September 17 2014 Latest news:
By Chris Bishop
Thursday, July 17, 2014
Environment Agency fisheries scientists were stunnned when they hauled in a 13lbs sea trout during a routine fish survey on a drain near King’s Lynn.
Sea trout are rare in the Fens, where rivers have been banked and diverted over the centuries. While sluices now divide freshwater and tidal reaches, the adaptable sea-going trout has started using man-made drainage channels as a short cut to its breedng grounds.
EA fisheries officers James Hooker and Paul Wilkanowski netted the trout on the Relief Channel - dug in the late 1940s to protect the area between King’s Lynn and Ely from flooding.
“It’s a cracking fish,” said Mr Hooker, who added the trout was returned to resume its migration after being weighed, measured and having a scale sample taken.
“We did the nets on Monday, it was the last of three surveys on the Relief Channel. We had quite good catches at Stowbridge and Wiggenhall. We had some silver fish, roach. perch, some pike and some juvenile zander. That was the only sea trout we caught.”
Scale readings showed that the trout was seven years old. Its destination is likely to be the River Wissey, which supports a small run of sea trout.
To get there, it would need to take the left hand fork at Denver, where the Cut Off Channel meets the Relief Channel, before turning off at Stoke Ferry waterworks, where a £500,000 fish pass links the drain to the Wissey.
Sea trout turn up occasionally in EA fishery surveys on the rivers and drains, while pike anglers have occasionally caught large trout on both the Cut Off and Wissey.
Sea trout are not a separate species. Scientists can not explain why some native brown trout spend their entire lives in freshwater, while others get the wanderlust and head out to sea.
Sea trout are commonest in Wales and the Westcountry, where there are fewer barriers to their migration inland. While they were once common in Norfolk’s chalk streams - particularly the Nar, Wissey and Burn - the straightening and dredging of rivers to improve drainage and the building of sluices has made their journey harder.