Last month we reported on the Intent to Sue letter delivered to the U.S. National Marine Fisheries Service by a coalition of environmental groups in an attempt to protect sea turtles in the Gulf of Mexico. Good News!
On January 29th, the Gulf of Mexico Fisheries Management Council voted to shut down longline, shallow water (above 300 feet) fishing off the Gulf Coast of Florida for a period of six months to begin by June 2009. The management council’s decision remains to be approved by the NMFS. Roy Crabtree, the NMFS southeast regional administrator stated, “We have obligations to protect them,” and indicated his agency would act as quickly as possible in the face of studies showing that 1,000 Loggerheads, Kemps Ridley, and Green sea turtles are taken incidentally by longline fisheries every 12-18 months.
According to an article published in the Orlando Sentinel on January 31, 2009, “During the shutdown, officials, fishermen and conservationists plan to draw up a long-term conservation plan, which could involve measures such as reducing the number of boats, banning squid bait and permanently ending long-line fishing.”
Dave Allison of Oceana stated in the Orlando Sentinel article that banning longline fisheries was not enough to save the sea turtles from extinction, “What we need to do is [pass] a Sea Turtle Protection Act to give sea turtles the same kind of protection that mammals get. There are a lot of other issues, as the fishermen point out. There are problems with nesting beaches, with lights on the beaches, with the armoring of the coast.”
Loggerheads, the species representing approximately 80% of the turtles taken by Gulf longliners, are the only members of the genus Caretta. One of the largest sea turtle species, they can weigh up to 800 pounds with carapaces (shells) 3 ½ feet long. Their skin is yellowish and their carapaces are rust colored although they may appear to be gray, green, and brown due to the various marine life that are attached. A Loggerhead’s carapace is a microcosm of marine life; scientists discovered over 100 distinct species of marine life, both plant and animal, attached to one Loggerhead’s carapace, more than found on any other species of sea turtle.
Loggerheads have large heads with powerful jaws that crush the mollusks, crustaceans, shrimp, crab, jellyfish, Portuguese-Man-O-War, and the occasional fish upon which they feed. Because they often forage in the sea floor, they are beneficial in turning over and helping to refresh bottom sands.
Loggerhead sea turtles are highly migratory, traveling long distances with one juvenile recently tracked by satellite crossing the open Pacific from Japan to Baja, California. Comparing genetics of Loggerhead in Baja to those in Japan, scientists had suspected for some time that the turtles were crossing the Pacific. Satellite tracking has now confirmed their theory.
Loggerhead nesting areas are found from Brazil north to the US in Florida, Georgia, and North and South Carolina, from Australia to New Guinea, and from South Africa to India. They’re also found in the Mediterranean, along the coasts of Italy, Libya, and Morocco. While Loggerheads are listed as threatened by the International Union for the Conservation of Nature (IUCN), they are listed as endangered in the U.S. Populations of breeding females have suffered a serious decline and continue to do so; 1/3 of the total world population of breeding females nest on Florida beaches, particularly along the Gulf Coast. Over the past 10 years, observers along Florida’s Gulf Coast have noted a 40% decline in the number of nesting Loggerheads making the 6 month closure of longline fishing a critical element to the preservation of the species.
Although little is known about the mating behavior of any sea turtle species, it is believed Loggerhead mating takes place between March and June. Females nest on beaches at night beginning as early as April and continuing through September with the heaviest activity taking place in June and July. Gravid females lay between 100-125 eggs. Incubation takes from 53-68 days depending upon the temperature. As with other turtle and many reptile species, the temperature of the nest determines the hatchlings’ sex.
The eggs hatch at night; the hatchlings are approximately 3” long when they emerge to begin their short but dangerous struggle to the sea. What draws them to the sea is light; the nighttime horizon over the sea is lighter than that on land. Tragically for the turtles, artificial light along the coasts from homes and commercial establishments confuses them so they move away from the sea and toward impending death. Even when they do head directly toward the sea they can fall victim to unleashed pets, wild animals, and careless beach goers who crush unhatched eggs or run over and step on new hatchlings.
The hatchlings that make it to the sea are gobbled up by waiting marine predators and sea birds before they can swim far off shore where scientists believe they live in flotsam and sargassum rafts for 3-7 years before returning to the coasts as juveniles. Out of a clutch of 100-125 eggs, only a very few live to adulthood.
Future columns will focus on the species of turtles affected by the January Florida ruling since they are found throughout All At Sea’s circulation area as well as many other parts of the world.
After 30 years as a wild and domestic animal rescuer, rehabber, and educator in the states, Becky Bauer became a scuba instructor and award-winning journalist covering the marine environment in the Caribbean. She is a contributing photographer to NOAA.