581 



Fiske, John D. 1968. 



The Massachusetts estuarine research program. Proc. Natl. Shellf. Assn. 

 58: 3 (abstract) . 



In the Pleasant Bay estuary 11,2 55 bu of quahaugs were taken in 1 yr from 

 about 640 acres of bottom. Production was valued at about $199/acre. The 

 year is not given, but it would be from the early to mid-1960s. - J.L.M. 



582 



Fiske, John D., John R. Curley, and Robert P. Lawton. 1968. 



A study of the marine resources of the Westport River. Mass. Dept. Nat. 

 Resour., Div. Mar. Fish., Monograph 7, vi+52 p. 



Despite many attempts to improve the shellf isheries of the Westport River, 

 Mass. , the overall trend has been downward. Mercenaria mercenaries has been 

 the mainstay of commercial and subsistence shellf ishermen, and the species 

 has remained the most reliable economic shellfish resource in annual 

 harvest. In 1966 1,747 bu of quahogs were harvested by Westport permit 

 holders, most of it by family permit holders. Average production per acre 

 was about 13 bu. Ranges of water temp and salinity in quahog production 

 areas were 36° to 78.3°F in the lower east branch of the River and 

 salinities from 10 to 33°/°° from May through November; and 36° to 73°F 

 and 12°/oo to 31°/oo during the same period in the west branch. Temperatures 

 seldom reach 76 C F, which was suggested by Belding (1931) as required for 

 quahog spawning. However, from June to Sept 70°F is reached, which is near 

 optimum for spawning. The major factor limiting quahog abundance seems to 

 be lack of favorable bottom. Eelgrass has been invading formerly productive 

 bottoms. Hard clams grow poorly in eelgrass, which interferes with 

 circulation and food supply. Future dredging projects might improve 

 circulation and favor quahog production. - J.L.M. 



583 



Fitzpatrick, George, and Albert F. Eble. 1973. 



Preliminary investigations of the ecological aspects of re-laying the hard 

 shell clam, Mercenaria mercenaria. Bull. N.J. Acad. Sci. 18(1): 20 

 (abstract) . 



Three samples of M. mercenaria were transplanted from a polluted to an 

 unpolluted estuary. Total coliform levels were measured in transplanted 

 clams, and depuration of Escherichia coli was observed in 2 samples. 

 Coliform levels rose before any decrease occurred. Rates of depuration 

 were related directly to water temp and salinity. At temps below 10°C 

 and salinities below 18°/°° rates of depuration decreased. Glycogen 

 levels in foot and anterior adductor muscle increased initially, then 

 were related directly to water temp. Stress was an important factor in 

 voluntary movement of adult clams, but movement of clams was unimportant 

 in planning transplants because voluntary movement is small. - J.L.M. 



584 



Flanagan, John. 1974. 



Spawning breaks in the hard clam, Mercenaria mercenaria. Bachelor's thesis, 

 Princeton Univ., 68 p. 



Growth of hard clam slows drastically during spawning. The regular pattern 

 of increment deposition is interrupted by a break followed by a few thin 

 daily additions. Twenty of 34 shells examined satisfied paleontologists' 

 criteria for having left a spawning record on shell. Spawning breaks were 

 identified by previous plankton samples which contained hard clam larvae. 

 Spawning breaks were found in 59% of samples, and this was attributed to 

 sexual dimorphism. - J.L.M. 



163 



