Mosquitoes “bug” SFEG and Skagit County crews during Mount Vernon fish rescue at salmon restoration construction site

This time of year, mosquito nets are not just a bold fashion statement for our hardworking restoration and construction crews working to enhance salmon populations on the South Fork of the Skagit River.  It is an essential piece of safety equipment when just standing near a wetland is akin to signing up for a local blood drive.  Fortunately, mosquitoes and other insect larvae are staple food sources for salmon fry, so we are used to seeing them while enhancing salmon habitat.  Last week SFEG staff “donated” plenty of blood to the South Fork mosquitoes during a fish rescue in a construction work site, leading to a very interesting food chain:

This restoration project is located on the South Fork of the Skagit River at the upper edge of the Skagit River estuary.  The water is not salty or brackish here but daily changes in the tide heavily influence the water depth.  Backwatering off channel habitats in this part of the estuary are extremely valuable rearing habitat for juvenile salmonids.   This site is a wonderful salmonid refuge in the winter, providing shelter for tiny salmon fry during harsh winter flooding conditions.  However, each spring this side channel disconnects from the Skagit before the salmon fry can escape.  By summer, this apparent fish paradise dries up and turns into a fish death trap, an issue that will be fixed during construction in summer 2022.

This project began in 2002 with a levee set-back project and a river side planting, led by Skagit County Public Works and Dike District #3.  County monitoring programs documented high fish presence at this site, including many juvenile Chinook salmon.  This final project phase will establish excellent natural water flow between the Skagit River, the floodplain, and the freshwater channel network and will allow 5.3 acres of wetted area to remain during low river conditions.  The final result will be excellent summer refuge for our young native fish with shade (from the 2002 native tree planting), shelter (newly constructed channel and pond habitat) and plentiful food (mosquitoes and other insect larvae).

For the construction phase of this project to take place, all the fish trapped in the work area in July 2022 had to be relocated.  Skagit County Public Works, the lead of this restoration project, invited SFEG to lead the relocation effort.  The same aspects of this site that make it excellent for salmon make it difficult for us to work in.  The native tree and brush cover is thick, the existing channel is large and full of woody debris, the pools are very deep, and the mosquitoes are horrendous.   In this setting the fish have quite the advantage and they are extremely motivated to stay out of the SFEG nets and buckets and away from the helpful grasp of our fish rescue crew.  Despite this we successfully rescued almost 8000 fish!

Next year, Skagit County public works will be done with construction and salmon fry born this coming winter will have better access to (and exits from) this excellent habitat.