Wearin’ o’ the Green

In honor of St. Patrick’s Day…. There is one sea creature that embodies “wearin’ o’ the green” – the Green Sea Turtle.  Green turtles are named not for the color of their exterior but for the color of their interior!  Adult greens have green fat!

(c) SeaPics
(c) SeaPics

You are what you eat!

And in the case of green sea turtles, literally.  While green turtle hatchlings eat a mixture of aquatic insects, worms, and plants, adults are exclusively herbivorous and feed on seagrasses and algae.

(c) SeaPics
(c) SeaPics

Natural history

Green sea turtles inhabit tropical regions throughout the world.  Adult females come ashore to nest as many as five times during the nesting season, laying an average of 135 eggs per nest.  Eggs incubate for two months.  Once they hatch, the tiny hatchlings run a gauntlet of land predators before reaching the comparative safety of the ocean.  They spend several years in the open ocean feeding on plants and animals near the surface.  As juveniles, the turtles begin to forage closer to the coastline and gradually move to a vegetarian diet.  As turtles grow to adulthood, they begin mating and laying nests of their own around 20 years of age.  Green sea turtles can live longer than 50 years.

Juvenile green sea turtle released back into the ocean.  Photo by Mendy Garron, NOAA.
Juvenile green sea turtle released back into the ocean. Photo by Mendy Garron, NOAA.

Stranding and rehabilitation in Massachusetts

While Kemp’s ridleys are the most common sea turtle to strand on Cape Cod, each year we see several green turtles as well.  The animals are juveniles, most less than one foot long and most weighing less than fifteen pounds.  The primary reason for stranding in our area is cold-stunning – or severe hypothermia – caused when the cold-blooded animals become trapped in Cape Cod Bay and can’t swim south for the winter.  Thankfully, volunteers from MassAudubon’s Wellfleet Bay Wildlife Sanctuary patrol the beaches every fall looking for stranded turtles.  The New England Aquarium receives the stranded turtles and performs emergency care.  When they are full, partner organizations such as the National Marine Life Center step in to accept animals and complete the rehabilitation process.  The effects of cold-stunning are complex and long-lasting, and many turtles must remain in care for 6-24 months before being released.

(c) Alejandro Fallabrino, Karumbe Photos
(c) Alejandro Fallabrino, Karumbe Photos

Conservation and how YOU can help!

Green turtles are endangered worldwide.  Threats include entanglement in fishing gear and ingestion of marine debris.  You can help by only consuming seafood that was fished sustainably with “turtle excluder devices” or TEDs.  (TEDs are mandatory in the U.S.)  Participate in beach cleanups and dispose of your own trash responsibly.  And, if you see a sick or injured sea turtle on the beach, report it to an authorized wildlife response agency as quickly as possible.

For more information

~ Click Here for the NOAA Office of Protected Species fact sheet on green sea turtles.
~ Click Here for a NOAA fact sheet geared towards kids.
~ Click Here for the NOAA sea turtle stranding and salvage network.

Green Sea Turtle in the Caribbean, by Don “The Turtle Guy” Lewis