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Numerical dominants are species that represent >1% of the total fauna collected in any regional study. Cosmopolitan species are those present at 50% or more of the stations in any regional study. Important prey species were identified from an analysis offish and lobster diets by Steimle et al. (2000). MDS indicators are species that are correlated (r > 0.4) with one or more multidimensional scaling axes during any one regional study. Other criteria: A = advantaged and D = disadvantaged by stress as determined by Pearson and Rosenberg (1978), Diaz and Boesch (1984), Diaz and Rosenberg (1995), and Adams et al. (1998). C = commercially important. O = opportunist, I = intermediate, and E = equilibrium species as identified by McCall (1977). Functional group codes are interpreted as follows. First character: I = infaunal and E = epifaunal. Second character: T = tube building and N = nontubiculous. Third character: M = motile and S = sessile. Last character: C = carnivore. Di = infaunal deposit feeder, Ds = surface deposit feeder, O = omnivore, S = suspension feeder.

Numerical dominants are species that represent >1% of the total fauna collected in any regional study. Cosmopolitan species are those present at 50% or more of the stations in any regional study. Important prey species were identified from an analysis offish and lobster diets by Steimle et al. (2000). MDS indicators are species that are correlated (r > 0.4) with one or more multidimensional scaling axes during any one regional study. Other criteria: A = advantaged and D = disadvantaged by stress as determined by Pearson and Rosenberg (1978), Diaz and Boesch (1984), Diaz and Rosenberg (1995), and Adams et al. (1998). C = commercially important. O = opportunist, I = intermediate, and E = equilibrium species as identified by McCall (1977). Functional group codes are interpreted as follows. First character: I = infaunal and E = epifaunal. Second character: T = tube building and N = nontubiculous. Third character: M = motile and S = sessile. Last character: C = carnivore. Di = infaunal deposit feeder, Ds = surface deposit feeder, O = omnivore, S = suspension feeder.

americana (42 percent), Tellinaagilis (41 percent), Heteromastusfiliformis (39 percent), Myaarenaria (37 percent), Pectinariagouldii (36 percent), Nereis succinea (34 percent), and Mercenaria mercenaria (31 percent). The hard clam, Mercenaria mercenaria, represents an important fishery species in the Lower Bay Complex. Because Lower Bay waters do not meet coliform standards, hard clams have been transplanted to other areas in New York and depurated in New Jersey prior to marketing.

The benthic fauna of the Lower Bay Complex represent twenty-three functional groups, based uponlifehabit andfeeding traits (Table 18.4). These groups consist of from two (ITSC and ENMS) to sixty-three (ENMO) species. Nineteen of the groups are representedby species in Table 18.2. The groups that are sometimes missing (ENSC, ITSC, ITSDi, and ITSS) were absent during many of the regional studies, and when present were low in abundance. The two infaunal, tubiculous, surface deposit feeding groups ITSDs and ITMDs were particularly abundant. Often more than half of the individuals collected during a survey were from one of these two groups. The next most abundant functional groups were two sessile suspension feeding groups INSS and ENSS; they represented about 30 percent of the total fauna collected during the regional surveys. Omnivore and carnivore groups generally had low abundances.

Benthic community structure in the Lower Bay Complexfollows, in abroad way, a north-south pattern that corresponds to the large-scale sedimentary and hydrodynamic regime (McGrath, 1974). The southern half of the Bay is dominated by muddy sediments running in a southeast to north west direction from Sandy Hook Bay to Raritan Bay (Fig. 18.2). In the northernhalf of the Bay, the sediments are predominantly sandy, except for muddy pit areas associated with dredging activity and a region in Gravesend Bay. The hydrographic regimes in the northern and southern parts of the Lower Bay Complex created by the eddy off Great Kills (Jeffries, 1962) closelyparallelthesedimentpattern (Dean, 1975).

The influence of the north-south physical regime in the Lower Bay Complex is clearly evident in the distribution of the amphipods Ampelisca abdita and Corophium tuberculatum and the blue mussel Mytilus edulis (Fig. 18.2). The two amphipods are associated with muddy sediments, while the blue mussel is restricted to sandy areas. Other species consistently more abundant either in the northern or southern region are given in Figure 18.3. With the exception of several dominants (i.e., the amphipods Ampelisca abdita, Unciola spp., and Corophium tuberculatum, and the mud crab Neopanope texana), most amphipod and decapod species have a higher frequency of occurrence and higher abundance in the northern region. In particular, haustorid and phoxocephalid amphipods, both of which are motile, infaunal, deposit feeders, are considerably less abundant in the south. All the decapods are omnivores and are associated with sandy areas. McGrath (1974) and Steimle and Caracciolo-Ward (1989) have discussed whether the distribution of these crustacean groups is natu-ralor due to anthropogenic factors. Thepersistence of the distribution throughout all of the regional studies suggests that the differences are related to sediment preferences.

Table 18.3. Species representative of the diverse life histories present in the Lower Bay Complex and good indicators of community structure and community change

Anthozoa:

Aschelminthes: Oligochaeta:

Polychaeta:

Table 18.3. Species representative of the diverse life histories present in the Lower Bay Complex and good indicators of community structure and community change

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