Kokanee salmon are present in Lake Tahoe. These fish are not native; their presence is a result of human introduction rather than natural distribution.
The Kokanee Salmon in Lake Tahoe
Kokanee salmon are a landlocked form of Sockeye salmon, completing their entire life cycle in freshwater lakes and rivers. In Lake Tahoe, they are typically silvery-blue. During their fall spawning season, they undergo a striking transformation, turning vibrant red with a green head.
Males develop a distinctive humped back and a hooked jaw, known as a kype, which aids in territorial defense during spawning. Kokanee in Lake Tahoe generally range from 12 to 18 inches in length. They are found in the lake’s well-oxygenated, cooler open waters, typically at depths between 30 and 100 feet.
A History of Introduction
Kokanee salmon were introduced to Lake Tahoe in the early 1940s, with the first stocking occurring in 1944. This introduction aimed to establish a recreational sport fishery in the lake.
While some accounts suggest an accidental release from the Tahoe City fish hatchery in 1944, others indicate an intentional stocking. State agencies began annual plantings once the fish demonstrated their ability to survive and reproduce. Between 1940 and 1960, an estimated 11.1 million Kokanee fry were introduced. The California Department of Fish and Wildlife continued to stock the lake with approximately 150,000 fingerlings annually.
Ecological Dynamics
Kokanee salmon occupy a specific niche within Lake Tahoe’s food web. Their primary diet consists of zooplankton, particularly Daphnia, often called water fleas. They also occasionally consume small fish and insects, adapting their diet based on food availability.
Kokanee serve as a food source for various predators in the Lake Tahoe ecosystem. Larger fish, such as lake trout (Mackinaw), prey on Kokanee in significant numbers. Terrestrial and avian predators, including bears, eagles, gulls, and waterfowl, also feed on adult salmon, especially during spawning runs. The eggs laid by spawning Kokanee are a food source for Mallards and other small aquatic creatures.
The introduction of Mysis shrimp in the 1960s and 1970s, intended as a food source for sport fish, had unintended consequences. These shrimp competed with Kokanee for their primary zooplankton food source, Daphnia, and also consumed Daphnia, leading to declines in zooplankton populations. Kokanee salmon are not considered an invasive species in Lake Tahoe; they have integrated into the food web and provide sustenance for other species.
Fishing and Conservation
Recreational fishing for Kokanee salmon is a popular activity on Lake Tahoe, attracting many anglers. While sometimes overshadowed by fishing for larger lake trout, its popularity continues to grow.
The most common method used by anglers is trolling with downriggers, allowing them to reach the depths where these fish typically school. Lures, often plastic-skirted “hoochies” tipped with corn, are frequently used to entice bites.
The Kokanee fishing season in Lake Tahoe generally runs from mid-June through October, with peak activity from late July through August. During the fall, particularly in October, the annual spawning run into tributaries like Taylor Creek attracts both anglers and wildlife observers.
Management efforts for the Kokanee population include regular stocking by the California Department of Fish and Wildlife to sustain the fishery. Organizations like Kokanee Power also assist with egg collection and hatchery programs. Stream conditions are managed to support successful spawning runs and prevent invasive fish species from impacting young Kokanee.