Best Practise

Catch and release

Each river has a conservation code, designed to create a balance between angling interests and maintaining a healthy population of fish. Every year, our Scientific Advisors review the year’s catch data and electro fishing results and recommend any necessary changes to the conservation codes.

Research shows that a high proportion of released fish survive, to breed and (possibly) to be caught again. The survival rate depends partly on anglers’ techniques for releasing caught fish. Below are guidelines to help anglers release fish successfully.

Six Simple Steps

  1. Use the strongest practical nylon cast to facilitate quick landing of fish. Long playing leads to the build up of harmful metabolites such as lactic acid which kills fish even after they appear to swim away unscathed.
  2. Use barbless hooks. These can be difficult to obtain but ordinary hooks can easily be adapted by carefully crimping down the barb with slim-jawed pliers.
  3. Try and plan your release strategy as you are playing the fish – think where the best area would be to net, unhook & release your fish. Avoid sandy beaches and silty bays, and where there are extensive areas where the water depth is shallower than the depth of the fish.
  4. Take great care in handling fish. It helps if there are two of you so try and fish in pairs. Do not pick the fish up by the tail and carry it to the bank for unhooking purposes. Use a wide-mouthed small knot-less mesh net to minimise handling and remove the hook and release the fish while still in the water. Wet the hands first or use surgical gloves and wet them as well, avoid the gill area, do not squeeze the stomach and take care not to rub off scales. Turning the fish upside down will often prevent it from struggling. Use your knees or the river bank to keep the frame of the net level and just above the water surface.
  5. Use long-nosed artery forceps or slim-jawed pliers for removing hooks.
  6. Try to minimise out of water and handling times. Return the fish as quickly as possible. Some photographers keep fish out of the water far too long, considerably reducing their chances of recovery. Support it until it has recovered enough to swim away.

Collecting Sea Trout Scales for Research

Findhorn ScaleAccording to Marcus Walters of the Moray Firth Sea Trout Project, sea trout populations appear to have declined in all three of the Trust’s rivers. At the moment, there is little data to help explain this decline. One way forward is to analyse sea trout scales. From scales, scientists can determine smolt age, sea age, overall age, age at first spawning and number of spawning occasions. Marine growth performance can be ascertained by fish size at sea age.

The Moray Firth Sea Trout Project is asking anglers to collect sea trout scales from retained and released sea trout (while protecting the fish as much as possible). Please download Collecting Sea Trout Scales for how to carry this out safely, and where to send the scales.

The last formal research on Moray Firth sea trout scales was carried out in the 1920-30s by G. H. Nall, who looked at the scales of hundreds of sea trout from rivers all around the Firth. When the scale characteristics are looked at across a whole population they can provide vital information on the structure and behaviour of the stock. If we can collect reasonable numbers of sea trout scales from the Findhorn, Nairn and Lossie then we will be able to not only compare differences between rivers but also look at how the recent collections differ from G.H. Nall’s results and this may help us understand how the stock has changed and give some insight into what may be causing the decline.