Applied Biology, Inc. (1979) studied offshore borrowing at Duval County, 

 Florida, and found no significant differences in the number of species or 

 density of macrobenthic animals between a borrow and control site 4 months 

 after dredging was initiated. It was concluded that the sampling interval of 

 the study may have exceeded the recovery period and the short-term impacts 

 were not detected. Pisapia (1974) reviewed the literature on inshore dredge 

 holes and concluded that recovery appears to be a function of water depth, 

 sediment-size distribution, and prevailing physical and water quality con- 

 ditions. The review indicated recovery is very slow to nonexistent. 



Turbeville and Marsh (1982) surveyed a borrow pit off Broward County, 

 Florida, and observed no long-term impacts as determined by number of species 

 and faunal densities. They observed enhanced productivity within the borrow 

 area compared to an adjacent control site. The borrow pit was still well 

 defined and had a rubble limestone and sand bottom low in organic material 5 

 years after dredging. 



Rogers and Darnell (1973) found that meiobenthos undergo a very low rate 

 of population recovery following dredging. Some sites showed evidence of some 

 recovery, but even after a period of 18 years the meiofauna had not recovered 

 to former abundance. This study indicated that in the new dredge cuts (3 years 

 old) the populations had recovered to about 32 percent of the original meio- 

 fauna population level. The older dredge cuts (18 years and older) recovered 

 to about 80 percent of the original meiofauna population. Pequegnat (1975) 

 also report incomplete recovery of meiofauna 7 years after dredging. 



2 . Motile Animals . 



It appears that motile fauna are generally not affected adversely by 

 dredging unless a major food source or habitat is removed or the quality of the 

 area is severely degraded. Studies have shown that fish will leave an area of 

 active dredging, but will return later (Courtenay, et al., 1972, 1974; Harper, 

 1973; Oliver, et al., 1977; Applied Biology, Inc., 1979; Courtenay, Hartig, 

 and Loisel, 1980; Holland, Chambers, and Blackman, 1980). However, Courtenay, 

 et al. (1972) noted that some motile animals were absent from a dredged area 

 for up to 9 months. On the other hand, some motile animals are attracted to a 

 dredged area as a new food source is made available (Maragos, et al., 1977). 

 The sediment plume from the dredge also provides temporary protection to some 

 motile animals (Harper, 1973) . Therefore, recovery rate is variable and ranges 

 from immediate for some species and up to a year or more for others, depending 

 on the nature of the habitat damage. 



3. Corals . 



Courtenay, Hartig, and Loisel (1980) and Marsh, et al. (1980) documented 

 the recovery of reef building corals from dredging after 7 years at Hallandale 

 Beach, Florida. They concluded that coral recovery depends on the extent of 

 reef damage. 



Maragos (1979) observed long-term effects of dredging on reef coral in 

 Hawaii as a result of sand dredging. Five years after dredging it was observed 

 that erosion at the base of coral resulted in its undermining (overturning, 

 tilting colonies, or creating overhangs). He did find evidence of recovery in 

 the form of small colonies of coral growing on rubble fragments. Maragos (1974) 

 also reported that some reef sites subjected to pre-World War II dredging in 



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