NEW YORK (June 23, 2011)Fish communities in the 21st Century live fast and die young. That's the main finding of a recent study by researchers from the Wildlife Conservation Society who compared fish recently caught in coastal Kenya with the bones of fish contained in ancient Swahili refuse heaps in order to understand how to rebuild the current fisheries.
Of course, modern fish communities are not victims of reckless living, but of overfishing which has caused an ecosystem-level transition that may not be easily reversible, according to the study. Over the centuries, human fishing has greatly reduced or eliminated larger and longer-lived species that were more commonly caught in the Middle Ages. The remaining fish communities today contain more species with shorter life spans, faster growth rates, smaller average sizes, and fewer top predators.
The studywhich utilized more than 5,475 samples of ancient fish remains dating between 1250 and 600 years before the present (approximately AD 7501400)appears in the current online edition of the journal Conservation Biology. The authors are Tim R. McClanahan and Johnstone O. Omukoto of the Wildlife Conservation Society.
"The ancient Swahili middens represent a time capsule of data, containing information on the composition of the region's fish assemblages and how human communities influenced the marine environment," said McClanahan, WCS Senior Conservationist and head of the WCS's coral reef research and conservation program. "The historical data suggest that fishing removes the slower-growing, longer-lived species over time and that marine protected areas are only partially successful in recovering the fish communities of the past."
Seeking to examine how fish populations are impacted by increasing fishing pressure over time, McClanahan and Omukoto compared data on the life histories of modern fish communities (gathered from fish caught in both heavily fishe
|Contact: Stephen Sautner|
Wildlife Conservation Society