Saloman (1974) studied the benthic fauna of offshore borrow pits at 

 Treasure Island, Florida, 3 years after dredging. The abundance and diversity 

 of benthic animals were lower than undisturbed substrata in adjacent areas. 

 The physical size of benthic animals from the borrow pits was very small com- 

 pared to undisturbed areas. Sediment in the pits contained a high percentage 

 of organic matter and hydrogen sulfide. The author concluded that the poor • 

 fauna of the offshore pits were due to siltation and low dissolved oxygen levels 

 resulting in a poor-quality habitat. Taylor Biological Company (1978) also 

 studied the borrow areas at Treasure Island, Florida, 4 years after dredging. 

 It was concluded that all the borrow pits were slow in recovering. 



Studies by Marsh, et al. (1978) indicated some beneficial aspects of off- 

 shore borrowing at Hillsboro Beach, Florida, done in 1972. Borrowing uncovered 

 limestone rubble which improved the available habitat and resulted in more 

 diverse and abundant macrobenthic and fish populations. The investigators 

 concluded that borrowing created a new habitat for some organisms and attracted 

 substrate sensitive larvae. Marsh, et al. (1980) reported on a similar benthic 

 study in Florida 7 years after a borrowing operation for beach nourishment. 

 The area showed no apparent detrimental effect of the 1971 project; coral reefs 

 damaged during early dredging apparently recovered. 



More recently, Turbeville and Marsh (1982) reevaluated the long-term 

 effects of borrowing at Hillsboro Beach, Florida. They noticed that species 

 diversity was higher at the borrow site than at the control site and related 

 this to uncovering a new habitat which attracted new species. This borrow area 

 remained unfilled, had not accumulated organic material, and had good water 

 quality 5 years after dredging. Gustafson (1972) also found enrichment of the 

 fauna due to borrowing. He considered manmade disturbances as comparable to 

 natural disturbances related to currents, winds, and tides. Saloman, Naughton, 

 and Taylor (1982) noted that dredging at Panama City Beach, Florida, caused 

 an immediate decline in benthic animals followed by a rapid population recovery. 

 Culter and Mahadevan (1982) studied the same borrow area 7 years later. They 

 concluded that, based on community analysis and sediment parameters, no signif- 

 icant differences were found between the borrow sites and surrounding areas. 



Studies on meiobenthic animals have generally been on their life history 

 and taxonomy and not related to beach nourishment operations. However, studies 

 have been made on the effects of dredging on these organisms. Rogers and 

 Darnell (1973) and Rogers (1976) reported on the effects of shell dredging in 

 Texas. They sampled meiobenthic organisms at monthly intervals for a period 

 of 8 months in dredge cuts. The researchers noticed that on recently dredged 

 bottoms the meiofauna population was less than half of that of an undisturbed 

 bottom. Dredge holes proved to be a poor environment for meiofaunal species. 

 Similarly, Pequegnat (1975) reported on the response of meiobenthos to 

 dredging. His major conclusion was that meiobenthic organisms respond nega- 

 tively to low levels of environmental disturbance and would be expected to 

 better reflect ecosystem degradation and recovery. 



3 . Effects on Motile Animals . 



Conceivably, motile animals will be least affected by borrowing operations 

 because of their ability to promptly escape any disturbed area. Research on 

 the after effects of dredging indicates that minimum damage to motile fauna 

 generally occurs. Occasionally, the productivity of a borrow area may actually 



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