Dell'Apa et al.: Modeiing the distribution of Squalus acanthias, by sex 
91 
Map of the study area. Black circles represent the locations of 1820 
trawl hauls conducted in inshore coastal waters of the mid-Atlantic 
during surveys by the Northeast Area Monitoring and Assessment 
Program. Data from these surveys were used to determine the dis- 
tribution of spiny dogfish (Squalus acanthias) between New England 
and North Carolina in 2007-2013. 
m, a 7.6-cm cookie sweep, and a 2.5-cm knotless liner 
in the eodend. The doors are 1.7-m Thyboron Type IV. 
Data collection, sources, and analysis 
Fishery-independent data on spiny dogfish were col- 
lected during the NEAMAP surveys in spring and fall 
of 2007-2013 on the FA^ Darana R. As described by 
Bonzek et al.^, for each haul, up to approximately 18 
spiny dogfish were examined to determine individual 
length (precaudal length [PCL] in centimeters), weight, 
sex, and maturity (males only, by external examination 
of the claspers). All other specimens were weighed in 
total and measured individually. In rare cases of very 
1 Bonzek, C. F., J. Gartland, R. A. Johnson, and J. D. Lange 
Jr. 2008. NEAMAP Near Shore Trawl Survey: peer review 
documentation. A report to the Atlantic States Marine Fish- 
eries Commission by the Virginia Institute of Marine Science 
(VIMS), Gloucester Point, VA. [Available from VIMS, P.O. 
Box 1346, Gloucester Point, VA 23062-1346]. 
large catches, those individuals not processed as de- 
scribed were counted (or weighed) in full without fur- 
ther processing, before being released. When subsam- 
pling occurred, the attributes of the subsampled por- 
tion (e.g., sex ratios and lengths) were expanded to the 
total catch (Bonzek et al.^). Additionally, for each haul, 
the date, starting and ending times, and location (lati- 
tude and longitude) were recorded. 
For the purpose of our analysis, the CPUE for spiny 
dogfish, by sex, for each trawl haul was calculated as 
the total number of individuals of each sex for each 
20 min of trawling. The length of individuals was con- 
verted from PCL to total length (TL) in centimeters by 
using the conversion factor iTL=PCL/0. 807) available 
for this species in FishBase (website). The analysis for 
this study included only adult females (>80 cm TL) and 
adult males (>60 cm TL), on the basis of the size at 
maturity reported for this species in the northwest At- 
lantic (Nammack et al., 1985). It is worth noting that 
at the time of the study by Nammack et al.’s (1985), 
