Boating impacts to seagrass in Florida Bay, Everglades National Park, Florida, USA: links with physical and visitor-use factors and implications for management

Abstract

Recreational motor boating in shallow water can damage submerged natural resources through propeller scarring and these impacts represent one of many factors that affect the health of seagrass ecosystems. Understanding the patterns of seagrass scarring and associations with physical and visitor-use factors can assist in development of management plans that seek to minimise resource damage within marine protected areas. A quantification of seagrass scarring of Florida Bay in Everglades National Park, using aerial imagery, resulted in the detection of a substantial number and length of seagrass scars. Geospatial analyses indicated that scarring was widespread, with the densest areas found in shallow depths, near navigational channels, and around areas most heavily used by boats. Modelling identified areas of high scarring probability, including areas that may experience increased scarring in the future as a result of a reallocation of impacts if management strategies are implemented. New boating-management strategies are warranted to protect seagrass in Florida Bay. An adaptive approach focusing on the most heavily scarred areas, should consider a variety of management options, including education, improved signage, new enforcement efforts and boating restrictions, such as non-motorised zones, or temporary closures. These methods and recommendations are broadly applicable to management of shallow water systems before and after resource impacts have occurred.

Habitat Use and Behavior of Multiple Species of Marine Turtles at a Foraging Area in the Northeastern Gulf of Mexico

“…Recreational scalloping fisheries are extremely popular in the CR region attracting thousands of users each year (Greenawalt-Boswell et al, 2007), which leads to significant increases of vessel traffic in the area during the scallop harvest season (Wildermann et al, 2018b). High density of vessels can increase the probability of marine turtle-vessel interactions (e.g., vessel strikes; Hazel et al, 2007;Work et al, 2010), and habitat degradation through pollution (e.g., oil leaks, marine debris) and anchoring (Hallac et al, 2012), among other sources, can potentially impact food source quality and quantity. Based on the behavioral patterns estimated in this study, most CM were distributed in shallow waters where there is potentially higher exposure to marine traffic, but those CM distributed in deeper waters (up to 12 m) are less exposed to marine traffic and have more room to avoid occasional vessels.…”

Long-term performance of seagrass restoration projects in Florida, USA

“…Nevertheless, we note that restoration via vessel damage repair may not be the preferred management prescription in all cases. For example, approaches focused on seagrass protection through education, channel markings, limited-motoring zones, and enforcement may be preferable to restoration where natural recovery is likely or ongoing vessel damage is expected 44 .…”

Assessing the effect of recreational scallop harvest on the distribution and behaviour of foraging marine turtles

“…Indirect effects of recreational fisheries to marine turtles could occur through impacts on seagrass beds (Hallac et al, 2012), which are important habitats for several species of marine turtles (Bjorndal et al, 1997; Schmid et al, 2003; Bjorndal & Bolten, 2010). A major impact of boating activities in coastal habitats is the fragmentation and degradation of seagrass beds as a result of extensive scarring and anchoring.…”