Katmai protects the pristine lake and river systems necessary for the perpetuation of the Bristol Bay red salmon fishery, the heartbeat of the economy, ecology, culture, recreation, and history of southwest Alaska. Weather, climate change, and geologic processes are also constantly changing Katmai. Volcanic eruptions and earthquakes are always a threat in this part of Alaska. Air pollution, water pollution, increased visitation, and changing use patterns are additional impacts that may affect Katmai.