Immediate Effects and Rates of Recovery," Report No. UMCEES 76-23cBL, 

 University of Maryland, Center for Environmental and Estuarine Studies, 

 Solomons, Md., 1977. 



This report discusses the first half of an ongoing project to assess 

 the effects of dredging in shallow-water tributaries of the Chesapeake Bay. 

 It outlines the establishment of sampling stations and the taking of initial 

 samples at two sites — Horn Point and Lewis Creek. An analysis of sediment 

 and organic carbon samples obtained is presented in tabular form. A list of 

 species of benthic invertebrates found at the two study sites is also included. 



130. PISAPIA, R.C., "Biological Implications of Dredge Holes," unpublished 

 report. U.S. Fish and Wildlife Service, Annapolis, Md. 



This paper discusses the environments in holes resulting from dredging 

 activities. Holes significantly deeper than the surrounding bottom can be- 

 come traps for sediments, organic materials, and pollutants. A number of 

 examples are cited to demonstrate the types of accumulations in dredge holes 

 and their adverse biological impacts. Recommendations to reduce the impacts 

 of dredge holes are provided. 



131. POMEROY, W.M., and STOCKNER, J.G., "Effects of Environmental Distur- 

 bance on the Distribution and Primary Production of Benthic Algae on 

 a British Columbia Estuary," Joumat of the Fishery Research Board of 

 Canada, Vol. 33, No. 5, May 1976, pp. 1175-1187. 



Construction of a river training dike at Squamish, British, Columbia, 

 has resulted in strong salinity, water transparency, and sedimentation gradi- 

 ents across the estuary face that have significantly affected the distribu- 

 tion and primary production of benthic algae. The estuary west of the dike 

 is now a very unstable habitat for algal colonization and growth because of 

 heavy sedimentation and salinities less than 3 parts per thousand during 

 river freshets. At other times of the year, a salinity range of up to 

 25 parts per thousand is common over a tidal cycle so algae in this area are 

 generally strongly euryhaline. The eastern part of the estuary has a more 

 stable benthic environment; lower sedimentation and higher salinity result 

 in greater species diversity, biomass, and primary production. Algae tend 

 to be weakly euryhaline, with optimum salinities between 15 and 30 parts 

 per thousand. Recent intrusion of Fucus vesiautosus strongly indicates that 

 the eastern estuary is developing into a more marine habitat. 



132. PULLEN, E.J., and TRENT, W.L., "White Shrimp Emigration in Relation to 

 Size, Sex, Temperature and Salinity," Food and Agriculture Organization 

 of the United Nations Fisheries Report, Vol. 3, No. 57, 1969, pp. 1001- 

 1014. 



This study was conducted on juvenile and subadult white shrimp, Penaeus 

 setiferus (Linnaeus), emigrating from Galveston Bay, Texas, to the Gulf of 

 Mexico. Surface, midwater, and bottom tows were made with a 3-meter otter 

 trawl on ebbtides from 1 August 1966 to 27 January 1967, usually during the 

 day. Five peaks of emigration occurred from 19 October to 25 December, coin- 

 ciding with water temperatures between 19° and 8° Celsius in the tidal pass. 

 The catch increased significantly from the surface to the bottom of the water 

 column. Sharp drops in water temperature appeared to stimulate shrimp emi- 

 gration. The mean lengths of shrimp caught were similar between water depths 



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