Factors affecting the distribution of wrasses in a fjord system: analysis by generalised linear models
Original version
This report is not to be cited without prior reference to the authorsAbstract
Background: Generalised linear models (GLMs, see McCullagh & Nelder 1989) form a modern, flexible and unified approach to
statistical modelling. GLMs are of particular value to the analysis of data from ecological surveys, because they
allow for deviation from the assumption of normality in the models. Thus one may for instance fit models with
Poisson or negative binomial (negbin) error terms and loganthmic link functions. The negbin distribution in
particular, frequently applied in ecology, and often gives a good approximation to typically skewed catch data (high
proportion of zero catch values, low means). Many of today’s statistical computer packages (e.g. S-Plus) have
inbuilt options for GLMs.