Patrick et al.: Use of productivity and susceptibility indices to assess vulnerability of fish stocks to overfishing 
313 
Ranking 
Low (1) 
Moderate (2) 
High (3) 
<25% of stock present in the area 
fished. 
Between 25% and 50% of the stock present in the 
area fished. 
>50% of stock present in the area fished. 
Stock is distributed in >50% of its 
total range 
Stock is distributed in 25% to 50% of its total 
range 
Stock is distributed in <25% of its total range. 
<25% of stock present in the 
depths fished. 
Between 25% and 50% of the stock present in the 
depths fished. 
>50% of stock present in the depths fished 
Seasonal migrations decrease 
overlap with the fishery. 
Seasonal migrations do not substantially affect 
the overlap with the fishery. 
Seasonal migrations increase overlap with the 
fishery. 
Behavioral responses of fish de- 
crease the catchability of the gear. 
Behavioral responses of fish do not substantially 
affect the catchability of the gear. 
Behavioral responses of fish increase the 
catchability of the gear (i.e., hyperstability of 
catch per unit of effort with schooling behavior). 
Species shows low susceptibility to 
gear selectivity. 
Species shows moderate susceptiblity to gear 
selectivity. 
Species shows high susceptiblity to gear 
selectivity. 
Stock is not highly valued or desired 
by the fishery (<$ 1/lb; <$500K/yr 
landed; <33% retention). 
Stock is moderately valued or desired by the 
fishery ($ l-$2. 25/lb; $500K-$ 10, OOOK/yr landed; 
33—66% retention). 
Stock is highly valued or desired by the fishery 
(>$2. 25/lb; >$10, OOOK/yr landed; >66% 
retention). 
Targeted stocks have catch limits 
and proactive accountability mea- 
sures; nontarget stocks are closely 
monitored. 
Targeted stocks have catch limits and reactive 
accountability measures. 
Targeted stocks do not have catch limits or 
accountability measures; nontargeted stocks 
are not closely monitored. 
<0.5 
0. 5-1.0 
>1 
B is >40% of B 0 (or maximum 
observed from time series of bio- 
mass estimates). 
B is between 25% and 40% of B 0 (or maximum 
observed from time series of biomass estimates). 
B is <25% of B 0 (or maximum observed from 
time series of biomass estimates). 
Probability of survival >67% 
33% < probability of survival <67% 
Probability of survival <33% 
Adverse effects absent, minimal 
or temporary. 
Adverse effects more than minimal or temporary 
but are mitigated. 
Adverse effects more than minimal or 
temporary and are not mitigated. 
scores. Such uncertainty in the data would help with 
the interpretation of the overall vulnerability score 
and also help in targeting areas of further research 
and data needs. 
Example case studies 
To demonstrate the utility of our PSA scoring process, 
we evaluated six U.S. fisheries including the Northeast 
groundfish multispecies, highly migratory Atlantic 
shark complexes, California nearshore groundfish fin- 
fish assemblage, California Current coastal pelagic 
species, skates of the Bering Sea and Aleutian Islands 
(BSAI) management area (a bycatch fishery of the BSAI 
groundfish fishery), and the Hawaii-based pelagic long- 
line fishery (both the tuna and swordfish sectors). In 
total, 162 stocks were evaluated (Appendix 1). These 
fisheries were chosen because they were expected to 
display varying degrees of productivity, susceptibility, 
and data quality. For descriptions of these fisheries and 
details on how our PSA scoring procedure was applied 
to each fishery, see Patrick et al. (2009). 
