First implementation of a Gadget model for the analysis of hake in the Mediterranean
| Autor: | Gunnar Stefansson, Lorna Taylor, Francesco Colloca, Valerio Bartolino |
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| Rok vydání: | 2011 |
| Předmět: |
0106 biological sciences
Mediterranean climate Population Fishing multi-fleet mediterranean Aquatic Science Fish stock 010603 evolutionary biology 01 natural sciences Mediterranean sea Hake length-based 14. Life underwater education hake Stock (geology) education.field_of_study biology 010604 marine biology & hydrobiology gadget statistical model Merluccius merluccius biology.organism_classification Fishery Geography |
| Zdroj: | Fisheries Research. 107:75-83 |
| ISSN: | 0165-7836 |
| DOI: | 10.1016/j.fishres.2010.10.010 |
| Popis: | An age-length structured model was built for European hake Merluccius merluccius in the central Mediterranean Sea using Gadget. This analytical framework allowed to integrate multiple sources of information, including fisheries-dependent and fisheries-independent data, collected at different scales and aggregation levels. The model includes the two main fisheries targeting hake in the area, the trawl and the gillnet fisheries, and account for differences in their selectivity and effort. Alternative models were used for testing different assumptions on recruitment and growth. The model is then used to predict the main trajectory of the stock during the next years and to evaluate the potential effects of implementing closed areas management scenarios in the hake nurseries as a specific tool to reduce fishing mortality on recruits. The modelling framework presented performed successfully also in a commercial landing data limited context, common for the Mediterranean. Our results provide statistical support for fast growth and multiple recruitment events assumptions. Including both these key features represent an unprecedented improvement of modelling hake population dynamics in the Mediterranean. We found that the reduction in the fishing effort that characterized the fisheries in the study area during the last few years, coupled with fast recovery abilities of the hake stock, has the potentiality to allow a moderate increase of the stock during the next years. Interestingly, our simulations show that the positive effects which might be expected from protecting hake nursery grounds are only marginally related to a reduction in hake recruits fishing mortality. Although our model relies on assumptions and surely represents an over-simplification of the real world, it still contributed to improve our understanding of the temporal dynamics of one of the most valuable fish stocks in the central Mediterranean. |
| Databáze: | OpenAIRE |
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