(Santa Barbara, California) Pathbreaking fisheries research from two different oceans yielded the same results, published as this week's cover story in Nature: chemical tests show that coral reef fish often spend their life cycle close to home, rather than drifting in the open ocean, thus providing important information for global fisheries management.
By studying the chemical composition and physical structure of the otolith -- the tiny crystalline stone in the inner ear of the fish -- scientists from the University of California, Santa Barbara discovered that significant numbers of larval fish return to reefs where they were spawned.
"These are the first numbers we've ever had on this. It's impressive that our results and those from Australia, also published in this issue*, are so similar," said Robert Warner, professor of biology at UC Santa Barbara**, and co-author of the Santa Barbara paper entitled, "Larval Retention and Recruitment in an Island Population of a Coral Reef Fish." Other authors are Stephen Swearer, graduate student, Jennifer Caselle, assistant research biologist and David Lea, associate professor of geological sciences, all of UC Santa Barbara.
"To manage and conserve any marine population, we must know the fate of the young produced by that population, and we must know something about the sources of young recruiting to that population," said Warner.
The study of the otolith holds great promise, according to Warner. "Previous researchers have assumed that after a 50-day planktonic larval duration, larvae would have been swept tens or hundreds of kilometers downstream," he said.
The UC Santa Barbara study, initiated by first author Steve Swearer, came out of his questioning of the prevailing view that individual larval fish settling to reefs were most likely spawned elsewhere.
"This was my approach to challenging that hypothesis," said Swearer, who chose to focus on a well-studied coral reef fish called the b
Contact: Gail Brown
University of California - Santa Barbara