Dolphin Deaths at Indian River Lagoon in Florida Due to Choking of Certain Fish
A team of scientists from SeaWorld and the Hubbs-SeaWorld Research Institute have discovered the cause of death among bottlenose dolphins in Florida's Indian River Lagoon. A study found that the dolphins were choking by ingestion of certain fish.
Between 1997 and 2011, 14 out of 350 dolphins in the Indian River Lagoon died of asphyxiation (choking), all because they choked on spiny fish they shouldn't be eating. More than a third of those cases the fish also had fishing lines or hooks still attached.
"This is the first study documenting a statistically significant number of dolphin deaths caused by choking," said Megan Stolen, M.S., Hubbs-SeaWorld Research Institute scientist and the study's principal author. "This research lays a critical foundation for future study because of environmental changes and invasive species altering prey populations."
"Over the next year, our work will be focusing on defining all of the significant causes of mortality for dolphins in the lagoon," said SeaWorld's Judy St. Leger, DVM, DACVP, one of the study's coauthors. "We also suspect that this choking concern might be happening in other dolphin populations. We hope this report spurs other researchers to look for and report trends like this."
Scientists at SeaWorld and the Hubbs-SeaWorld Research Institute have been monitoring the lagoon's 700+ dolphin population since 1987.
The Indian River Lagoon where these deaths are occurring, covers about 40 percent of the Florida coastline and about 700 bottlenose dolphins live there and do not leave.
“Because they are so tied to home, when things change in the environment, they are vulnerable to the changes every time,” said Judy St. Leger, co-author of the study published in PLOS One.
The lagoon has been undergoing significant changes in the last few years, which is likely due to nutrient pollution from lawns and farms.
In 2011, an algae superbloom killed off 60 percent of the sea grass. Since then, 111 manatees, 300 pelicans and 46 dolphins have died of unknown causes.
Dolphins choking on fish and fishing line is unrelated to the unknown deaths, but it does suggest human impact on the animals in the lagoon.
Fishing line, lures, and hooks have always been a danger to marine animals, including manatees, sea turtles and dolphins. SeaWorld has rescued and rehabilitated thousands of animals that have become entangled and they encourage fishermen to properly use and dispose of their gear.
Dolphins dying at alarming rate in Indian River Lagoon
Several more dolphins wash up dead in Brevard County, and now experts are looking into the cause.
Migrating Sharks in Florida Force Beaches to Close
Annual Beach Pollution Report by NRDC: 2013 Best and Worst Beaches
Teen Rides Whale Shark off Gulf of Mexico in a Once in a Lifetime Experience
Two-headed Bull Shark Fetus Found by Fisherman in Gulf of Mexico