fall months, but an expected heavy migration of redfish and black drum did not 

 occur. In 1957-58 when the pass was closed, many of the same species were found. 

 These normally appeared at a later date than when the pass was open. Many typical 

 gulf species were not present in 1958. 



It is suggested that discharge from the Guadalupe River, together with 

 northern storms, is responsible for maintaining this inlet, which is prone to 

 close during periods of drought. 



149. SLEIGHT, H., Ill, "Effects of Suspended Marine Sediments on Selected Com- 

 mercially-Valuable Fishes and Shellfish of Massachusetts," Proceedings of 

 the Seventh Annual Offshore Technology Conference, Vol. 1, 1975, pp. 133- 

 141. 



As part of the Commonwealth of Massachusetts' research into the environ- 

 mental effects of offshore sand and gravel mining, acute bioassays were per- 

 formed on several commercially valuable marine fish and shellfish utilizing 

 various levels of suspended, fine-grained marine sediment. The species tested 

 displayed a remarkable tolerance for short-term exposures to the levels of 

 suspended sediments that they might encounter in the dredge plume of an offshore 

 sand and gravel mining operation. 



150. SLOTTA, L.S., et al., "Effects of Hopper Dredging and In-Channel Spoiling 

 (October 4, 1972) in Coos Bay, Oregon," Interdisciplinary Studies of the 

 Oregon State University School of Engineering and School of Oceanography, 

 Corvallis, Oreg., July 1973. 



The chemical, physical, and biological effects associated with the dredg- 

 ing and disposal methods of a hopper dredge were studied. Field investigations 

 and subsequent laboratory analyses vjere organized to evaluate the nature and 

 magnitude of environmental changes resulting from dredging activities on 4 Octo- 

 ber 1972 at Coos Bay, Oregon. Assessment methods and evaluation techniques are 

 discussed, and postdredging conditions are compared with a predredging base line. 



151. SLOTTA, L.S. et al., "An Examination of Some Physical and Biological 

 Impacts of Dredging in Estuaries," RANN GRANT Gl 34346, Oregon State 

 University, National Sciences Foundation, Corvallis, Oreg., Dec. 1974. 



This research was focused on four major topics: (a) The effects of 

 dredging on estuarine systems, (b) the system properties of estuaries, (c) the 

 ways in which estuarine research can be used effectively by user groups, and 

 (d) the development of concepts and techniques for monitoring impacts of dredg- 

 ing and other alterations to estuaries. Emphasis has been placed on benthic 

 rather than pelagic systems because changes in the sediments are less transitory 

 than those in the overlying water and because dredging, by its nature, involves 

 the estuarine bottom. 



Specific examples include the study of the concepts of estuarine stability 

 that has led to specific questions about the role of subtidal clam populations, 

 probable impacts of dredging, and the role of activities such as marine traffic. 



152. SMITH, G.F., "Observations on the Effects of Dredging to Subtidal 

 Communities at Keystone Harbor Whidbey Island, Washington," Huxley 

 College of Environmental Studies, Western Washington State College, 

 Bellingham, Wash., 1976. 



This report presents the results of observations on the effects of dredging 

 on subtidal communities at Keystone Harbor on Whidbey Island, Washington. Main- 



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