A proposed 325-slip marina at the shuttered Miami Seaquarium on Virginia Key would bring megayachts and hundreds of luxury boats to Biscayne Bay, the same waters where residents across Miami-Dade County fish, kayak and boat. State regulators are already pushing back.

Miami-Dade County submitted the permit application to the Florida Department of Environmental Protection, or FDEP, during the week of July 7, according to WLRN reporting. The county is the landowner; the marina design comes from developer David Martin's consultant. FDEP responded with a six-page list of unanswered questions covering seagrass damage, coral impacts, dredging plans and water quality, none of which were addressed in the application.

The marina, planned for the 36-acre, county-owned waterfront property, would include nearly 90 slips for yachts longer than 80 feet, a dry-stack tower storing up to 500 additional boats, and a fuel dock exceeding 19,000 square feet. Floating docks and finger piers would stretch more than halfway across the channel separating Virginia Key from surrounding seagrass flats. A breakwater doubling as a fishing pier would extend roughly 1,400 feet around the piers.

Developer Would Keep 95% of Slip Profits Under Proposed County Deal

Martin, CEO of the Terra Group, tentatively secured a lease from the county in December 2025 after the Seaquarium's parent company filed for bankruptcy. Under the proposed deal, Martin would receive 95% of profits from the marina's boat slips, according to WLRN.

Martin did not respond to a request for comment from WLRN reporters. In a Miami Herald opinion piece, he described his vision as "rooted in accessibility, sustainability and community benefits," promising a fisherman's village and aquarium.

County officials told WLRN that the marina design is entirely the developer's work. They said the county's environmental department would be a key partner in coral conservation efforts at the site.

Bay Already Lost Up to 90% of Seagrass, Report Finds

The permit application lands as Biscayne Bay struggles. The bay has lost between 70% and 90% of its seagrass flats in the past decade, according to WLRN's reporting. The 2026 Biscayne Bay Report Card, released in May by Miami-Dade's Department of Environmental Resources Management, or DERM, found all regions remain in poor or fair health. The bay contributes roughly $64 billion to the county's economy, according to that report.

"You put all these big yachts in there, they might as well dredge those flats right now because they're going to be wiped out," said Capt. Bob Branham, a retired fishing guide with 50 years on Biscayne Bay, who described the area near the old Seaquarium as still productive for bonefish, permit and tarpon.

Laura Reynolds, policy advisor for Friends of Biscayne Bay, told WLRN that the bay's shallow depth makes it unsuitable for megayachts, noting that Fort Lauderdale handles that industry because of its deeper waters.

Three manatees were killed by vessel strikes in Biscayne Bay in 2025, and the county's Manatee Protection Plan relies on existing zoning to determine boat density. The county building department will determine whether the marina plans comply.

Rezoning, Voter Approval Among Remaining Hurdles

County commissioners have not yet approved the special district rezoning needed for the site. A comprehensive plan amendment application was accepted during the week of July 7 and remains under staff review.

The county's shoreline advisory committee has not reviewed the marina plans. County environmental staff who oversee bay-impacting projects have not weighed in either, though officials said they are part of lease negotiations.

The county charter requires that public land remain "unimpaired for the enjoyment of future generations." Changes within the Biscayne Bay Aquatic Preserve require approval by two-thirds of county voters. Two other Virginia Key marinas in the permitting pipeline will need that voter approval.

No public hearing date has been announced for the commission vote on the special district. Residents can monitor the Miami-Dade County Commission agenda at miamidade.gov for upcoming hearings on the Virginia Key rezoning.