1673 



Shuster, Carl N., Jr. 1975. 



The thermal component of Atlantic coast estuarine environments. Proc. 10th 

 Ann. Conf., Mar. Tech. Soc . (1974): 629-638. 



Mentions a report by Sung Y. Feng in 1967 at the 1st Natl. Conf. on Depuration 

 (apparently unpublished) which demonstrated a 3-dimensional pattern of 

 behavior of Mevcenavia mevcenavia within a matrix of salinity and temp. 

 Salinity and temp were plotted on x and y coordinates and clam responses on 

 the z axis. The diagram showed a mound of activity, in which all activity 

 stopped beyond the broad outline of the base of the mound, and maximum 

 activity formed a plateau at the peak of the mound. Such multidimensional 

 analyses provide a more realistic view of ecological interactions than single- 

 factor analyses. - J.L.M. 



1674 



Shuster, Carl N., Jr., and Albert F. Eble. 1962. 



Techniques in visualization of organ systems in bivalve mollusks. Proc. Natl. 

 Shellf. Assn. 52: 13-24. 



Three-dimensional representation of organ systems greatly increases the ability 

 of the observer to visualize ramifications and relationships to other parts. 

 Details are given of tested methods for embedding and sectioning of shell and 

 entire specimens, rubber molds of shell cavity, and vinyl acetate injections 

 of vascular and digestive systems, with subsequent plastic embedding and 

 sectioning of corrosion and cleared preparations. - modified authors' abstract - 

 J.L.M. 



1675 



Shuster, Carl N., Jr., and Benjamin H. Pringle. 1968. 



Effects of trace metals on estuarine mollusks. Proc. 1st Mid-Atlantic 

 Industrial Waste Conf., Univ. Delaware, CE-5: 285-304. 



Magnitudes of present trace metal levels were measured by atomic absorption 

 spectrophotometer in 100 samples of Cvassostvea vivginica, Mevcenavia mevcenavia 

 and Mya avenavia from Maine to N.C. Uptake of trace metals by these bivalves 

 was measured for up to 20 weeks in the laboratory by exposure to controlled 

 flows of seawater containing specific concentrations of trace metals. Trace 

 metal levels in the oyster have increased slightly over the last 35 years. No 

 earlier data for comparison were available for clams. The general pattern of 

 toxicity to hard clam, from greater to lesser effects, was copper, cadmium, 

 chromium, and zinc. At environmental levels of 0.025 to 0.5 ppm copper for 

 periods up to 15 weeks the concentration in quahaug tissues increased 

 moderately. At 0.1 and 0.2 ppm cadmium, concentration in quahaug tissues 

 increased as much as 21-fold in 5 weeks. At 0.1 ppm lead, concentration in 

 quahaug tissues increased 86-fold, and at 0.2 ppm lead 171-fold in 5 weeks. 

 At 0.01 ppm chromium, concentration in quahaug tissues rose about 2.4-fold in 

 10 weeks. Trace metal levels in quahaug from natural environments ranged from 

 11.5 to 40.2 ppm per kg of wet tissue weight for zinc, 1.0-16.5 for copper, 

 9.0-83.0 for iron, 0.7-29.7 for manganese, 0.10-0.73 for cadmium, 0.1-7.5 for 

 lead, 0.19-5.8 for chromium, 0.1-2.4 for nickel, and 0.1-0.2 for cobalt. Levels 

 in Oysters were higher than in clams for zinc, copper, iron, and cadmium, but 

 about the same order of magnitude for manganese, lead, chromium, nickel, and 

 cobalt. Accumulation studies led to the following conclusions: 1) species 

 differ in uptake and concentration of a given metal; 2) duration of exposure 

 affects uptake rate and tissue level; 3) temperature and physiological 

 condition are related to uptake and concentration; and 4) apparent toxicity 

 of a metal for a species may determine uptake, concentration, and duration of 

 the experiment. Limited data suggested that zinc-exposed quahaugs produced 

 more purple-shell than controls or those exposed to cadmium. Mortalities of 

 8 quahaug populations exposed to 2 concentrations of 4 metals differed from 

 oyster experiments in several ways. Extreme mortalities (62 and 74%) occurred 

 in 0.025 and 0.05 ppm copper within 15 weeks. Only one clam died in controls. 

 No quahaug exposed to zinc died. Cadmium-exposed quahaugs died in substantial 

 numbers, 2 3% in the 0.2 ppm experiment. Uptake is a function of water 

 temperature. - J.L.M. 



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