CHAPTER 12 



TRAWL AND DREDGE SURVEYS 



July survey results (Azarovitz, unpublished data; Ropes 

 1976a) indicated that benthic fauna at stations in a small 

 area 5 to 10 km east-northeast of Barnegat Inlet (fig. 12-3) 

 were severely impacted — greater than 50 percent total 

 mortalities for all invertebrates collected. Surf clams were 

 affected most; other mortalities included: burrowing ane- 

 mones (Ceriantheopsis americanus); mollusks — sea scal- 

 lops (Placopecten magellanicus). razor clams (Ensis direc- 

 tus), moon snails (Lunatia heros). and ocean quahogs 

 (Arctica islandica); polychaete worms (mostly Sigalion 

 arenicola but including Aglaophamus circinata, Orhitua 

 swani, Glycera dibninchiata, Lumhrineris fragilis. and 

 Nephtys longosetosa); unidentified sipunculans; crusta- 

 ceans — rock crabs, mud shrimp (Axius serratus). lobsters, 

 and mantis shrimp (Phitysquilla enodis); and echinod- 

 erms — starfish, sand dollars (Echinarachnius parma), and 

 sea cucumbers (Caiidma cirenata). Moderate impacts 

 (10% to 50% total mortalities) involving the same species 

 were found over a wider area, from Long Branch to Beach 

 Haven, N.J., and between 5 and 35 km offshore. Other 



species, many that normally burrow in the sediments be- 

 low the penetration of grabs, trawls, or dredges — for ex- 

 ample, larger polychaetes, mud shrimp, mantis shrimp, 

 sea cucumbers, sipunculans, and surf clams — were col- 

 lected in finfish trawls, alive but in an obviously stressed 

 state (fig. 12^). Very little impact was observed within 

 3 km of shore except during two short periods when sus- 

 pected upwellings of anoxic bottom water occurred in the 

 surf zone; large numbers of dead calico crabs {Ovalipes 

 ocellafus). rock crabs, and lobsters, as well as some finfish 

 washed up on beaches near Manasquan and Beach Haven. 



Surveys in August through November (Azarovitz 1976; 

 Ropes 1976b, 1976c) showed the impacted area had ex- 

 panded to that outlined in figure 12-3. Moderate impact 

 was found as far south as Cape May and, as in July, the 

 surf clam mortalities were the most extensive in relative 

 numbers and biomassof dead animals collected. Putrifying 

 surf clam meats were found in trawls at several stations 

 during August collections. 



Surveys in October and November showed continued 

 scattered evidence of mortalities; mostly "clapper" (de- 

 fined in ch. 1 1 , pt. I ) razor clams and ocean quahogs were 



FIGURE 12^. — Normal deep-burrowing benthic species collected in trawl nets (clockwise from upper right): Nereis longosetosa. Sigalion arenicola, 

 Axius serratus. Spisuta solidissima (meats only), Ensts directus. Caudina arenala. Cancer irroratus (not a burrower), more Caudina. and near center 

 Platysquilla enodis. Compare size with nickel. 



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