|Florida Bay Seagrass Scars © John Kipp|
Florida Bay, a sub-tropical estuary mostly encompassed by the boundaries of Everglades National Park (ENP), is a world-renowned destination for recreational flats fishing thanks to lush seagrass beds that shelter fish and shallow water in which to sight them. ENP recently released a comprehensive report that documents the extent of propeller-caused damage in this unique estuary, “Patterns of Propeller Scarring of Seagrass in Florida Bay: associations with physical and visitor use factors and implications for natural resource management”. This report analyzes prop scarring using different methodologies than previously used and thus it is difficult to definitively say that scarring has increased a certain percentage since earlier studies. However, it is clear from the report that prop scars are directly related to water depth and they cover a large proportion of shallow areas throughout the bay. The report also notes that heavily used areas that are continually scarred are unlikely to recover under current boating pressure. Research indicates that boating use in ENP has increased 2 – 2.5 times in the past 30 years.
Damage from prop scarring goes beyond uprooting a portion of a seagrass bed: without the rooted vegetation to stabilize sediments, scars contribute to degradation of water quality. The nursery function of the seagrass bed is also reduced when the shelter and food provided by the vegetation disappears. The vast expanses of seagrass that flourish in Florida Bay enable it to host one of the most species-rich assemblages of fish-eating birds in North America. Prop scarring in the bay has reached unacceptable frequency, severity, and densities, and as the report notes, the problem is unlikely to improve without implementing new resource management strategies. As ENP prepares to release a series of revised alternatives for their General Management Plan within the next few months, Audubon is prepared to advocate for managing the resources of this designated Wilderness Area in a way that preserves the function of the ecosystem for generations to come.