ElbeXtreme-Fish - Impact of extreme weather events on fish in the Elbe estuary

Lead Institute FI Institute of Fisheries Ecology

Extreme climatic events are risk factors for coastal ecosystems including fish, which are the focus of the research activities of the Thünen Institute for Fishery Ecology. Extreme events can pose direct threats to the survival of fish, such as low oxygen levels in the water or high temperatures. Impacts of extreme events that are not acutely harmful to fish could lead to indirect impairments if combinations of several factors are changed or possible cumulative effects occur in the course of climate change (higher temporal frequency, rising sea levels, repeated heat waves, etc.).

Background and Objective

The main goal of the present sub-proposal (ElbeXtreme-Fish) is to assess the consequences of extreme events on fish, as fundamental components of marine ecosystems and fisheries resources, and their ecosystem services. Knowledge deficits exist with regard to the effects of multiple stressors (stress on stress response) and cumulative effects of extreme events on the health of fish. Therefore, stressors, individually and in combination, will be investigated in laboratory experiments with regard to possible effects on fish health.

Approach

The three-spined stickleback (Gasterosteus aculeatus) will be used as a model fish species, which is typically native to the brackish water of estuaries, has been scientifically well studied and is easy to keep under laboratory conditions. The factors to be tested are selected in cooperation with stakeholders (WP 1), from analyses of historical data series (WP 2), current ElbeXtreme data assessment in the field (WP 3) and ecosystem modelling (WP 5). Results from ElbeXtreme-Fish are reflected back into the ElbeXtreme WPs in order to optimize strategies for data collection (early warning systems) and ecosystem modelling. In cooperation with the other WPs, the results of ElbeXtreme-Fish will be used to identify and characterize factors (monitoring parameters) that enable sensitive predictions regarding the impact of extreme events on fish stocks and coastal ecosystems. In addition, the project can provide the basis for management concepts to improve the resilience of coastal ecosystems and their biota to extreme events.