Washington, Dec 26: Climate change is adversely affecting top predators like sharks, whales, dolphins, tunas, billfish, sea turtles and sea birds in the world’s oceans.

All of these species are being affected by such changes in climate as variability in winds, ocean currents, air and sea temperatures, and rainfall levels.

To investigate the impact of climate change on these predatory marine creatures, a symposium was held in Mexico from December 3-7, 2007.

This symposium also marked the start of a 10 yr project known as “Climate Impacts on Oceanic Top Predators” (CLIOTOP).

A report at the symposium addressed several aspects of how climate change will affect top predators, for example, how potential changes in the base of the oceanic food web will affect the feeding of top predators, the migration patterns of hatchling sea turtles, and the size of tuna populations.

"Global warming may lead to severe contraction of favorable reproductive zones for some species of tunas that will have larger effects than fisheries on tuna stocks by the end of the twenty-first century, " Dr John Sibert, manager of the PFRP (Pelagic Fisheries Research Program), told ENN (Environmental News Network).

CLIOTOP provides a framework for scientists to carry out collaborative and comparative research across different oceans. Such comparative research will deepen our understanding of the ecosystem impacts of climate change.

"Oceanic top predators respond to changes in their environment by changing their behavior and shifting their distribution. As a result, ocean ecosystems may experience changes in the relative abundance of different species, as well as changes in overall productivity, " said Dr Sibert. "This can have major economic impacts and may determine the food security of many coastal communities in the developing countries of the world, " he added.

The CLIOTOP Project has established five working groups to investigate a variety of scientific topics related to the general them of how climate change impacts top predators. (ANI)