polychaete worn;s. These species have sim- 

 ilar life histories, such as prolific 

 reproduction (often with several broods 

 per year), early rraturation, and high mor- 

 tality rates (e.g., the classic pollution 

 indicator species, the polychaete worms, 

 Capi tella capi tata and St reblospio bene- 

 dicti ). These so-called "opportunists" 

 are gradually replaced by slightly larger, 

 taxonomical ly more diverse assemblages 

 that typically exhibit slower growth 

 rates, lower mortality rates, delayed 

 reproduction, and reduced reproductive 

 rates. Rhoads et al. (1978) have also 

 noted changes in benthic infaunal life 

 mode during the recolonization of dis- 

 turbed subtidal soft-bottom habitats. 

 Early colonists on spoil disposal sites 

 tended to live in the upper layers of the 

 sediment and to isolate themselves from 

 the surrounding sediment through tube- 

 building activities. As the sediments 

 were increasingly affected by bioturba- 

 tion, (e.g., by organisms burrowing and 

 feeding), larger, subsurface burrowing 

 animals invaded the spoil site. 



Patterns of temporal change reported 

 in the literature correlate recovery rates 

 of disturbed shallow-water areas with 

 habitat, type of disturbance, and the size 

 and degree of isolation of the affected 

 area. In one study, over 3 years were 

 needed to establish a stable number of 

 benthic species (Dean and Haskins 1964), 

 while Sanders et al. (1980) found that 

 complete recovery of a benthic community 

 following a small oil spill had not oc- 

 curred over a period of more than 5 years. 

 On a smaller scale, recolonization may 

 take weeks to months (Grassle and Grassle 

 1974; McCall 1977; Zajac 1981). Recruit- 

 ment by benthic organisms into soft- 

 bottoms can be accomplished by planktonic 

 larval settlement as well as migration of 

 adults from surrounding areas. This colo- 

 nization is relatively rapid when compared 

 to marine rocky substrate systems (Osman 

 1977) in which repopulation of disturbed 

 sites is almost exclusively planktonic. 



Life histories of infaunal species 

 inhabiting New England tidal flats include 

 a range of strategies. Niany species dis- 

 play life histories characteristic of the 

 earliest stages of recolonization. Tem- 

 perate tidal flat environments are con- 

 tinually exposed to extremes of natural 



physical and biological change (See Chap- 

 ters 1 and 3). The organisms inhabiting 

 flats, therefore, are well-adapted to 

 withstand natural perturbations and per- 

 sist by recovering rapidly. Other species 

 have life histories more similar to those 

 found in the later stages of recoloniza- 

 tion. These organisms are more sensitive 

 to disturbance and do not inhabit tidal 

 flat areas that are continually exposed to 

 environmental fluctuation. In Maine, dense 

 populations of Mya arenaria are commonly 

 found in areas that are not abraded by ice 

 scouring (L. Watling; University of Maine, 

 Walpole; February 1981; personal communi- 

 cation). 



Fish and birds respond differently to 

 habitat perturbations. They are more 

 mobile and move from the impacted area. 

 Fish and birds may not be affected by the 

 loss of small portions of a tidal flat, 

 but a bigger loss of that habitat would 

 have an effect upon species abundance and 

 composition. The remarkable recovery of 

 many populations of New England coastal 

 birds following near annihilation in the 

 last century was almost certainly depend- 

 ent upon the existence of undisturbed 

 feeding and nesting sites. Inshore fish 

 communities also appear resistant to small 

 habitat losses or modifications (e.g., 

 Nixon et al. 1978) but more pronounced 

 alterations of these habitats would un- 

 doubtedly result in decreased abundance of 

 certain fish species. Spinner (1969), for 

 example, reported the decline in menhaden 

 population abundance after loss of estua- 

 rine nursery areas in Connecticut. 



The effects of more subtle habitat 

 degradation can readily be seen on both a 

 regional and historical basis in New 

 England. The southern New England coast- 

 line is more heavily populated than north- 

 ern New England and many tidal flats are 

 exposed to residential, municipal, and 

 commercial pollutant discharges. Increased 

 pollution (e.g. from sewage, heavy metals, 

 bacteria) has drastically reduced tidal 

 flat shellfisheries in southern New Eng- 

 land. In upper Narragansett Bay, Rhode 

 Island, oyster populations were once so 

 abundant that they were used to fatten 

 pigs by early New England colonists. 

 While the upper bay supported a viable 

 oyster industry for many years (peaking in 

 the early 1900's), no oysters have been 



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