Environment

Nearly all the seagrass in Biscayne Bay is dead. County commissioners want to know why.

Biscayne Bay lost more than 80 percent of its seagrass meadows over the last decade.
Biscayne Bay lost more than 80 percent of its seagrass meadows over the last decade.

The past decade has not been good for Biscayne Bay: More than 25,000 acres of seagrass meadows have vanished as Miami boomed and climate change drove seas ever higher.

In a report released last week, Miami-Dade County environmental regulators blamed chronic pollution for the massive die-off, brought on by dirty canals, increasing floodwater and leaky septic tanks in older neighborhoods. The once gin-clear bay — one of the few places on the planet inhabited by all seven species of seagrass — now has wide swaths of barren bottom, muddy water and clumps of macroaglae rolling around like tumbleweeds.

But on Tuesday, the bay enjoyed a mini love fest when county commissioners ordered not one, but two reports on how to fix problems.

“While we need to continue studying, we also need to identify solutions before there’s nothing left,” said Commissioner Daniella Levine Cava, who asked for the seagrass study.

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Biologist Felix Alvarez, left, and Miami-Dade environmental resources project supervisor, John Ricisak, remove a casita from Biscayne Bay in 2016. The lobster traps and other debris can damage seagrass and other marine life. CARL JUSTE cjuste@miamiherald.com

About 10 months overdue, the report suggested continuing a number of ongoing efforts, including monitoring water quality and the bay bottom. But it failed to suggest more specific fixes like identifying and dealing with sources of pollution. Clearly frustrated, Levine Cava asked county environmental chief Lee Hefty to come back in six months with more detailed recommendations for problems that have escalated in recent years.

In 2016, an alarming seagrass die-off in the Tuttle basin wiped out most of the grass in just two months and reignited scrutiny of ongoing issues, including a busier and bigger port and cooling canals at Turkey Point that continue to leak into the bay. A coral disease that started off Virginia Key in 2014 has now spread to Key West. And in November, the county issued a dire septic tank forecast. Leaky tanks have for several years been blamed for polluting the bay with nitrogen, which fuels macroalgae. But the November assessment predicted that as sea levels climb and drive up the water table, more tanks will leak.

Commissioners also voted to create a nine-member task force suggested by Commissioner Rebeca Sosa and gave it six months to draft its own report.

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Trash often piles up along the shoreline of the urban bay, including behind the Vizcaya Museum & Gardens in 2016. Vizcaya Museum & Garden

The task force will include Hefty, along with the county’s chief resiliency officer. Remaining members will be appointed by commissioners and include two reps from the real estate and tourism industries and two from communities with an interest in the bay. The three remaining seats will be filled by an engineer and experts in water quality and coastal management.

“Now is the moment, with today’s approval of the Biscayne Bay task force, that we will be able to get the experts to sit down and come back to us with their recommendations,” Sosa said.

Jenny Staletovich is a Florida native who covers the environment and hurricanes for the Miami Herald. She previously worked for the Palm Beach Post and graduated from Smith College.
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