Recruitment dynamics of European hake

Clasification on sampled fish during research survey

The European hake, Merluccius merluccius L., is one of the most important economical fisheries in the North-East Atlantic, being exploited mainly by Spain, France and Portugal. Aside from its fisheries importance, hake plays an important role in the marine ecosystem, as a predator on small pelagic species, but also of food for sharks and other larger predators. After the implementation by the EU of various recovery plans for both stocks (EC Nº811/2004 y EC Nº2116/2005), the spawning biomass has recently recuperated, after more than two decades under the security limits. However, recruitment remains highly variable, and in the case of the Southern stock still decreasing.

Plancton sampling and later inspection of smples onboard during the research survey

The overall objective of the project is to analyze the causes that determine hake recruitment with special attention to the demographic and environmental causes; and in particular consider the fishing pressure and climate change are ascertaining the recruitment pulses, reversing historical trends and encouraging the northern population. This proposed project is a logical continuation of CRAMER project. However it presents innovative aspects: some not studied op top now, as the study of the two seasonal components, trophic dynamics of larvae, or differential recruitment between sexes; other little studied, such as connectivity changes induced by fisheries and resilience; while others require further analysis, such as parental effects, the daily growth, larval distribution and the effect of environmental conditions on recruitment dynamics. To address these objectives more effectively, information from further north (Norway) and further south (Portugal) is included, and for that we have the collaboration of three foreign research agencies (University of Bergen, Bergen Research Institute, Norway, and the Portuguese Institute of Marine and Atmospheric). This knowledge will improve recruitment processes assessment and management of this population, which in turn will allow the sustainable exploitation and more effective recovery plans.

Lab work onboard during research survey