Biological interaction between species (WP 1)

The objective of WP1 is to construct multispecies models which take account of prey availability, spatial overlap between predators and prey and of the technical interactions between catches of different species fishery. These models will then be used to develop multispecies indicators of the sustainability of fishing and to provide the model basis needed in WPs 2, 3 and 4 in order to provide an improved overall understanding of optimal ecosystem management.  

The partners involved in WP1 have a long history in modelling multispecies interactions, and hence operational multispecies models already exist within the consortium covering both the Barents Sea, Norwegian Sea, the Icelandic waters, the Baltic Sea and the North Sea.  

In task 1.1, the project will produce enhanced multispecies models by including new predator-prey relationships and the models of fishing fleets. The new predator-prey relationships will focus on the effect of changes in the amount of alternative food and spatial distribution of predators and their prey. Currently, the amount of alternative food and spatial distribution are considered constant, assumptions known to be wrong at least in the North Sea. The modelling of technical interactions will be changed from the current assumption of constant exploitation patterns and independence between fishing mortalities of different species to a dynamic relationship. This will allow the prediction of fishing pattern under changing densities, technical interactions and different fisheries management plans. The inclusion of these factors will make the models capable of realistic assessments of stock dynamics and ecosystem responses under changing management regimes and environmental conditions.    

In task 1.2, the project will develop a multispecies model of the Aegean Sea. This will be the first time that a multispecies model is developed for the eastern Mediterranean Sea and a first step is therefore to choose the most appropriate model type. This model should be able to describe not only predator-prey interactions but also the effect of fishing in different fleets as the fisheries management system in the Mediterranean Sea (thus also in the Aegean Sea) mainly depends on effort restrictions and technical regulations.  

In task 1.3, the project will compare the utility of the improved multispecies models to the current multi- and single- species models in order to identify whether additions to the models significantly change our perception of historic ecosystem status and dynamics. 

In task 1.4, the project will use the knowledge gained during Task 1 and Task 2 to identify relevant multispecies indicators, and to suggest methods for estimating multispecies reference points. The development and analysis of the improved multispecies models, and the associated insight into indicators and reference points, provides an important step towards an ecosystem based approach to fisheries management.
27 JANUARY 2022