The Maine Department of Inland Fisheries and Wildlife is investigating a large fish kill in Lake Auburn caused by a lack of oxygen. The fish kill, which began late last week, involves lake trout or togue, some suckers and other deep-dwelling lake fish. Regional fisheries biologist Francis Brautigam says the lack of dissolved oxygen in the cooler, deeper parts of the lake causes fish to suffocate. The Auburn Water District and Lewiston Water Division are cooperating with state biologists to monitor increased algae activity on Lake Auburn. Public drinking water quality has not been affected. Lake Auburn’s long been a good lake trout fishery with high water quality. But it’s been added to the state’s watch list as a result of deteriorating water quality and fall algae bloom.