713 



Greene, Gregory T. 1978. 



Growth and mortality of hard clams, Mercenaria mercenaria , at selected 

 locations in Great South Bay, New York. In Sea Grant Assn. , Student 

 abstracts. Oregon State Univ. Sea Grant Coll. Progr. Communic. Staff: 24. 



Extensive natural populations of Mercenaria mercenaria in Great South Bay, 

 Long Island, N.Y. are threatened by intensive harvesting. Research to 

 determine natural growth rates, to estimate mortality rates, and to identify 

 major predators and assess their impact on the resource, and to estimate size 

 frequency distributions on harvested and unharvested beds, are under way. 

 - J.L.M. 



714 



Greene, G. T. 1978. 



Growth of clams (Mercenaria mercenaria) in Great South Bay, New York. Natl. 

 Shellf. Assn., 70th Joint Ann. SINA-NSA Conv. & Meeting, 18-22 June 1978, 

 Abstracts: page not numbered. 



Growth rates were determined by analysis of shell growth structure of 

 individual clams, size frequency distributions of samples, and planting- 

 recovery experiments. Natural stocks were sampled at 15 locations in a 

 variety of Bay environments. Growth rates were highest in spring and fall. 

 Seasonal effects were most pronounced in very shallow waters. Growth rates 

 were greatest at stations with well circulated waters and sandy sediments, 

 lowest at stations with silty sediments near river mouths. Maximum sizes 

 varied greatly with location. At some stations clams blunted and essentially 

 stopped growing at 5 or 6 yrs old and 60 to 70 mm long. At other stations 

 blunting did not occur until age 8 or 9 and 90 to 100 mm long. Most clams 

 reached legal harvesting size (1 inch thick or 48 mm long) after 3 to 3 1/2 

 yrs. Some clams required as little as 2 1/2 yrs or as much as 4 1/2 yrs to 

 reach legal size. - J.L.M. 



715 



Greene, G. T. 1979 



Growth of clams (Mercenaria mercenaria) in Great South Bay, New York. 

 Proc. Natl. Shellf. Assn. 69: 194-195 (abstract). 



Growth rates were highest in spring and fall. Seasonal effects were most 

 pronounced in clams from shallow waters. Significant variations were found 

 in clams from different stations, and growth was greatest in well circulated 

 waters and sandy sediments, poorest at stations with silty sediments near 

 river mouths. Maximum sizes also varied greatly. At some stations clams 

 blunted and essentially stopped growing at 5 or 6 yrs and length 60 or 70 

 mm. At other stations they did not blunt until 8 or 9 yrs and length of 

 90 to 100 mm. In most areas most clams reached harvestable size in 3 to 

 3 1/2 yrs. Some clams required as little as 2 1/2 yrs or as much as 4 1/2 

 yrs to reach harvestable size. Information on growth rates will be valuable 

 to management programs. - J.L.M. 



716 



Greene, Gregory T.,and D. Scott Becker. 1977. 



Preliminary report of an assessment of the effects of the unusually severe 

 winter of 1976-77 on the mortality of the hard clam (Mercenaria mercenaria) 

 in Great South Bay, New York. Manuscript report from Marine Sciences 

 Research Center, State University of New York, Stony Brook, N.Y.,ii+8 p., ill. 



The winter of 1976-77 was one of the coldest on record in the Long Island 

 area. Ice up to 2 ft thick covered most parts of Great South Bay for about 

 1 1/2 months. Clammers reported heavy kills of hard clams after ice broke up. 

 Thirty-one stations in areas of the Bay controlled by the towns of Islip and 

 Brookhaven were sampled with rakes and tongs. Where possible, 200 or more 

 clams were taken. Mortality did not appear to be excessively high in most 

 places. The exception was Patchogue Bay, where mortalities ranged from 3.3 to 

 27.2% of samples. Average mortality for 8 stations in this area was 12.4%, 



201 



