Nesting Begins to Pick Up

Nesting activity on Sanibel and Captiva has begun to pick up. There are now seven loggerhead nests on Sanibel and four on Captiva. In addition to monitoring for nesting activity, we also aided in the rescue of a very sick Kemp's ridley turtle this week. Two very kind boaters found it floating and lethargic near Sanibel's lighthouse. We met them at the dock and transported it to CROW for care.

Nest #4 on Captiva before it was staked for protection.

First nest laid east of Tarpon Bay Road on Sanibel.

A very sick Kemp's Ridley being transported to rehab.

Species Spotlight: the Kemp's Ridley Turtle

Meet the Kemp’s ridley turtle (Lepidochelys kempii). The Kemp’s ridley is both the smallest and most endangered of sea turtle species. At maturity, they are 2-2 ½  feet long and around 100 lbs. Their carapace (top shell) is usually almost as wide as it is long, giving it a very round shape. They are found almost exclusively in the Gulf of Mexico. 

Female Kemp's ridley after nesting on Sanibel Island in 2011.

Juveniles use the estuaries on the west coast of Florida as nursery areas. 95% of nesting occurs in Tamaulipas, Mexico along three main beaches. There is also some nesting in Texas and the occasional nest in Florida. Kemp’s ridleys are unique from the other turtles that are found in Florida’s waters in that they often nest during the day. On the beaches of Mexico, the Kemp’s ridley nests in large groups called arribadas.

Red Tide Turtles Released

A red tide bloom began at the end of November and lasted until approximately mid-January at the mouth of San Carlos Bay. Many species including birds, fish, and sea turtles were affected by the toxin produced by the red tide organism Karenia brevis. During this time frame, a total of 11 Kemp’s ridley turtles were found on and near Sanibel. Nine were dead and two were found alive and taken to rehabilitation facilities.

A newly released juvenile Kemp's ridley. Photo by: R. Flynn

The two live turtles from Sanibel and an additional Kemp’s ridley from Lover’s Key State Park were released into Pine Island Sound on February 27 after receiving a clean bill of health. The SCCF Marine Lab provided boat transportation. SCCF staff were accompanied by Rhonda Bailey of the Florida Fish and Wildlife Conservation Commission and Eve Haverfield of Turtle Time, Inc. A video of the release can be seen at http://youtu.be/ij2FtWeDY14.

2011 Sea Turtle Season

While no sea turtle season could ever be considered dull, this season proved to be full of surprises. We documented more rare species nesting on the islands than ever before. Sanibel’s nesting season started with the nesting of a rare Kemp’s ridley (Lepidochelys kempii) and continued with a total of seven green turtle (Chelonia mydas) nests. Captiva even got in on the fun with the first green nest documented on the island since 2007. In all, Sanibel had a total of 277 nests and 443 false crawls and Captiva had 75 nests and 54 false crawls.

A green turtle nest laid on Sanibel.

2011 was the sixth best year for nesting since 1996 on the islands.  The overall hatch success (the percentage of eggs to hatch) was 67.7% for Sanibel and 70.4% for Captiva.  The emergence success (the percentage of a nest’s hatchlings to leave the nest) was 59.7% for Sanibel and 61.9% for Captiva.  This is compared to last year’s hatch success of 65.75% and emergence success of 60.3% on Sanibel and 57.34% on 45.8% respectively on Captiva.  Overall, the islands produced approximately 25,411 eggs and approximately 15,786 hatchlings reached the Gulf.

We're off to an early start!

While May 1 is the official start of sea turtle nesting season in Southwest Florida, sea turtles often follow their own calender. On Friday, April 22 a rare Kemp's Ridley turtle (Lepidochelys kempii) came ashore on Sanibel and gave us our first nest of the season. We didn't quite have the first nest in Lee County, that honor went to Cayo Costa with a Loggerhead nest the night before; we had the most interesting nester. Kemp's Ridleys typically nest during the day, but rarely in Florida. There were only eight nests in the entire state in 2011! Their main nesting ground is Rancho Nuevo, Tamaulipas, Mexico, with additional nesting at Padre Island, Texas. Even though they don't often nest in Florida, this isn't Sanibel's first nest. The last documented Kemp's Ridley nest was in 1996. While they are uncommon on Florida's beaches, they are often found in our waters, which provide important foraging habitat. The Kemp's Ridley is the smallest and rarest sea turtle in the world. They are approximately 100 pounds and measure 2- 2 1/2 feet in length at maturity. They are protected under the U.S. Endangered Species Act where they are listed as endangered.