McBride et al.: Interspecific comparisons of searobin, Prionotus spp., movements, size structure and abundance 
31 I 
Figure 8 
Annual biomass indices for northern searobins (open symbols) and striped searobins (filled symbols). Mid- 
Atlantic Bight indices (left) are based on sampling by Northeast Fish. Sci. Center, NMFS, resource surveys 
(Table 2). Massachusetts indices (right) are based on the Massachusetts (Mass. Div. Mar. Fisheries [MDMF]) 
coastal surveys (note the scale of the ordinate is doubled for MDMF Spring). All values are log-transformed 
and plotted with ±1 standard error bar. See text for details of strata selection and statistical calculations (e.g. 
spring and autumn strata are different). 
correlated, so that they were espe- 
cially useful in evaluating popula- 
tion trends. On the other hand, the 
inshore strata selected for autumn 
cruises in the Mid-Atlantic Bight 
were adequate for sampling striped 
searobins but were too shallow for 
northern searobins because the lat- 
ter occupied a mean depth of 31 m 
during that season. 
Searobins are not important fish- 
ery species in the United States but 
are components of bycatch in com- 
mercial and sport fisheries; their 
population sizes could be affected by 
fishing or other factors. However, 
their population size varied without 
a specific directional trend during 
three decades. The long-term trend 
of annual biomass indices for sea- 
robins is similar to other demersal 
finfish such as white hake ( Urophycis 
