The ecological role and trophic relations of seasonal cohorts of the Patagonian Squid (Doryteuthis gahi) in the marine ecosystem of the Falkland Islands

 

This project wants to investigate the ecological role of the Patagonian squid Doryteuthis gahi (known as Loligo gahi) within the waters of the Falkland Islands. There are three main aspects of this project. First is to investigate the diet of D. gahi by analysing stomach content analysis, revealing the foraging spectrum, the food consumption and feeding strategies and behaviour. Second aspect is the trophic position of the Loligo squid. This will be investigated by measuring Stable Isotope rations of carbon and nitrogen of D. gahi individuals of all available size classes in five areas around the Falkland Islands and in all seasons of one year. Muscle tissue will be measured to gain a short term signal of the trophic position; Gladii-parts of the squid will be measured to detect ontogenetic changes within a lifespan of an individual. To link the trophic position of the squid to the ecosystem, important commercial species and ecological related species of D. gahi will also be analysed with Stable Isotope measurements. Last aspect is to build an ecosystem model of the Falkland Island waters with the freeware ‘Ecopath with Ecosim’, which will allow tracing energy flows within the ecosystem and make future predictions of biomass changes.  

Stable Isotopes food web example for homepage

This project falls into objective #3 of the FIG-FD, as it will give insights in the biology and ecology of one of the commercially most important species of the Falkland Islands, the Patagonian squid Doryteuthis gahi.  By investigating the diet and trophic position of the squid and giving an ecological context by comparing it with other important species of the Falkland Island ecosystem can help to manage and maintain the Falkland Islands fishing grounds. An ecosystem based model can also support the ongoing stock assessment procedures.

       Scientist

          Tobias Büring

          Alexander Arkhipkin

          Jessica Jones

          Graham Pierce

          Francisco Rocha

          Paco Bustamante

       Associated institutes

          University of Vigo 

          Littoral Environnement et Sociétés (LIENSs) 

          Vigo logoLIENSs Logo