8293

• UCREFRP Catalog Number: 8293
• Author: Trammell, M. and T. Chart.
• Title: Evaluation of Sampling Efficiency in the Interagency Standardized Monitoring Program ‎(ISMP)‎ for YOY Colorado Squawfish.
• USFW Year: 1998.
• USFW - Doc Type: Moab, Utah.
• Copyright Material: NO

.~ntroduct.i,gn
The. Interagegcy. S:tandarctizecl ~nitorinf~ Pr ~ran~ ~IS~P-~ is: part
of the multi-agency Recove-ry iatp~e~entation: Program (RrP-1 for tie
endangered . fish af- the~~ ~o-lorado River. A sampling protocol fir
poung.-o-f-year (YOY~ Cal_aradb s€~awf:sh was- established ~fQ-r the IS~lP
in Zg8~~. Each backwater sampled was se%ned in .two lacatiogs with a
4m A I~. 5m 1.6mm mesh. seine-. Eurt.~ier .standards were defined. for
preferred backwater halaitats based .on s-ze-, depth, tempe-rature, and
turbidity. All- YOY standardized montoring.is~now conducted in tree
bacl~ta-ters- that must Yie at least 3Q~? in surface .area, . 3 ~t. deep,
and should be 2D wa-rmer than the- maims channel . Si~ila-r . sampling
methods-are applied to many other studies within the RAP.
However, analyses of i~P data an YOY squawfisli distribution,
abundance and relative catch rates- are eo~slicated by:.a high. degree
of variation within and between backwaters and river reaches: The
var-iabhilitg observed ~za~r be attributable to differences -in use ~f
the habitats-based an physical parameters. Conversely, ot~~- sampling
ef-ficiency may be a-ff-eet~g -our- a~h-li~t~ - tv ana~~rz~---da~~a~ ~~far
electivity. is our sa~l~g representat~•ve of the fist{ community
within each backwater aad- ~ri.~thin stag. reaches? That affects
sampli-ng• -efficiency? ResQlvng:~ the i~s:sn:e of back~rater sa~ap,ling
efficiency is`: import~t to all YOY studies; is the Recouery- P=fl~gra3n.
To test sampliag:;efficiency-; s~ hypotheses were-de4eioged~to
test the' passible. diftere~nces. in~~° spe-cies~ composition: and relative
abundanz~ hatween that Qhserved: ~ in- the first _ seine= haul and.: tie
composition. af.:.the entire backwater. . ar a: backed Portiaa. tYrereo~ .
Other.: hypotheses were -proposed.. to test the-.. differ-en-ce- ~n~ capture
prohablity between sailing tifaes~ location:-within.:back~ater:.and
perceived: difficulty-f ease o£ se~;ning.. The .first :.hypathesis:~ _has
pro~red to be easily e~a,hir~~F. -hQwever-~diffi~ulties. have-: arisen .in
testing.. the others. due ta~ the:- similarity of haYsitats. in. the
sections of river tested acid the- time-consuming.: nature of: tie
sampling process, which- have resulted: in: small sample s.i:zes .