SHOCK: A study published by the Cemagref Public Agricultural and Environmental Research Institute in Lyon, France, has said that fish have lost half their average body mass and smaller species are making up a larger proportion of European fish stocks as a result of global warming. Martin Daufresne, study author, said "size is a fundamental characteristic that is linked to a number of biological functions, such as fecundity - the capacity to reproduce." Smaller fish usually produce fewer eggs and they also provide less sustenance for predator, including us -- humans, which could have a significant effect on the food chain and the ecosystem
Earlier research has already established that fish have shifted their geographic ranges and their migratory and breeding patters in response to rising water temperatures. It has also been established that warmer regions tend to be inhabited by smaller fish.The results of this study are extremely startling and we cannot continue to take global warming and its effects lightly.
Daufresne and his colleagues examined long-term surveys of fish populations in rivers, streams and the Baltic and North Seas and also performed experiments on bacteria and plankton. They found the individual species lost an average of 50 percent of their body mass over the past 20 to 30 years while the average size of the overall fishing stock had shrunk by 60 percent.
This was a result of a decrease in the average size-at-age and an increase in the proportion of juveniles and small-sized species, Daufresne said. "It was an effect that we observed in a number of organisms and in a number of very different environments - on fish, on plankton, on bacteria, in fresh water, in salt water and we observed a global shrinking of size for all the organisms in all the environments," Daufresne said in a telephone interview. AFP