Abstract

In fisheries science, length and age are important aspects of fish life history. Length is a function of growth, which provides an integrated measure of the environmental and endogenous conditions, e.g. genetics, affecting individuals and populations. Length at age data can be used to assess quality and quantity of habitat, food availability, or the need for and influence of management activities. Statistical mixture techniques may be used as a means to effectively model fish length distribution. A three-component mixture model, based on normal variates, was employed to describe length distribution in mountain whitefish species. The resulting model provided parameter estimates with meaningful biological interpretations, which were in turn used for inferential and comparative purposes. The technique will be demonstrated with reference to seven years of bio-monitoring data collected from the Kootenai River in Northern Idaho prior to and post nutrient addition treatment.

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Apr 25th, 9:05 AM

MODELING FISH LENGTH DISTRIBUTION USING A MIXTURE TECHNIQUE

In fisheries science, length and age are important aspects of fish life history. Length is a function of growth, which provides an integrated measure of the environmental and endogenous conditions, e.g. genetics, affecting individuals and populations. Length at age data can be used to assess quality and quantity of habitat, food availability, or the need for and influence of management activities. Statistical mixture techniques may be used as a means to effectively model fish length distribution. A three-component mixture model, based on normal variates, was employed to describe length distribution in mountain whitefish species. The resulting model provided parameter estimates with meaningful biological interpretations, which were in turn used for inferential and comparative purposes. The technique will be demonstrated with reference to seven years of bio-monitoring data collected from the Kootenai River in Northern Idaho prior to and post nutrient addition treatment.