Pettersson, Magnus2011-02-182011-02-181997-02-010349-8034http://hdl.handle.net/2077/24561Statistical surveillance are methods for repeated analysis of stochastic processes, aiming to detect a change in the underlying distribution. Such methods are widely used for industrial, medical, economical and other applications. By applying these general methods on data collected for environmetrical purposes, it might be possible to detect important changes fast and reliable. We exemplify the use of statistical surveillance on a data set of fish catches in Lake MaIaren, Sweden, 1964-1993. A model for the in-control process of one species, vendace (Coregonus albula), is constructed and used for univariate monitoring. Further, we demonstrate the application of Hotelling's T2 and the Shannon-Wiener index for monitoring biodiversity, where a set of five economically interesting species serve as bioindicators for the lake.30engVendaceRecursive ResidualsShewhart testAR processFourier seriesSpecies correlation matrixShannon-Wiener indexHotelling's T2Lake MälarenCatch dataText