New York, Massachusetts, Maine, and Canada 

 were compared with the data for the hard clams 

 sampled at the New Dorp Beach and Ward Point, 

 Raritan Bay sites. Growth of Raritan Bay clams 

 was about midway between the fastest (Florida) 

 and the slowest (Canada). At Ward Point, growth 

 to age 4 was about equal to New Jersey growth, 

 but at New Dorp Beach, gi-owth was consistently 

 greater. After age 4, clams at Ward Point grew 

 much slower than New Jersey clams, and even 

 slower than Maine clams after age 5. These obser- 

 vations support the conclusion by Ansell ( 1968) of 

 extreme local variations in the annual growth of 

 hard clams. 



The absence of large, old hard clams in the 

 present samples may be the result of pollution 

 effects, as Jefferies (1972) found for Providence 

 River, RI, hard clams stressed by hydrocarbons. A 

 high Ci5, hydrocarbon value of 3,672 ppm in sed- 

 iments at Ward Point was reported by Koons and 

 Thomas (1979). Nevertheless, mortalities (e.g., 

 paired valves containing dead bodies) were not 

 evident at any site. 



Food availability is considered an important 

 factor for growth of hard clams by Ansell (1968). 

 Jefferies ( 1962) considered the nutrient content of 

 Raritan Bay to be rich and the environment capa- 

 ble of supporting dense biotic communities, be- 

 cause of a sluggish circulation pattern. Patten 

 (1962) found that phytoplankton species diversity 

 decreased up bay (towards Ward Point) from the 

 higher values in the Lower Bay. A lower diversity 

 of phytoplankton in the vicinity of Ward Point 

 may have resulted in lower amounts of food or- 

 ganisms being available for the nutritional needs 

 of the clams, and was probably reflected in their 

 slower growth and poor meat condition. 



Gonadal development culminated in spawning 

 at three Raritan Bay sample sites. This suggests 

 that the reproductive capacity of hard clams in 

 Raritan Bay was not being affected by pollutants. 

 However, some differences were noted in a com- 

 parison of the results based on available informa- 

 tion about the time and duration of spawning and 

 larval production at several northwestern At- 

 lantic coast locations. At more northern locations, 

 Belding (1912) and Deevey (1948) in Massachu- 

 setts, Landers (1954) in Rhode Island, and Car- 

 riker (1959, 1961) in Long Island, NY, and Little 

 Egg Harbor, NJ, observed that spawning was ini- 

 tiated 1 to 2 months earlier than was observed in 

 Raritan Bay during 1974. Similarly, at more 

 southern locations. Keck et al. (1975) in Dela- 

 ware, Sieling (1956) in Maryland, Ropes (1971b) 



and Chanley and Andrews (1971) in Virginia, 

 Porter (1967) in North Carolina, and Eversole 

 and Michner (1980) in South Carolina observed 

 that spawning was initiated 1 to almost 3 months 

 earlier. A spawning beginning about three- 

 fourths of a month earlier than the present study 

 was observed by Jefferies (1962) in Raritan Bay, 

 but Loosanoff (1937) in Long Island, NY, ob- 

 served that spawning began at the same time as 

 in Raritan Bay during 1974. No particular trend 

 in the time of peak spawning was evident in the 

 several studies, except that the peak spawning in 

 1974 at all Raritan Bay sample sites was later 

 than reported in any of the other studies. Spawn- 

 ing ceased somewhat earlier at more northern 

 locations, and was not as prolonged at more 

 southern locations as was observed in Raritan 

 Bay during 1974. 



The project was initiated under the premise 

 that heavy metal pollution in Raritan Bay could 

 be affecting the viability of adult hard clams. 

 Studies indicated that tests for copper and lead 

 should be specifically included, because high con- 

 centrations of both have been found in Raritan 

 Bay sediment and water samples (Greig and Mc- 

 Grath 1977; Waldhauer et al. 1978). 



The negative results of histochemical tests for 

 heavy metals in Raritan Bay hard clams are not 

 readily explained. Eisler (1981) has listed studies 

 that found 15 heavy metals (including those 

 tested for in the present study) in field collected 

 hard clams. However, heavy metals can occur in 

 several forms (Waldichuk 1979; Fayi and George 

 1985), suggesting that the histochemical tests 

 may not have been specific for those occurring in 

 Raritan Bay hard clams. Pringle et al. (1968) re- 

 ported lower levels of copper in field collected 

 hard clams than oysters iCrassostrea virginica 

 and C. gigas ). The positive result for copper in the 

 oysters from Ward Point is probably related to the 

 species greater sensitivity and accumulation of 

 more of the metal in their tissues than hard 

 clams. Copper may have been at a level too low for 

 detection by the histochemical test, although lim- 

 its for detection of copper or other metals were not 

 given in Pearce (1972). 



Hydrographic conditions (not specifically sam- 

 pled for during the present study) probably influ- 

 enced the growth and survival of hard clams in 

 Raritan Bay. Based on current flow observed by 

 Jefferies (1962) and Patten (1962), the New Dorp 

 Beach area is influenced principally by water 

 from the Hudson River and the ocean; the Ward 

 Point area is influenced by an eddy formed from 



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