The Sensitivity of Coastal Environments and Wildlife to Spilled Oil in South Florida

Getter, Charles; Michel, Jacqueline; Scott, Geoffrey; Sadd, James

EXECUTIVE SUMMARY: A shoreline assessment was conducted throughout South Florida by means of aerial overflights, ground stations, and literature review. A total of 23 maps, this report, and six data supplements were produced. The 23 maps show RPI' s Environmental Sensitivity Index which depicts shoreline and wildlife sensitivity to spilled oil on a scale of 1-10. The following shorelines were shown on color-coded maps: - Exposed, vertical Rocky Shores and Seawalls (ESI=l) - Exposed Rocky Platforms (ESI=2) - Fine-Grained Sand Beaches (ESI=3) - Coarse-Grained Sand Beaches (ESI=4) - Mixed Sand and Gravel Beaches and Fill (ESI=S) - Gravel Beaches and Riprap (ESI=G) - Exposed Tidal Flats (ESI=7) - Sheltered Rocky Shores and Seawalls (ESI=8) - Sheltered Tidal Flats (ESI=9) - Mangroves (ESI=lOa) - Sheltered Mangroves (ESI=lOb). The following oil-sensitive wildlife were also shown on these maps: - Resident Mammals - Marine Birds - Sea Turtles and Crocodiles. The first subject of this report was to describe the environments and wildlife which appear on the maps. Special features related to placing booms, skimmers, and access for cleanup during oil spills are also shown on the maps and discussed in this report in detail. Additional detail is given in this report concerning cleanup techniques. Also described are resources which are more variable in their sensitivity to oil, usually being less sensitive since they are either underwater habitats or animals capable of avoiding oiled areas: - Coral Reefs - Seagrass Beds - Whales and Dolphins - Marine Fisheries. Mangroves sand beaches, and man-made structures are the dominant shorelines of South Florida. The barrier island system from Boca Raton to Key Biscayne affords protection of inner, more oil-sensitive environments within the intercoastal waterway and northern Biscayne Bay. Oil which physically impacts these outer beaches would be relatively easy to clean, and these efforts would be aided by natural processes (waves and currents). Efforts to protect the in ner bays and waterways should be concentrated at the four large inlets which connect inner bays and waterways to the Straits of Florida. Biscayne Bay and Card Sound are exposed through a tenmile- wide corridor to the Straits of Florida. Biscayne Bay is a productive and sensitive estuary which contributes a vital support to the local economy as it supports fisheries and nursery stock (including a lobster sanctuary) for fish and shellfish and numerous forms of marine recreation. In addition, southern Biscayne Bay and Card Sound are ringed with oil-sensitive mangroves, bird rookeries, and crocodile forage areas. Biscayne Bay and Card Sound afford the greatest potential of any area in South Florida for severe biological and economic damages due to a large oil spill. The Florida Keys are characterized by numerous channels and creeks in which booms and skimmers are recommended. There are numerous lagoons filled with sheltered mangroves which are often connected by only narrow tidal creeks which are easily boomed. Numerous bird rookeries are found throughout the many offshore islands in this region. In general, oil-spill protection in South Florida involves ocean-going skimmers at the spill site (first line of defense), deflection booms at inlets, channels, and creeks (second line of defense) , and containment booms across canals in sheltered waters (third line of defense). In addition, sorbent booms in front of mangroves may trap oil before and after they become oiled. Cleanup techniques are recommended which utilize natural processes whenever possible. Techniques which utilize manual labor and natural processes are much less environmentally damaging and are recommended for cleanup in nearly every case over the use of heavy machinery and dispersing chemicals.