Precautionary management of Baltic Sea cod (Gadus morhua callarias) under different environmental noise and harvesting strategies

Many cod stocks have decreased during the last decades due to heavy exploitation.One reason is the difficulty to fit complex population dynamics, assessment methods and economic interests together.Moreover, strong environmental fluctuations, such as climate change, affect the success of population management.We consider precautionary harvest strategies in the management of Baltic cod (Gadus morhua callarias).We address the following questions: How does the frequency structure in environmental noise affect cod abundance under alternative harvesting strategies?What are the possibilities and limits for precautionary management of Baltic cod?We compare proportional and two threshold harvest strategies.The proportional strategy creates more stable economy while the threshold strategies produce higher sustainable yield and spawning stock biomass, although annual catch may vary substantially.