Another massive fish kill has struck Florida waters — this time affecting menhaden in a Vero Beach state park. The Sebastian Inlet State Park became inundated with swathes of dead fish last week. According to one report, some residents have estimated that there are “millions” of dead fish, and the area is now inundated with a strong odor from the decay.
According to Carli Segelson, spokesperson for the Florida Fish and Wildlife Conservation Commission, the kill is likely due to low dissolved oxygen levels in the water.
On Feb. 4, the FWC received reports of dead fish near sebastian inlet boat ramp. Our field staff obtained fish and water samples, and observed several species, including Spot, Sheepshead, and Red Drum, but the vast majority were Menhaden. The water quality data do show levels of Dissolved Oxygen low enough to cause fish kills, but the analysis did not indicate an algae bloom. However, because algae blooms can come and go rather quickly, scientists can’t always observe them directly and low dissolved oxygen levels can be a sign of a recent or ongoing bloom.
A similar fish kill occurred in Northeast Florida in the summer of 2010, which many environmentalists attributed to nutrient pollution. Nutrients like nitrogen and phosphorus — which come from industry runoff, as well as home fertilizers — often contribute to the widespread growth of algal blooms. As the blooms die off, they use up large amounts of oxygen, which leads to low levels of dissolved oxygen in the waterbody.
Engelson says that the Fish and Wildlife Conservation Commission hasn’t received any calls of dead or dying fish since last Friday, but she encourages those who spot any such fish to call the Fish Kill Hotline.