Loggerhead sea turtle hatchlings (Caretta caretta) are popping up on Southwest Florida beachfronts this time of year. The annual birthing process begins when female loggerheads come ashore to nest soon after the start of sea turtle season on May 1. Two to three months later, newborn baby sea turtles pip or break out of their shells and seek the moon glow as natural light for their swim south to the Sargasso Sea.
But not everything goes as planned for the 100 or so sea turtle hatchlings that emerge from each nest. First, some or many of the newborns may become disoriented due to artificial lighting instead of the moon glow. Second, due to excessive heat during the incubation process, some hatchlings may have or develop congenital abnormalities that limit or impede their progress toward the water. Thirdly, they may become victim to predatory attacks before or during the use of the Gulf Stream in hopes of reaching the Sargasso Sea where they spend the first years of their lives.
From July 19 to August 1, 22 loggerhead sea turtle hatchlings were admitted to CROW from the beaches of Sanibel and Captiva. Some of these hatchlings were reportedly born with congenital defects, while others became disoriented and exhausted while making their way to the ocean.
“This is the time of year when we typically see hatchlings admitted to the hospital, the numbers thus far are similar to previous years,” said Dr. Robin Bast, CROW’s staff veterinarian. “Reasons for admission include disorientation, congentinal abnormalities or predator attack. These are hatchlings that typically have not made it to the water’s edge yet and/or struggled to get out of the nest for one reason or another.”
While Dr. Bast did state some of the 22 hatchlings were admitted with congenital defects that severely impaired their ability to swim and, consequently, were not released, she did report that most were still releasable. In fact, 15 of them were released in the Gulf of Mexico later the same evening of the day they arrived under the cover of darkness.
CROW officials remind beachgoers that they can help the many hatchlings emerging on our beaches by filling in any large holes in the sand, removing items from the beach at night such as chairs or anything that may impede a hatchling, and turning off any lights that are visible from the beach. A hatchling’s natural instinct is to head towards the brightest spot, which is the moon reflecting off the water. Disorientation occurs when hatchlings head the wrong direction and toward property lights.
“Hatchlings may become disoriented by artificial lighting on or near the beach, which is why there are restrictions regarding outdoor lighting during active nesting season. Instead of heading out to sea, they can mistakenly follow artificial lighting sources and end up going the wrong direction. They can inadvertently end up in parking lots, swimming pools, etc. Make sure not to use flashlights on the beach at night, and if you see a disoriented hatchling, report it immediately so it can be evaluated,” said Dr. Bast. “Hatchlings have a few days after they hatch before the yolk sac that provides a temporary source of nutrition for them absorbs. The hope is that they reach the sargassum beds within that time frame, although they face obstacles such as predation on the way, and many hatchlings never make it to breeding age.”
Excessive heat before the hatchling has even pipped is another problem that the sea turtle population is facing. “Due to global warming, more nests are incubating at higher temperatures. This results in mostly females hatching and less males, which will ultimately affect the ability of the population to breed and have genetic diversity later on,” said Dr. Bast. “Higher nest temperatures have also resulted in an increase in the number of congenital deformities in hatchlings.”
CROW Case of the Week stories are written by Bob Petcher and appear weekly in the Island Sun and River Weekly Newspapers.