A study of nine sites along Florida’s coasts projects that sea-level rise would dramatically alter the extent and composition of important coastal habitats throughout the region if global warming continues unabated.
“Fishing as we know it could disappear in a matter of decades,” said Manley Fuller, president of the Florida Wildlife Federation. “Our coastal habitats are shrinking and if we lose our coastal fisheries to rising seas, the effect on fish and wildlife Floridians have worked so hard to protect will be devastating.”
The Florida Wildlife Federation and the National Wildlife Federation commissioned an independent researcher to study nine areas along Florida’s coast (including Pensacola Bay, Apalachicola Bay, Tampa Bay, Charlotte Harbor, Ten Thousand Islands, Florida Bay, Biscayne Bay, St. Lucie Estuary and Indian River Lagoon) to see how a 15-inch rise in average sea level during this century would affect coastal habitats.
The study found that nearly 50 percent (approximately 23,000 acres) of critical saltmarsh and 84 percent (166,572 acres) of tidal flats at these sites would be lost. The area of dry land is projected to decrease by 14 percent (174,580 acres), and roughly 30 percent (1,000 acres) of ocean beaches and two-thirds (5,879 acres) of estuarine beaches would disappear.
As sea level rises, the area of open-ocean and estuarine water is projected to increase by 64 percent and 18 percent, respectively (totaling 266,110 acres), and mangroves are expected to expand in some areas, increasing by 36 percent (92,541 acres). The area of brackish marsh is projected to increase more than 40-fold (73,695 acres), mostly around Apalachicola, taking over much of the current hardwood swamp land.
In addition, global warming is expected to lead to an increase in marine diseases, harmful algal blooms, more-extreme rainfall patterns and stronger hurricanes, all of which would have a significant impact on the state’s prime fisheries.
“Fishing is a way of life in Florida,” said Fuller. “Not only is it a wonderful pastime, it’s an economic boon to the state.” According to the Florida Fish and Wildlife Conservation Commission, in 2005 anglers spent $3.3 billion on saltwater recreational fishing in Florida, supporting nearly 60,000 jobs.
Scientists agree that a significant increase in the rate of sea-level rise due to melting glaciers and ice caps and the thermal expansion of the oceans is one of the most direct consequences of global warming.
“Florida’s game fish are on the front line,” said Patty Glick, global warming specialist for the National Wildlife Federation and author of the report, Unfavorable Tide: Global Warming, Coastal Habitats and Sportfishing in Florida. “As sea level rises, fish species that need the protection of saltmarshes and tidal flats during their early larval or juvenile stages will be most vulnerable.”
According to the Intergovernmental Panel on Climate Change (IPCC) the global average sea level has already risen about 6 inches over the past century. Based on recent trends, scientists’ mid-range projection is that sea level will rise another 15 inches by the year 2100.
Glick said that along Florida’s gradually-sloped shores, this would translate into a horizontal advance of water inland by as much as 250 feet, contributing to coastal erosion, inundation and changes in wetlands and mangroves.
The projected 50 percent loss of saltmarsh habitat, for example, would be a significant reduction in fish nursery habitat, Glick said. In addition, significant declines in beaches and tidal flats in some areas would reduce habitat for species that rely on those areas to feed.
Among the top 10 game species considered most at risk are Bonefish; Flounder; Gag grouper; Gray snapper; Permit; Pompano; Redfish; Snook; Spotted seatrout; and Tarpon. In many areas, sea-level rise would also reduce essential habitat for important prey species such as shrimp, crabs and smaller fish, causing ripple effects throughout the marine food web.
“This list is by no means comprehensive, nor is it a ‘prediction’ of what is to come; but it does signify the extent to which sea-level rise could threaten Florida’s treasured sportfishing traditions,” Glick said.
Glick said there are signs that the rate of sea-level rise in the future could actually be considerably greater than current projections, due to a recently discovered increase in the rate at which the ice sheets of Greenland and Antarctica are melting.
Along the Gulf Coast and in South Florida, the most vulnerable habitats are saltmarshes and tidal flats. Along the East Coast, the greatest problems are likely to be significant erosion of beaches and inundation of dry land.
“The vast majority of Florida’s marine fish and shellfish species depend on saltmarshes, seagrass beds and other habitats found in the state’s bays and estuaries, so the projected changes to these habitats due to sea-level rise would have an enormous impact on Florida’s commercial and recreational fisheries,” Fuller said.
Glick said that all of the changes caused by global warming would fall on top of the numerous other stressors that threaten Florida’s coastal resources.
“While it is difficult to know exactly what each and all of these problems combined would mean for Florida in the decades to come, there is no question that without meaningful action to address these multiple threats the future of the state’s coastal habitats, the fish and wildlife they support and the livelihoods and quality of life of the people who depend on them would be dramatically and irretrievably different from what they are today,” Glick said.
Glick said that reducing global warming pollution can minimize the threat of global warming. In addition, developing and implementing more-rigorous fishery and coastal resource management strategies that fully incorporate the likely impacts of global warming on habitats is essential to protecting coastal Florida’s fishing resources.