This study investigated the relationships between behavioural responses of Atlantic salmon Salmo salar smolts to saltwater ( SW ) exposure and physiological characteristics of smolts in laboratory experiments. It concurrently described the behaviour of acoustically tagged smolts with respect to SW and tidal cycles during estuary migration. Salmo salar smolts increased their use of SW relative to fresh water ( FW ) from April t...

This study provides the first direct observations that photoperiod controls the initiation of downstream movement in Atlantic salmon Salmo salar smolts. Under simulated natural day length (LDN) conditions and seasonal increases in temperature, smolts increased their downstream movements five‐fold for a period of 1 month in late spring. Under the same conditions, parr did not show changes in downstream movement behaviour. When...

Between 1951 and 1979, total phosphorous concentrations in Lake Constance increased from 7 to 87 μg L −1 . Following wastewater treatment, phosphorus levels were brought under control, returning to 7.6 μg L −1 by spring 2007. The biological and chemical data from 1980 to 2004 were first modelled by seasonal time series analyses and then used to create a general model. Excluding collinear variables allowed the data set to be co...

In the present study, groups of ruffe Gymnocephalus cernuus , reared singly, were exposed to defined numbers of Anguillicoloides crassus or Camallanus lacustris under controlled laboratory conditions. Infection took place orally through feeding G. cernuus with axenically cultured and laboratory infected copepods, in which the parasites had developed to the infective third stage (L3). Mean prevalence (94·3%) and infection proba...