66 



67 



68 



problems, including legal and social aspects. (Abstracter's note: its 

 scientific stature is suspect because specie is used several times where 

 species is meant. Review by a competent biologist would have been 

 advisable.),- J.L.M. 



Anonymous. 1971. 



Ocean quahog becomes more important as surf and bay clams dwindle. Comm. 

 Fish. Rev. 33(4) : 17-19. 



"Once thought inexhaustible, resources of hard clams, Mereenavia mevoenaria, 

 are dwindling rapidly; at the same time, demand is increasing con- 

 stantly." Narragansett Bay once was the best setting ground for hard clam 

 in the world. Blount Seafood Corp., Warren, N.H., once derived 76% of their 

 production from the Bay. Now they handle only a few thousand bushels of 

 hard clam, and process ocean quahog, Aretica islandioa , almost exclusively. 

 - J.L.M. 



Anonymous. 19 72. 



Economic potential of clam operation. Va . Inst. Mar. Sci., manuscript 

 rept., 17 p. (apparently unpublished) . 



(Abstracter's note: the copy received through inter library loan did not 

 identify author, date, or agency) Cost and return estimates were based on 

 culture of clam larvae and juveniles in a hatchery system, assuming the 

 operation would be in an area where clam culture techniques would work. 

 Hatchery costs were based on actual costs of construction in 1969 and 1970, 

 and equipment costs 1969-71. It is assumed, although the paper does not so 

 state, that the clam was Mevcenaria meraenavia . Estimated clam production 

 of about 34.5 million clams was based on actual experience in the 1st half 

 of 1972. It was concluded that the method used would provide some profit 

 potential, provided that unforeseen problems did not arise. Costs of 

 $29.9 million over a 10-yr period were estimated to produce average annual 

 profits of about $30,879 per yr. A similar economic survey of bay scallop 

 culture concluded that a modest profit would be realized. - J.L.M. 



Anonymous. 19 72. 



Clams from polluted areas show measurable signs of stress. Maritimes, 

 Grad. School of Oceanogr . , Univ. R. I., p. 15-16. 



Stress from hydrocarbons and other organic compounds dumped into the Provi- 

 dence River causes the meat to be darker, development of a ridge on the 

 inside edge of the shell, where the mantle retracts from the edge, and some- 

 times a mud-blister infestation which makes the inner surface of the shell 

 around the hinge look as if it has a thin smearing of brownish mud. The 

 clam may also have small pinhead-sized discolorations on the surface of the 

 inner shell. This mud-blister infestation is caused by a parasitic worm 

 not normally found in clams. The clam usually lives beneath the surface but 

 may come to the top when exposed to an irritant. Clams from polluted areas 

 have a smaller average size than clams from clean areas. (Abstracter's note: 

 this might be because no harvesting is allowed.) Kidneys of clams from 

 polluted areas are plugged with a black substance that is a residue of 

 organic compounds. In a normal clam the ratio by weight of taurine to 

 glycine is two to one. In clams from the Providence River, however, the 

 ratio is about five to one. Other reactions to stress are lower amounts of 

 carbohydrates and slightly altered fatty acid patterns. Clams from the 

 polluted area may die in 6 to 8 yrs . Healthy clams may live 12 yrs. When 

 the clams are kept in a clean environment for a year, most symptoms remain. 

 Some hydrocarbons are absorbed by bacteria, leaving a complex of organic 

 materials to be filtered by the clams. These are the irritants that start 

 the syndrome. One way to help the industry might be to leave the clams in 

 the River to provide a spawning stock. Much of the larvae will be carried 

 down to clean areas of the Bay. - J.L.M. 



18 



