patterns of erosion and deposition following jetty construction disagreed with 

 the earlier study and it was concluded that the changes resulted from local re- 

 arrangements of the beach due to the disrupted equilibrium following jetty con- 

 struction, but at the same time maintaining an overall condition of zero net 

 littoral drift. Thus, severe coastal erosion can result from jetty construc- 

 tion, even in areas of zero net littoral drift. 



A new south jetty has been recently completed. This jetty has resulted in 

 further realinement of the shoreline with accretion and shoreline advance 

 immediately south of the south jetty. This provides further evidence that 

 a zero net littoral drift exists in the area. 



89. KUENZLER, E.J., et al., "Water Quality in North Carolina Plains Streams and 

 Effects of Channelization," Report No. 127, University of North Carolina, 

 Water Resources Research Institute, Chapel Hill, N.C., Oct. 1977. 



A study was made of the physical and chemical characteristics of seven 

 small Coastal Plain streams in eastern North Carolina. Three natural streams 

 were compared with four streams that had been channelized to reduce agricultural 

 losses caused by flooding. Two or three sampling stations were established on 

 each stream. Some stations on natural streams were essentially pristine, but 

 others received point-source inputs of livestock farm wastes. The natural 

 streams had broad flood plains and low stream velocities, even during flood 

 stages. Freshets occurred in all seasons, but high discharge and concomitant 

 flooding of natural swamps were usually greatest during the winter and spring. 

 The waters of channelized streams, however, were restricted; they attained 

 higher velocities, carried greater particulate loads, and were more turbid than 

 natural streams. Some channelized streams were enriched by sewage, by live- 

 stock wastes, or by agricultural fertilizer. 



90. KUTKUHN, J.H., COOK, H.L., and BAXTER, K.N., "Distribution and Density of 

 Pre juvenile Penaeus Shrimp in Galveston Entrance and the Nearby Gulf 



of Mexico (Texas)," Food and Agriculture Organization of the United 

 Nations Fisheries Report No. 57, Vol. 3, 1967, pp. 1075-1099. 



In early 1959 the Bureau of Commercial Fisheries began a study to deter- 

 mine when, from what direction, at what stage of development, under what condi- 

 tions, and in what quantity prejuvenile shrimp of the commercially important 

 Penaeus enter the extensive Galveston (Texas) estuary. The findings were to 

 aid in circumscribing offshore spawning areas and thereby provide information 

 on the degree to which the progeny of shrimp reproducing in each area are 

 nurtured in specific estuaries bordering the northern Gulf of Mexico. 



An analysis of more than 3,000 samples collected systematically during a 

 1-year period revealed the following: the frequency of sampling, although 

 high, was insufficient to trace the rapid onshore movement of recently hatched 

 broods of Penaeus; the gross horizontal distribution of Penaeus larvae and 

 postlarvae in the gulf and vertical distribution of postlarvae in the Galves- 

 ton entrance changed markedly from season to season; Penaeus larvae rarely 

 occurred within 10 kilometers of shore and were not bottom dwellers; Penaeus 

 postlarvae did not frequent the bottom in winter and otherwise were usually 

 more abundant at middepths than at the bottom. For estimating density of 

 prejuvenile penaeids, the study's sampling scheme was relatively efficient 

 in controlling spatial variation, but comparatively inefficient in accounting 

 for wide temporal variation in organism abundance. 



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