Fishery Management

A.

After 5 years of running Wyebank and Courtfield as one overlapping fishery 2011 sees the commencement of a new fishery management programme. An overview of the results of management since 2006 and details of the way the fisheries will be run from 2012 will be written up soon.

B.

Barbel versus salmon debate.

In 2011 I wrote to Dr Perikles Karageorgopoulos the Senior Technical Specialist (Fisheries) Environment Agency, South East, who is experienced with barbel in the river Itchen, to express concern over the possibility of salmon egg predation by barbel. We wrote back and forth and Peri gave me the valuable consensus opinion from many informed colleagues that barbel were not predating on salmon eggs or alevins by digging up redds. His reasoned argument and those of his many colleagues was convincing. The conclusions were backed up by several scientific papers on the subject, which are the product of some first class research.

The following “Barbel diet Sava” is of particular interest and shows pretty conclusively that barbel are not likely to feed on salmon eggs or alevins by design.

Barbel diet Sava

The following Paper on barbel migration is of particular interest for a better understanding of barbel movements within the river system. Also prove of activity indicates that winter barbel fishing is probably not out of the question, more a matter of knowing where to fish and for that very short window of opportunity only towards dusk. I have included the abstract below for those of you reading this who may be interested in obtaining the Paper.

Lucas & Batley (1996) Seasonal movements and behavior of adult barbel

Journal of Applied Ecology © 1996 British Ecological Society

Abstract

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.

In late November 2012 I received a further contact from Dr Perikles to tell me that my enquiry had “sparked an EA wide review” the result of which is now published and can be read at:-

http://www.environment-agency.gov.uk/static/documents/Barbel_and_salmon_-_our_position_at_March_12.pdf

I feel confident with this review and relieved that on the river Wye we can benefit from the marvelous fishing resource provided by salmon and barbel.