in these ponds. Preliminary results with oysters 

 were not promising when high water temperatures 

 resulted in excessive mortalities (Matthiessen, 

 1970b). 



Texas 



In 1970, 4.6 million pounds of oyster meats were 

 harvested from Texas. The center of production is 

 Galveston Bay. Harvesting has been confined al- 

 most entirely to the 22.000 acres of natural reefs 

 (Hofstetter. 1959). although there are some 3.000 

 acres of leased bottom. Lack of good bottom for 

 leasing has been a deterrent to oyster cultivation. 



Considerable interest has developed recently in 

 the pond culture of oysters (More and Elam. 1970). 

 At Palacios, Texas, the Parks and Wildlife Depart- 

 ment has built 21 artificial ponds ranging in size from 

 a quarter of an acre to 4 acres. Studies on disease 

 resistance to the fungal pardsile Labyrinthomi.xa sp. 

 are being conducted. Attempts are also being made 

 to relate water depth and type of pond construction 

 to oyster growth and survival. 



THE HARD CLAM 



The hard clam, Mercenaria menenaria, (also 

 called quahog, quohog, and quahaug) is distributed 

 along the Atlantic coast and the Gulf of Mexico. 

 They reached their peak of production in 1950 when 

 21 million pounds were harvested. Production then 

 dropped until 1955 when 14.2 million pounds were 

 landed. Since then, production has remained fairly 

 stable fluctuating between 13.3 and 15.8 million 

 pounds, and in 1970 approximately 15.4 million 

 pounds of meats were produced. New York is the 

 leading producer (7.9 million pounds) while five 

 states — Virginia, New Jersey, New York, Mas- 

 sachusetts, and Rhode Island — accounted for 919^ 

 of the total U.S. landings. The entire fishery comes 

 from wild stocks although some attempts are being 

 made to utilize hatchery stocks. 



In New York the center of the resource is on the 

 southern shore of Long Island in the sheltered hays 

 such as Great South Bay. Many types of gear have 

 been used to harvest clams. These include tongs, 

 rakes, dredges, by hand, hoes, and grabs. In 1967, 

 New York harvesting was divided among three 

 types of gear — dredges, 2.6 million pounds: tongs, 

 2.5 million pounds; and rakes, 1.9 million pounds. 

 Introduced into this industry in recent years was the 

 hydraulic escalator dredge which harvests clams 



with surprisingly little damage (Engle, 1970) to either 

 the clams or the clam beds. This gear is also used in 

 Chincoteague Bay, Md. 



The hard clam fishery appears to be in excellent 

 condition although there is some concern over the 

 increasingthreat of pollution. In New York there are 

 an estimated 450.000 acres of potential shellfish pro- 

 ducing bottoms of which 156,892 acres or approxi- 

 mately 359f of the total are uncertified. Considerable 

 effort has been devoted by the New York Conserva- 

 tion Department to develop depuration techniques. 

 A PL 88-309 project entitled. ""Operation of a depu- 

 ration plant for hard clams {Merceiuirhi 

 nwrrcncirid)." was completed in 1969 (MacMilian 

 and Redman, 1971). Results of the study, using a 

 ""pilot"" scale depuration system, indicated that the 

 depuration of hard clams is feasible, both economi- 

 cally and bacteriologically when such shellfish are 

 harvested from restricted growing areas (Median 

 Coliform MPN range: 70-700). The successful oper- 

 ation is greatly enhanced utilizing seawater obtained 

 from a saltwater well. It was estimated that hard 

 clams could be depurated at a cost of $1.76 per 

 bushel. 



The most intensive efforts towards propagation on 

 a commercial scale have been made on Cape Cod 

 and Long Island (Miller et al.. 1970). Clams are 

 artificially spawned to setting using methods de- 

 scribed by Loosanoff and Davis (1963). The seed 

 clams are held in especially designed hatcheries and 

 then transplanted to controlled growing areas. 

 Heavy losses from predation have been a serious 

 problem following planting on the growing grounds. 

 To solve this problem the Virginia Institute of 

 Marine Science has developed the use of aggregates 

 on the bottom to protect the seed clams from pred- 

 ators (Castagna, 1970). Three types of aggregates 

 were found successful: 1) crushed oyster shell. 2) 

 crushed stone, and 3) stream bed gravel (pea gravel). 



An average of more than 809f of the seed clams 

 planted with aggregates survived compared to 

 16-30% survival on plots without any aggregates. 

 Clams should be at least match-head size before 

 planting and should be scattered over the aggregate 

 at a rate of about 25-50 per square foot. 



One of the largest clam hatcheries is located in 

 North Carolina (Tyler. 1970). Since early 1970. 

 Coastal Zone Resources Corporation has been en- 

 gaged in producing hard clam sets using hatchery 

 techniques (David A. Adams, pers. comm.). Ap- 

 proximately 4 million clam larvae are produced each 

 week. Metamorphosis occurs in about 2 \\k. They 



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