3. Fouling Communities . 

 (Ye. P. Turpaeva) 



The term "fouling" is usually used to mean a complex of animals and 

 plants, which settles onto artificial structures. The formation of 

 fouling communities on structures submerged in the water depends on the 

 capability of certain species of animals and plants to develop 

 successfully in a situation created by man. The basic components of 

 fouling communities include the attached forms: cirripedian 

 crustaceans, bivalve mollusks, hydroids, Bryozoa, sedentary polychete 

 worms, sponges, Tunicata, as well as certain algae. Furthermore, the 

 overgrowth includes mobile animals: crabs, Nudibranchiata, errant 

 Polychaeta, Nematoda, Harpaticoida, Pycnogonida. The total number of 

 species of animals and plants recorded in the fouling communities 

 reaches 2,000. 



The qualitative composition of the fouling communities on all 

 artificial substrates is determined by the composition of the flora and 

 fauna of the surrounding regions, the number of species fouling being 

 always less than the number of species inhabiting the region. The 

 epibiotic fauna of the littoral regions usually number 50-100 species. 

 The total number of species in macroscopic fouling communities in the 

 open seas of the USSR is not over 25, in the southern seas--10. Fully 

 formed fouling biocenoses in the southern seas of the USSR usually 

 consist of 3-5 species (2-3 attached, 1-2 unattached), while the 

 quantitative development of one of the attached species is usually 

 significantly more than the development of the remaining forms. A 

 similar peculiarity is characteristic of the oligomyctic benthic 

 biocenoses. Epibiotic biocenoses represent an extreme case in this 

 respect. 



The species which settle in epibiotic associations usually reach 

 significantly greater quantitative development than in natural biotopes; 

 correspondingly, the total biomass of fouling biocenoses is usually 

 great, frequently one or two orders of magnitude more than the biomass 

 of natural communities. For example, the biomass of the fouling 

 associations in the Sevastopol' Bay may reach 100 kg/m^, the fouling 

 associations of Balanus in Kerchenskiy Strait--40 kg/m^, the fouling 

 associations of hydroids in Taganrog Bay--15 kg/m^ (Turpaeva, 1971). 



The overwhelming majority of species of animals which compose these 

 communities have a pelagic larval stage. The larvae of some mass 

 species from these communities (numerous forms of bivalve mollusks, and 

 cirripedian crustaceans, live in the plankton for rather long periods of 

 time--up to several weeks). In temperate water, the breeding of fouling 

 organisms stops in winter. They winter over in the mature stage, and 

 begin to breed again in the spring, with the beginning of the 

 development of phytoplankton. In accordance with this, the settlement 

 of organisms and development of the epibiotic biocenoses are also 



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