Algal Blooms Disrupt Juvenile Green Turtles' Diets in Indian River Lagoon

Harmful algal blooms — a recurring threat in the Indian River Lagoon — are disrupting the foraging behavior of juvenile green sea turtles in ways that could undermine their long-term survival, according to a peer-reviewed study published this year.

The research used stable isotope analysis — a technique that traces what animals have been eating by examining chemical signatures in their tissues — to document shifts in diet among juvenile green turtles exposed to harmful algal bloom conditions, Long C.A. et al., Marine Ecology Progress Series, 2024. The findings suggest that when blooms degrade seagrass beds, young turtles are forced to pivot away from their preferred food sources, potentially affecting their growth and health during a critical developmental stage.

The Indian River Lagoon stretches along the coastlines of Indian River, St. Lucie, and Martin counties. It has experienced repeated and intensifying algal bloom events in recent years, driven largely by nutrient pollution from stormwater runoff and agricultural discharge. The lagoon is a documented foraging habitat for juvenile green turtles (Chelonia mydas), a federally threatened species.

Seagrass loss has been one of the most visible consequences of algal blooms in the lagoon, with thousands of acres disappearing over the past decade. Because juvenile green turtles rely heavily on seagrass as a primary food source, any sustained disruption to those beds forces the animals into nutritionally inferior or unfamiliar diets — a stress that the study's isotope data appears to confirm.

The research adds scientific weight to concerns long voiced by local marine biologists and conservation groups monitoring turtle strandings along Treasure Coast beaches. Sea turtle nesting and foraging surveys are conducted annually in Martin and St. Lucie counties, and health data from stranded animals has previously pointed to algal toxin exposure as a contributing factor in some cases According to initial reports,.

The full study is available at https://doi.org/10.3354/meps14488. Local residents concerned about water quality conditions in the lagoon can report algal bloom sightings to the Florida Department of Environmental Protection's online HAB reporting portal.

This article was generated with AI assistance using publicly available information. It was reviewed and approved by a human editor before publication. TC Sentinel uses AI writing tools in accordance with FTC guidelines.