Vasslides and Able: Importance of shoreface sand ridges as habitat for fishes 
97 
to BHR-5 of 4.7 m, indicating the transition from 
the Little Egg Inlet to nearshore coastal waters. 
Although a number of previous studies incor- 
porating a variety of techniques were used to de- 
termine habitat homogeneity, the similarity in 
descriptions when the same station was sampled 
by multiple sources provided confidence in the ac- 
curacy of the habitat descriptions, as well as the 
stability of the habitat over time. 
Species abundance and richness 
The specific patterns in species abundance and 
richness varied with sampling gear and habitat. 
The locations near the ridge typically had the 
largest number of species and individuals and 
the inshore, top of ridge, and locations offshore 
of the ridge had the least, regardless of sampling 
gear (Fig. 3). Fish abundance was higher in late 
summer than mid-summer for both gears, but the 
spatial patterns in species abundance were simi- 
lar between seasons. There was no difference in 
species richness between seasons for either gear. 
Beam trawl catches were dominated by demersal 
fish families including Triglidae, Gobiidae, and 
Serranidae, whereas the dominant families found 
in the otter trawl consisted of Engraulidae, Stro- 
mateidae, Sciaenidae, Triglidae, and Bothidae 
(Tables 2-4). 
In beam-trawl tows during 1991-95 (n- 97), 
2049 individuals were collected (primarily de- 
mersal but also some pelagic fishes) belonging to 
34 species. Fish abundance (CPUE) was lowest 
inshore, increased slightly towards BHR-5, in- 
creased significantly (df=94, PcO.OOOl) at the sta- 
tions on either side of the ridge (BHR-6<BHR-7), 
and was highest at the offshore station (BHR-9) 
(Fig. 3). The station on top of the ridge (BHRTOP) 
had significantly lower fish abundance than the 
stations on either side of the ridge and offshore 
( df— 89, PcO.OOOl), but higher abundance than at 
the inshore stations. In otter-trawl tows during 
1997-2006 (zi = 389), 39,402 benthic and pelagic 
fishes from 52 species were captured. Fish abun- 
dance (CPUE) was highest near the ridge (BHR- 
5> BHR-7>BHR-6) and significantly lower (df=381, 
PcO.OOOl) at all other stations (Fig. 3). Fish abundance 
at the top of the ridge was not significantly different 
from that at the inshore station or the offshore stations. 
The beam trawl typically captured smaller individuals 
(mean = 38.8 mm, standard error [ SE ] = 1 . 2 ) than did 
the otter trawl (mean=104.1 mm, [SE =1.1] Tables 2-4; 
Fig. 4). 
Species richness was highest at the near-ridge sta- 
tions and decreased offshore across both gear types 
(Fig. 3). The mean species richness per tow (RPUE) 
for the beam trawl was significantly higher (df=89, 
PcO.OOOl) at the sides of the ridge and offshore than 
at the other beam-trawl stations. The RPUE for the 
otter trawl was significantly higher (df=312, PcO.OOOl) 
32 
31 
w 30 - 
Q. 
29 
Salinity 
28 
28 
24 
Q 20 
16 
12 
8.0 
76 
sd 7-2 
U) 
E 68 
64 
60 
81 
8 0 • 
7 9 • 
Q_ 7,8 • 
7 7 * 
7.6 • 
™ 12 
CD 
c 10 
« 8 
“ E 6 
4 
8 2 
CO 0 
Temperature 
Dissolved oxygen 
pH 
Water transparency 
BHR-t SMR-2 8 HR-3 BBR-4 8HR-5 BHfi-6 BHRTOP BHfi-7 8HR-9 8HR-10 BHR-tl 
Sampling location 
Figure 2 
Environmental data (mean bottom values) for the 1991-95 
beam trawl samples (O) and 2001-06 otter trawl samples 
(•). Vertical lines represent standard error. Sampling with 
a beam trawl at BHR-2 was conducted in midsummer 1995 
only and at BHR-9 in midsummer 1993 only. Otter-trawl data 
at BHRTOP was collected in 2005 and 2006 only. Dissolved 
oxygen, pH, and a Secchi reading were not recorded at BHR-2, 
BHR-3, or BHR-4 during sampling with a beam trawl. See 
Figure 1 for station locations. 
at the near-ridge stations than at all other remaining 
stations. 
Fish-assemblage structure based on beam-trawl samples 
Canonical correspondence analysis revealed no dis- 
cernible pattern in fish-assemblage structure at the 
stations in midsummer (Fig. 5A), which is in contrast 
to late summer when there were two distinct, discrete 
assemblages: the inshore locations (BHR-2, BHR-3, 
BHR-4, BHR-5) and the near-ridge+offshore stations 
(BHR-6, BHRTOP, BHR-7, BHR-9) (Fig. 5B). However, 
within the midsummer samples there was variability 
in the species associated with each station between 
years (Fig. 5C). In late summer the near-ridge+offshore 
