Final update from Miami-Dade County on recent fish kill

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. This will be the last daily press release until RER-DERM concludes its investigation and has new information to report regarding the cause of the fish kill.

Follow-up assessment

Based on incremental improvements in dissolved oxygen (DO) levels documented each day, from Saturday through Monday, it appears this fish kill event is ending. Neither DERM nor its collaborative partners received any reports yesterday of struggling fish, nor did field staff make any such observations.

Analysis and cleanup

DERM biologists were out on the water again yesterday, continuing the sampling and monitoring efforts. They noted that the DO levels across most areas in north Biscayne Bay have continued improve. At the set sites surveyed over the last week, there are no longer any areas completely devoid of oxygen at the bay bottom or surface. DO values at the mouths of both the Little River and Biscayne Canal extending eastward are recovering, but still exhibit lower DO values in the range of 2-4 mg/L at the bottom; however, those values have also increased each day since Saturday. On the eastern side of the bay (near Miami Beach), lower DO values were also documented at the bay bottom and are much improved from those levels reported over the weekend and are currently in the 4-5 mg/L range. 

In addition, samples collected and analyzed late last week indicate that red tide conditions were not present.

Kearns Construction Company was out again removing dead fish. As of 2:30 p.m. Monday, a total of 420 lbs. of biomass was removed, bringing the running removal total for the past five days to approximately 3,750 lbs. Kearns re-visited the hardest-hit areas, including along the north side of the 79^th Street Causeway, near Pelican Harbor and the North Bay Village islands, the finger canals north of the Little River, and the San Souci canals. They reported that there were no large accumulations of fish. DERM staff have observed some fish and crab carcasses at the bay bottom that cannot be recovered without potentially impacting natural resources. There is no additional cleanup of dead fish at the bay surface warranted at this point, and the vendor ended removal activities yesterday.

DERM biologists will continue sampling activities throughout the work week, as well as data analyses and monitoring efforts to evaluate the status of the fish kill event.

The Health of Biscayne Bay

Miami-Dade County continues to invest in critical, long-term, comprehensive solutions to improve the wellbeing of Biscayne Bay. These include the ongoing septic-to-sewer transition, water infrastructure upgrades, pollution reduction policies, increased water quality testing, and enhanced monitoring and updates to the public via the annual Biscayne Bay Report Card.

How the community can help protect the Bay

Residents have several options for reporting a fish kill. The DERM hotline, 305-372-6955, and email, [email protected], are available 24/7. Residents can also report via 311. Use the 311Direct App (Android or Apple), 311 Online at www.miamidade.gov/311direct or call 311. DERM is best able to respond quickly when they are contacted directly and provided with information that includes an address or precise location. Photos and videos are also helpful.

Miami-Dade County reminds residents that their daily actions can help or harm Biscayne Bay and the local watershed. Following these tips consistently contributes to a healthier environment.