About the Project
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Why are you doing this study?
Our goal is to learn when and how loggerhead turtles reach coastal waters of the eastern Pacific. Studying loggerhead movements in the context of environmental parameters such as sea water temperature and currents will help us understand their environmental preferences; this information will also aid in predictions of where, when and how long these creatures may be impacted by offshore industrial fisheries and other threats present in international, U.S. and Mexico waters. Will 2-year old aquarium-reared loggerheads be able to survive when released into the wild? The technique of rearing hatchling turtles until they reach ~2-years old has been conducted for several sea turtle species in many areas worldwide. These captive-reared turtles have largely thrived after being introduced into natural settings, aided by their natural instincts to successfully forage and navigate in the marine realm. Moreover, North Pacific loggerheads have been shown to maintain their homing instincts even after having been in captivity for a decade or more. |
Who is funding this project?
The Loggerhead STRETCH project includes a team of researchers that are funded both privately and by their host institutions (e.g., Nagoya Aquarium, Stanford University, NOAA Southwest Fisheries Science Center, National Autonomous University of Mexico) as well as private organizations and foundations (e.g. Gordon and Betty Moore Foundation, National Geographic Society, etc.)
How will this project help to save the North Pacific loggerhead turtle? What are the conservation benefits?
The more we can learn about where, when, and how loggerhead turtles are able to move into coastal waters of the eastern Pacific, in California U.S.A and Baja Mexico, the better-informed management agencies will be for developing protection plans to reduce or eliminate human threats in the areas where loggerheads occur.
The Loggerhead STRETCH project includes a team of researchers that are funded both privately and by their host institutions (e.g., Nagoya Aquarium, Stanford University, NOAA Southwest Fisheries Science Center, National Autonomous University of Mexico) as well as private organizations and foundations (e.g. Gordon and Betty Moore Foundation, National Geographic Society, etc.)
How will this project help to save the North Pacific loggerhead turtle? What are the conservation benefits?
The more we can learn about where, when, and how loggerhead turtles are able to move into coastal waters of the eastern Pacific, in California U.S.A and Baja Mexico, the better-informed management agencies will be for developing protection plans to reduce or eliminate human threats in the areas where loggerheads occur.
Loggerhead FAQs
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How long had loggerheads been on Earth?
Like all sea turtles, loggerheads are descendants of some of the most ancient animal lineages on Earth, having undergone very few evolutionary changes in the last 80 million years. How much do adult loggerhead turtles weigh? Adult loggerheads range in weight from 180-250 lbs (82-113 kg) How long do loggerhead turtles live? Loggerheads can live 60 years or more. How long does it take for loggerhead turtles to reach adulthood? Loggerheads mature at variable ages, with an average of about 25 years old. |
"Loggerhead sea turtle (Caretta caretta)" by Nataša Stuper is licensed under CC BY 2.0.
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Where do North Pacific loggerheads nest?
While loggerheads are found all across the North Pacific, genetics and survey data indicate that they only nest on beaches in southern and central Japan, mostly on the Pacific side of the islands.
Do all loggerheads born in Japan make it across to the Eastern Pacific to grow?
We still don`t know what proportion of the total number of hatchlings born in Japan reach U.S and/or Mexican waters. What we do know is that the hatchlings are transported to the Central North Pacific by strong regional currents; some remain there, and a portion continue an eastward trajectory all the way to the coasts of southern California U.S.A. and Baja California, Mexico. How this happens is something we are trying to find out with the STRETCH project.
Where do North Pacific adult loggerheads feed after they return to Japan?
Satellite tracking and stable isotope studies have shown that there are three foraging destinations for Adults: East China Sea, coastal areas of mainland Japan, and oceanic zones in the North Pacific Ocean.
While loggerheads are found all across the North Pacific, genetics and survey data indicate that they only nest on beaches in southern and central Japan, mostly on the Pacific side of the islands.
Do all loggerheads born in Japan make it across to the Eastern Pacific to grow?
We still don`t know what proportion of the total number of hatchlings born in Japan reach U.S and/or Mexican waters. What we do know is that the hatchlings are transported to the Central North Pacific by strong regional currents; some remain there, and a portion continue an eastward trajectory all the way to the coasts of southern California U.S.A. and Baja California, Mexico. How this happens is something we are trying to find out with the STRETCH project.
Where do North Pacific adult loggerheads feed after they return to Japan?
Satellite tracking and stable isotope studies have shown that there are three foraging destinations for Adults: East China Sea, coastal areas of mainland Japan, and oceanic zones in the North Pacific Ocean.
"Loggerhead sea turtle hatchlings make their way to the ocean" by CapeHatterasNPS is marked with Public Domain Mark 1.0.
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How often do female loggerheads nest?
On average, each female in the Japanese breeding population nests every 3 years, and during each nesting season they deposit up to 3 clutches of about 90-100 eggs. How long does it take before the eggs hatch? Sea turtle eggs have an incubation period of about two months. How many years can female loggerheads nest and reproduce? There are records of individual loggerhead turtles nesting across a range of 46 years in the SE USA, 33 years in Greece, and 32 years in Brazil. How many nests are laid in Japan each year? Along the Japan coast, loggerheads lay about 10,000-12,000 nests each year, which equates to about 8,700 individual nesters. What is the youngest loggerhead ever found along the coast of North America? In July 28th, 2015, NOAA researchers dip-netted a 20.5-cm (straight carapace length), 2-kg loggerhead from surface waters 50 miles off the coast of San Diego USA. This turtle was likely no more than 2 years old. |
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How many species of sea turtles are there in the Pacific Ocean?
Five species of sea turtles can be found in the North Pacific:
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How many species of sea turtles are listed as endangered or threatened?
All five species in the North Pacific are listed as either threatened or endangered on the U.S. Endangered Species Act (ESA), and most are also listed in a threat category (Vulnerable, Endangered, Critically Endangered) on the IUCN Red List. North Pacific loggerheads, in particular, are listed as Endangered on the ESA and as Least Concern on the IUCN Red List. This disparity in listings is due to differences in the assessment criteria and timeframe of assessments. |
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What threatens sea turtle survival?
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"Loggerhead Sea Turtle" by Cumberland Island NPS is licensed under CC BY-SA 2.0.
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For More Information
- https://www.fisheries.noaa.gov/feature-story/10-tremendous-turtle-facts
- https://www.seeturtles.org/loggerhead-turtles
- https://www.nationalgeographic.com/animals/reptiles/facts/loggerhead-sea-turtle
- https://www.worldwildlife.org/species/loggerhead-turtle
- https://conserveturtles.org/information-sea-turtles-loggerhead-sea-turtle/
- https://oceana.org/marine-life/loggerhead-turtle/
- https://visittybee.com/article/10-fascinating-facts-about-loggerhead-sea-turtles
Header photo credit: Paula Olson (NOAA)
