Royal Tern Deaths To Be Studied


The sudden increase in dead royal terns near the Sanibel Causeway will be studied thanks to an $8,000 federal grant. The Sanibel Captiva Conservation Foundation Marine Lab will analyze some of the dead birds that were collected, along with baitfish. The thought is the cause of the increase in Royal Tern deaths may be in the food chain.

The grant is being provided by the National Center for Coastal Ocean Science Harmful Algal Bloom Event Response Program.

Back in February, CROW noted a substantial increase in admissions of royal terns to their hospital. The large number of sick and dead birds, especially located around the Sanibel Causeway, were not consistent with routine beach sampling or high-concentration bloom “patches” visible from satellite imagery.

A team of experts from CROW, University of Florida, SCCF and FWC met to discuss the issue and agreed that studying the “food web of the terns’ diets may hold the key to understanding what was causing their illness and mortality”. A proposal to study the food web was submitted to NOAA’s Harmful Algal Bloom Event Response Program and they granted $7,820 to fund isotopic and toxin analysis.

CROW volunteers collected and preserved deceased birds to be used in the study. In addition, fishing guides provided 20 bags of baitfish collected near the Sanibel causeway which were delivered by Coastal Watch President Pete Squibb in early March.

A final report is expected by the end of 2021.