The problem lies in the current management system, said Kotak, which allows commercial fishers to catch a maximum quota no matter the health or number of fish in the lake. Market prices for walleye means commercial fishers target those fish especially, said Kotak. “The commercial catches of walleye from 2000 to 2010 reached record levels of over 5 million kg but were based on a house of cards – one strong year class in 2001 – which could not last,” said Dr. Scott Forbes, an ecologist at the University of Winnipeg.