Joint effects of climate and fishing on dynamics of exploited ecosystems

Informations

Funding country

Norway

Acronym

-

URL

-

Start date

1/1/2019

End date

12/31/2023

Budget

613,893 EUR

Fundings

Abstract

Marine ecosystems are important providers of food and other services. Many ecosystems worldwide are under heavy pressure from fisheries. While some areas have seen trends toward better sustainability, other areas need better management in order to secure their healthy state and continued ability to provide services. At the same time, warming of the oceans poses new challenges, most obviously manifested as species ranges that are shifting poleward. It is therefore necessary to better understand the dynamics of ecosystems under the simultaneous pressures from fisheries and climate change. This project is set to address these challenges, specifically asking the following questions: * How will productivity of the key organismal groups change under a range of future climate scenarios? * How do changes in productivity translate into changes in opportunities for fisheries exploitation and potential benefits to the fishing sector? * Can we reduce negative climate impacts on the fisheries sector by changing the species/functional group profile of exploitation? Can we obtain positive fisheries effects, with or without climate change, by such measures? * What are the interaction effects between climate change and fisheries management measures? The project focuses on two areas, the Norwegian-Barents Seas in the Northern Atlantic, and the Yellow-East China Seas in the Northwestern Pacific, joining forces of research groups in Bergen, Norway, and Qingdao, China. In Norway, we have investigated temperature impacts on life-history and population processes of Atlantic cod. In the Barents Sea, this species is near its northern range boundary. Not surprisingly, its growth and maturation are positively influenced by warming, offsetting a small and uncertain negative temperature effect on survival, and thus increasing productivity. We have also studied the changing distribution of Atlantic hake, another species that is considered a climate winner in our waters. In the northern North Sea, the species has undergone a boom-and-bust cycle, becoming an important revenue source for larger vessels. However, northward range expansion in the North Sea is limited by lack of suitable shelf habitat. The dynamics of the stock component along the Norwegian coast is weakly coupled to the North Sea stock component. Here the shelf habitat is not restricting its northward range expansion, and it is occasionally caught well north of its traditional range. In China, we have studied how harvest regulations could be used to avoid unwanted long-term impacts of harvesting on life-history traits of Japanese Spanish mackerel. The results suggest harvesting with gillnets would drive less unwanted change than harvesting with trawls.