Boulder beaches consist mostly of boulder-sized particles derived mainly from 

 glacial till deposits or from jointed bedrock ledge exposed to very high 

 energy wave conditions. 



Productive elements on boulder beaches are identical to those of bedrock 

 shores as discussed above. The one exception is that, since boulders provide 

 more surface area per unit of shoreline, the absolute productivity on boulder 

 beaches may be slightly higher. 



The single study available on Maine boulder beaches (Larsen and Doggett, in 

 press ) showed that these beaches have a diversity comparable to exposed 

 bedrock shores, although the density of individuals is not as high. Boulder 

 beaches have many microhabitats which allow for the high diversity. No 

 zonation studies have been conducted on boulder beaches but the sharp zonation 

 of mussels and barnacles that is obvious on bedrock shores is not as well 

 defined in boulder areas. 



The species present on boulder beaches generally were found also on exposed 

 bedrock shores (Larsen and Doggett, in press ) . The infaunal species of 

 boulder beaches are similar to those found in pockets of sediment at protected 

 rocky shore areas. The following species were present on six boulder beaches 

 in Maine (Larsen and Doggett, in press ) : 



Platyhelminthes 



Nematodes 



Nermerteans 



Oligochaetes 



Acmaea testudinalis 



Littorina littorea 



Littorina obtusata 



Littorina saxatilus 



Thais lapillus 



Mytilus edulis 



Balanus balanoides 



Jaera sp. 



Gammarus oceanicus 



Marinogammarus stoerensis 



Carcinus maenas 



Flatworm 

 Roundworm 

 Ribbon worm 



Chinaman's hat 

 Common periwinkle 

 Smooth periwinkle 

 Rough periwinkle 

 Dog whelk 

 Blue mussel 

 Rock barnacle 

 Isopod 

 Amphipod 

 Amphipod 

 Green crab 



Shorebirds and gulls are the two major groups of waterbirds that feed 

 extensively on exposed rocky shores. Eiders feed mostly on benthic 

 invertebrates in the intertidal and subtidal zones. Seaducks, loons, and 

 grebes feed in these areas, also. In winter the purple sandpiper is the 

 primary shorebird species using rocky intertidal areas, while ruddy turnstones 

 and least sandpipers are the primary species during the fall and spring 

 migrations. Other small sandpipers (peeps), black-bellied plovers, and 

 pectoral sandpipers use rocky intertidal areas to a lesser extent. Rocky 

 ledges are used as resting areas for semipalmated sandpipers, semipalmated 

 plovers, short-billed dowitchers, yellowlegs, black-bellied plovers, and 

 turnstones, especially where extensive flats are bordered by rocky shores 

 (i.e., Indian River flats in Jonesport, region 6, and in the Harrington- 

 Millbridge area, region 5). Preferred roosting sites [gravel and sand spits 

 (bars) and beaches] are in short supply in these areas. Waterfowl and gulls 

 use rocky shores and ledges as resting areas and nocturnal roosts. 



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