Antarctic copepods, Calanus propinquus. (Photo: Queen Mary University of London)
Aquatic animals 'shrink' more than terrestrial ones due to climate change
Wednesday, November 07, 2012, 02:50 (GMT + 9)
Scientists of Queen Mary of London and of Liverpool universities, the UK, found out that warmer temperatures cause a greater reduction in the size of aquatic animals as adults than in the case of the land fauna.
The research results were published in the journal Proceedings of the National Academy of Sciences (PNAS).
The study shows that the body size of marine and freshwater species is disproportionately affected by high temperatures, which could influence on aquatic food chains and food production through aquaculture, Europa Press reported.
The research team compared how the adult size of 169 land, freshwater and marine species varied at different non-harmful temperatures.
According to the research co-author, Andrew Hirst, of Queen Mary's School of Biological and Chemical Sciences, "aquatic animals dwindle 10 times more than the terrestrial species having the size of large insects or of small fish."
"Whereas animals in the water get smaller by 5 per cent per each warming degree Celsius, the species of similar size on land are reduced on average by only 0.5 per cent," the researcher added.
During the research, the scientists discovered that the size difference could be due to a greater reduction in the availability of oxygen in water than in air.
Warming increases the need for oxygen organisms on land and in the water have, but water resources have to perform a greater effort to meet this growing demand for air.
David Atkinson, of the University of Liverpool, explains that "to meet an increased demand for oxygen at higher temperatures, the aquatic species have fewer options."
He adds: "Reducing the size they have as adults is the way to balance the supply and the demand of oxygen."
According to the study's lead author, Jack Forster, of Queen Mary's School of Biological and Chemical Sciences, "because the fish and other aquatic organisms provide three million people with at least 15 per cent of their consumption of animal protein, the work highlights the importance of understanding how warming in the future will affect the species that live in oceans, lakes and rivers."
- Smaller fish could result from warmer waters: study
By Analia Murias