The landward side of the island, on the other hand, which is not as 

 open to ocean waves and currents as it is to be "backwash" or eddies that 

 come around the island, has a larger amount of life than might be expected 

 in an area with somewhat excessive water turbidity. Small kelp beds 

 develop here in the summer months, and the presence of great numbers of 

 small fish testifies to the value of an area protected from the assaults 

 of the open ocean. 



The other two sides provide an intermediate environment and each, 

 because of the difference in exposure to the prevailing currents and waves, 

 has a somewhat different ecology. The north side has a great variety of 

 marine algae near the surface and contains the largest gorgonian coral 

 formations around the island, one of which is over 50 feet long and 20 feet 

 wide. Tlie side of the island with the more southerly exposure has the 

 least amount of algae growth, but the large population of sea urchins here 

 may be contributing factor to this lack of foliate algae. Gastropods are 

 the predominant form of invertebrate life on this side, with a fairly well- 

 developed and varied bivalve population also present. 



The three seaward sides of the island have a "talus slope" of mussel 

 and bivalve shells detached by wave action which in some areas extends 

 15 feet above the toe of the rock slope. This formation is important in 

 helping to keep down sediments and in providing small shelter areas for 

 nudibranchs, gobies, and various marine worms. While the landward side has 

 a small footing of this type, it is probably not so prominent because of 

 the lack of large mussel beds and the destruction and dispersing of the 

 mussel beds by wave action on the other three sides. 



In summarizing the impact of the island, Brisby states that the con- 

 struction of Rincon Island has encouraged the development of a mature and 

 balanced reef out of an area which might well have been previously consi- 

 dered a biological desert. The total number of species present before 

 construction probably numbered no more than 25 to 30 (by count only 14 

 species were observed), and now, after construction has been completed and 

 sufficient time has elapsed for a climax community to be established, 

 298 species have been recorded, representing all of the major marine phyla. 

 and there probably are more present. 



Two major advantages have made possible this climax marine community: 

 (1) the establishment of a substrate conducive to the attachment of various 

 marine forms, and (2) the island's position one-half mile off the coast, 

 which has allowed the relatively undisturbed growth of marine organisms. 

 Brisby notes that Rincon Island has demonstrated the potential that an 

 offshore structure can have in establishing biological communities with 

 diverse and sometimes rare forms of life. Such a structure can be used to 

 study various marine forms and to provide seeding ground for the distribu- 

 tion of these forms to adjacent areas. 



10. Aesthetic Effects 



Richfield has incurred high costs in establishing palm trees and 

 shrubbery on the island. All topsoil for the trees and shrubbery was 



50 



