In the 1960s, fish managers in Montana sought a way to help kokanee salmon grow larger for sport anglers. These small red salmon were considered too small for the region's fishing industry. The solution they chose was to introduce Mysis, a tiny freshwater shrimp, into lakes to serve as food for the salmon. The plan was to fatten the fish and improve the sport fishing experience. However, this well-intentioned move led to an unexpected ecological disaster that affected not only the salmon but also the white-tailed eagles that relied on them. The introduction of Mysis began in 1968 in Whitefish and Ashley lakes, and continued in Swan Lake in 1975. These lakes were part of a larger hydrographic network connected to Flathead Lake, the largest natural freshwater body in the western United States. Despite the managers' efforts to contain the shrimp to specific areas, the Mysis quickly spread throughout the connected lakes. By 1986, their population had grown to an astonishing 70 to 80 billion individuals. This massive increase had unintended consequences: while lake trout, a species introduced in 1905, thrived on the abundant shrimp, the kokanee salmon faced a food shortage. The Mysis fed on the same zooplankton that the young salmon needed, hiding at the lake's bottom during the day when the salmon were active. Every autumn, thousands of kokanee salmon returned to spawn in McDonald Creek, a stream in Glacier National Park. This event attracted a large number of white-tailed eagles, which gathered to feed on the spawning fish. At its peak, McDonald Creek was home to more than 600 eagles, making it a prime location for ornithological observation. However, by 1989, the kokanee salmon had disappeared from Flathead Lake, and with them, the eagles left the area. A study published in the Proceedings of the National Academy of Sciences in 2011 confirmed that the Mysis had created a lasting shift in the lake's ecosystem, allowing lake trout to dominate the food web. The ecological impact of the Mysis introduction was documented in a 1991 article in the journal BioScience, titled "Shrimp stocking, salmon collapse, and eagle displacement." The study highlighted how a decision intended to benefit sport fishing instead led to the loss of a key species and the displacement of top predators. Efforts to reintroduce kokanee salmon between 1988 and 1991 were unsuccessful, and today, Flathead Lake remains dominated by lake trout. The Mysis continue to thrive in the lake's deep waters, a presence that local managers now recognize as permanent.