FISHERY BULLETIN: VOL. 75, NO. 2 



showed that large numbers of recently set calico 

 scallops may be eaten by A. articulatus and that 

 though continued examination of their stomach 

 contents, knowledge may be gained concerning 

 when and where calico scallop setting takes place. 

 During May and June 1972, numerous small scal- 

 lop valves appeared in the stomachs of this sea star 

 (Table 10). Valve numbers/100 stomachs were not 

 nearly as many as the 3,000/100 stomachs re- 

 ported by Porter ( 1972a) for June 1971. It is infer- 

 red from this that the 1972 scallop set on the sam- 

 pled grounds was relatively small. Note that 

 numbers of dead scallop shells increased from July 

 through October when the fishery collapsed ( Table 

 11). Also, the presence of L. clathrata decreased 

 while A. articulatus presence increased during the 

 March to October period (Table 11). 



Stomach content data (Table 10) suggested that 

 if there were scallop spawnings following the ini- 

 tial May spawning as we have theorized, then the 

 set from these and the May spawnings either did 

 not survive after June or the setting occurred in an 

 area not covered by the sampling. Stomach 

 analysis data of sea stars continues to be worked 

 up and evaluated. 



TABLE ll. — Average monthly numbers of dead shells and sea 

 stars per bushel catch (TV) occurring on the calico scallop beds in 

 1972. 



DISCUSSION 



We had expected to find that the calico scallop 

 bed(s) that sustained the 1972 North Carolina 

 fishery to have been distinct in either physical, 

 chemical, or biological features. Instead, few dif- 

 ferences were found which could be pinpointed as 

 factors that made the bed(s) more unique than the 

 surrounding shelf areas. We noted that bottom 

 texture within and without the beds studied were 

 nearly identical (Table 3). Likewise, no extremes 

 of water temperatures, salinities, or phytoplank- 

 ton population (as measured by chlorophyll a 

 levels) seemed to exist in 1972. While the fish and 



invertebrate faunas were diverse and speciose, 

 they too were little different from that noted from 

 the nearby reefs or areas (Pearse and Williams 

 1951; Wells et al. 1964; Cerame-Vivas and Gray 

 1966). Seasonal shifts in the fishes and inverte- 

 brates inhabiting the bed(s) occurred but these 

 were directly related to seasonal water tempera- 

 tures, salinities, or their natural migrating 

 movements (Tables 5, 7). Most populations of 

 fishes apparently moved over the bed(s) con- 

 stantly, some 24 species (of 33 most abundant) feed 

 on scallops. Of the macroinvertebrates, 3 species of 

 sea stars and 19 other macroinvertebrates were 

 predators. Whether the fishes and sea stars or 

 other macroinvertebrate predators, which were 

 definite predators of calico scallops, were attracted 

 to the area because of the scallops or the activities 

 of the fishery, which created available food in the 

 form of broken scallops, remains unresolved. One 

 interesting correlation was noted in that the 

 painted wrasse, Halichoeres caudalis, appeared 

 over the bed, in September and October, as in- 

 creased numbers of dead scallops occurred just 

 prior to the demise of the 1972 fishery on 28 Oc- 

 tober. This relationship has also been noted for the 

 Cape Canaveral calico scallop beds of Florida 

 (George Miller pers. commun.). 



While we document the fish and macroinverte- 

 brate faunas and the ecology of a North Carolina 

 bed(s) that sustained the 1972 fishery, we are still 

 at a loss as to what creates the vacillations of 

 scallop availability in a bed or why one bed pre- 

 vails over another during any one or succeeding 

 years. Note that while the experimental bed was 

 fished and did possess scallops throughout 1972, it 

 as well as the commercial bed failed to support 

 scallops in the years 1973 through 1976. We can- 

 not ultimately conclude that the 1972 bed and 

 fishery collapsed as a sole result of overfishing but 

 that the levels of scallops available after 28 Oc- 

 tober could not economically support the fleet. 

 Sampling the planktonic stages of calico scallops 

 may resolve the repopulation aspects of the beds 

 for we still do not know whether we are simply at 

 the northern edge of its range, which may be de- 

 pendent on larval drift and recruitment from more 

 southern areas, or are dealing with a population 

 dependent upon native larvae for repopulation. 

 Additional field observations of the shelf water 

 mass movements and how they affect the survival, 

 growth, and existance of scallops needs refinement 

 while laboratory experiments which vary a 

 number of ecological parameters will hopefully 



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