Cf. Rabeni et Sp. Sowa, INTEGRATING BIOLOGICAL REALISM INTO HABITAT RESTORATION AND CONSERVATION STRATEGIES FOR SMALL STREAMS, Canadian journal of fisheries and aquatic sciences, 53, 1996, pp. 252-259
Successful habitat conservation or restoration must be biologically ba
sed, which requires an understanding of habitat variables most influen
cing fish; the relative influence of each habitat variable and the spa
tial scale over which each operates. Determining necessary habitat con
ditions requires examination from several perspectives, including obse
rvation of individual fish during all seasons and population analysis
over a range of spatial scales. There is a definite spatial hierarchy
of influences that must be addressed to separate those habitat conditi
ons responsible for presence and abundance from those habitat conditio
ns responsible for within-stream distribution. A case study of habitat
factors influencing smallmouth bass (Micropterus dolomieu) in Missour
i streams indicates that examination at the smallest spatial scales al
lows one to determine the influence of habitat conditions (depths, vel
ocities, cover factors) relating mainly to the fish's distribution in
a stream reach. Evaluation of populations at the stream-system level a
llows an understanding of how individual fish preferences relate to am
ounts of habitat as determined by geomorphic and fluvial dynamic force
s and how this influences standing stocks throughout a stream system.
Evaluation at the ecoregion level shows the overriding influence of ph
ysiographic variables on both the presence and abundance of fish acros
s stream systems, as well as the importance of land use.