this deposit-feeding animal was absent from the wave-rippled sand 

 in the site center (another ampeliscid, Byblis serrata. is found on 

 sandy bottom) . In 1975, it was not clear whether the absence of A. 

 agassizi on the silty disposal material edges was a result of 

 failure to colonize or due to sediment toxicity. By 1987, dense 

 populations of A_j_ agassizi had colonized dredged material at mound 

 edge stations (3 and 10) . This may be the result of processes 

 which have made the sediment either more attractive or less toxic 

 to A_j_ agassizi. 



Changes in other species : The density and distribution 

 of the more than 100 species found in the Brenton Reef study area 

 follow a variety of patterns reflecting substratum requirements, 

 feeding types, response to disturbance, breeding cycles, and 

 natural variability. Data on natural history are lacking for many 

 of the shelf species which are present. A few of the long-term 

 changes observed are listed here: 



A. Capitella sp. (deposit-feeding polychaete) , an opportunistic 

 species often characterized as a "pollution indicator", was 

 found in moderate numbers on dredged material in 1974 and 

 1972 (maximum 59 per 0.1m 2 ), but was rare or absent in 

 subsequent samples. 



B. Tharvx spp. (deposit-feeding polychaete) , which can be 

 abundant in organic sediments, was an early colonizer and 

 increased in density on the site edges up to 1987. 



C. Prionospio steenstrupi (suspension-feeding polychaete) 

 naturally present in ampeliscid beds was also an early 

 colonizer of site edges. 



D. Scalibregma inf latum (deposit-feeding polychaete) has 

 increased steadily in density at all dredged material stations 

 up to the most recent survey. 



E. Phoronis muelleri (tube-dwelling, suspension-feeding phoronid) 

 was an early colonizer but never became numerous. This 

 species was an early colonizer at some disposal sites in 

 central Long Island Sound. 



F. Arctica islandica ("ocean quahog" , suspension-feeding bivalve) 

 juveniles were abundant on dredged material in 1971 and 1973, 

 possibly as the result of reduced predation, but has been less 

 abundant since. 



G. Nephtys incisa (deposit-feeding polychaete) was uniformly 

 distributed in moderately high densities (25 per 0.1m 2 ) in 

 1971-1973, but decreased in subsequent samples. 



H. Periploma papyratium (bivalve) also found in silty sediments, 

 colonized dredged material edges after 1973. 



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