114 
Fishery Bulletin 113(2) 
10° "i A 
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Figure 5 
Availability of spiny dogfish ( Squalus acanthias ) to the sink gillnet (SGN; black lines) and otter 
trawl (OT; gray lines) fisheries in the northeast U.S. shelf large marine ecosystem between 1989 
and 2009 during autumn (solid lines) and spring (dashed lines) for (A) all dogfish at all stages 
combined, (B) neonates (<26 cm in total length [TL]), (C) immature males (>26 cm TL and <60 
cm TL), (D) mature males (>60 cm TL), (E) immature females (>26 cm TL and <80 cm TL) and 
(F) mature females (>80 cm TL). Availability was estimated collectively and separately for each 
life-history stage as the percentage of total survey catch in grid cells representing areas fished 
by commercial fishermen divided by the entire survey catch. 
delman, 2009). Further, presence of nontargeted spiny 
dogfish can reduce the quality of target groundfish spe- 
cies in gillnet catches (Rafferty et al., 2012). 
In this study, we addressed the question of whether 
recent increases in spiny dogfish abundance, as identi- 
fied by fishermen (Tallack and Mandelman, 2009), have 
resulted from increased availability of the spiny dogfish 
stock to major fisheries. Examination of SOq revealed 
2 periods of contrasting overlap during autumn: 1) a 
low period before 1998 during which spiny dogfish were 
infrequently caught in both fisheries and the bottom 
trawl survey and 2) a high period, thereafter, reflect- 
ing a greater area where spiny dogfish were captured 
by the survey crew and each fishery. Interestingly, the 
year separating the 2 distinct periods, 1998, was also 
the year in which the stock was declared overfished 
