Post by wnion on Sept 1, 2006 16:28:27 GMT -1
Salmon shows recovery of the River Don
Aug 31,2006 by Elton Murphy
The Environment Agency has had further positive proof that salmon are beginning to return to the River Don after the fisheries survey team captured an 11lb salmon below Sprotborough Weir this month.
The salmon was captured in a routine fish survey and scales from the fish were then sent to our laboratory at Brampton. These scale samples identified this salmon as a ‘1 sea winter fish’, meaning it had been away at sea for only one year.
Despite several reported observations of salmon trying to ascend the river each Autumn during the last few years, this is the first specimen to be accurately recorded since a salmon was caught by a local angler in Doncaster in 2002. This was the first River Don rod and line caught salmon for over 150 years.
This is major development in the recovery of the River Don and shows the improvements in water quality that have been made, despite the recent pollution incident on the river which killed thousands of fish.
The salmon also had a lot of erosion at the scale edge and to the fins, which indicates that it had been in the river for a while, probably trying to ascend the weir, well before the pollution incident.
Environment Agency fisheries technical specialist Neil Trudgill said: “This is positive news following the pollution incident in July, and the fact that this salmon survived the pollution bodes well for the more tolerant coarse fish species, indicating that many would have survived the incident.”
The low oxygen levels that cause many fish to die were a result of a period of dry weather and low river flow followed by an intense rainfall event, causing sewage from storm overflows to enter the river in Sheffield and Rotherham.
Environment Agency officers worked against the clock to save hundreds of coarse fish in the River Don, using the latest methods to help reoxygenate the river, whilst using large pumps to remove the sewage sludge.
Despite the improvements to water quality over the last few years, which has allowed the formation of viable coarse and trout fisheries, the weirs on the river still act as a major obstacle to some River Don fish populations.
There are approximately 30 weirs still present on the main river and of these, five (including Sprotborough) have been identified as major obstacles in preventing gravel spawning species such as barbel, chub and salmon from reaching the major spawning grounds around Rotherham and Sheffield.
Aug 31,2006 by Elton Murphy
The Environment Agency has had further positive proof that salmon are beginning to return to the River Don after the fisheries survey team captured an 11lb salmon below Sprotborough Weir this month.
The salmon was captured in a routine fish survey and scales from the fish were then sent to our laboratory at Brampton. These scale samples identified this salmon as a ‘1 sea winter fish’, meaning it had been away at sea for only one year.
Despite several reported observations of salmon trying to ascend the river each Autumn during the last few years, this is the first specimen to be accurately recorded since a salmon was caught by a local angler in Doncaster in 2002. This was the first River Don rod and line caught salmon for over 150 years.
This is major development in the recovery of the River Don and shows the improvements in water quality that have been made, despite the recent pollution incident on the river which killed thousands of fish.
The salmon also had a lot of erosion at the scale edge and to the fins, which indicates that it had been in the river for a while, probably trying to ascend the weir, well before the pollution incident.
Environment Agency fisheries technical specialist Neil Trudgill said: “This is positive news following the pollution incident in July, and the fact that this salmon survived the pollution bodes well for the more tolerant coarse fish species, indicating that many would have survived the incident.”
The low oxygen levels that cause many fish to die were a result of a period of dry weather and low river flow followed by an intense rainfall event, causing sewage from storm overflows to enter the river in Sheffield and Rotherham.
Environment Agency officers worked against the clock to save hundreds of coarse fish in the River Don, using the latest methods to help reoxygenate the river, whilst using large pumps to remove the sewage sludge.
Despite the improvements to water quality over the last few years, which has allowed the formation of viable coarse and trout fisheries, the weirs on the river still act as a major obstacle to some River Don fish populations.
There are approximately 30 weirs still present on the main river and of these, five (including Sprotborough) have been identified as major obstacles in preventing gravel spawning species such as barbel, chub and salmon from reaching the major spawning grounds around Rotherham and Sheffield.
