1886 



Van Winkle, W. , S. Y. Feng, and H. H. Haskin. 1976. 



Effect of temperature and salinity on extension of siphons by Mercenaria 

 mercenaries.. J. Fish. Res. Bd. Canada 33(7): 1540-1546. 



Extension of siphons is only a crude index of activity, but it can be studied 

 quickly, easily, and cheaply. Thus, the index is useful for initial definition 

 of limits for temp, salinity, and some other variables in depuration of 

 shellfishes. Results can provide guidelines for more detailed and 

 sophisticated studies on activity and purification. The study showed 

 considerable phenotypic plasticity. Temp limits shifted upward from April to 

 May. Salinity limits shifted upward from late winter to late summer. 

 Activity was relatively low in summer. Some results were unexpected, e.g., 

 a pronounced decrease in upper temp limit associated with an increase in 

 acclimation temp. This demonstrated the effects of other variables, and of 

 the physiological state of clams, and is consistent with results of previous 

 studies in N.J. which showed decreased growth rate in summer. Mercenaria 

 mercenaria is only moderately euryhaline. Purification should not be 

 considered at salinities below 20°/°° and is likely to be most successful 

 above 22°/°° to 23°/°°. It is also suggested that temps below 10°C are not 

 advisable. Heated water should be used in winter. Purification probably 

 also should not be considered at temps above 30°C and is most likely to be 

 successful at 25 °C or below. It may be difficult to purify quahogs during 

 June to August, regardless .of temp or salinity. Depuration should not be 

 attempted when activity levels drop below 50%. Extension or non-extension 

 of siphons was the criterion of activity, not the distance extended. - J.L.M. 



1887 



Vanderborgh, G. 19 66. 



A report on shellfish farming in Long Island waters: Critical needs. 

 Nassau-Suffolk Regional Planning Board, Oceanographic Committee. 



The only report we could locate that appeared to be similar to the one cited 

 above was: Stephan, E. C. (chairman). 1966. The status and potential of the 

 marine environment. Rept. of the Oceanographic Committee to the Nassau-Suffolk 

 Regional Planning Board, Hauppauge, N.Y.,ix+92 p. in 3 parts plus an appendix, 

 each numbered separately. The shellfish industry of New York State is 

 discussed in various places. Among the conclusions and recommendations are: 

 1) unpolluted waters are essential to commercial shellfish production; 2) duck 

 farm wastes have created a nutrient imbalance harmful to shellfish production; 

 3) Long Island (at the time of writing) had 400,000 acres of fully approved 

 active shellfish areas; 4) L.I. was the leader in national hard clam 

 production with landed value of $5.5 million, but this was only 60% of what it 

 was 20 years earlier; 5) declines in shellfish production have been caused by 

 sewage pollution, duck farm wastes, destruction of wetlands, spraying of DDT 

 and other insecticides, and dredging. In addition to man-made factors, natural 

 factors also add complications, such as: destruction of seed by adverse 

 weather; predation; and silting of inlets. Legal and zoning problems have 

 contributed: 1) inadequate and outmoded leasing practices for shellfish 

 bottoms; and 2) lack of suitable shorefront property for land-based segments 

 of industry. The most creative activity of industry was identified as 

 development of shellfish hatcheries. Industry also had helped itself through 

 research and adoption of good management techniques. Discussion of eelgrass 

 problems is included. Detailed information is given on open and closed 

 shellfish areas by locality. - J.L.M. 



524 



