Numerous research projects have been conducted on least cisco throughout Alaska. Studies conducted by ADF&G biologists have included efforts to determine fecundity, size, and abundance of least cisco in the Chatanika River where recent research indicates that populations of least cisco have not fully recovered from the collapse of the fishery during the 1980s. Similar stock assessment studies have been conducted by USFWS biologists to determine distribution and migratory timing for least cisco in the Kuskokwim River watershed. These projects use radio telemetry (biologists place radio transmitter tags into fish and then follow the signal to track the fishâ€˜s movements). Researchers may also use fish weirs (essentially a fence installed across flowing water to block the passage of fish) to count whitefish or salmon as they migrate upstream. The weir prevents fish from migrating upstream until a gate is opened which allows passage through an opening in the weir. Weirs are typically used in relatively clear, narrow, and shallow streams. The information gathered is used to better manage and protect least cisco stocks and habitat. Future studies that delineate critical spawning habitat will be important to ensure these areas are adequately protected.