TALLAHASSEE, Fla.— A group of leading international turtle experts urged the state of Florida today to require the use of excluder devices on crab traps, endorsing a rule sought by the Center for Biological Diversity and allies in a petition last week.

The expert group, convened by the International Union for the Conservation of Nature, sent its letter to the Florida Fish and Wildlife Conservation Commission. The agency has 30 days from the Center’s Jan. 28 petition to make a decision.

Diamondback terrapins are found along the Atlantic and Gulf coasts from Massachusetts to Texas — the only turtles in the world that live exclusively in coastal estuaries. These estuaries are also home to blue crabs, which are trapped in pots by an active fishery.

“Diamondback terrapins are an iconic animal of our inland coastal waters,” said Craig Stanford, chair of the IUCN Species Survival Commission’s Tortoise and Freshwater Turtle Specialist Group. “They become trapped and drown by the thousands in crab pots, which pose a grave mortality risk to their future survival in the state of Florida. This mortality can be easily reduced by attaching bycatch reduction devices to crab pots.”

Last week’s petition, filed by the Center for Biological Diversity, Florida Turtle Conservation Trust and Diamondback Terrapin Working Group, asked the state to require bycatch reduction devices (BRDs) on all recreational and commercial blue crab pots. When affixed to crab-pot entrance funnels, these small and inexpensive devices prevent most terrapins from entering the pot while having little to no effect on crab haul.

“The world’s top turtle experts agree that Florida should protect terrapins from dying in crab pots,” said Elise Bennett, a Center attorney who focuses on protecting reptiles and amphibians. “These turtles are the shining jewels of our coasts. Adopting common-sense, science-based measures can save lives and keep terrapins around for years to come.”

Baited blue crab pots are known to trap and drown terrapins, while fleets of traps are capable of steadily removing individual turtles until a population cannot sustain itself. Abandoned or lost traps — called ghost pots — can capture terrapins by the dozen.

A 2009 study reported finding 133 dead terrapins among two abandoned crab pots in a tidal marsh in Georgia. Experts agree that blue crab pots pose the greatest threat to the diamondback terrapin.

In a 2007 study, Dr. Joe Butler and George Heinrich tested BRDs in Florida waters and found that 73.2% of trapped terrapins would have been excluded from pots with the devices. The researchers found no significant difference between the sex,

measurements or number of crabs captured in standard crab pots when compared with crab pots fitted with BRDs. At least eight other studies from across the terrapin’s range have reached similar results.

The IUCN Red List ranks the diamondback terrapin’s global status as vulnerable and describes its population trend as decreasing. Threats to the species include habitat destruction and degradation, road mortality, crab-pot mortality, sea-level rise caused by global climate change, pollution, boat strikes, predation, collection for commercial and personal purposes, and inadequate regulatory measures to address these threats.

If Florida required BRDs, it would join New York and New Jersey, which require bycatch reduction devices on recreational and commercial pots, and Delaware and Maryland, which require the devices on recreational pots. North Carolina is currently considering measures to reduce the impacts of its crab fisheries on terrapins.

Background

The diamondback terrapin is known for its stunning diamond-patterned shell and speckled skin. It lives in coastal marshes, tidal creeks, mangroves and other estuarine habitats where it primarily feeds on snails, clams, mussels and small crabs. The terrapin is potentially a keystone species in salt marshes and mangroves, helping to maintain the ecological health of those ecosystems.

There are currently seven recognized subspecies of diamondback terrapin, and Florida is home to five (three of which only live there). Florida also has the most coastal habitat of all the states in the species’ range.