A new study has determined that due to climate change, the composition of algae is changing, as a result of which their nutritional value for other aquatic life is decreasing.
This is the conclusion of researchers from the Netherlands Institute for Ecology (NIOO-KNAW) and the Universiteit van Amsterdam.
The researchers wanted to know whether an increased CO2 (carbon dioxide) concentration exerted an influence on underwater life.
They therefore examined freshwater micro-algae: small, floating and mostly unicellular algae.
The experiments were performed in large tanks called limnotrons. These were aerated with ordinary air or with air containing an elevated concentration of CO2.
The researchers then examined the ratio between the important elements: carbon, nitrogen and phosphorous.
The micro-algae grew faster at a higher CO2 concentration, exactly as the researchers had expected. Yet, this growth was also associated with a change in the composition of the algae.
The algae cultured at a higher CO2 concentration contained relatively more carbon and relatively less phosphorous.
This meant a reduction in the nutritional value, which could have detrimental effects upon the small animals that eat the algae such as water fleas.
As they are the first link in the underwater food chain, the algae ultimately influence the entire ecosystem.
This research has shown that climate change can also exert significant effects on the underwater food chain.