2008 Report

To read the full report please click here

The River Dee was granted a licence in 2008 to extend its rod and line fishing season from 30 September to 15 October for a trial period of 3 years, from 2008-2010. A condition of the licence was that the fishing extension period be monitored to determine if there were any impacts of the fishery on the sustainability of the salmon population.

In 2008 a pilot monitoring project was undertaken to develop and refine methods for monitoring the fishery extension in 2009/10. The four methods used to assess impact of the fishery extension on the salmon population were: rod catch analysis; scale sampling; radio tracking of individual salmon; and redd count surveys.

654 salmon (multi sea winter and grilse) and 33 sea trout were caught in the October extension period. Data from a sample of fishing beats showed that on the Lower Dee (downstream of Banchory), almost half of the salmon were not coloured (i.e. fresh or clean fish) whereas on the Middle Dee (downstream of Aboyne Bridge to Banchory), 20% of salmon were fresh or clean.

Scale samples showed that Spring salmon comprised a small but significant component of the Lower Dee salmon stock (downstream of Banchory; 22% of the sample) and a larger component of the Middle Dee salmon stock (downstream of Aboyne; 44% of the sample).

The radio tracking pilot study allowed the methods, logistics and man effort required for the tracking studies in 2009/10 to be determined. In addition, information on the movements of 20 tagged fish was gained. 15 fish showed upstream migration but four fish showed no further movements upstream (one fish was lost from the study). Fish that had recently entered the Dee (i.e. fresh fish) showed the greatest upstream migration (maximum of 54 km, average of 23.5 km) whereas Spring salmon showed the least upstream movement (average of 2.6 km). Spring salmon reached their highest upstream position in mid – late November, suggesting spawning at this time, whereas two late-entry fish migrated upstream until mid January. Three fish were confirmed to have spawned (one was observed and two were recaptured).

Redd count surveys showed earlier spawning of salmon in the tributaries of the Upper Dee (early - mid November) compared to tributaries on the Lower Dee (late November onwards). However, it was undetermined how spawning times along the main stem relate to the observed spawning in tributaries.

This report has developed the following recommendations for monitoring the fishery extension period in 2009/10:

1. Rod catch analysis using statutory returns to the Dee DSFB to continue, with additional information on individual fish to be collected by a sample of beats in September and October of 09/10.

2. Scale sampling to continue as part of the sampling programme initiated in 2008.

 

3. Radio tracking of 30 fish caught in the last two weeks in September and 30 fish in the two weeks of October to be undertaken in 09/10, to allow comparison of fish behaviours/movements captured at different times in the season. Fish should be sampled from the Lower Dee fishery in 2009 and from the Middle Dee fishery in 2010.

4. Redd count surveys on tributaries to continue in 2009/10 plus weekly surveys including six sites along the main stem of the Dee.

To read the full report please click here

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