46 
Fishery Bulletin 1 14(1) 
Table 1 
Details from dives of remotely operated vehicles (ROVs) on the continental shelf of the Middle Atlantic Bight during 2012 
(ROV Kraken II) and 2013 (ROV Jason II), which were conducted from the NOAA ship Nancy Foster and the NOAA ship 
Ronald H. Brown. For site names, W=shipwreck sites; SS=shallow, soft-substrata site; NHB=natural hard-bottom site. Total 
time and depth range are for times when the ROV was on the bottom. Daytime (D)=0800-2000 h EDT; nighttime (N)=2000- 
0800 h EDT. n/a=not available. 
Dive no. 
Site 
name 
Date 
Time 
Total 
time 
(min) 
Start 
latitude 
(N) 
Start 
longitude 
(W) 
End 
latitude 
(N) 
End 
longitude 
(W) 
Depth 
range 
(m) 
ROV-2012-NF-21 
SS 
20-Sep-12 
D 
304 
37°10.90' 
74°56.24' 
37°10.85' 
74°56.26' 
42-43 
ROV-2012-NF-22 
W-l 
22-Sep-12 
D 
622 
37°09.40' 
74°45.30' 
n/a 
n/a 
81 
ROV-2012-NF-23 
W-2 
23-Sep-12 
D 
612 
37°09.40' 
74°34.60' 
37°09.20' 
74°34.40' 
113 
ROV-2012-NF-24 
W-3 
24-Sep-12 
D 
519 
37°13.90' 
74°33.00' 
37°14.00' 
74°33.00' 
124-126 
ROV-2012-NF-26 
W-4 
26-Sep-12 
D 
223 
37°11.50' 
74°34.40' 
37°11.50' 
74°34.40' 
100-106 
ROV-2012-NF-27 
W-5 
26-Sep-12 
D 
363 
37°16.90' 
74°32.10' 
37°17.20' 
74°32.00' 
118-119 
ROV-2012-NF-28 
NHB 
27-Sep-12 
D 
291 
37°01.06' 
74°39.26' 
37°00.92' 
74°39.64' 
98-117 
ROV-2012-NF-29 
W-6 
27-Sep-12 
D 
251 
36°54.80' 
74°42.40' 
36°54.80' 
74°42.40' 
84-85 
ROV-2012-NF-30 
W-7 
28-Sep-12 
D 
174 
37°11.90' 
74°45.40' 
37°11.90' 
74°45.40' 
68-69 
ROV-20 13-RB-692 
W-4 
19-May- 13 
N 
295 
37°11.50' 
74°34.50' 
37°11.50' 
74°34.40' 
91-105 
ROV-2013-RB-693 
W-2 
20-May-13 
D 
894 
37°09.40' 
74°34.40' 
37°09.40' 
74°34.70' 
90-116 
ROV-20 13-RB-694 
W-3 
21-May-13 
D 
861 
37°13.90' 
74°33.10' 
37°14.00' 
74°33.10' 
101-126 
ROV-20 13-RB-695 
W-5 
22-May-13 
D 
504 
37°16.80' 
74°32.10' 
37°17.00' 
74°32.20' 
106-121 
ROV-2013-RB-696 
W-2 
23-May-13 
D 
197 
37°09.40' 
74°34.50' 
37°09.40' 
74°34.60' 
90-114 
Adams, 1993; Diaz et al., 2003). Similar assessments in 
deeper waters of the middle to outer shelf are lacking, 
aside from those obtained from submersible surveys di- 
rected toward tilefish (Lopholatilus chamaeleonticeps ) 
at depths of 117-268 m (Grimes et al., 1986). In these 
studies, the physical structure of habitat was observed 
to be correlated with fish distribution patterns. High- 
er profile, more complex habitats generally supported 
greater fish species richness and higher abundance 
for some species. Bioengineering by tilefish and asso- 
ciated species in and near canyon heads also created 
complex habitats for other outer shelf fauna (Grimes 
et al., 1986). 
Non-natural hard substrata (e.g., shipwrecks) ag- 
gregate fish and invertebrates. The effects of artificial 
reefs composed of shipwrecks and other structures (e.g., 
drilling platforms and fish attracting devices) are well 
known but their use as fish habitat is still being de- 
bated (Stephan and Lindquist, 1989; Grossman et ah, 
1997; Perkol-Finkel et al., 2006). It is unclear whether 
artificial reef structures actually increase populations 
of fish as opposed to simply concentrating them, and 
understanding the role of artificial reefs is increasing- 
ly important considering the decline of natural reefs 
worldwide (Perkil-Finkel et al., 2006). However, Arena 
et al. (2007) reported that vessel-reefs off southeastern 
Florida supported significantly higher fish species rich- 
ness and abundance than at natural reefs and that dif- 
ferent community structures and trophic patterns were 
observed for the 2 habitat types, and they suggested 
that vessel-reefs enhanced local fish populations. The 
extent to which artificial reefs mimic natural reef func- 
tions requires further study, and artificial reefs may 
only approach the functions of natural reefs if their 
physical structures are similar (Perkol-Finkel et al., 
2006). 
As part of a larger survey of submarine canyons 
and nearby features in the MAB, historically impor- 
tant shipwrecks, naturally occurring hard bottom, and 
sandy bottom areas on the outer continental shelf near 
Norfolk Canyon were surveyed with remote operated 
vehicles (ROVs) in 2012 and 2013. In this article, we 
document 1) species of overall fish communities on 
shelf-depth artificial (shipwrecks) substrata and natu- 
ral hard substrata and nearby soft-bottom habitats, 2) 
relative abundance of fish species in those communi- 
ties, and 3) behaviors and distributions of fishes on 
shipwreck and nonshipwreck open bottom for 2 seasons 
(fall in 2012 and spring in 2013). The degree to which 
fishes were associated with hard bottom and the degree 
to which such habitats supported unique communities 
were investigated. 
Materials and methods 
Study area 
On the middle to outer continental shelf (depths of 42- 
126 m) of the southern MAB, 9 locations in the vicinity 
of Norfolk Canyon were surveyed with ROVs (Table 1, 
Fig. 1). These study sites had been mapped with mul- 
tibeam sonar in 2011. The shallowest location (site SS) 
was the only one entirely composed of flat, soft sediment 
