Restoration, monitoring, and management of boat propeller seagrass scars in St. Andrews Bay, Florida.
   Ron Mezich, Florida Fish and Wildlife Conservation Commission

Abstract: The ecological effects of prop scars include loss of primary productivity and essential marine habitat, re-suspension of sediments, light reduction, and erosion. All of these factors contribute to decreased water quality (increased turbidity, nutrient loading) and further loss of seagrass. More than 50% of the seagrass beds in St. Andrews Bay have been scarred by boat propellers (Sargent, et. al., 1994).The project involves seagrass habitat restoration, management and protection. This will be achieved by restoring prop scar elevation to ambient grade, and creating suitable conditions for seagrass recruitment by providing sediment consistent with adjacent substrates. In addition, installation of non-regulatory signs strategically placed throughout the project area will establish a seagrass protection zone, and our public outreach efforts will promote public stewardship.Within the three-year monitoring period, seagrasses directly adjacent to the treated prop scars are anticipated to coalesce and be visually indistinguishable from surrounding seagrass meadows. Recovery of seagrass habitat within the area will increase the availability of this essential habitat, increase an important food source, improve water quality, through natural filtration, enhance primary productivity, and stabilize sediments within the region.Sediment Tubes® developed by Seagrass Recovery Inc. are biodegradable, cotton fabric tubes filled with sediment that in approximately 4-5 months. They will be positioned side-by-side into pre-selected prop scars within the project area. Methods designed to measure percent-cover and shoot counts will be used to compare recovery rates of prop scars located within treated and untreated locations of the project area. A minimum of four quarter-meter quadrates, subdivided into 10-cm by 10cm cells, will be randomly positioned along each prop scar for the purpose of measuring percent-cover. Within each quadrate, five 10-cm by 10-cm cells will be randomly chosen for shoot counts. Permanent transects will be incorporated into the study in order to monitor changes in the number of prop scars in both the sign-protected and unsigned areas. Aerial photography will be performed once each year, in late summer, for a period of three years to monitor the numbers and healing rates of prop scars within the project area.

Award Matching Funds Total
$27,143.00 $27,143.00 $54,286.00

Year Funded Starting Date Ending Date
2006 6/1/2007 6/30/2010

Location: Bay County