Audubon: Tigertail lagoon restoration could impact nesting habitat for threatened birds
The plan to restore Tigertail lagoon on Marco Island to pre-Hurricane Irma conditions puts in jeopardy the nesting grounds of hundreds of threatened birds, according to Audubon Florida.
The project, which is in its conceptual stage, consists of expanding the dredged area at the entrance of the lagoon to the north tip of an adjacent sandbar, called Sand Dollar Island, and using the sand to create a barrier to reduce coastal erosion.
Audubon Florida policy associate Brad Cornell said Audubon cannot support the project because removing sand from the north end of Sand Dollar Island would harm the nesting habitat of state threatened birds like black skimmers and least terns.
"There are serious problems with this proposal," Cornell said.
Adam DiNuovo, Audubon Florida's Lee and Collier bird stewardship project manager, said hundreds of birds have been nesting on Sand Dollar's north tip in recent years.
"My concern would be that that nesting habitat would be removed and the birds wouldn't have a place to nest on the north end of Marco," DiNuovo said.
The Florida Shorebird Database, monitored by the Florida Fish and Wildlife Conservation Commission, shows approximately 186 black skimmer nests were active on Sand Dollar's north tip last year.
Bird observers counted 340 in 2019, 410 in 2018 and 500 in 2017.
Black skimmers and least terns are colony nesters, meaning they nest in groups, which allows them to exchange information about food sources as well as to detect and mob predators, according to FWC's website.
These birds nest on the beach sand in open areas with little or no vegetation during the summer, said Ricardo Zambrano, regional biologist with FWC.
Black skimmers' and least terns' main threat is habitat loss as the human population and development increases along the coasts, according to FWC's website.
Other threats are predators, recreational activities, and climate change resulting in sea-level rise.
DiNuovo said the sand barrier proposed for the middle of Sand Dollar Island may not be a suitable shorebird nesting habitat because these birds like wide and flat sandy areas.
"I just don't know if there is a way to make it attractive for beach nesting birds and have it be a barrier to the water at the same time," DiNuovo said.
The project includes an additional smaller dredge in the middle of the lagoon, which may negatively impact seagrass, in an effort to improve tidal flow and water quality.
Seagrasses are flowering plants found submerged in coastal marine waters that provide habitat for many species and become food source for animals like manatees, according to FWC's website.
DiNuovo said the lagoon's water quality issue won't necessarily be resolved by just improving tidal flushing and that more studies are needed.
"There are a lot of factors that are exterior to this lagoon that have not been addressed," DiNuovo said.
Veterinarians diagnosed the birds with bacterial dermatitis, tendinitis and osteomyelitis, but the source of the pathogen is unknown, FWC spokeswoman Michelle Kerr told the Naples Daily News last month.
The city's Hideaway Beach Tax District, a special district in charge of paying for its beach maintenance, hired an engineering firm for the planning and permit application stages of the lagoon's restoration project.
Mohamed Dabees, vice president of Humiston & Moore Engineers, said they understand the importance of Sand Dollar Island's north end for shorebird nesting.
"We will continue to coordinate with Rookery Bay, Audubon and FWC (to find a way to) maintain the stability of Sand Dollar Island as well as avoiding or minimizing potential effects to bird nesting," Dabees said.
Dabees said during a City Council meeting Jan. 4 that waves hitting Sand Dollar Island have been eroding its middle section for years. The situation worsened in 2017 when Hurricane Irma made landfall on Marco.
The waves created an optimum area for shorebird nesting on Sand Dollar Island's north tip.
"The north tip of Sand Dollar grew over 12 acres from pre-Irma conditions to date," Dabees said.
Sand Dollar's center could collapse if nothing is done
If nothing is done, Dabees said the remaining barrier in the middle of Sand Dollar will collapse, permanently closing off part of the lagoon, worsening its water quality and exposing nearby infrastructure to waves coming from the Gulf of Mexico.
"In the case of an extreme (weather) event, we are not going to be as vulnerable as we are right now," Dabees said during the council meeting.
Dabees said the district funded smaller dredges on the lagoon's entrance in 2013, 2016 and 2019.
The district spent about $3 million in dredges and other related activities, said Linda Ryan, board member of the district.
On Jan. 7, Cornell said Audubon Florida and Audubon of the Western Everglades support these smaller dredges because otherwise the north tip of Sand Dollar Island would have already merged with Hideaway Beach.
"Predators and humans would easily be able to walk out anywhere on Sand Dollar, and that would be a conflict with the nesting colony and other wildlife," Cornell said.
Council supports dredging, restoration plan
During the meeting, City Council unanimously passed a motion in support of a dredging and restoration plan.
The motion also instructed city staff to work with Collier County, owner of the nearby Tigertail Beach Park, to move the project forward.
Councilor Erik Brechnitz said during the meeting the county could use tourist tax dollars, a 5% charge on hotel and other short-term rental stays, to fund the project.
"It is the county's responsibility to maintain this and to keep it as a tourist development attraction," Brechnitz said.
Collier Commissioner Rick LoCastro, who represents East Naples and Marco Island, said during the meeting he supports the project.
"I'm not going to ignore this issue or kick the can," LoCastro said.
On Jan. 15, LoCastro said he does not necessarily support the project as presented because more information is needed.
The county is already spending more than $1 million in park improvements like a new upper-level deck next to the the food concessions area, new playground attractions and additional restrooms.
"Collier County looks forward to the ongoing discussions with the City of Marco Island regarding these important natural resources," Amy Patterson, director of the county's capital project planning, impact fees and program management division, wrote in an email Jan. 12.
On Jan. 12, Brechnitz mistakenly said there are no birds nesting on the north tip of Sand Dollar Island. He also said shorebirds need foliage to nest, but biologists say that is not a requirement for black skimmers and least terns.
"There is not one single bird nesting on the sand we propose to take, not one," Brechnitz said.
City Council Chairman Jared Grifoni said efforts to control erosion and improve water quality in the lagoon should not create a new problem.
"It's important to make sure that everybody's voice is being heard so we can make sure that whatever ultimately ends up going forward it takes into account the environmental impacts for the whole Tigertail area," Grifoni said.
Cornell said Sand Dollar Island and Tigertail lagoon are part of a coastal ecosystem essential for thousands of birds in Florida.
"It is the most important beach nesting habitat that we have on Marco," DiNuovo said.