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Maximum
Length: 70-100 cm
Breeding: Oviparous
Nesting mean size: 87 cm
Clutch mean size: 112 eggs
Time to reach maturity: 30+ years
(more
than double that of humans)
Habitat: Tropical, sub-tropical and temperate
waters worldwide.
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North
Pacific Loggerhead Turtle
The migrations of juvenile loggerhead turtles can last up to
two decades and span the entire Pacific Basin. Hatchlings of
the endangered North Pacific loggerhead population leave their
Japanese nesting beaches and forage pelagically as juveniles,
some reaching the Pacific coast of Mexico. At maturity, loggerhead
turtles return to Japanese beaches to reproduce.
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| Adelita
This was a loggerhead turtle released by fishermen and scientists
from Santa Rosalia, BCS on August 10, 1996. Adelita was a mature,
223 pound KG, loggerhead female; the first one to be tracked in
her trans-pacific journey back to her nesting beach by a satellite
transmitter. Adelita accomplished her 8,000 miles (12,000 km)
journey in 368 days.
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Status
The Pacific loggerhead turtle is among the most endangered large
marine vertebrates, with fewer than a few thousand nesting annually.
Annual censuses on Japanese beaches indicated a 50% decline
in the number of nesting loggerhead turtles between 1990 and
2002. As a result identifying and mitigating their sources of
mortality may be essential for the Pacific loggerhead to survive.
Área
de Alto Uso de Tortugas Amarillas en Baja California Sur
In the northeast Pacific Ocean, loggerhead
turtles are found primarily along the 1,000 mile Pacific coast
of the Baja California peninsula (BCP), and research conducted
by Proyecto
Caguama and partners has shown that juvenile loggerheads
aggregate at extraordinarily high densities in the unusually
rich waters of Baja California Sur, feeding their way to maturity
for several decades. This loggerhead hotspot offers an unusual
conservation opportunity: unlike with many endangered highly
migratory animals, a large proportion of loggerhead can be protected
in a very small area
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Diet
In the open Pacific Ocean, loggerhead turtles feed opportunistically
on epipelagic prey including crabs and jellyfish. But these prey
occur in ephemeral patches, and loggerheads have to cover much
ocean to get their fill. Alternatively, the nutrient-rich waters
of the Baja California peninsula produce massive plankton blooms
which in turn fuel vast swarms of pelagic red crabs. Bright red
with large paired claws and a crawfish tail, pelagic red crabs
resemble cooked Maine lobsters in miniature. They measure just
four centimeters on average and turn the blue pacific a striking
red with their dense swarms, attracting whales, sharks, rays,
tuna, albatross, and sea turtles. The red crabs’ reliably
high abundance along the Baja California Peninsula explains the
loggerhead hotspot: thousands of loggerhead turtles grow their
way to maturity on the red crabs unique to the waters of the baja
California peninsula. |
| Threats
Like all marine turtles, loggerheads face an array of natural
threats including predation and disease. But human related threats
have driven their decline. As with sea turtles wordwide, destruction
of nesting habitat in Japan due to burgeoning seaside development
is a major threat. Accidental capture and mortality of turtles
due to fishing (bycatch) is the leading threat to loggerheads.
Bycatch occurs in all fisheries, ranging from industrial scale
offshore operations to nearshore artisanal fisheries. Where intense
local fishing overlaps with the juvenile loggerhead foraging hotspot
at Baja California Sur, loggerhead turtles are bycaught frequently,
resulting in one of the greatest known threats to their persistence.
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| Reproduction
and nesting
Loggerhead
turtles spend most of their life feeding off Baja California Sur
waters. When they reach sexual maturity (approx. 87 cm of lenght),
they migrate back to Japan to reproduce. Mating commonly occurs
in the coastal waters of the nesting beaches. After mating, loggerhead
turtles will come out at night to nest. This species lays around
112 eggs per nest and the incubation time of these eggs can vary
from 50 to 80 days, depending on the certain characteristics of
the nesting beach (temperature, humidity and gas exchange).
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