Karen Twine's PhD work over here on the Gt. Ouse - we managed to collect 25 barbel between 5lb and nearly 16lb from the river last week, and tagged 20 with radio transmitters.
The surgery was performed under Home Office licence, with anaesthetic and utmost care by experienced fish health specialists. All fish appeared to recover well and swam off strongly. Most have remained within a few hundred meters of their release points, apart from one cheeky individual who decided to swim 5km upstream on the first night and was later joined by another fish. Overall, we've had some very interesting results so far in just one week.
We are out doing daily tracks at the moment, with some 24-hour sessions planned soon. The tags will last for two years, so we're hopeful for a valuable look at movement and behaviour over that time, along with several other spin-off investigations related to spawning, over-wintering and predation pressures.