homepage logo

Scientists explain record number of loggerhead nests

By Staff | Sep 9, 2020

Loggerhead sea turtle. SCCF

On Sept. 2, the Sanibel-Captiva Conservation Foundation reported that there are 659 loggerhead sea turtle nests on Sanibel, breaking the previous record number of 649 set in 2017. The record for loggerhead nests on Captiva was broken earlier this season; there are now 265 nests on the northern island, well beyond the previous record of 194 nests set in 2016.

This season’s nest counts are encouraging and are a testament to over 60 years of conservation work on the islands, as well as the entire state and surrounding waters. The SCCF reported that it is important, however, to keep in mind that monitoring population trends based on nest counts is complicated.

Sea turtles have complex life cycles. Females lay more than one nest per year and do not typically reproduce every year, so even when the population is stable, it is natural to see fluctuations in nesting from year to year.

A 2019 review by the Florida Fish and Wildlife Conservation Commission revealed that there was no evidence for an increasing or a declining trend in the breeding female population from 1998-2018. It remains a fragile population that is still facing many threats, including bycatch in fisheries, habitat loss, pollution and climate change.

While the SCCF cannot make inferences on the population as a whole, its data from the last six years clearly show that Sanibel provides high-quality nesting habitat for loggerheads. The average number of loggerhead nests on Sanibel from 1998-2013 was 236 nests per year. For the past six years — 2014 to 2019 — that average has skyrocketed to 561 nests per year.