Hopper dredges can also kill turtles caught in dragheads. Green turtles eat a wide variety of marine debris such as plastic bags, plastic and styrofoam pieces, tar balls, balloons and plastic pellets. Effects of consumption include interference in metabolism or gut function, even at low levels of ingestion, as well as absorption of toxic byproducts. NMFS is currently analyzing stranding data and available necropsy information to determine the magnitude of debris ingestion. It is estimated that before the implementation of TED requirements, the offshore commercial shrimp fleet captured about 925 green turtles a year, of which approximately 225 would die.
Most turtles killed are juveniles and sub-adults.
Bluefish, croaker and flounder trawl fishing are also serious threats. Turtles are be taken by purse seine fisheries in the Atlantic and Gulf of Mexico, but the magnitude of take is currently not known. Several thousand vessels are involved in hook and line fishing for various coastal species. The capturing of turtles is not uncommon, but the number is not known. Significant numbers of turtles may be killed by gill and trammel net fisheries off the eastern coast of central Florida.