MIAMI – After yet another massive fish kill in Biscayne Bay caused by widespread pollution, researchers are working to assess the damage.
“Our bay is really crying for help at this point,” Miami-Dade County’s Chief Bay Officer Irela Bague said.
In the past seven days, the county has removed more than 2 tons of dead fish from the waters of the bay’s northern basin, from Bay Harbor Islands, south to Morningside and east to Miami Beach, centered around the highly-polluted Little River Canal.
Conditions have seemingly improved and the fish kill has subsided, but scientists are trying to figure out why it happened.
It comes two years after a fish kill that left more than 27,000 fish dead.
“This October has been the worst fish kill that we’ve seen since (2020),” Rachel Silverstein, the executive director for Miami Waterkeeper, said.
It’s another dagger in the big blue heart of our community.
“The bay is not dead but we need to pay attention to it,” Piero R. Gardinali, with Florida International University’s Institute of Environment, said. “Everybody needs to do something.”
Two days after the fish kill began, Local 10 News joined a research team from FIU’s Institute of Environment on the bay to try and pinpoint the trigger spots: pockets of anoxia—no oxygen—causing marine life to suffocate and die.
The group sampled 10 sites and the readings were grim.
“There’s zero oxygen,” a researcher said.
We could see schools of fish struggling on the surface.
Some died right before our eyes, as hungry seabirds took advantage of an easy meal.
The Little River Canal consistently shows low oxygen levels.
The low dissolved oxygen, or DO, levels are caused by too much pollution entering the watershed.
But this time, it wasn’t just happening near the outfalls of the canals. Data showed the low oxygen was coming from the bottom of the bay.
“The river always brings low-oxygen water into the bay, but this time it’s an event that is happening in the bay,” Gardinali said.
It’s historically dirty water, caused by too much pollution, that’s been accumulating in our groundwater for decades. But why was it suddenly released into the watershed on a cool, windy October day, when the bay typically gets a break?
“It is pollution coming from septic tanks, from storm water runoff, from sewage leaks and from fertilizer,” Silverstein said. “But why the fish kills are happening on this particular day on this particular week is something we don’t yet understand.”
Every time it rains, it all flushes into the canal system that dumps out into Biscayne Bay—and it’s killing it.
“Everything we do on land is connected to what’s getting into the water and the canals are bringing all of that pollution into the bay,” Silverstein said.
Silverstein has been consulting with scientists to try to get to the bottom of the latest fish kill.
“Potentially, the king tides and having very high tides; the poor water quality and the low oxygen is potentially coming from some interaction between the groundwater, the canals and the bay,” she said.
Bague is charged with the daunting task of reducing pollution and restoring the watershed. It won’t be an easy fix.
“We’re in a dire situation and we are now taking actions that should have been taken over 20 years ago,” she said. “We have all hands on deck and we have the state partners working together with the county, we have the federal partners working together with us as well.”
Together, they’re setting goals to reduce the deadly nutrients entering our waterways, procuring funding to improve infrastructure and fast-tracking a program to get properties off failing septic tanks, as well as connecting them to sewer lines.
The county also now bans the use of fertilizers during the rainy months of May through October. Everything makes a difference.
“This is going to be a multi-year fix that we have to start now,” Silverstein said. “We have to get this pollution out of the bay. We have to stop any more pollution from getting into the bay.”
A spokesperson for the South Florida Water Management District said the agency is committed to improving the bay:
“The South Florida Water Management District is absolutely committed to supporting the health of Biscayne Bay, one of the key estuarine systems in our state. To support the Bay, the District undertook two massive restoration projects through the Comprehensive Everglades Restoration Plan (CERP): Biscayne Bay Coastal Wetlands and Biscayne Bay Southeastern Everglades Ecosystem Restoration Project. In fact, our Board recently awarded the contract to start the final component of the Biscayne Bay Coastal Wetlands restoration project, and this component of the bay restoration project will break ground by the end of the year.
The water management district also operates the regional flood protection system in South Florida. This canal system, which receives 50+ inches of rain each year, provides critical flood protection to millions of residents. Flood protection operations of the canals involve judiciously opening and closing flood gates to protect homes and businesses from flooding. Stormwater washes into the canal system from local governments’ drainage systems and brings with it anything it collects on its way. This is why we’ve installed additional debris-collecting booms to capture debris in canals and remove the collected debris frequently. We’re also ready to partner with local governments and stakeholders on additional efforts to improve Biscayne Bay and the water quality of stormwater making its way into the regional flood protection system from local drainage systems.
Biscayne Bay is the liquid heart of Miami-Dade County, and we look forward to implementing our restoration projects and working together with partners to support the health of this precious ecosystem.
Sean Cooley, SFWMD Communications Manager
Miami-Dade Mayor Daniella Levine Cava said she’s making the bay a priority.
“We have reduced the fertilizers, right during the rainy season, we’ve been very aggressive on enforcement of pollution around building sites,” she said. “We know we have some really, very polluted inflows to the bay, and we’re working aggressively on those as well.”
But this is on all of us. If we really want to save Biscayne Bay, everything we do on land matters.
“Things are not getting better,” FIU research tech Jeff Absten said. “You know, I think that, for me, I think that we’re part of the problem, you know, but if we’re part of the problem, we’re also part of the solution. You know, I think there’s a lot that we can do.”
What you can do
Residents can stop using fertilizers on lawns and gardens during the rainy season, refrain from throwing lawn clippings into any body of water, especially Biscayne Bay, pick up pet waste, stop littering and stop using single use plastics.
Right now, scientists are bracing for a possible algae bloom, like we saw in 2020.
County officials are asking the public to please stay vigilant and report any signs of algae blooms or more dead marine life.
To do so, call 311 or email baywatch@miamidade.gov.