56. GUNTER, G., BALLARD, B.S., and VENKATARAMIAH , A., "Salinity Problems of 

 Organisms in Coastal Areas Subject to the Effect of Engineering Works," 

 Contract Report H-73-3, Office of the Chief of Engineers, U.S. Army, 

 Corps of Engineers, Washington, D.C., 1973. 



The nongaseous substances normally moving in and out of animal and plant 

 cells are metabolites, water, and salts. The common salts in seawater deter- 

 mine both salinity and composition. The relationships of salinity to animals 

 and to plants living in the coastal waters are reviewed, with emphasis on the 

 estuaries of the Gulf of Mexico and the Atlantic coast of the United States. 

 Each bay, sound, or estuary is an individual case with regard to salinity 

 and should be appraised by biologists acquainted with the local fauna and 

 flora to minimize and possibly even enhance their biotic potential in connec- 

 tion with salinity changes related to engineering projects. 



57. GUNTER, G., CHRISTMAS, J.Y., and KILLEBREW, R. , "Some Relations of 

 Salinity to Population Distributions of Motile Estuarine Organisms, with 

 Special Reference to Penaeid Shrimp," Eoology , Vol. 45, No. 1, 1964, 



pp. 181-185. 



The types of shrimp species in coastal waters change with wet and dry 

 years and also with wet and dry seasons as salinities either rise or fall. In 

 waters of the northern gulf coast of the United States, the lower salinity 

 limits of the commercial shrimp are: white shrimp {Penaeus fluviatilis) , 0.42 

 part per thousand; brown shrimp (P. azteous) , 0.80 part per thousand; and 

 pink shrimp (P. duoranm) , 2.50 parts per thousand. The south Florida waters 

 have very few white shrimp. The brown and pink shrimp are found in these 

 waters and in waters with lower salinity. Investigations have shown that 

 young white shrimp are most abundant in waters with salinities lower than 10 

 parts per thousand; brown shrimp are most abundant at salinities of 10 to 

 20 parts per thousand; and pink shrimp are most abundant at salinities of 

 18 parts per thousand and above. Commercial catch statistics show that the 

 greatest amount of white shrimp are produced in the low salinity waters of 

 Louisiana, the greatest amount of brown shrimp in the saltier bays of Texas, 

 and the greatest amount of pink shrimp around the southern Florida islands where 

 the salinities are oceanic. Three lines of evidence — lower salinity limits, 

 abundance at various salinities by count, and commercial production from areas 

 of different salinities — all indicate that the three commercial shrimp of the 

 south Atlantic and gulf coasts of the United States may be ranked in order of 

 adaptation or "preference" to salinity in the younger stages as low, inter- 

 mediate, and high for the white, brown, and pink shrimp, respectively. Addi- 

 tionally, pink shrimp have been found in the hypersaline Laguna Madre at 

 salinities of 65 parts per thousand; the other two species have not been 

 found above 45 parts per thousand. This indicates that salinity is a limiting 

 factor to the distribution and abundance of shallow-water penaeid shrimp. 



58. GUSTAFSON, J.F., "Ecological Effects of Dredged Borrow Pits," World 

 Dredging and Marine Construction, Vol. 8, No. 10, Sept. 1972, pp. 44-48. 



Various studies on the effects of suspended sediment, dredge spoil, and 

 borrow pits are reviewed, and a defense of the industry and criticisms of the 

 studies are presented. The typical daily resuspension of bottom material by 

 tides, currents, and winds dwarfs any of man's present activities, such as 

 local dredging. Dredged borrow pits are examples of ecological enhancement 

 and show the healing capacity of nature and the low detrimental effects of most 

 dredge spoils. It is recommended that the industry improve its techniques to 



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