VarMer

Context

Between 2010 and 2015, the biomass of the northern hake stock increased significantly, reaching unprecedented levels due to high recruitment between 2004 and 2008. However, since 2016, the biomass has been decreasing and is approaching the MSY trigger level, which could lead to a reduction in allowable catches. There are also inconsistencies in the assessment model, which could lead to the stock being reclassified to a lower category. On the other hand, the large increase in abundance has led to the expansion of the stock into the North Sea, which has been the subject of debate, without it being possible to conclude whether the expansion is solely due to the increase in abundance or also due to climate change. For better management, it is considered key to analyse the factors that have influenced recruitment, stock expansion, the relationship between density and productivity, and to improve the assessment model.

Objectives

The general objectives of the project are to identify the causes of variability in the abundance of the northern hake stock and to improve stock management.

These two general objectives will be implemented through the following operational objectives:

1. Develop a model of the spatial distribution of the stock as a function of environmental variables.
2. Identify the density-dependent processes in the productivity of the stock.
3. Identify the factors that explain the variability in recruitment.
4. Improve stock assessment.

Expected impact

Knowledge of the causes of variability in stock productivity is essential to improve stock management. No solo permitirá un cálculo más preciso de los puntos de referencia, sino que también contribuirá a la mejora del modelo de evaluación utilizado. Esto, a su vez, traerá beneficios prácticos significativos. Ya que una gestión más informada y precisa resultará en una mejor alineación de las oportunidades pesqueras con la biomasa real de la población.

This approach will allow better decisions on fishing quotas, ensuring that fishing activities are sustainable in the long term. The ability to predict and adapt to changes in stock productivity will reduce the risk of overfishing and help maintain ecological balance.