During dredging the average number of benthos was reduced compared with 

 predredging samples. However, when the dredging stopped, the fauna in the 

 affected area began to recover, aided by recruitment during the winter. At 

 the time of the postdredging survey, there were about half as many individuals 

 in the dredged area as in the control area. This indicates that recovery of 

 benthos can occur quickly. 



In winter the average number of nekton and their biomass were higher in 

 turbid water than in clear water, while in summer the average number of nekton 

 (and presumably the biomass) were similar in both turbid and clear water. 

 Furthermore, only 1 of 12 dominant species in the experimental trawls appeared 

 to be repelled by turbid water and this species may not actually be respond- 

 ing to the silt. The data indicate that the mud plume from an operating dredge 

 is not repellent to nektonic organisms and may be beneficial by providing pro- 

 tection against predators. 



62. HASTINGS, R.W., "The Origin and Seasonality of the Fish Fauna on a New 

 Jetty in the Northeastern Gulf of Mexico," unpublished Ph.D. Disserta- 

 tion, Florida State University, Tallahassee, Fla., 1972. 



A 2.5-year study was conducted of successional and seasonal changes of 

 fish fauna around a newly constructed jetty at East Pass, Choctawhatchee Bay, 

 Florida. Information was obtained by diving observations and specimen collec- 

 tion. Observations were also made and compared with older jetty habitats. 

 The jetties were colonized soon after construction by species common to the 

 area originally, by species from other habitat areas such as offshore reefs, 

 and by tropical species carried by currents. 



63. HEADRICK, M.R., "Effects of Stream Channelization on Fish Populations in 

 the Buena Vista Marsh, Portage County, Wisconsin," Wisconsin Cooperative 

 Fishery Research Unit, Fish and Wildlife Service, Office of Biological 

 Services, Steven Point, Wis., Sept. 1976. 



Fish populations from ditches 6 to 8 years old and 52 to 62 years old 

 within the Portage County Drainage District were compared with populations in 

 adjacent parts of natural streams. Two study areas were selected: an up- 

 stream zone of plentiful brook trout (Satvetinus fontinatis) and a downstream 

 zone in marginal trout waters where white suckers (Catostomus aommersoni) 

 were numerous. Each area included a new ditch, an old ditch, and a natural 

 stream, all with similar discharge. Estimates of the annual production, 

 population, and biomass of brook trout and white sucker, and the total 

 catch records for other fish species were derived from electrof ishing samples 

 in June, August, and September 1974 and April, May, July, and September 1975. 

 A creel survey was conducted during the 1975 trout season. 



64. HELFRICH, P., "An Assessment of the Expected Impact of a Dredging Project 

 for Pala Lagoon, American Samoa," UNIH l-SEAGRANT-TR-76-02, University 



of Hawaii, Honolulu, Hawaii, Oct. 1975. 



Dredging of the harbor at Pala Lagoon in American Samoa would have detri- 

 mental environmental effects. Altering of the sill near the lagoon entrance 

 would affect the biota. It also was concluded that the flow of raw sewage 

 into Pala Lagoon could be dangerous to persons swimming in and collecting sea- 

 food from the lagoon. 



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