Director’s Message-October 2012

Published: September 27, 2012

Record-breaking Summer for Turtles

I’m stunned!

Wellfleet Bay staff and volunteers retrieve a live leatherback from Truro marsh.

Usually it’s the chilled sea turtles we deal with in the fall that are stunned, but not this year. It’s all of us sea turtle rescuers, biologists and researchers who are.

This summer has been like no other in terms of of sea turtle sightings with an unprecedented number of leatherbacks and loggerheads being reported by boaters, fishermen, and sailors. These reports can be seen on our web site, seaturtlesightings.org. We thought 2010 was a big year but this year tops it.

Why is this happening? Usually, when it comes to turtles, the easy answer is temperature. Warmer waters bring more sea turtles. With the ocean temperature more than 6 degrees above normal, this certainly seems to be the reason why so many loggerheads are in our waters.

Food is also a prime motivator and the bottoms of Cape Cod and Buzzards Bays and Nantucket and Vineyard Sounds are covered in spider crabs, moon snails, and invertebrates that the hard-shelled turtles like to eat. In the summer, there always seems to be plenty to eat for these juvenile sea turtles.

Leatherbacks, however, are warm blooded; they don’t mind a chilly ocean. They are also jellyfish feeders. Since we don’t really keep track of jellyfish concentrations, we don’t know if there is link between the large number of leatherback sightings and more jellyfish in our waters. For all we know, leatherbacks are just cruising through our waters searching, but not finding food, and moving on.

This summer we had over 50 dead leatherbacks and 15 dead loggerheads washed ashore—a record. By the end of a typical summer, we’d find 10 leatherbacks and 3 loggerheads dead on our beaches. If you go back to when I first started keeping records, in 1979, we were likely to get only one leatherback and one loggerhead in a summer.

All strandings have their own set of unique circumstances. We had a loggerhead tangled in fishing line in Hyannis, which is unusual, but there’s more. It was a tagged loggerhead that was released in June in the Gulf Stream off Fort Piece, Florida. It had previously been used by the National Marine Fisheries Service in a study of fishing gear to reduce sea turtle mortality. 

Another tagged turtle that showed up in Mattapoisett turned out to be from much farther away than Florida. This one was tagged in the Mediterranean Sea! It had been accidently hooked by a fisherman who took it to a rehabilitation center on the island of Lampedusa, an Italian-owned island off the coast of Tunisia. It was released in June of 2008 and eventually made its way across the Atlantic Ocean to New England. This is the first documentation of a turtle tagged in the Mediterranean crossing the Atlantic Ocean.

With all this summer sea turtle action, what does it mean for our cold-stun sea turtle season? There seems to be a strong correlation between summer sightings and fall strandings. We are anticipating one of the busiest seasons ever. If you are going to be on the Cape in November, December and January, I think we’re going to need your help. To volunteer either as a beach patroller or driver (to get live turtles up to the aquarium’s hospital in Quincy) please contact Volunteer Coordinator Diane Silverstein by email or phone: (508) 349-2615.