Twelve DEL-MEM souls boarded the mullet boat at Rookery Bay, armed with machetes, herbicide, and lots of water. Keewaydin Island would serve as the battle ground on this day, where the war on invasive plants threatening the estuarine ecosystem rages on. By removing invasive trees and bushes, Keewaydin Island can better support nesting bird and sea turtle populations. Invasive plant species are especially abundant in South Florida, and wreak havoc on fragile ocean, coastal, and estuarine ecosystems. Florida’s mild climate, abundant rainfall, and lack of natural predators for alien species promotes rapid proliferation of invasive plant and animal species that alter habitats and crowd out native species. Keewaydin Island is part of the Ten Thousand Islands on the Gulf coast of Florida, within the Rookery Bay National Estuarine Research Reserve.
Greg and Jill, the natural resource managers at Rookery Bay, instructed us on how to differentiate invasive and native plant species, and we set out on the island. Our goal was to help transform the southern tip of Keewaydin Island back into its native state—that being open sandy areas with patches of native vegetation.
We targeted two invasive plant species for removal. Australian pine (Casuarina glauca) was imported from Australia to Florida in the 1880s for use as an ornamental and windbreak along property lines. However, this type of tree
grows unchecked in coastal areas, crowding out native plant species and acidifying soils with needle litter. Additionally, the Australian pine has a shallow but sprawling root system that is ill-adapted to hurricane and storm prone areas. These trees topple over in storms and exacerbate erosion in the process. Our group manually pulled out hundreds of these invasives, sometimes using the group tug-of-war method for the big ones.
We also waged war on a second invasive, naupaka (Scaevola sericea). This rapidly spreading shrub species
grows thick stalks and long lateral root systems. For Scaevola plants that were too well-established to be manually pulled out, a machete was used to sever the stalks, followed by herbicide spray to ensure the root system was killed.
Participating in this important Rookery Bay restoration effort was an excellent way to spend a beautiful 80° day in January.