Review of existing models for evaluating fish population changes


Johnson, B. L.  1993.  Review of existing models for evaluating
fish population changes relative to environmental impacts.  Report
by the U.S. Fish and Wildlife Service, National Fisheries Research
Center, La Crosse, Wisconsin, for the U.S. Fish and Wildlife
Service, Environmental Management Technical Center, Onalaska,
Wisconsin, July 1993.  EMTC 93-S005.  25 pp.  (NTIS # PB94-102514)


ABSTRACT

The objective of this review was to evaluate the ability of
existing models and modeling approaches to explain and predict
temporal changes in fish abundance in the Upper Mississippi River
System (UMRS) based on environmental factors.  Information on
models was obtained through a literature review and personal
contacts with Federal and academic specialists.  Models were
evaluated based on their assumptions, data requirements, outputs
generated, and applicability to UMRS fishes.  Many existing models
can incorporate environmental effects on fish populations, but
none were developed specifically for large rivers.  The models
reviewed were of three types:  analytical, empirical, and
mechanistic.  Of these three model types, empirical regression
models, developed from UMRS data, would probably be the most
useful for addressing questions regarding mean abundance of a
species over space or time.  Mechanistic population dynamics
models have the most potential for following and predicting
population or community dynamics and for incorporating empirically
determined environmental effects. 


KEYWORDS

fish, models, rivers