What are Redds?
Redds are the nests made out of various sizes of gravel and stones that trout and salmon use as building tools to provide a place to lay their eggs. These underwater structures are often found in shallow, ripple areas of a lake or stream typically occur near the shore to ensure proper temperature, protection from predators, and that enough oxygen is delivered to the eggs.
To create a redd, the females use their tails to flap a depression in the gravel using a brushing-like motion. In this depression, they lay their eggs in which it is fertilised by a male. A redd can be distinguished by a cleaned-out, oval or bowl-like area of gravel on the stream or riverbed. For less trained eyes, a trick that can be used to identify a redd is searching for areas with clean gravel that is free of algae and mud in comparison to its surrounding sediment before verifying an overall round shape. For a more clear illustration, some pictures are included at the end of this article to help with visualization that you can use the next time you are near a creek or river.
Lake Windermere and the tributaries in the area can be seen having rainbow trout predominantly, while the Columbia River Watershed is known to provide habitat for other trout species such as bull trout. Kokanee salmon are also known to create redds in the Kootenay Valley as well. Therefore, redds are plentiful in this region of BC.
Pressures and Endangerment of Redds
Despite their crucial role in fish reproduction, redds are highly vulnerable to environmental pressures and human activity. Several factors can threaten the survival of eggs and the integrity of redds including sedimentation, streambank erosion and habitat degradation, trampling and recreation, variable temperatures ranging from extreme heat and unseasonably cold weather which may kill the fish and eggs, and pollution which may create compromised water quality that increases mortality of fish and their eggs.
When Are Redds Most Commonly Seen?
Certain species of trout, brown and brook trout in particular, spawn in the fall. October and November are the heavy spawning months.
For Lake Windermere and tributaries, the spring season is also spawning season for rainbow trout, so caution during aquatic recreational activities in the springtime is advised to not accidentally destroy a redd.
Fishing Regulations Surrounding Redds in BC
For the Columbia River watershed, fishing regulations regarding trout and redds varies from tributary to tributary and are strictly enforced. A resource for fishing regulations regarding specific tributaries in BC can be found here:
BRITISH COLUMBIA FRESHWATER FISHING REGULATIONS 2025-2027
Redds are critical to sustaining healthy fish populations, so protecting redds is not only essential for individual species but also for the overall health of freshwater ecosystems.
Image Source: The Fly Crate
References
Forth Rivers Trust. (2019, October 3). Redd counting. Redd Counting. https://forthriverstrust.org/science/data-collection/redd-counting/
Lazzari, Z. (2021). Spawning season: How to identify and protect Rainbow Trout Redds. Mystic Outdoors. https://www.mysticoutdoors.com/blogs/news/spawning-season-how-to-identify-and-protect-rainbow-trout-redds#:~:text=This%20spring%20season%20is%20also,beds%20or%20redds%20and%20reproduce.
Staff, O. (2023, April 14). Classic pro tips: Spring fishing is great, but don’t tread on Redds. Orvis News. https://news.orvis.com/fly-fishing/classic-tuesday-tip-spring-fishing-great-dont-tread-redds
Treichler, N. (2021, December 2). What is a “redd” and how to recognize them. The Fly Crate. https://theflycrate.com/blogs/fly-fishing/what-is-a-redd-and-how-to-recognize-them#:~:text=Certain%20species%20of%20trout%2C%20brown,their%20way%20as%20it%20is.
Wild Trout Trust. (2023, November 29). Redd spotting. Wild Trout Trust. https://www.wildtrout.org/wttblog/redd-spotting