Wiltshire and Swindon Biological Records Centre

Wiltshire Redd Recording Society


WRRS is a new organisation whose aim is to record the wild brown trout (Salmo trutta) nests, or 'redds' on the rivers of Wiltshire. The abundance of these redds tell us about the population of spawning trout and about the quality of our rivers.

Redd recording is easy and can be carried out by anyone. There are two ways to get involved in redd recording:

Become a WRRS Redd Surveyor, redd surveying takes place on the same stretch of river approximately every two weeks between November and March, the brown trout spawning season, you register your stretch with a six figure grid reference for the start and end of the stretch and then can send in your redd sightings after each visit.

If you do not have time to regularly survey then you can just send in sightings of any redd that you see at any place with the standard recording requirements.

All redd sightings need to have:

  • Number of redds seen
  • Six figure grid reference
  • Name of river/stream where redd was seen
  • Name of recorder
  • Date redd was seen

Also helpful are the following:

  • Name of town/village nearest to redd
  • Were fish seen spawning?
Redds, Harry Forbes/ WSBRC

Redds look like mounds of clean gravel about 1-3 feet in length. There is usually a scrape like dip in the river bed next to the redd. It is important not to disturb redds as they are extremely delicate, WRRS advises all inexperienced redd surveyors to stay on the bank while redd surveying, to protect the redds and for safety, especially near deep water.

If you see a redd which is about 3-5 feet in length then it may be a salmon redd, these are only found on some rivers in Wiltshire and are much rarer than brown trout redds, they are usually made in November and December, where as most brown trout redds are usually made in January and February.

Redds are usually found in areas of fast flowing river, with clean gravel. They can be made in water of about 10cm deep, up to 80cm deep although 20-40cm is the preferred depth.

Redd training days are held on the River Kennet near Marlborough each redd season, in January and February. The free training days are open to all interested in recording redds, please contact WRRS if you would be interested in attending.

Please send all data, questions, requests for the WRRS newsletter 'Redd Alert' and enquiries to: WRRS Recording Director Harry Forbes wrrs@hotmail.co.uk