44. O'CONNOR, J.M., NEUMANN, D.A., and SHERK, J.A., Jr., "Sublethal Effects of 



Suspended Sediment on Estuarine Fish," TP 77-3, U.S. Army, Corps of Engineers, 



Coastal Engineering Research Center, Fort Belvoir, Va., Feb. 1977, NTIS AD No. 



A040 646. 



The objective of this study was to determine the effects, if any, of sublethal 



concentrations of suspended materials on the fish in estuarine systems. The suspensions 



were of natural sediment, obtained from the Patuxent River estuary, Maryland, or 



commercially available fuller's earth. 



1978 



45. JOHNSON, G.F., and deWIT, L.A., "Ecological Effects of An Artificial Island," MR 



78-3, U.S. Army, Corps of Engineers, Coastal Engineering Research Center, Fort 

 Belvoir, Va., Sept. 1978, NTIS AD No. A062 065. 



This study documents marine ecological conditions at Rincon Island, located 

 approximately one-half mile offshore between Ventura and Santa Barbara, California, in a 

 depth of 14 meters (45 feet). The island, which was constructed between 1954 and 1959 to 

 serve as a permanent platform for oU and gas production, is particularly suitable for 

 ecological study. Habitat features associated with the armor rock and concrete tetrapods 

 surrounding the island support a "microecosystem" which differs in biotic composition 

 from surrounding natural bottom areas. 



A major part of the study was devoted to analysis of seasonal dynamics in biotic 

 composition. Permanent transects extending from the high intertidal to natural bottom were 

 established normal to each of the four cardinal sides of the island. All macrobiota were 

 censused in duphcate 1-square meter quadrants along each transect during each of the four 

 seasons. Other studies included a gUl net survey of fish fauna, mapping of mussel "talus" 

 beds at the base of the island, and a survey of biota along a natural bottom transect between 

 the island and shore. 



46. JOHNSON, G.F., et al., "Ecological Effects of An Artificial Island," Proceedings of 



Symposium on Technical, Environmental, Socioeconomic and Regulatory Aspects 

 of Coastal Zone Planning and Management, American Society of Civil Engineers, 

 Vol. 4, Mar. 1978. 



Rincon Island's rock revetments offer a diversity of habitat features for a great variety 

 of marine species which do not occur in adjacent natural bottom areas. This study added 

 160 taxa of macrobiota to the master species list for the island, bringing the total to 458. 

 Densities of 53 common taxa occurring in permanent transects on each of the four sides of 

 the island were analyzed for seasonal variabihty. Approximately tliree-fourths of these 

 showed statistically significant variation. Nine distinctly different major species associations 

 were identified on the island. Twenty -three species of fishes were captured in gill nets placed 

 on all four sides of the island. Rockfish, surfperch, toadfish, and swell sharks dominated the 

 catch. The biota along a transect over natural bottom from near the island to shore were 

 considerably lower in abundance or density and in number of species relative to biota at 

 corresponding deptlis on the island's revetments. Natural sediments were dominated by 

 polychaete worms (35 percent of biomass and 50 percent of species), small crustaceans, 

 clams, ribbon worms, and brittle stars. 



