Climate change - a serious threat

Climate change are threatening human survival and species diversity globally. Species have evolved to live within certain temperature ranges and in certain habitats, and when these are altered and species cannot adapt to the new environment they may go extinct.

Climate change in the Baltic Sea

According to current predictions of climate change, the Baltic Sea will face higher temperatures and eutrophication (excess amount of nutrients), and salinity will decrease. Climate change are also likely to alter biogeographical conditions in coastal landscapes due to sea level rise, that will flood islands and terrestrial habitats and small islands may disappear under the water column. The Baltic Sea has about 200 000 islands.

Sunny day at work. In photo: Alma Strandmark. Photo credit: Gundula Kolb.
Sunny day at work. In photo: Alma Strandmark. Photo credit: Gundula Kolb.

 

- A moderate sea level rise of 0.5 meters will decrease the total number of islands in the outer part of Stockholm archipelago with about 25 %, says Alma Strandmark, who is defending her PhD thesis today. Alma has focused on climate related changes that are unique for coastal ecosystems, especially sea level rise.

Investigating abundance and distribution of species close to the water column. Photo credit: Gustaf Almqvist.
Investigating abundance and distribution of species close to the water column. Photo credit: Gustaf Almqvist.

 

Changes in the sea affect species on land

Alma has also studied the arthropod fauna, e.g. crustaceans and spiders, within the boundary zones between land and waters and found that arthropod diversity and abundance are threatened by climate change. Warmer temperatures and increased eutrophication are expected to reduce biomass of bladderwrack (Fucus species), which will decrease diversity and abundance of detritivores living in the deposits of seaweed. In turn, predatory arthropods, like spiders and beetles, that feed on detritivores will decrease in diversity, abundance and in size. Additionally, the sea level rise are likely to decrease the arthropod diversity even further due to a decrease in island size. Loss of large and predatory arthropods can have serious consequences further up in the terrestrial food chain, such as for shore birds feeding on these arthropods.

- Climate change may hence not only directly impact species but also indirectly when the species it depends on, e.g. as food source, cannot adapt to the new environment” says Alma, who has very much enjoyed her PhD studies on the sunny days in Stockholm archipelago.