600 



Fishery Bulletin 104(4) 



and -0.254 for temperature and depth, respectively) 

 indicating that larger bluefish were associated with 

 relatively cool surface water and shallow water depths. 

 Before analyzing spatial and temporal variations in 

 temperature and depth with an ANCOVA model, we 

 examined the transect-sampling date interaction ef- 

 fect. There were no significant interactions between 



0-6 n 



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 tj 



u 



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 Q. 



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a 0.8 



jr 



o 



6 0.6 



c 



(D 



D 



a- 



2 0.4 



LL 



0,2 



00 

 0.8 



0.6 



0.4 



August 



□ Shell (surface Methot trawl) 



I Shelf (bottom otter trawl) 



n Ocean beach (seine) 



I Estuary and inlet (seme) 



I I I I I I I I nW I I I I I I I I 1 



30 60 90 120 150 180 210 240 



Early to mid-September 



jyL,,,,jib^, 



30 60 90 120 150 180 210 240 

 Mid to late September 



flllU 



T f^ ITfTlllirTITTIlltl 



30 60 90 120 150 180 210 240 

 October to November 



30 60 90 120 150 180 210 240 

 Bluefish size (mm SL) 



Figure S 



Composite length-frequency histograms for bluefish 

 iPomatomus saltatrix) collected from multiple habitats 

 in summer and early fall ( 1998 ) in southern and central 

 New Jersey. Additional information regarding habitat 

 location and sampling protocols is found in the text. 

 Table 1, and Figure 1. 



transect and date for both analyses (two-way ANOVA; 

 depth-transect X date: F=0.72, df= 3,132, P=0.5401; 

 temperature-transect X date: F=1.87, df=3,132, P= 

 0.1385). Water depth significantly increased as dis- 

 tance from the coastline increased (ANCOVA; F=231.24, 

 df=3,135, P<0.0001) (Fig. 3C), and surface temperature 

 significantly decreased during the sampling period (AN- 

 COVA; F=916.49, df=l,135, P<0.0001) (Fig. 3D). 



Transitional bluefish (25-34 mm SL) and juveniles 

 (35-50 mm SL) were a major portion of the overall size 

 composition of bluefish collected in August (Fig. 5). For 

 example, bluefish 25-50 mm SL constituted 40.1% of 

 the individuals collected during this time period. In 

 subsequent months, however, these bluefish were absent 

 from remaining survey tows. Conversely, larval bluefish 

 (3-11 mm SL) and small transitional bluefish (12-24 

 mm SL) were collected on all sampling dates and were 

 numerically dominant in August and thereafter (Fig. 5). 

 From August to late September, length-frequency dis- 

 tributions of bluefish <25 mm SL generally broadened 

 in range and shifted to larger body sizes. 



Synoptic analysis of habitat use 

 by summer-spawned bluefish 



Bluefish abundance and size-structure were compared 

 among diverse inshore and coastal habitats in an effort 

 to provide a more synoptic examination of summer 

 habitat use across ontogenetic stages. In the process, 

 bluefish were examined from shallow estuarine, inlet, 

 and ocean beaches to surface and deeper waters on the 

 inner continental shelf. As previously discussed, all 

 individuals collected by Methot trawl tows from shelf 

 surface waters were <50 mm SL, and therefore defined 

 as summer-spawned larval, transitional, or juvenile 

 bluefish (Fig. 5). 



Bluefish catches in the Great Bay estuary were low; 

 33 seine hauls collecting five bluefish from August 

 to October (0.1-0.4 bluefish/haul) (Table 1). With the 

 exception of one bluefish, all individuals in the estu- 

 ary were designated as summer-spawned fish (Fig. 5). 

 Relatively few bluefish were collected in seine hauls 

 at inlet sites located at the margin of Little Egg Inlet 

 (55 bluefish from 36 hauls) that were primarily sum- 

 mer-spawned (Table 1; Fig. 5). In contrast to estuarine 

 and inlet sites, substantial numbers of bluefish were 

 collected from August to early November along ocean 

 beaches north and south of Little Egg Inlet (6440 blue- 

 fish from 115 hauls) (Table 1). Spring-spawned bluefish 

 were consistently collected along ocean beaches dur- 

 ing the survey, but abundances were low compared to 

 those of summer-spawned individuals that represented 

 98.4% of the total catch (Fig. 5). Compared to the sizes 

 of bluefish collected from surface waters of the inner 

 continental shelf, the sizes of the overwhelming major- 

 ity (99.4%) of fish collected at inshore sites (estuary, 

 inlet, and ocean beaches) were >50 mm SL (i.e., the 

 sizes of juvenile fish). The only exception to this pattern 

 occurred along ocean beaches from mid-September to 

 early November (Fig. 5). 



