Below is an abstact from a paper written in 1996. Seasonal movements and behaviour of adult barbel Barbus barbus, a riverine cyprinid fish
1. To provide information on the movements and localized activity of barbel Barbus barbus (Cyprinidae) in a river containing potentially obstructing weirs, 31 adult barbel were radio-tracked in the River Nidd, a tributary of the Yorkshire Ouse, North East England between June 1993 and September 1994.
2. Barbel exhibited substantial movements, ranging from 2 to nearly 20 km. Four fish are known to have moved between the Nidd and the Ouse, demonstrating that at least a part of the barbel population utilize the Nidd and Ouse at different times of the year.
3. Range of upstream movement was restricted by the presence and nature of several weirs, including Skip Bridge flow-gauging weir. Low levels of spawning downstream of Skip Bridge weir appear to have been due to a lack of suitable spawning habitat.
4. Movements followed a seasonal pattern, with males and females migrating upstream in spring to spawn on gravel beds. Females moved downstream more quickly than males over the summer months. Both sexes moved downstream in autumn and winter. Day length and water temperature were the best predictors in relation to distance moved up the River Nidd. Descriptive models, relating movement to water temperature and day length, are provided.
5. For both sexes, localized activity varied greatly on both diel and seasonal scales, and was mainly associated with foraging. During summer there was typically a bimodal pattern of diel activity with peaks usually in early morning and late evening. In winter, mean daily activity was less than 20% of peak summer levels and fish were relatively dormant. In winter, diel activity patterns exhibited a single peak towards dusk. Mean daily activity levels for each month were linearly correlated with mean monthly water temperatures, even during the months where movement to and on the spawning sites occurred.
6. The importance of natural migrations and seasonal activity patterns for barbel, and likewise many other riverine cyprinids, has probably been underestimated for a wide variety of river systems. As major components of riverine fish communities, the importance of seasonal movements of mobile cyprinid species should be considered when constructing weirs and other obstructions. Greater consideration should be given to ways of mitigating effects of existing barriers to movement of non-salmonid species.
Jason
, your asking something there are'nt you
