Ross et al.: Fish species associated with shipwreck and natural hard-bottom habitats 
47 
Figure t 
Locations of the 9 sites, 7 shipwreck sites (W-l through W-7), 1 mostly natural 
hard-bottom (NHB) site, and 1 soft-bottom (SS) site, where remotely operated 
vehicles (ROVs) were used to collect data concerning fish assemblages on 20-28 
September 2012 and 19-23 May 2013. Depth contours are given in meters. The 
inset illustrates the Middle Atlantic Bight; the rectangle indicates the study 
area. 
bottom. All other sites comprised predominately hard, 
complex substrata, but they were also surrounded by 
soft substrata (see “Habitat definitions” section). The 
natural hard-bottom (NHB) location was dominated by 
hard, rough bottom, including boulders, rubble fields, 
and walls of consolidated mud. The dominant habitat 
in 7 of the study sites (e.g., W-l) was composed of 8 
historically important shipwrecks, all sunk during the 
early 1920s (i.e., 6 of the ships were part of the “Billy 
Mitchell fleet” [Lee, 1949]). These shipwrecks had the 
following lengths and maximum heights off bottom: 
W-l (45x6 m), W-2 (167x18 m), W-3 (141x7 m), W-4 
(301x3 m), W-5 (2 shipwrecks about 685 m apart; 64x3 
m and 53x2 m), W-6 (171x14 m), W-7 (72x3 m). The 
shipwrecks were surrounded by soft substrata (sand or 
gravel). All shipwrecks were covered to varying degrees 
with lost fishing gear (trawls, Fig. 2, A and C). 
Remotely operated vehicle 
Dives of the ROV were conducted with the Univer- 
sity of Connecticut ROV Kraken 11 deployed from the 
NOAA Ship Nancy Foster on 20-28 September 2012 
and, during a second research cruise, with the Woods 
Hole Oceanographic Institution ROV Jason II deployed 
from the NOAA Ship Ronald H. Brown on 19-23 May 
2013. The site SS, the site NHB, and sites W-l, W-6, 
and W-7 each were sampled with 1 ROV dive, and each 
of the other shipwreck sites were sampled either 2 (W- 
3, W-4, and W-5) or 3 (W-2) times for a total of 14 ROV 
dives (Table 1). The position of the ROV was recorded 
continuously by using an ultrashort baseline tracking 
system, and navigation data were time synchronized 
with all imagery and samples. An SBE 911plus' con- 
ductivity, temperature, and depth (CTD) instrument 
(Sea-Bird Electronics Inc., Bellevue, WA) was attached 
to the ROVs to record conductivity (in microSiemens 
per centimeter), temperature (degrees Celsius), salin- 
ity, density (a0, in kilograms per cubic meter), dis- 
solved oxygen (DO, in milliliters per liter), depth, and 
pH at a frequency of once per second during each dive. 
Only temperature, salinity, and DO data recorded dur- 
ing dives while the ROVs were on or near bottom are 
presented. 
Digital video was collected as the ROVs moved along 
transects at slow speeds, <~25 cm/s (<0.5 kt), across all 
habitat types and with the vehicles as near to bottom 
as possible. At each shipwreck, video and still image 
photo-mosaics were recorded over a series of parallel 
transects that covered the entire shipwreck. This digi- 
tal imagery was used for vessel identification, examina- 
tion of present ambient conditions and documentation 
1 Mention of trade names or commercial companies is for iden- 
tification purposes only and does not imply endorsement by 
the National Marine Fisheries Service, NOAA. 
