

Sublegals 



Legals 



Year 



15-47 mm 



over 4 7 mm 



1950 



0.26 



0.30 



1951 



0.47 



0.41 



1952 



0.33 



0.39 



1953 



0.13 



0.44 



1954 



0.17 



0.33 



1742 



Stringer, Louis D. 1955. 



Greenwich Bay hard clam productivity studies. In 5th Conf. on clam research, 

 Boothbay Har. , Me. U.S. Dept. Interior, Fish Wildl. Serv.: 1-9. 



Number of legal size has remained nearly the 

 same, but the number of sublegals has dropped 

 sharply. A predicted shortage of "necks" in 

 1954 was borne out. Geographical distribution 

 has remained nearly the same. The 3 areas of 

 high abundance, at the mouth of Apponaug Cove, 

 entrance to Greenwich Cove, and middle of 

 eastern section, have occurred in all years 

 from 1950 to 1953. The area at the mouth of Apponaug Cove has almost dis- 

 appeared, as expected. A new area appeared from Cedar Tree Point to 

 Buttonwoods Point, and is one of the most dense in the Bay. Average is 5.3/ 

 ft 2 with maximum densities over 20/ft2. These were spawned in 1952. The 

 cause of these high and low abundance areas is unknown, except for bottom 

 type. When large quantities of shell are present, abundance of hard clams is 

 high (mud, sand and shell 1.54/ft 2 , sand and shell 0.98, mud and shell 0.60, 

 mud and sand 0.60, sand 0.54, mud 0.27). Three principal subtidal communities 

 were recognized, the Ampelisea community, with relatively few hard clams; the 

 Crepidula community, with relatively abundant hard clams; and the sand-bottom 

 community, with some hard clams present. Boats vary from less than 10/day in 

 January to about 60/day in August. Mean number of hours fished/day is just 

 over 5 and mean number of days/week about 4 . Mean number of boats/day was 

 1950-38; 1951-34; 1952-34; 1953-32; and 1954-29. Areas of high abundance are 

 found and receive the heaviest effort. Removals are about equal to re- 

 cruitment. Removals: 1950-59 total, 32 legal, 9 removed; 1951 - 93, 44, and 

 7; 1952 - 76, 41, 8; 1953 - 60, 46, 7; and 1954 - 53, 35, and 5. Total catch 

 has remained almost constant, but a smaller proportion of "necks" is taken; 

 1.2 bu necks, 1.3 bu large in 1950; 0.7 bu necks, 1.8 bu large in 1954. When 

 necks drop, some boats move to other portions of Narragansett Bay. - J.L.M. 



1743 



Stringer, Louis D. (undated). 



The population abundance and effect of sediment on the hard clam. U.S. 

 Fish Wildl. Serv., Appendix E, 17 p. (Note: exact reference was not clear.) 



A clam shell bucket was used to sample the bottom of Narragansett Bay to 

 survey the hard clam population in 1956 and 1957. Best clam beds are in the 

 upper shallow areas of the bay. Hard clam abundance varies from year to 

 year, but the location of areas of abundance remain constant. Successful 

 settings occur at infrequent and variable intervals. By analyzing relative 

 abundances of different size classes, relative success of spawning during 

 the year when the given size class was spawned can be determined. The range 

 of estimates for the rate of sedimentation in Narragansett Bay is 0.02-0.1 

 ft/year. All clams tested resumed pumping after having 1 1/2-2 1/2 inches 

 of sediment dumped on them. It is thought that a hovering layer of sediment 

 will have an adverse affect on clams. Surveys showed that hard clams were 

 most abundant in sediment of mud, sand, and shell. Pure mud and sand bottoms 

 had the lowest abundance. Hurricane barriers constructed in lower 

 Narragansett Bay will not markedly affect the hard clam resource through 

 changes in sedimentation. - D.L. 



1744 



Stringer, L. S. 1956. 



Population characteristics of the hard clams in Greenwich Bay, Rhode Island. 

 Trans. Am. Fish. Soc. 85. 



Interlibrary loan could not identify as given. Search terminated. - J.L.M. 



482 



