Listing Status
- Federal Status: Endangered
- FL Status: Federally-designated Endangered
- FNAI Ranks: G3/S1 (Globally: Rare/State: Critically Imperiled)
- IUCN Status: CR (Critically Endangered)
Appearance
The hawksbill sea turtle is the rarest sea turtle that regularly occurs in Florida (Meylan and Redlow 2006). Hawksbill sea turtles can reach a carapace (upper shell section) length of 35 inches (89 centimeters), and a weight range of 100-200 pounds (45.4-90.7 kilograms) (National Oceanic & Atmospheric Administration 2012). This species is recognized by its beak-like mouth. The carapace is shield-shaped with brown, yellow, and black blotches or streaks. The plastron (lower shell section) is white to yellow and sometimes contains dark blotches. The hawksbill sea turtle has two pairs of prefrontal scales (located between the eyes), four pairs of coastal (lateral) scutes, and one nuchal (cervical) scute. The species also has two claws on each flipper (Meylan and Redlow 2006).
Its raptor-like jaws give the hawksbill its name. This small agile sea turtle, about a yard long and 100 to 200 pounds, is known for its tortoise-colored shell. The hawksbill was sought after in the past to use its beautifully patterned shell for jewelry, hair ornaments and other decorative items. Today, use of its shell is banned in most of the world but tortoiseshell goods still may appear in stores and people are asked not to buy them. The hawksbill has an oval body, narrow head, overlapping shields on its kaleidoscopic armor, a serrated edge on the rear of its shell and two claws on each flipper.
Habitat
Hawksbill sea turtles can be found in subtropical and temperate oceans of the world (Meylan and Redlow 2006. Map Data From: Carr et al. 1966, Dalrymple et al. 1985, McMurtray & Richardson 1985, Lund 1985, Wilmers & Wilmers 1998, Wyneken & Hicklin 1988, J Wyneken pers. comm., L. Fisher pers. comm., M. Markey pers. comm., O. Clayton pers. comm., P. Wells pers. comm., T. Wilmers pers. comm., T & E Wilmers pers. comm., W. Teas pers. comm. as cited in Meylan and Redlow 2006).
Warm tropical seas are where people are most likely to see hawksbills. In Florida, hawksbills are found primarily on reefs in the Florida Keys and along the southeastern Atlantic coast.
Behavior
The diet of the hawksbill sea turtle primarily consists of sponges.
The age that hawksbill sea turtles reach sexual maturity is not known (Meylan and Redlow 2006). Nesting primarily occurs from June to August in Florida. Females come on shore and develop nests on sandy beaches mainly during daytime hours. This species prefers developing nests near or under vegetation; however, they may develop nests in any zone along the beach. It can take up to 1.5 hours for the female to finish building the nest. Hawksbill sea turtles average three to five clutches per year, with an average of 130 eggs per clutch. Eggs are incubated for 48-91 days. Hawksbill hatchlings migrate to the marine waters when they first emerge from the nest.
Hawksbills’ raptor-like jaws are perfectly adapted for grabbing sponges, their favorite food. While sponges are composed of tiny glass-like needles, they apparently cause no harm to hawksbills.
Threats
The main threat that the hawksbill sea turtle faces is accidental capture in shrimp and fishing nets. When captured in nets, the hawksbill sea turtle cannot escape and eventually drowns. Longlines can entangle or snag sea turtles. Development of nesting beaches is also a threat to the species, as their nests can be destroyed, and it makes available nesting sites limited. Coastal development also increases artificial lighting which can cause hatchlings to migrate towards the lights instead of the ocean. Beach armoring (ex. seawalls) is a threat as the structures prevent the natural maintenance of beaches and sand dunes. Other threats include increased predation of eggs, hits by watercraft, and habitat degradation from contaminants and pollutants (ex. oil spills).
Conservation and Management
The hawksbill sea turtle is protected as an Endangered species by the Federal Endangered Species Act, as a Federally-designated Endangered species by Florida’s Endangered and Threatened Species Rule, and by Florida's Marine Turtle Protection Act (379.2431, Florida Statutes).
Florida Statutes (F.A.C. Rule 68E-1) restrict the take, possession, disturbance, mutilation, destruction, selling, transference, molestation, and harassment of marine turtles, nests or eggs. Protection is also afforded to marine turtle habitat. A specific authorization from Commission staff is required to conduct scientific, conservation, or educational activities that directly involve marine turtles in or collected from Florida, their nests, hatchlings or parts thereof, regardless of applicant's possession of any federal permit.
References
Carr, A., Hirth, H., And Ogren, L. 1966. The ecology and migrations of sea turtles, the hawksbill turtle in the Caribbean Sea. American Museum Novitates 2248:1-29.
Dalrymple, G.H., Hampp, J.C., and Wellings, D.J. 1985. Male biased sex ratio in a cold nest of a hawksbill sea turtle (Eretmochelys imbricata). Journal of Herpetology 19(1):158-159.
Meylan A., A. Redlow. 2006. Eretmochelys imbricata – Hawksbill turtle. Sea Turtle. In Biology and Conservation of Florida Turtles. Pages 105-127.
McMurtray, J. D., and Richardson, J. I. 1985. A northern nesting record for the hawksbill turtle. Herpetological Review 16(1):16-17.
National Oceanic and Atmospheric Association. (27 February 2012). Retrieved June 14, 2012, from NOAA National Marine Fisheries Service:
www.nmfs.noaa.gov/pr/species/turtles/hawksbill.htm
Lund, P.F. 1985. Hawksbill turtle (Eretmochelys imbricata) nesting on the east coast of Florida. Journal of Herpetology 19(1):164-166.
Wilmers, T.J., and Wilmers, E.M. 1998. Eretmochelys imbricate (Hawksbill). Herpetological Review 29(1):50.
Wyneken, J., and Hicklin, J.A. 1988. Confirmed hawksbill, Eretmochelys imbricata, nesting in Broward County, Florida. Marine Turtle Newsletter 42:6.