Reptiles
(Loggerhead sea turtle)
Vocabulary
BASKING- exposing the body to the warmth of the sun.
BYCATCH- species caught secondary to the target species being fished for such as sea turtles being caught in longline swordfish fisheries.
CLUTCH- a single batch of eggs laid by a sea turtle.
EPIBIONT- one organism living on another, such as a barnacle attached to a sea turtle.
FALSE CRAWL- an adult female sea turtle attempts to nest but returns to the water without laying eggs.
PIPPING- the process of a hatchling breaking out of their egg shell.
SUBTROPICAL- the region bordering the tropics, usually between ~20 and 40 degrees latitude in both hemispheres
BYCATCH- species caught secondary to the target species being fished for such as sea turtles being caught in longline swordfish fisheries.
CLUTCH- a single batch of eggs laid by a sea turtle.
EPIBIONT- one organism living on another, such as a barnacle attached to a sea turtle.
FALSE CRAWL- an adult female sea turtle attempts to nest but returns to the water without laying eggs.
PIPPING- the process of a hatchling breaking out of their egg shell.
SUBTROPICAL- the region bordering the tropics, usually between ~20 and 40 degrees latitude in both hemispheres
Classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testidunes
Family: Cheloniidae
Genus: Caretta
Species: caretta
Phylum: Chordata
Class: Reptilia
Order: Testidunes
Family: Cheloniidae
Genus: Caretta
Species: caretta
Morphology
Carapace: moderately broad; lightly serrated posterior margin in immatures; thickened area of the carapace above the base of the tail (at the fifth vertebral) in subadults and adults; five pairs of costal scutes, the first (anterior) pair the smallest; straight carapace length (SCL) to about 105 cm in northwestern Atlantic, smaller in some other areas, the smallest adults being in the Mediterranean (to about 90 cm).
Head: large and broadly triangular in shape; width to 28 cm; two pairs of prefrontal scales.
Limbs: front flippers relatively short compared to other species; two claws on each flipper.
Coloration: dorsally light to dark brown in hatchlings, generally unmarked reddish-brown in subadults and adults; underside
brown in hatchlings, yellow to orange in subadults and adults.
Plastron: three pairs inframarginal scutes.
Distribution: all oceans, usually temperate waters, sometimes subtropical and tropical.
Weight: to about 180 kg in the western Atlantic and to about 150 kg in Australia; less than 100 kg in the Mediterranean.
Head: large and broadly triangular in shape; width to 28 cm; two pairs of prefrontal scales.
Limbs: front flippers relatively short compared to other species; two claws on each flipper.
Coloration: dorsally light to dark brown in hatchlings, generally unmarked reddish-brown in subadults and adults; underside
brown in hatchlings, yellow to orange in subadults and adults.
Plastron: three pairs inframarginal scutes.
Distribution: all oceans, usually temperate waters, sometimes subtropical and tropical.
Weight: to about 180 kg in the western Atlantic and to about 150 kg in Australia; less than 100 kg in the Mediterranean.
Biology
The greatest threat is loss of nesting habitat due to coastal development, predation of nests, and human disturbances (such as coastal lighting and housing developments) that cause disorientations during the emergence of hatchlings.
Other major threats include incidental capture in longline fishing, shrimp trawling and pollution. Incidental capture in fisheries is thought to have played a significant role in the recent population declines observed for the loggerhead.
Distribution Map
Loggerheads are circumglobal, occurring throughout the temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans. Loggerheads are the most abundant species of sea turtle found in U.S. coastal waters. In the Atlantic, the loggerhead turtle's range extends from Newfoundland to as far south as Argentina. During the summer, nesting occurs primarily in the subtropics. Although the major nesting concentrations in the U.S. are found from North Carolina through southwest Florida, minimal nesting occurs outside of this range westward to Texas and northward to Virginia. Adult loggerheads are known to make extensive migrations between foraging areas and nesting beaches. During non-nesting years, adult females from U.S. beaches are distributed in waters off the eastern U.S. and throughout the Gulf of Mexico, Bahamas, Greater Antilles, and Yucatán.
The majority of loggerhead nesting occurs in the western rims of the Atlantic and Indian Oceans. The loggerhead nesting aggregations in Oman, the U.S., and Australia account for about 88% of nesting worldwide. In the southeastern U.S., about 80% of loggerhead nesting occurs in six Florida counties (Brevard, Indian River, St. Lucie, Martin, Palm Beach, and Broward Counties). In Brevard and Indian River Counties, a 20 mile (32.2 km) section of coastline from Melbourne Beach to Wabasso Beach comprises the Archie Carr National Wildlife Refuge (ACNWR). ACNWR is the most important nesting area for loggerhead turtles in the western hemisphere. Twenty-five percent of all loggerhead nesting in the U.S. occurs in the Refuge. Researchers have recorded nesting densities of 1,000 nests per mile (625 nests per km) within the ACNWR.
In the eastern Pacific, loggerheads have been reported as far north as Alaska, and as far south as Chile. In the U.S., occasional sightings are reported from the coasts of Washington and Oregon, but most records are of juveniles off the coast of California. The west coast of Mexico, including the Baja Peninsula, provides critically important developmental habitats for juvenile loggerheads. The only known nesting areas for loggerheads in the North Pacific are found in southern Japan.
The majority of loggerhead nesting occurs in the western rims of the Atlantic and Indian Oceans. The loggerhead nesting aggregations in Oman, the U.S., and Australia account for about 88% of nesting worldwide. In the southeastern U.S., about 80% of loggerhead nesting occurs in six Florida counties (Brevard, Indian River, St. Lucie, Martin, Palm Beach, and Broward Counties). In Brevard and Indian River Counties, a 20 mile (32.2 km) section of coastline from Melbourne Beach to Wabasso Beach comprises the Archie Carr National Wildlife Refuge (ACNWR). ACNWR is the most important nesting area for loggerhead turtles in the western hemisphere. Twenty-five percent of all loggerhead nesting in the U.S. occurs in the Refuge. Researchers have recorded nesting densities of 1,000 nests per mile (625 nests per km) within the ACNWR.
In the eastern Pacific, loggerheads have been reported as far north as Alaska, and as far south as Chile. In the U.S., occasional sightings are reported from the coasts of Washington and Oregon, but most records are of juveniles off the coast of California. The west coast of Mexico, including the Baja Peninsula, provides critically important developmental habitats for juvenile loggerheads. The only known nesting areas for loggerheads in the North Pacific are found in southern Japan.
Importance
(Ecological,Economical)
Loggerhead sea turtles are some of the largest predators of benthic invertebrates and may play an important role in structuring the composition and dynamics of benthic communities.
The western North Atlantic population of loggerhead sea turtles is ecologically important. It plays a significant role in the marine ecosystem and food web. This population of loggerheads is genetically and behaviorally distinct from loggerhead populations in the South Atlantic, Mediterranean, Pacific and elsewhere. If the western North Atlantic population becomes extinct, the loggerhead will disappear from the East Coast of the United States.
Loggerheads are an important part of the southeast coastal ecosystem. Future generations of Americans should be able to enjoy the beauty of new hatchlings and mature loggerheads. “Through destructive fishing and global warming pollution, we are endangering the loggerhead and its ecosystem. We may lose a species which roamed the Earth millions of years before we arrived,” said Eric Bilsky, a senior attorney for Oceana.
It feeds on large numbers of invertebrates, affecting their populations and allowing their broken shells to be used as a calcium source for other species. Also, a substantial portion of the eggs laid become food for predators. Finally, over 100 species from 13 phyla may live on the carapace of loggerheads, making it somewhat of a mobile reef. (Spotila, 2004)
Economic Importance for Humans: Positive Caretta caretta is beneficial to humans in many ways. Sea turtles are an attraction for ecotourism and popular with people wanting to snorkel or dive with these animals, as well as for those wanting to watch the nesting process.
Loggerhead sea turtles are the most common sea turtle in U.S. waters and therefore most sea turtle research is carried out on this species. Also, in many countries, especially in Central and South America, Africa, Asia, and the Mediterranean, these turtles and their eggs are exploited for food. ("MarineBio", 2006; "NOAA Fisheries", 2006; Ernst, et al., 1994; Spotila, 2004)
The western North Atlantic population of loggerhead sea turtles is ecologically important. It plays a significant role in the marine ecosystem and food web. This population of loggerheads is genetically and behaviorally distinct from loggerhead populations in the South Atlantic, Mediterranean, Pacific and elsewhere. If the western North Atlantic population becomes extinct, the loggerhead will disappear from the East Coast of the United States.
Loggerheads are an important part of the southeast coastal ecosystem. Future generations of Americans should be able to enjoy the beauty of new hatchlings and mature loggerheads. “Through destructive fishing and global warming pollution, we are endangering the loggerhead and its ecosystem. We may lose a species which roamed the Earth millions of years before we arrived,” said Eric Bilsky, a senior attorney for Oceana.
It feeds on large numbers of invertebrates, affecting their populations and allowing their broken shells to be used as a calcium source for other species. Also, a substantial portion of the eggs laid become food for predators. Finally, over 100 species from 13 phyla may live on the carapace of loggerheads, making it somewhat of a mobile reef. (Spotila, 2004)
Economic Importance for Humans: Positive Caretta caretta is beneficial to humans in many ways. Sea turtles are an attraction for ecotourism and popular with people wanting to snorkel or dive with these animals, as well as for those wanting to watch the nesting process.
Loggerhead sea turtles are the most common sea turtle in U.S. waters and therefore most sea turtle research is carried out on this species. Also, in many countries, especially in Central and South America, Africa, Asia, and the Mediterranean, these turtles and their eggs are exploited for food. ("MarineBio", 2006; "NOAA Fisheries", 2006; Ernst, et al., 1994; Spotila, 2004)