Thursday, 7 August 2014

A visit to the (Welsh) river Dee fish trap

by Stephen Greogry - sgregory@gwct.org.uk

Anton Ibbotson and Stephen Gregory of project Morfish recently paid a visit to the Cyfoeth Naturiol Cymru/Natural Resources Wales fish trapping facility on the river Dee in Chester.

Ian Davidson and Rich Cove kindly gave us a guided tour and showed us the fantastic facility in action.


The schematic below shows the trap which is located at the tidal limit. Ian and Rich are currently catching good numbers of both salmon and trout in the Dee.

 

The potential benefits of catching returning spawning fish are obvious to Anton and I. With the fish in your hand you're able to measure length and weight precisely and take biological material such as scales and fin clips.
 
We currently use a passive monitoring system for spawners meaning we detect the returns on either the adult counter or the PIT tag system. By having biological data on the returning spawners we would be able to investigate changes in the condition over time, allowing us to investigate possible drivers of stock sizes over time.
 
One last photo - Anton Ibbotson chasing fish around the trap floor: