500 



Dow, Robert L., and Dana E. Wallace. 1951. 



A method of reducing winter mortalities of quahogs (Venus mercenaria) in 

 Maine waters. Dept. Sea Shore Fish., Augusta, He., Res. Bull. 4, 31 p. 



High densities of hard clams (50 to 80/ft2) were residue of a set in 1938, 

 39 or 40. Most were stunted to less than the State's legal size of 2 

 inches The clams formed a windrow which had higher mortalities than clams 

 in surrounding flats. Stunted clams grew well and had high survival when 

 transplanted to less populated and less exposed areas. The following re- 

 commendations were made: 1) high density concentrations of quahogs should be 

 transplanted before growth has created stratification of the population; I) 

 transplanting should be done as soon as possible after high concentrations 

 have been discovered, so more clams can be transplanted with less effort; 

 3) transplanting should not cause points of elevation in the planted area, 

 planting should be uniform with clams well spread out. - D.L. 



501 



Dow, Robert L., and Dana E. Wallace. 1952. 



Observations on green crabs (C. maenas ) in Maine. Maine Dept. Sea Shore 

 Fish., Circ. 8, p. 11-15. 



Green crab had recently become increasingly important in waters of the State 

 as a predator of soft clam, My a arenaria. In laboratory tanks green crabs 

 could not eat quahogs, Mercenaria mercenaria, larger than 1/2-inch diameter. 

 The crab is hardy, and burrows into the bottom to obtain food. Crabs use 

 their large claws to scoop out burrows and kill their prey. - J.L.M. 



502 



Dow, Robert L., and Dana E. Wallace. 1953. 



A method of reducing winter mortalities of Venus mercenaria in Maine waters. 

 Natl. Shellf. Assn., Convention Addresses 1951: 15-21. 



Although Maine does not have a very large hard clam fishery it is important 

 to the economy of towns on Casco Bay. It is primarily an intertidal fishery. 

 Good sets are infrequent; the last one was in 1947. Most of this year class 

 was just reaching littleneck size in summer 1951. When heavy concentrations 

 occur in an area their growth is often slow and mortality is high. Mortality 

 is high when storms expose quahogs at low water in winter, and when density 

 is so great as to make elevations or ridges in the normal gradient of the 

 flat. Clams in depressions covered with sediment survive cold weather well. 

 Clams near low water mark survive better than those higher on the beach. 

 Transplantation to areas near or below mean low tideline, spreading clams 

 thinly to allow room to dig and to grow, is feasible and beneficial. Trans- 

 planting should be done as early as possible because the same number of clams 

 can be moved with less labor and at less cost. In summer 1950 they moved 

 3,012 bushels from an area that contained concentrations of clams as high as 

 167/ft2. Sizes ranged from 27 to 59 mm and averaged 43 mm. - J.L.M. 



503 



Dow, Robert L., and Dana E. Wallace. 1954. 



The seed quahog dredge, Venus M. Me. Dept. Sea Shore Fish., Fish. Circ. 

 15, 12 p. 



A commercial fish pump of the type used to transfer herring from nets to 

 carriers and from carriers to processing plants handled a maximum of 6 to 7 

 bu quahog seed/min. Breakage was negligible when the pump engine was 

 operated at 580 to 600 rpm. More breakage occurred on deck than from 

 dredging. With a larger pump and suction units it was believed that 

 commercial quahog harvesting would be practical. - J.L.M. 



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