October 7, 2016

Restoring Kokanee Numbers in Kootenay Lake

Kokanee, a land-locked sockeye salmon, have significant cultural and recreational importance in B.C. These shiny silver fish prefer to roam in the deep, clear waters of our largest lakes and reservoirs, and are known for their willingness to aggressively bite flashy lures. Kokanee can provide great year ’round family fishing. With bright pink flesh, kokanee are also acknowledged to be great-tasting … and it seems our province’s wild predators (like large rainbow trout, bull trout, grizzly bears, and eagles) share this opinion.

The number of kokanee stocked into our provincial waters has been slowly increasing during the last decade. In the most recent year, the Freshwater Fisheries Society of BC has stocked between one and 1.2 million kokanee. That is a lot of fish, and a lot of work behind the scenes. However, it can be very humbling to compare our efforts to the natural productivity of some of our province’s healthy ecosystems. For example, fall assessments on Kootenay Lake by staff of the provincial Fish and Wildlife Branch have shown that an average of about 18 million fry are produced annually.

Unfortunately, the survival rate of Kootenay Lake kokanee has recently undergone a dramatic downward shift. Typically 500,000 to 1,500,000 spawners are expected to return to streams to deposit their eggs each year, but these numbers have plummeted to below 40,000 spawners during the last two years. This decline has, in turn, impacted the predator population, with numbers of Gerrard rainbow trout spawners also dropping sharply. These changes have had a negative effect upon the highly valued Kootenay Lake fishery, and the health of the broader ecosystem.

Concern from government biologists and stakeholders on the state of Kootenay Lake has led to the formation of the Kootenay Lake Fisheries Advisory Team. The team recommended that immediate intervention be taken in an attempt to speed recovery of the kokanee population. It was decided to augment the Kootenay Lake kokanee population by obtaining kokanee eggs from other lakes that had historically been stocked with Kootenay Lake fish. However, the vast size of Kootenay Lake would require significant numbers of eggs to have any meaningful impact. The recovery team set a lofty target of five to seven million eggs – which represents a five- to seven-fold increase in production for the Society, not to mention the eggs that would be needed to maintain recreational fisheries in other lakes already being stocked. Furthermore, since there was no single lake around the province that could supply such a vast amount of eggs, staff would need to get them from numerous spawning tributaries across the province.

Society staff were more than willing to take on this challenge. Their managers immediately began a plan of attack, including changes to hatchery infrastructure to accommodate the increased egg quantities; identification of potential egg sources, their timing, location, and genetic origins (Kootenay Lake origin fish were targeted); and, finally, a complicated shuffling of staff and equipment to coincide with fish timing and locations. Installing a fish spawning fence in flowing water always means a continual battle with nature as debris, leaves, high water-flows, and predators constantly threaten to destroy the work put in.

In 2016, the kokanee egg requirements involved capturing fish from a total of 10 different spawning locations spread throughout the province. The fall spawning period was hectic, with long shifts, long travel distances, and many ups and downs. However, the staff’s professionalism and dedication prevailed until all egg targets were met or exceeded. This was a huge success for the Society, with our kokanee incubation sites completely full, and holding a promising future for Kootenay Lake fish. The eggs will be planted into Meadow Creek this fall, and Fish and Wildlife assessments will track their success from there. We can all be satisfied that everything that could be done has been done. Now, we can only hope that Mother Nature will carry these eggs through their maturation time in the lake to produce the next generation of kokanee.

This blog series has been established as a way to inform freshwater anglers in B.C. about projects, such as this one, that their angling licence dollars support. In 2015, the Freshwater Fisheries Society of BC began receiving 100% (up from 70%) of all freshwater angling licence fees. With this additional funding, the Society committed to broadening the scope of its activities to include joint initiatives with the Provincial Government to support projects that benefit freshwater recreational fishing around B.C.

Author: Paul Askey, Freshwater Fisheries Society of BC
Photo Credit: Diana Koller & Craig Schelter, Freshwater Fisheries Society of BC