382 
Fishery Bulletin 1 13(4) 
Figure 2 
Photograph of derelict crab pots retrieved from Bogue Sound and the 
Newport River, North Carolina, in May 2010: (left) a pot in poor condition 
(rank of 9), with a partial wall collapse that allowed unrestricted move- 
ment of organisms, and (right) a pot in fair condition (rank of 5), well 
fouled yet structurally intact and capable of trapping organisms. 
Crab pots were distinguished from other benthic ob- 
jects and debris in images from the side-scan sonar on 
the basis of their square shape, dimensions, and acoustic 
shadow distal to the nadir (Havens et al., 2008; Morison 
and Murphy, 2009). The crab pots typically used in both 
the commercial and recreational hard-shell blue crab 
fishery are 60 cm in length, 60 cm in width, and 50 cm 
in height, and they are constructed of vinyl-coated wire, 
with a center chamber in which bait is secured (Fig. 2). 
Metal rebar is often wired to a pot’s bottom surface to 
ensure that it is properly oriented as it settles upon 
the estuarine floor after deployment. When a DCP was 
discovered, the time and GPS coordinates were recorded. 
A 30-m waterman’s rope (a rope to which bent nails are 
attached in increments of 30 cm) or a grapple was used 
to retrieve DCPs and haul them aboard the boat for 
inspection and to record bycatch metrics; in some cases, 
pots were in such poor condition that they were ripped 
apart upon haul-out and only pot parts were recovered. 
Data on DCP construction (wire type and pot de- 
sign) and condition (functionality ranking, from 1 to 
10, with 1 for structurally sound and 10 for totally di- 
lapidated; Table 2), an estimate of each DCP’s time in 
water (soak time), and the identifica- 
tion and percent cover of fouling or- 
ganisms on each DCP were recorded. 
Estimates of DCP soak times were 
determined by the same researcher in 
each region who had participated in 
the technique-standardization trip, on 
the basis of the degree of fouling and 
bivalve recruitment that had accumu- 
lated on pots. Although soak time was 
a subjective measure, each of the re- 
searchers who estimated soak times 
had >40 years of experience working 
in estuaries to guide their estimates. 
These estimates were consistent with 
the descriptions and images of crab 
pots after known soak times in North 
Carolina high-salinity (annual mean 
salinity=30) estuaries that were pro- 
vided in the NCDMF 1 report. In gen- 
eral, DCPs that received a condition 
score of <4 had estimated soak times 
of <1 year, and pots that had a condi- 
tion rank >9 had estimated soak times 
of >2 years. 
Environmental data (temperature, 
salinity, and dissolved oxygen) for each 
cell were recorded with a YSI ProPlus 
water quality meter (YSI, Inc., Yellow 
Springs, OH), and, for each DCP found 
in a cell, its distance from shore was 
recorded. Aquatic organisms found in 
bycatch or living on recovered DCPs 
were identified (according to Gosner, 
1971, Robins et al., 1986; Ruppert 
and Fox, 1988; FishBase, vers. 2/2010, 
available at website) to the lowest 
possible taxonomic level, classified as living or dead, 
counted, measured, and released. The total length of 
fishes and the carapace width (CW), point to point (dis- 
tance between posterior lateral spines of the carapace) 
of crabs were used as standard measures of organism 
size. For blue crab, adults were distinguished from ju- 
veniles by having a CW >5.6 cm CW, the smallest size 
considered mature for a female crab with a full apron 
(NCDMF 9 ); legal market size for this species in North 
Carolina is >12.5 cm CW for males and >17 cm CW for 
females (NCDMF 9 ). For Florida stone crab, adults were 
distinguished from juveniles by having a CW >3.0 cm; 
coloration patterns did not differ with age (Lindberg 
and Marshall 10 ). 
9 NCDMF (North Carolina Division of Marine Fisheries). 
2004. North Carolina Fishery Management Plan: Blue Crab, 
133 p. +app. Div. Mar. Fish., North Carolina Dep. Environ. 
Nat. Resour., Morehead City, NC. [Available at website.] 
10 Lindberg, W. J., and M. J. Marshall. 1984. Species profiles: 
life histories and environmental requirements of coastal fish- 
es and invertebrates (south Florida) stone crab. U.S. Fish 
Wildl. Serv. FWS/OBS-82/11.21 and U.S. Army Corps Eng. TR 
EL-82-4, 17 p. [Available at website.] 
