shellfish beds have been closed because of sewage-related 

 pollution. Sewage and other pollutants, including heavy metals, 

 PCB's, and PAH's have affected sediments of the Bight, changing 

 some of them from clean sands and muds to foul "black 

 mayonnaise." Altered silty sediments no longer support 

 populations of clams and oysters, and crabs and lobsters often 

 have odors characteristic of petroleum or hydrogen sulfide. 

 Affected sediments are known to contain heavy metals, PCB's, 

 PAH's, coprostanol, viruses, and pathogenic protozoans of concern 

 to human and animal health. The persistence of enteric viruses 

 in the environment has been documented by Goyal (1989) who 

 recovered them from gills of rock crabs and from sediments at the 

 Philadelphia-Camden disposal site 17 months after the cessation 

 of sludge dumping. Shell disease in rock crabs and lobsters has 

 been noted by biologists and commercial fishermen, and is 

 recognized as affecting marketability because of their unsightly 

 appearance . 



A major study of shell disease and its possible association 

 with pollution in the New York Bight was reported by Pearce 

 (1971) and Young and Pearce (1975). Lobsters and rock crabs from 

 grossly polluted areas of the Bight apex were found to be 

 abnormal, with appendage and gill erosion a most common sign. 

 Exoskeletal erosion occurred principally on the tips of the 

 walking legs, ventral sides of chelipeds, exoskeletal spines, 

 gill lamellae, and around areas of skeletal articulation where 

 contaminated sediments could accumulate. Gills of crabs and 

 lobsters were usually clogged with detritus, had a dark brown 

 coating, contained localized thickenings, and displayed areas of 

 erosion and necrosis. Similar disease signs were produced 

 experimentally in animals held for six weeks in aguaria 

 containing sediments from sewage sludge or dredge material 

 disposal sites. Initial discrete areas of erosion became 

 confluent, covering large areas of the exoskeleton, and often 

 parts of appendages were lost. The chitinous covering of the 

 gill filaments was also eroded, and often the underlying tissue 

 became necrotic. 



Histological studies on crabs and lobsters have revealed 

 numerous internal lesions in the gill, intestine, and 

 hepatopancreas, and similar lesions have been induced 

 experimentally by both biological agents and chemicals (Greig et 

 al., 1982; Sawyer, unpublished data). Black discoloration of 

 crustacean gills has been found to result from accumulations of 

 black mud and silt that may interfere with respiration. Internal 

 blackening (melanization) of gill tissue denotes areas of 

 cellular death and has been termed "endogenous" to differentiate 

 the condition from external or "exogenous" blackening caused by 

 sediment deposits. Blackened gill cuticle has been observed as a 

 result of mechanical blockage of respiratory surfaces by dense 

 bacterial mats, diatoms, or gill fouling protozoans. 



