Modeling diurnal variation of marine populations.
A number of marine populations exhibit diurnal variations in their behavioral pattern, and this phenomenon has been studied by several authors looking at a variety of species. But to our knowledge, fully adequate statistical tools have not been used in a comprehensive and systematic way. It is the goal of this article to bring forward relevant statistical techniques and to demonstrate how they can be used. Both parametric and nonparametric methods are employed, and we concentrate on such basic statistical issues as testing for the presence of diurnal variations using a nonparametric test and on estimating and testing the shape of diurnal oscillations. We indicate how this can be used to examine the effect of light on diurnal behavior. Our methods are illustrated using data from bottom trawl catches of cod (Gadus morhua) collected during winter surveys in the Barents Sea in the period 1985-1999.
Hjellvik
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Institute of Marine Research, Bergen, Norway. vidarh@imr.no
Godø
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Tjøstheim
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D000818:Animals; D001522:Behavior, Animal / Q000502:physiology; D001699:Biometry; D002940:Circadian Rhythm; D005399:Fishes / Q000502:physiology; D016014:Linear Models; D008386:Marine Biology / Q000706:statistics & numerical data*; D008954:Models, Biological; D015233:Models, Statistical