Major Fish Kill in Miami-Dade investigated
From David Volz
The Department of Regulatory and Economic Resources, Division of Environmental Resources Management (RER-DERM), has been investigating a fish kill across the northern basin of Biscayne Bay. Response efforts are detailed below.
Recently, DERM field staff continued their work, responding to additional reports of live, struggling fish. Accumulations of dead fish were reported to the environmental complaints desk, mainly in the areas of North Bay Village, Quayside and Broad Causeway. Staff observed several areas of fish grouping and struggling at the surface of bay waters to gain access to areas in the water column with potentially higher oxygen levels. They continue documenting sightings of live and dead fish to determine the extent of the areas impacted, as well as recording current weather conditions, to correlate with the water column conditions. Winds have picked up throughout the day and have shifted to the North-Northwest. It is unclear if this will help the situation by mixing up the water column and oxygenating bottom waters. Continued sampling and monitoring over the next coming days by staff will assist with data analysis on this issue.
As a precaution, samples to test for harmful algal blooms, and specifically red tide, were also collected yesterday and are being sent out to Florida Fish and Wildlife Conservation Commission (FWC) for analysis. This is to confirm that the incident was not caused by red tide. Each day of sampling and testing provides more insight into the bigger picture of how Biscayne Bay’s water chemistry is fluctuating and what may be occurring in the Bay.
The DERM laboratory has been processing the samples collected from staff biologists over the past few days, testing nutrients and wet chemistry parameters using the State of Florida and National Environmental Laboratory Accreditation Conference (NELAC) certified methods with low detections in a saline water matrix. These sample analyses are vital to evaluating the water quality and bay conditions that are contributing to the fish kill event. The DERM lab has also been integral in the fish kill response by preparing proper sampling kits with bottles for the field team each day, receiving samples and coordinating distribution to the contract lab as needed for metals and bacteria samples within sensitive holding times, all while maintaining quality control and quality assurance procedures.
Kearns Construction Company continued cleaning up the accumulated fish, reducing the potential negative effects of decomposing fish on the amount of available oxygen, which could further exacerbate the problem.
