Depending on the amount of surf action to which a shoreline is 

 exposed, various authors distinguish from 4-5 (Beauchamp, 1914; Lewis, 1964) 

 to 8 (Ballantine, 1961) types of shores. The scheme of degrees of surf 

 action recognized by Soviet investigators of the intertidal zone is as 

 follows (Gurjanova et al . , 1930a, b; Kussakin, 1958a, 1961; Gurjanova, 

 1968). 



First degree--closed bays, no surf; 



Second degree--partially closed bays, well protected shore, surf 

 very rare and wery weak; 



Third degree--less protected shore, surf frequent, but weak due to 

 comparatively great distance from open sea; 



Fourth degree--open sea, surf almost constant, but not great due to 

 comparatively mild acceleration of waves; 



Fifth degree--open sea shore, almost constant strong surf, great 

 acceleration of waves; 



Sixth degree--open ocean shore, continuous, strong surf, \/ery great 

 acceleration of waves. 



It must be emphasized that the degree of surf action depends not only 

 on the distance of the shore from the open sea, but also on the topography 

 of the shore and morphology of the substrate. If a shoreline is greatly 

 broken, even on an open sea coast, there are always areas which are 

 protected to some extent from the surf. This is observed most clearly 

 in areas of scattered rocky reefs and banks of pebbles and boulders. 

 Even the different sides of a single lump of rock differ in the degree 

 of exposure to the surf and may be populated by different communities. 



The composition of littoral communities depends to a great extent 

 on the nature of the sediment. The population of loose sediments depends 

 largely on sediment particle size, mobility, degree of grading, water 

 content in the sediment and the quantity of organic matter present. In 

 surf habitats on loose sediments, there are no macrophytes or almost none, 

 and relatively little microscopic algae. Therefore, the basic food for 

 the inhabitants of sandy beaches, in addition to plankton, consists of 

 allochthonic organic matter (detritus and algae thrown up on the beach). 

 In habitats protected from the surf, where the loose sediment has been 

 silted, there are usually rather rich stands of eelgrass and, in the 

 tropical zone, mangrove as well. In sandy sediments, infauna predominates 

 over epifauna, but in surf habitats it is also quite sparse. Gravel and 

 rocky beaches are still more sparsely populatied. 



The population of rocky and stony sediments is significantly more 

 varied. Here, green, brown and red algal macrophytes are usually well 

 developed, with a rich fauna of small mobile animals, plus settlements 

 of sestonophages (barnacles, oysters, mussels). The great biomass of 

 the macrophytes is mostly not eaten by the phytophagous animals; most of 



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