Descrição
There is a need to quantify the multivariate quality of a recreational fishery at the site scale to
better communicate the relative quality among sites to the public and anglers. Borrowing on the general
approach of multimetric indices of biotic integrity (IBIs), we developed fishery quality indices (FQIs) from
species quality indices (SQIs) based on measures of fish abundance and size structure for northern and central
Portuguese streams. Our FQIs showed regional patterns indicating a range in fishery quality. Higher coldwater
FQI scores were mostly found in the northwestern (Minho and Lima), northeastern Douro, and northern Tagus
basins. Higher warmwater FQI scores occurred in the eastern Tagus basin. The species that contributed the
most to warmwater FQI scores were largemouth bass Micropterus salmoides, pumpkinseed Lepomis
gibbosus, the cyprinid Luciobarbus bocagei, chubs Squalius carolitertii and S. pyrenaicus, and nases
Pseudochondrostoma duriense and P. polylepis. The chubs, nases, and brown trout Salmo trutta contributed
the most to coldwater FQI scores. As expected, our indices were correlated with river size and with
disturbance at the catchment, segment, and site scales. Regression models for separate coldwater and
warmwater FQIs were stronger than those for the individual SQIs and for an all-site FQI. The correlation was
positive between the coldwater FQI and a coldwater IBI but negative between the warmwater FQI and
warmwater IBIs. The proposed FQIs offer a quantitative approach for assessing relative fishery quality among
sites and for making regional assessments given an appropriate study design. The component SQIs and SQI
metrics of the FQIs can be disassociated to determine the population and species characteristics most affected
by various environmental variables.
; Ferreira, Maria T. 
