The role of benthic fauna in the coastal food web under environmental stress
Climate-driven change has become a severe threat to coastal ecosystems over the past decades. Factors such as rising temperature and decreasing salinity force a reorganization of benthic habitats and communities, especially in the land-locked, low-saline environment of the Baltic Sea. While serving as important food-resource for fish, zoobenthos plays a crucial role in energy acquisition for higher trophic levels and is further an acknowledged indicator of environmental status. We aim at analyzing temporal trends in the development of coastal zoobenthic communities in relation to climate induced environmental change, using a long-term data set, spanning 40 years (1973-2013), and assembled around the Åland Islands, Northern Baltic Sea. With its highly mosaic-structured geography, the Åland archipelago creates a heterogeneous environment with steep gradients of abiotic parameters, comparable with patterns found in the entire Baltic Sea, and serves therefore as model area for understanding general aspects on larger spatial scales.
Our study uses 40 years of data (1973-2013) from the Åland archipelago (N Baltic Sea) as a fundament for further analysis of spatiotemporal trends in biomass (production), biological traits (functional diversity), and food web models (trophic status) under climate-change scenarios for the region.
The aim of my thesis is to enhance the understanding of how the composition, diversity and functions of marine coastal communities, with focus on benthic fauna, are shaped by environmental drivers over time and space. In the studied system, the Åland Islands in the northern Baltic Sea, the coupling between zoobenthos and fish is strong as the majority of fish rely on the benthos as food recourse. Changing benthic communities may therefore not only affect functional characteristics in general but may also influence higher trophic levels through altered interactions and different functionality. My thesis is based on four chapters assessing (I) the impact of eutrophication and climate change on coastal fish and zoobenthos communities, (II) long-term progression of zoobenthos communities and the environmental drivers shaping them, (III) how diverging community patterns affect functional aspects (diversity and structure) of the benthic fauna, and (IV) whether functional changes in prey communities (zoobenthos) affect food quality and linkage structure for predator (fish) communities.
Presentation: Climate change promotes risk of hypoxia in coastal zones
threatening zoobenthic communities and their function