known precisely, but the same restrictions apply within the outlines of the East Flower Garden bank. It is thought that the East Flower Garden reef is situated in the southern portion of the bank. The additional stipulation of no structures, drilling, or pipelines within one mile of the live reef was included because of the possibility of the reef being near the edge of the bank. Additional operating procedures may be necessary to preclude the threat of sedimentation from operations one to three miles from the reef. It is felt that the combination of special stipulations, operating orders, and review of development plans offers sufficient safeguards to protect the reef and its biota. Additionally, a monitoring program will be used as a device to identify any adverse impacts on the reef caused by oil and gas operations. These impacts will be reported immediately so that operating orders may be tightened to prevent or minimize further damage to the reef. Figure 50. West Flower Garden Bank Area. Live reef is located or pipelines are to be permitted in shaded stipulated area. Underlined numbers are tract numbers; other numbers are block numbers. C. Impact on the Biological Communities of the Coastal Zone This proposed sale is somewhat unique from all past sales in that its threat to biota of the coastal zone is lower than ever before. The reasons are: 1) all tracts offered are considered to be only gas prone. A range of 8 to 12 bbl of liquid hydrocarbons per well 2) all tracts but five are located more than 30 miles from 3) 1. shore. The closest is 13 miles. at the most, two new pipelines and one new onshore treatment facility will be required. Impact on Artificial, Hard Substrate Communities Along the Texas coastline, these communities are very small and widely scattered, located primarily on pilings and jetties. Few investigations have been made of the effects of oiling on these specific types of communities, but for the purpose of this discussion, it will be assumed that there would be some similarity to an oiling of the rocky intertidal areas of other coasts that have been subjected to spilled oil. Studying the effects of the Chedabucto Bay spill of bunker C oil, Thomas (1973) found that most of the approximately 20 species observed, with the exception of those smothered by heavy oil, appear to have been little affected. Barnacles showed no unusual mortalities and settlement of larvae occurred in following seasons. Periwinkles, the most common intertidal animals, remained abundant and still occupy generally the same zones. A seaweed, Fucus, was reduced or eliminated at the locations where oiling was severe, and recolonization has not been successful. The seaweed did not die abruptly but declined gradually in the 10 months or so following initial oiling. Common grazers, the limpets, After studying the effects of pollution from Torrey Canyon, Bellamy, et. al. (1967) hypothesized that the oil pollution caused an alteration of the balance of ecosystems dominated by attached seaweed by destruction of the grazing organisms. were apparently reduced by about 40%. The severity of the impact to grazers was greatly increased by the use of detergents but there is no long-term direct damage to the algae by either oil or detergent. The effects of oiling on the rocky intertidal areas near Santa Barbara (Nicholson and Cimberg, 1971) and San Francisco (Chan, 1972) were attributed primarily to smothering. During the study of the effects of a tanker spill of Bunker C and diesel near Panama, Rutzler and Sterrer (1970) observed that the characteristic intertidal algal community on the red mangrove stilt roots were practically eliminated in all oil exposed areas. Also killed were the sedentary animals of this zone such as oysters, mussels, barnacles, sponges, tunicates, and bryozoans. |