Ecosystems fish management
Conventionally, commercial fish species have been managed separately. However, such methods neglect the high predation rate affecting juveniles, leading to overestimates of eventual adult fish stocks and population crashes in some cases. The EU-funded project GADCAP (Implementation of a multispecies model gadget to the ecosystem of Flemish Cap and incorporation to the fisheries stock assessment of NAFO; a case study) developed the first multi-species model. Researchers used the model to examine the interactions of cod, redfish and shrimp in the Flemish Cap region, off Canada's eastern coast. The study especially investigated the ecosystem's response to commercial fishing. Results were to be incorporated into the Northwest Atlantic Fisheries Organization (NAFO) roadmap. GADCAP's model quantified all interactions in question. The model predicted estimation of multi-species maximum sustainable yields, a key element of the ecosystem approach to fisheries. Results indicated that disregarding species interactions would seriously underestimate the magnitude and variability of natural mortality, leading to overestimations of exploitable population size. The model also considered predator-prey relationships in conjunction with population sizes. Additionally, the project conducted a training programme. The International Council for the Exploration of the Sea (ICES) and the EU Joint Research Centre both conducted supplementary training for project personnel. Staff attended several meetings and conferences, linked to a relevant industry working group. GADCAP's new multi-species approach to fisheries management is generally applicable beyond the study area. The work represents an important tool for sustainably managing fish populations.
Keywords
Ecosystems, multi-species, fisheries, Flemish Cap, GADCAP
