Fish distribution & productivity in Inner Danish waters

Coastal fishermen have observed that in recent decades commercial fish species in coastal waters have declined dramatically in the Kattegat, but not in the Western Baltic (Støttrup et al., 2014). Preliminary analysis of available data showed a concurrent decrease in fish biomass in coastal waters (Munk et al., 2014), supporting the fishermen’s observations. In this case study, we will identify causal relationships and explore management options to resolve this problem. We will draw on extensive datasets of fish stock dynamics and fisheries patterns, on nutrient loadings and their drivers, and climatically-driven abiotic parameters, such as temperature and salinity, to establish the causal mechanisms behind the observed changes in fish stock distribution and productivity. The spatial distributions of fishes will be analysed using the Log Gaussian Cox Process (LGCP). Scenario simulations including ecological and socio-economic information will explore consequences of different management options. We will move from static indicators to process driven simulations predicting the impact of management strategies on fish resources and their economic value. This task will draw from results gained in the ongoing BONUS INSPIRE project. We perceive this as a first step to link Water Framework Directive objectives (nutrient loading) to Marine Strategy Framework Directive indicators (biodiversity, commercial fish species, food webs), accounting also for socio-economic indicators and stakeholder participation.

CCS Inner Danish Waters kick-off presentation