DIASPARA
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DIAdromous Species: moving towards new PARadigms to achieve holistic scientific Advice |
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Summary
Despite numerous commitments for their conservation, the Atlantic salmon and the European eel are currently endangered. Developing assessment tools to quantify the effects of multiple pressures on populations is particularly timely and challenging for those diadromous fishes, whose life-cycle is shaped by long-range migrations from rivers towards offshore marine spawning (eel) or feeding (salmon) habitats, where individuals from different spatial origins (subunits) mix. Salmon and eel life cycles are therefore affected by a combination of drivers acting in a hierarchy of nested spatial scales, ranging from global factors that can affect large numbers of subunits to regional/local factors that affect only parts of a few subunits.
The DIASPARA project aims at providing tools to enhance the scientific basis of the assessment process from data collection to stock assessment. The final objectives is to support more holistic advice to inform cross-boundary management of these species, while adapting it to the upcoming challenges such as climate change, and related changes in ecosystems.
The project has strong connections with ICES working groups WGNAS (Atlantic salmon in the North Atlantic), WGBAST (Atlantic salmon in the Baltic) and WGEEL (European eel). It will address several challenges raised in the road maps of those expert groups for future development of their assessment framework. Such a multispecies approach will foster interactions and transfer of knowledge between scientific communities.
The project is structured in three main technical work packages.
1. Spatio-temporal variations of life history traits
This work-package aims at improving the consideration of spatial and temporal variations in key life history traits (e.g., growth) that influence stock productivity. DIASPARA will undergo an inventory of available data and make recommendations for potential improvement in the data collection, in order to facilitate an effective collection, management and use of biological data in stock assessment models (SAM).
2. Enhancing data base
This work package aims at advancing the development of an international pan-European database to better handle nested spatial scales and diversity of stressors in order to support an holistic assessment of migratory fishes. We will develop database to facilitate the use of data required for the assessment. This will include biological data, fisheries data, but also habitat data to monitor the impact of dams and hydropower plants to support the river continuity restoration.
3. Enhancing stock assessment models
This work package aims at improving SAMs used by ICES working groups WGNAS, WGBAST and WGEEL to provide a better understanding of past changes in stock productivity and to improve our capacity to forecast population dynamics and productivity in the context of climate change. Specifically, the project will address two objectives:
i) Improving the biological realism of the models through a better consideration of the spatio-temporal variation of life history traits and the consequences for key demographic transition rates and population dynamics. The project will review and compare different approaches to model spatio-temporal variability of key demographic transitions rates, and assess the possibility to integrate those approaches in SAMs;
ii) developing algorithms and tools to improve computational efficiency of eel and salmon statistical integrated SAMs. This requires benchmarking of the models against different algorithms/softwares (e.g., Nimble, STAN, TMB). This is of paramount importance to further enhance accessibility and dissemination of large dimensional stage-based integrated population models, and in the perspective of complexifying the models to capture the spatio-temporal variability and covariation of key life history traits.
People involved
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NEVOUX Marie, Scientist Phone : +33 2 23 48 50 15 Email : marie.nevoux@inrae.fr |
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RIVOT Etienne, Scientist Phone : +33 2 23 48 59 34 Email : etienne.rivot@institut-agro.fr |
Funding and Support
Fundings : Commission Européenne (call EMFAF-2023-PIA-FisheriesScientificAdvice, grant 101155914)
EU is not responsible for the content of the project
DIASPARA partners