116 
Fishery Bulletin 113(2) 
support was provided by the lower percentage of catch 
retained by the OT fishery (autumn: 8%; spring: 5%) 
than by the SGN fishery (autumn: 61%; spring: 81%). 
The observed fishing patterns for the OT fishery likely 
are linked to target species distributions rather than 
to spiny dogfish distribution. 
For the spatial analyses presented here, we relied 
on numerous assumptions. Trends within NEFOP data 
were assumed to represent those of domestic fishing 
fleets since 1989. This time period encompassed the de- 
velopment of the directed domestic fishery (1990), its 
collapse (late 1990s), and the onset of recovery (late 
2000s). For analyses of spatial overlap of spiny dog- 
fish distribution and fishery effort and catch, we as- 
sumed that the selected grid cell size was appropriate 
for both the rasterization and interpolation of station 
data. In contrast with our grid cell size, grid sizes of 
much smaller sizes (185-261 km 2 ) have been used in 
other distributional studies in which the same fishery- 
independent data set within the same geographic re- 
gion have been analyzed (Methratta and Link, 2007; 
Nye et al., 2009). For spatial overlap analyses, results 
were not available on a stage-specific basis because of 
limited reporting of sex within fisheries data. Further 
investigation of interactions of spiny dogfish and fish- 
eries at the level of life-history stages could provide in- 
sight into stage-dependent availability, elucidating the 
potential relationship between fishermen and spawn- 
ing stock biomass (i.e., mature female abundance), ma- 
ture male biomass (i.e., alternative harvest by way of 
a male-selective fishery), and recruitment (i.e., neonate 
abundance). 
Acknowledgments 
The authors thank all those individuals who have 
worked or volunteered aboard the NOAA Ships Alba- 
tross IV and Henry B. Bigelow, Woods Hole, Massachu- 
setts, for assistance with survey data collection. In ad- 
dition, special thanks are extended to those observers 
who collected the NEFOP data and all fishermen who 
participated within NEFOP. This project was funded 
by the Sea Grant Fellowship in Population Dynamics 
of the National Marine Fisheries Service. 
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