Hurricane Irma: Impacts on Florida Wildlife & Habitat
As every Gulf Coast resident knows, hurricanes are natural events. In Florida, we joke that there really are only two seasons – tourist season and hurricane season. Native wildlife species are adapted to survive and recover from these storms. The problem now is that humans have not only altered the natural landscape – putting both people and wildlife at greater risk from these storms – but have also altered the climate in ways that make these storms more severe.
Hurricane Irma was the strongest Atlantic hurricane on record and maintained winds of 185 mph for longer than any other tropical cyclone in the world. This extreme storm ripped across the Caribbean and struck the Florida Keys as a Category 4 hurricane, eventually affecting nearly the entire state. As my hometown of Naples, and the rest of Florida, begin to recover, the fate of many of the state’s unique wildlife species and native habitats remain unknown.
Hurricane Irma first made Florida landfall in the Florida Keys, the string of islands just south of Everglades National Park. Perhaps one of the most famous animals unique to these islands is the endangered Key deer. This very small subspecies of the white-tailed deer measures only about three feet tall, and they only live on a few islands in the Keys. Currently, there are fewer than 1,000 Key deer remaining in the wild, and they’ve been plagued in the past by disease and habitat loss as humans developed the islands. The deer’s habitat was hit by some of the worst of Irma’s winds and rain, but it’s too early to tell how most of the deer population fared in the aftermath of the storm. Fortunately, the deer are strong swimmers and they have survived many storms. However, even if most of the deer survived, their habitat may have sustained serious damage. In particular, saltwater from the hurricane’s storm surge may dramatically alter deer habitat in the refuge’s already diminishing tracts of upland pine forest. The National Key Deer Refuge plans to assess the status of the deer when it is safe to return to the islands, but several surviving deer have already been spotted since the storm hit.
Florida is home to the third-largest coral barrier reef system in the world – the Florida Reef Tract, which stretches more than 300 miles from the Dry Tortugas at the southern end of the Florida Keys to West Palm Beach on the Atlantic Coast. These reefs provide critical habitat for fish and wildlife, including spiny lobster, goliath grouper, and parrot fish. The reefs help to naturally reduce wave action and protect the Keys and Florida’s coasts from storms like Irma.
Since they’re on the front line, however, coral reefs are the first to bear the brunt of waves when storms roll through the area. Large hurricanes and storms generate powerful waves that can break coral branches and disrupt coral colonies. Heavy rain on land can result in increased sediment and nutrient-polluted runoff that can lower the salinity of coastal waters, and it can decrease water quality, which further stress the corals.
Florida’s coral reefs have survived many hurricanes over the millennia, but the ability of these corals to recover after severe storms has been damaged by rising water temperatures, pollution, and overfishing. Less than 10% of the reef is now covered with living coral. Fewer live coral results in less of a buffer for the coast from waves and storms, not to mention the devastating impact on Florida’s reef ecosystem and recreation economy.
Nearly 90 percent of sea turtle nesting in the United States happens on Florida’s beaches, from March through October. There are five sea turtle species that nest on Florida beaches – the loggerhead, the green turtle, the leatherback, the hawksbill, and, infrequently, the Kemp’s ridley. All five species are listed as either threatened or endangered under the Endangered Species Act.
Sea turtles are evolved to cope with tropical storms and hurricanes. Female sea turtles nest in several places along Florida’s coast, usually an average of five to seven nests per season. This instinctive behavior increases the chances that at least a few nests will hatch successfully, even if some are hit by storms and washed away. Also, sea turtle nests are designed to drain well, so even if a nest is temporarily submerged, there’s a chance the eggs will survive.
Florida’s birds are also adapted to prepare for hurricanes. Birds are sensitive to barometric pressure, so they can sense when a major storm is on the way. Birds then adjust their behavior to prepare in a variety of ways. Some migratory birds migrate sooner than they otherwise would. Other birds have been known to fly into, ahead of, or through a storm, or get trapped inside the storm, which can often end up relocating birds to places they aren’t normally found in. For example, a roseate spoonbill likely somehow displaced by Irma or Harvey was recently seen in New Jersey. In 2016, radar images of Hurricane Matthew showed a flock of birds trapped in the eye of the storm as it moved across Florida.
Birds that don’t migrate often shelter in place, trying to find cover wherever they can. In residential areas, plantings of dense shrubs and other native vegetation can provide cover for birds during extreme storms. In the end though, hurricanes are likely to at least temporarily affect habitat and food sources, which can put pressure on already stressed species.
Many unique native species call the greater Everglades ecosystem their home. South Florida’s threatened wood stork population nests in bald cypress trees in Corkscrew Swamp Sanctuary and Everglades National Park. These wading birds are the only stork native to North America and were once abundant in South Florida wetlands and their breeding behavior has adapted to reflect the natural flooding and drying conditions of the Everglades. However, if water levels are severely disrupted resulting in a lack of sufficient food, wood storks cannot nest successfully.
The Everglades are also home to the Florida panther, a unique subspecies of mountain lion. Florida panthers are critically endangered – there are fewer than 100 estimated to live in South Florida today. In the nearly two hundred years since humans began transforming “the river of grass” into agricultural fields and cities, the panthers face threats from habitat loss and fragmentation. Interstate 75 and Alligator Alley both cut through their historic range, bringing them into sometimes deadly contact with cars. Through intensive conservation efforts, Florida panthers have been making a comeback and will likely recover from the immediate impacts of the storm. However, as Hurricane Irma swept over their remaining habitat, it provided a stark reminder about how human impacts have left panthers and other endangered species vulnerable.
In addition to the habitat that the Everglades provides to wildlife, it also provides enormous benefits to people through naturally absorbing, cleaning, storing, and conveying freshwater, replenishing aquifers and protecting communities from floods. The Glades’ marshes and mangrove forests help buffer the coast, reducing the impact of flooding, surge, and erosion during storms. Ongoing efforts to help reconnect and restore the natural flow of freshwater throughout the Everglades ecosystem are crucial to help these habitats and wildlife recover and thrive.
As we shrink habitat for these wild creatures, we reduce their chances of recovery from major disturbances like hurricanes – and leave ourselves more vulnerable as well. As we move forward, we must implement common-sense policies to help rebuild a more nature-based resilient landscape along our coasts to better protect people and wildlife in the face of future disasters.