Water samples were obtained from three dredging locations in Charles town 

 Harbor and from undisturbed control areas. The samples for each location were 

 taken from the dredge site, 183 meters downstream, and the site of the diked 

 disposal area. Daphinia were used for location I with a salinity of parts 

 per thousand, Paleomonetes for location II with salinities of 8 to 15 parts per 

 thousand, and Polydora for location III with salinities of 10 to 13 parts per 

 thousand. Rates of survival, metabolism, and swimming activity of three test 

 species were measured to determine the toxicity level of the water samples. 

 Weir water proved the most toxic; the sample taken 183 meters downstream was 

 intermediate in effect. The water from the dredge site was the least toxic. 



40. DINEEN, C, and DARNELL, R.M, "The Effects of Shell Dredging on the Food 

 Habits of Fishes in San Antonio Bay, Texas," Environmental Impact Assess- 

 ment of Shell Dredging in San Antonio Bay, Texas, Vol. Ill, App. BIO-E, 

 Texas A & M Research Foundation, College Station, Tex., Sept. 1973. 



pp. 225-231. 



The fishes of San Antonio Bay may be grouped into five general classes 

 based on their presumed feeding habits. The field capture data show three 

 of the species predominate in the populations inhabiting the bay — the bay 

 anchovy, the large-scale menhaden, and the Atlantic Croaker. These belong to 

 different feeding classes, and the rest of the fish community represents minor 

 variations of these three feeding themes. Further analysis of the possible 

 effects of dredging on the food habits of the fishes must take these factors 

 into account. 



41. DURBIN, A.G., "The Role of Fish Migration in Two Coastal Ecosystems: I. 

 The Atlantic Menhaden, Brevoortia tyrannus, Narragansett Bay, Rhode 

 Island, II. The Anadromous Alewife, Alose pseudoharengus in Rhode 

 Island Ponds," American Doctoral Dissertations, University of Rhode 

 Island, Kingston, R.I., 1975-76, and University Microfilms International, 

 Ann Arbor, Mich., 1977. 



The impact of the Atlantic menhaden and the anadramous alewife on plankton 

 populations has been examined through laboratory observations of the feeding 

 behavior and filtering rates. Adult menhaden were offered five species of 

 phytoplankton and two species of zooplankton as food. The food ration of 4.5 

 X 10^ kilograms of menhaden, a typical population size in Narragansett Bay, has 

 been estimated both from the energy budget and by assuming that the fish consume 

 an equivalent of 3 percent of their body weight per day. Menhaden are major 

 zooplankton predators and would be capable of reducing zooplankton standing 

 stocks in the upper bay to very low levels in a matter of days. 



Sea-run alewives do not feed while in freshwater, and through mortality, 

 excretion, and the release of spawning products, they contribute substantial 

 amounts of nutrients of marine origin to the freshwater systems. Thus the ale- 

 wife acts as a nutrient source to the system, rather than merely as a means of 

 nutrient regeneration. 



42. DURONSLET, J., LYON, J.M., and MARCELLO, F., "Vertical Distribution of 

 Postlarval Brown, Penaeus aztecus, and White, P. setiferus. Shrimp During 

 Immigration Through a Tidal Pass," Transactions of the American Fisheries 

 Society, Vol. 101, No. 4, Oct. 1972, pp. 748-752. 



Knowledge of the vertical distribution of postlarvae penaeid shrimp as 



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