnerable socio-economic stock characteristics and the resultant safe operating spaces are to changes in ocean temperature.
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| Causes of Carryover |
Funds from this grant could partially be saved and carried over because additional funding sources could be secured for covering a part of the originally planned expenditures. The further usage will unfold in accordance with the original plans while enabling intensified collaborative efforts together with this project's international partners.
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