Pacific leatherback turtles face extinction
provided by Drexel University
here will soon be no leatherback turtles (Dermochelys coriacea) left in the Pacific Ocean, according to Drexel University environmental science professor Dr. James Spotila and his colleagues. Following a 12-year study, these findings appear today in the "Brief Communications" section of the June issue of the journal Nature.
The team's findings are based on a survey of the nesting population of leatherbacks in Playa Grande, Costa Rica - the world's fourth largest colony of the species. Using the colony, Spotila and team constructed a mathematical model of future population trends.
According to Spotila, this population is "in the midst of a collapse." The number of nesting females has fallen from 1,367 in 1988-89 to 117 in 1998-99. Each year, about one-third of the population dies after falling prey to fishing nets or lines. Spotila and team conclude that unless there are serious changes to fishing practices in the Pacific, there will be fewer than 50 nesting females in the entire ocean by 2004.
The world's largest turtle, the leatherback weighs roughly 800 lbs. Oceanic by nature, the leatherbacks approach land only during breeding season. Most breed every other year and lay clutches of eggs totaling between 80 to 100 at roughly 10-day intervals before returning seaward.
Excerpt from the article: "The dwindling numbers of leatherback turtles are signaling a threat to biodiversity in the oceans. A mathematical model based on our assessment of a once-large leatherback population predicts that unsustainable adult morality, apparently due to human fishing activity, will soon drive this population to extinction."