THE FLORIDA BAY FISH-HABITAT ASSESSMENT PROGRAM (FHAP)

• Principal Investigators: Michael J. Durako, The University of North Carolina at Wilmington, Center for Marine Science, Wilmington, NC 28409; M. O. Hall, Florida Marine Research Institute, FWCC, St. Petersburg, FL 33701
• FHAP is based on a three-tiered effort. Similar approaches are also being applied in the FKNMS seagrass monitoring program (Durako is a Co-PI in this effort) and the DERM/SFWMD monitoring program in northeast Florida Bay.
• The study elements outlined below provide information for spatial assessment and resolution of both intra- and inter-annual variability in the seagrass-macroalgae communities
• FHAP data will provide baseline data to monitor responses of these important benthic communities to possible future federal and state water management alterations or other restoration activities.
• Abundance and distribution: This study element assesses the species distribution and relative abundance of macrophytes at a bay-wide scale. Sampling is being conducted twice-yearly, during the spring (April) and the early fall (October) at more than 300 stations. Species distribution and abundance of macrophytes is assessed using a modified Braun-Blanquet frequency/abundance scale. At each sampling station, 10 short-shoots are also collected and screened for Labyrinthula and related microbes. In each of the ten selected basins, station locations are randomly chosen from within each of about 30 fixed, tesselated hexagonal grids. This type of sampling design results in systematic random sampling and scales the sampling effort to the size of the basin.
• Structure: This study element assesses the spatial and temporal variability of seagrass-habitat structure (ecoindicators). Structural characteristics of the benthic macrophyte communities (standing crop for all macrophytes; seagrass short-shoot morphometrics:short-shoot and apical density, leaf area index, leaf length and width, shoot age) are being determined during the spring Braun-Blanquet sampling. At each station, a quantitative core sample is taken in one of the four Braun-Blanquet sample quadrats.
• Population dynamics: An examination of the population age structures and demographics of Thalassia is being conducted to determine the efficacy of the recently developed reconstructive aging techniques to assessing population health. Estimates of short-shoot recruitment, mortality, shoot turnover rates, mean, median and maximum shoot ages, and cumulative age structure in this dominant seagrass will be calculated. These indices will be examined to assess population status in terms of predicted population expansion or decline.