The coast is the major wintering area in Maine for crows. Many crows feed on 

 intertidal invertebrates of the rocky shore. Other passerines feed along the 

 strand line and in the exposed algae along rocky shores (i.e., song sparrows 

 and yellow-rumped warblers). 



Harbor seals haul out on intertidal rocky ledges. Those areas are important 

 to this species for resting and whelping. Intertidal rocky ledges, important 

 to harbor seals, are included in atlas map 4. 



Class: sand beach . Sand beaches form from the deposition of sand by 

 wave swash and wind processes. The sand-sized particles are derived from wave 

 erosion of coastal or submerged glacial and glaciof luvial deposits or from 

 sediment transported to the shore by present-day rivers. The latter source, 

 within the characterization area, is limited to the Kennebec River. According 

 to preliminary NWI data sand beaches are scarce in Maine, making up <1% of the 

 characterization area. 



Three types of sand beaches exist: barrier beaches and spits, strandplain 

 beaches, and pocket beaches. Barrier beaches separate estuaries, lagoons, and 

 estuarine emergent wetlands form open marine waters. Barrier spits include 

 inlets to enclosed lagoons or wetlands. Strandplain beaches are directly 

 backed by the upland from which their sediment is derived. They occur largely 

 along the landward margins of bays where glacial and glaciof luvial deposits 

 are being eroded by waves. Sand from these deposits is added to the beach 

 sediment during storm wave activity. Pocket beaches are small barrier 

 beaches, spits, and strandplain beaches. Pocket beaches are to be 

 distinguished from the other beach types by their total inclusion within small 

 embayments; they derive their sand from submerged glacial deposits flooring 

 the embayment (see atlas map 2). 



The composition of sand beaches ranges from fine sand to coarse sand mixed 

 with gravel. Many sand beaches are resting on gravel beach deposits; and 

 sandy beaches may have significant amounts of gravel on their surfaces as 

 storm-lag deposits or from the throwing of gravel from submerged glacial 

 deposits onto the beach by storm waves. Particle sizes on sandy beaches range 

 from 0.125 mm to 16 mm (0.004 in. to 0.6 in.). Beach sands are very well 

 sorted and are composed mainly of quartz and feldspar minerals but also 

 contain minor amounts of metaraorphic rock fragments and common heavy minerals, 

 such as garnet and amphibole. 



Waves, tides, and winds are the major physical forces that control the beach 

 environment. Beaches exhibit seasonal changes during the winter months. When 

 northeast storms occur, beaches are eroded. Their faces are steepened and 

 become featureless. After storms and during spring, summer, and fall, beaches 

 become accretional (i.e., build up material) and form berms and ridges on 

 their upper and lower faces, respectively. 



Waves move sand laterally along the beach at variable rates of transport, 

 varying according to sediment size, direction of wave approach, orientation of 

 the beach, tide stage, and other factors. Rates of longshore transport are 

 not well established on Maine beaches except Wells beach, which is outside the 

 characterization area but is under the same wave influence as many exposed 

 Maine sand beaches. Byrne and Zeigler (1977) estimated gross littoral 

 transport rates at Wells to be 35,000 to 55,000 cu yds/year to the north and 



4-86 



