The Productivity-Susceptibility
Analysis (PSA) is a
semi-quantitative and rapid risk assessment tool that relies on the
life
history characteristics of a stock (i.e., productivity) and its
susceptibility
to the fishery in question.First used
to classify differences in bycatch sustainability in the Australian
prawn
fishery in 2001, this assessment has a long history of use in
evaluating
fisheries and is recommended by several organizations and work groups
as a
reasonable approach for determining risk.
The productivity and
susceptibility of a stock is determined
by providing a score ranging from 1 (low) to 3 (high) for a
standardized set of
attributes related to each index (productivity = 10; susceptibility =
12).When scoring these
attributes, the user has
the ability to also assess the data quality associated with each
attribute
score, and customize the analysis by weighting these attributes
according to
the fishery.The scores for the
productivity and susceptibility indices are then automatically
calculated and
graphically displayed on an x-y scatter plot.Stocks that receive a low
productivity score and high susceptibility
score are considered to be at a high risk of becoming depleted, while
stocks
with a high productivity score and low susceptibility score are
considered to
be at low risk of becoming depleted.
This version of the PSA has
been customized to specifically
assess the vulnerability of U.S.
fish stocks from becoming overfished (BCURRENT
< ½BMSY)
or undergoing overfishing (FCURRENT
> FMSY),
with an emphasis on
assessing data-poor stocks.Where, vulnerability
has been identified by NOAA-Fisheries as a useful measure for: 1) identifying stocks that
should be managed and
protected under a fishery management plan, 2) grouping data-poor stocks
into
relevant management complexes, and 3) developing precautionary harvest
control rules.In addition, scoring of
the data quality used to define vulnerability may help in determining
species
of interest for further data collection and particular data gaps across
species.
