MELBOURNE, Fla. (AP) -- Catches of blue crabs and stone crabs appear to be dwindling in the same central Florida lagoon area where manatees, dolphins and other wildlife have died in large numbers.
While crab harvests in the Indian River Lagoon region can vary widely year-to-year, an analysis of state data by Florida Today shows that the long-term trend has been a downward spiral.
Brevard County's commercial blue crab catch in 2012 was less than one-tenth what it was 25 years ago and the lowest since Florida began collecting the data in 1986. The county's commercial stone crab harvest also dropped in the last 30 years, from a peak of 6,742 pounds, almost 57 pounds per trip in 1989, to 2,875 pounds last year, just 8.3 pounds per trip.
"This is the worst year we've seen for local crab," said Jan Walker, vice president of Clayton's Crab Company, which has been in business 46 years.
As supply dropped, Clayton's crab prices rose 20 percent over the past year, Walker said, with jumbo blue crabs recently going for $8.49 a pound.
Blue crabs are considered a "keystone" species, providing prey for many other important species and serving as a valuable scavenger along the lagoon bottom.
There are many theories about the crabs' decline. Some speculate that natural population cycles or runoff feeding algae blooms are to blame. Others say crabbers have taken too many young female crabs, or past overharvesting of clams has contributed to cloudier waters.
In general, the overall mass of blue crabs in Florida dropped from the 1950s through the 1980s, increased a bit during the early to mid-1990s before significantly dropping during the late 1990's, according to research by the Florida Fish and Wildlife Conservation Commission.
"About the mid '90s there was a climate shift," said Ryan Gandy, a research scientist with the Florida Fish and Wildlife Conservation Commission.
After decades of wetter weather, Florida started experiencing a higher incidence of droughts from the mid-1990s onward, Gandy said. That can drive blue crabs into smaller areas near river mouths to find proper salt levels, making them more susceptible to predators and more cannibalistic.
"They're very closely tied to freshwater inflow. That's always a good indicator of their population," Gandy said. "You really can tie climate and rainfall into blue crab populations."