Long Term Resource Monitoring Program Procedures: Fish monitoring
Dates
Publication Date
1995-07
Summary
Fishes are one of the most diverse and abundant natural resources of the Upper Mississippi River System (UMRS) (Carlander 1954; Rasmussen 1979; Van Vooren 1983; Fremling et al. 1989). Several features contribute to the great amount of interest fishes receive from the general public, fishery managers, and aquatic ecologists: a. UMRS fishes support multimillion-dollar commercial and sport fisheries. b. Fishes respond to a variety of hydrologic, water quality, and habitat variables. c. Scientists and fishery managers recognize fish communities as an integrative index to a complex set of physical and biological conditions on the UMRS; that is, fish are indicators of the biotic integrity of the UMRS. In addition, impacts of sedimentation, [...]
Summary
Fishes are one of the most diverse and abundant natural resources of the Upper Mississippi River
System (UMRS) (Carlander 1954; Rasmussen 1979; Van Vooren 1983; Fremling et al. 1989). Several
features contribute to the great amount of interest fishes receive from the general public, fishery managers,
and aquatic ecologists:
a. UMRS fishes support multimillion-dollar commercial and sport fisheries.
b. Fishes respond to a variety of hydrologic, water quality, and habitat variables.
c. Scientists and fishery managers recognize fish communities as an integrative index to a complex
set of physical and biological conditions on the UMRS; that is, fish are indicators of the biotic
integrity of the UMRS. In addition, impacts of sedimentation, increased navigation, and altered
water levels in the UMRS are often perceived by the general public in terms of changes in the fish
community or fish habitat.
d. Recent research demonstrates that fishes often have major controlling effects on other organisms,
including vegetation, aquatic macroinvertebrates, zooplankton, and phytoplankton, and even on
nutrient cycling and sediment resuspension (Northcote 1988). Therefore, information on fish is
often required to understand other organisms and some physical/chemical processes.
The value of fishery data collected using standardized methods was clearly recognized in the planning
documents that preceded the Environmental Management Program (Jackson et al. 1981), and there have
been few disagreements about including fish as a major resource component for trend analysis. The
following procedures address these concerns by standardizing collections based on commonly accepted
methods and stratifying collections over space, season, and flow.
The basic unit of measurement related to the fishery component is the fish collection. A fish collection
is defined as all of the fishes collected during a single deployment of a sampling gear at a defined place
and time.
Trend analysis under the Long Term Resource Monitoring Program (LTRMP) emphasizes two attributes
of the UMRS fishery resource: community and population structure. Sampling methods for these
attributes are equivalent, but hypotheses related to the attributes require different analytical approaches;
therefore, they are discussed in separate sections.
