( Scientists can predict how the distance...)Ocean temperature predicts spread of marine species

Most marine life, including commercially important species, reproduces via larvae that drift far along ocean currents before returning to join adult populations. The distance larvae travel before maturing, called dispersal, is directly linked to ocean temperature, the researchers found. For example, larvae from the same species travel far less in warmer waters than in colder waters, said lead author Mary O'Connor, a graduate student in marine ecology in UNC's curriculum in ecology and the department of marine sciences in the College of Arts and Sciences.

"Temperature can alter the number and diversity of adult species in a certain area by changing where larvae end up," O'Connor said. "It is important to understand how a fish population is replenished if we want to attempt to manage or conserve it."

Using data from 72 marine species, including cod, herring, American lobster, horseshoe crabs and clams, O'Connor and her colleagues developed a model that predicts how far larvae travel at a certain temperature. The predictions appear to hold for virtually all marine animals with a larval life cycle.

"We can apply this rule to animals without having to go out and measure every species," O'Connor said. "Our general model gives us a powerful new way to study larval movement with knowledge about ocean temperature, which is much easier to come by. With models such as this, we can see what large-scale changes in ocean temperature may mean for adult populations."

The study appeared online the week of Dec. 25 in the Proceedings of the National Academy of Sciences Early Edition.

Knowing dispersal distance is a critical component for managing commercially important
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Source:University of North Carolina at Chapel Hill