Karl English has spent most of his career designing and implementing studies to improve the quality and quantity of information available for the management and assessment of Pacific salmon and steelhead stocks. Karl has conducted projects throughout British Columbia and in Washington State, Alaska, and the Yukon. He has designed catch monitoring programs for commercial, sport, and First Nation fisheries; directed multi-year studies to assess fish distribution, abundance, and migration behaviour in coastal waters and large river systems; and provided expert advice to First Nations, industry, NGOs, university researchers, and all levels of government.

A sample of the salmon and steelhead projects directed by Karl includes: the 1982−1985 International Salmon Tagging Studies conducted in northern British Columbia and southeast Alaska; the Nisg̱a'a Fisheries Program; the 1986−1999 Georgia Strait Creel Survey; the 1996−2002 Yukon River Basin Salmon Harvest Study; and radio telemetry studies to assess migration behaviour and abundance on the Nass, Skeena, Fraser, Bella Coola, and Columbia rivers (1992−present). Karl has also directed research on other fish species including: white sturgeon, Arctic cisco, broad whitefish, and reviewed research and stock assessment programs associated with the fisheries in the Canadian Great Lakes. In additional to his research and project management skills, Karl has extensive experience in Treaty negotiations process through his role as fisheries advisor during the negotiation of the Nisg̱a'a Treaty and Tsawwassen Treaty.