53 



Anonymous. 19 58. 



Gulf of Mexico explored for hard clams and scallops (M/V Silver Bay Cruise 

 10). Coram. Fish. Rev. 20(9): 41-43. 



Tows for hard clam were made between Cape Romano, Fla. and Anclote Keys. 

 Venus sp. was taken in all tows. Best catches were off Pass-a-grille Beach, 

 Venice, and Marco Island in depths from 16 to 22 ft (from a few clams to 1.5 

 bu/15 min tow). Clams were 2 to 4 1/2 in, 75% about 3 in. Yield was about 

 one gal meats/bu. Clams were held in a wooden tank in circulating seawater 

 for 15 days with negligible loss. Forty-six tows between Cape San Bias and 

 Horn Island in 20 ft of water caught no clams. - J.L.M. 



54 



Anonymous. 1958. 



The commercial shellfishes of Long Island. In Report of the New York State 

 Joint Legislative Committee on Revision of the Conservation Law 1957-1958, 

 Legislative Doc. (1958) 11: 45-63. 



(Abstracter's note: in addition to hard clam this document deals with other 

 molluscan species, and includes a section on nets used by commercial 

 fishermen and another on recommended legislation. Only specific references 

 to hard clam are included in this abstract.) Hard clam is normally found 

 in lower part of estuary, and infrequently in upper estuary or ocean. 

 Larval period may vary from 7 to 30 days depending on temperature. Tidal 

 flushing would remove fewer from the estuary when larval life is short. 

 Short larval period also may reduce predation and increase survival. 

 Between larval life and permanent setting clams may swim or crawl. Growth 

 rate and maximum size is related to food supply. Overcrowding reduces 

 growth. Hard clam can utilize dense concentrations of phytoplankton that 

 inhibit feeding of oysters. Hard clam in relict populations in Gulf of St. 

 Lawrence grow less than half as fast as those at Cape Cod. Sand favors 

 faster growth of hard clam than does mud. Hard clam lives at or near low 

 tide mark and down to depths of several fathoms. Throughout life clams 

 retain some powers of locomotion. If disrupted they can reestablish in the 

 substrate. Small clams can do this within minutes, larger ones in a few 

 hours. Hard clams have been found high up on beaches after storms. 

 Predation on small clams may be high because young predators are more 

 abundant than adults. Newly set clams suffer high mortality from this 

 cause even when adults are scarce. Hard clam matures in its second year 

 and can produce 2 million eggs at 2 1/2 inches long. Numbers of eggs 

 increase with size of female with no decline in quality. Hard clam may 

 live much longer than 12 years. There is no direct evidence that 

 exploitation affects propagation adversely. There is no evidence that 

 power dredging affects a hard clam fishery differently than bullraking. 

 The proposed law that prohibits taking of hard clam less than one-inch 

 thick is a conservation measure because in certified waters of N.Y. there 

 is no surplus of young clams for planting on leased grounds. There is 

 presently no simple, inexpensive method of populating barren areas with 

 young clams, although some hard clam farms are in operation. The future 

 does not appear bright for profitable commercial farming of hard clam. 

 - J.L.M. 



55 



Anonymous. 1960. 



Proceedings at preliminary conference called by Governor Christopher DelSesto 

 of the State of Rhode Island with advisors in regard to oil pollution of 

 Narragansett Bay by "The Thirtle"; also as to the effect on marine life in 

 the Bay. Sept. 8, 1960, State House, Providence, R.I. ,29 p. (stenographic 

 record) . 



The only substantive reference to Mercenaria meraenaria is a statement by 

 Prof. Steacy D. Hicks of the University of Rhode Island that after 25 

 washings of crude oil with water, the water is still toxic to marine life, 

 and will depress filtering rate of clams and quahaugs. - J.L.M. 



15 



