Spawning time has arrived!

At this time of year, if you happen to be walking along the river you may be lucky enough to spot some of the Teigns adult salmon returning to spawn. One of the most amazing sights in nature is that of the mature salmon leaping up waterfalls, weirs and fish passes on its way home to spawn. It’s a sight that can be guaranteed to fascinate onlookers, whether they fish or not. For many people, it may well be the first and only time they see salmon, and come to appreciate what a truly marvellous animal this is, and how it earned its Latin name: Salmo salar, salmon the leaper.

Salmon spawning usually occurs on the Teign from late November to mid January; our sea trout are also spawning now, they generally start to spawn earlier than salmon in early/mid November.

Female fish lay their eggs in gravel depressions known as ‘redds’. As a female releases her eggs, an adult male (or mature juvenile) immediately fertilises them. The female then covers the fertilised eggs with gravel. We are going to be carrying out surveys over the next few weeks to record where the redds are; this will help us to understand where the fish are spawning (and just as importantly, where they aren’t). In particular we want to ascertain whether areas where juvenile fish survey numbers are low is the result of poor spawning  or other factors such as barrier to migration, sedimentation, overshading and pollution

This photo shows two sea trout redds, (or perhaps good size brown trout redds) that appeared near Chagford in mid November 2021. Each redd is about 1.5 metre in length, and the depression at the left of each redd is where the female dug out gravel that drifted downstream to cover her eggs in the mound at the downstream end of the redd. The eel like item in the bottom redd is a piece of wood caught in the gravels as it drifted by.

Salmon usually spawn in relatively shallow water, often on pool tails where the upslope helps force water through the redd. The key characteristic of a successful redd is a pit at least 6 inches deep and two or more feet long and wide with a pile of gravel immediately downstream where the eggs are buried. Smaller ‘scrapes’ may be areas where a fish has decided ‘not good enough’ or where a redd has been started but not completed.

Salmon prefer a mix of gravels up to 4 inches across. Unless the gravel is exceptionally clean, you may see:

  • A clean area where the algae/silt covered top layer has been disturbed;
  • An area of gravel where the smaller sizes are more visible than the surrounding area;
  • Salmon actually in position
The photo above shows a redd, probably made by salmon or large sea trout, appearing in late November 2021 near Chagford. Note the slightly faster water and larger gravel. This redd is about the size of a car bonnet.

It is very important not to disturb any redds, and walking on the bank is usually sufficient to be able to see redds. Wearing polarised glasses can help enormously to reduce the glare from the water.

If you would like to know more about how to identify redds, the Wild Trout Trust has some great information on their website.

We are looking for volunteers to help us with redd surveys: please contact Geoff if you would like to join a redd spotting session near Chagford or Steps Bridge, and Louise if you would like to help on the Lower Teign and Bovey. We would be really pleased to hear from you!