and cell density and species of phytoplankton fed to the clams. At high 

 cell densities (2xl0 8 and 5xl0 8 cells/liter) retention of cobalt-60 by clams 

 was reduced with increasing cell density and size of clam. More than 43% of 

 the radioactivity introduced into the pallial cavity of the clams with the 

 diatom Nitsahia alosterium at cell densities less than 5xl0 7 cells/liter was 

 retained in clams two days after feeding. Nitschia alosterium gave the 

 largest retention at all clam sizes of the three phytoplankton organisms 

 tested. The other two, Dunaliella sp. and Platymonas sp. lost more than 90% 

 of the radioactivity in the first few hours in the pseudofeces. - modified 

 authors' abstract - J.L.M. 



2182 



Nixon, S. W. , C. A. Oviatt, and S. S. Hale. 1976. 



Nitrogen regeneration and the metabolism of coastal marine bottom communities. 

 In The Role of Terrestrial and Aquatic Organisms in Decomposition Processes. 

 J. M. Anderson and A. Macfayden (eds.) The 17th Symp. of the British Ecol. 

 Soc, Blackwell Sci. Pubs., Oxford: 269-283 (paper no. 11). 



Three subtidal bottom areas chosen for study included an assemblage of macro- 

 fauna (>0.75 mm) dominated by hard clam, Meraenaria meraenaria, in the lower 

 west passage; a polychaete-bivalve community with Nepthys inaisa and Nucula 

 annulata in the middle of the Bay; and an amphipod mat of Ampelisaa abdita 

 in the upper west passage. Metabolism of the lower bay station where Mer- 

 aenaria was abundant was significantly different at the 95% confidence level 

 from metabolism of bottom at the other two stations. Oxygen uptake ranged 

 from 10 to 150 mg/m 2 /hr, with an annual total of about 360 g 2 /m 2 . Inor- 

 ganic nitrogen was released to the water column almost totally as ammonia at 

 rates up to 400 uM/m 2 /hr. The total annual flux of inorganic nitrogen 

 (about 870 mM/m 2 ) was only about half that expected on the basis of oxygen 

 uptake or inorganic phosphate regeneration. The anomalously low inorganic 

 nitrogen flux may be balanced by high rates of dissolved organic nitrogen 

 release from the bottom. Rapid regeneration of inorganic nitrogen by bottom 

 communities plays a major role in maintaining high rates of primary produc- 

 tion in coastal waters, but the incomplete metabolism of nitrogen on the 

 bottom may be responsible for the low N/P ratios characteristic of shallow 

 waters and for the importance of nitrogen as a limiting factor in these 

 areas. - J.L.M. 



2183 



Odum, Howard T. 1957. 



Biogeochemical deposition of strontium. Inst. Mar. Sci., Univ. Texas, 

 Publ. 4 (2) : 38-114. 



Reproducibility of the reprecipitation procedure and variation in methods 

 and in skeletal materials were measured with analysis of variance of 48 

 duplicate analyses of 6 Venus meraenaria clam shells. The average error 

 was 5%. In shells of V. meraenaria where prismatic and nacreous layers are 

 aragonite, Sr/Ca ratios were not statistically different. In various organs 

 of Venus from Morehead City, N.C. the Sr/Ca ratio varied from 3.50 to 2.39. 

 These tissues were permeated by white phosphate deposits, which were separa- 

 ted where possible, but the values are probably affected by that which re- 

 mained. The ratios are expressed in atoms/1000 atoms. - J.L.M. 



2184 



Painter, S. D., and M. J. Greenberg. 1978. 



Elapid a-toxins have no effect on the cholinergic responses of bivalve myo- 

 cardia. Experientia (Basel) 34(12): 1608-1609. 



Elapid a-toxins do not affect the myocardial nicotinic ACh receptors of 

 Meraenaria meraenaria. - J.L.M. 



607 



