Great Lakes Reduce Dead Zones

FISHERY MANAGEMENT
Climate-driven changes in fish populations and communities will combine with current stresses on species to produce numerous impacts on existing fisheries. Although the commercial fishing sector in the region is relatively small, the recreational fishing sector includes ten million anglers that actively fish in the region and contributes nearly ten billion dollars to local economies. Several changes in human activities that affect fish populations could help protect this resource from the worst impacts of climate change.


Solution strategies:	REALLOCATE HARVEST	MANAGE HABITATS	REDUCE DEAD ZONES
A “dead zone” is an area of water that contains no oxygen to support life. Dead zones are caused by many factors, but often they result from warmer waters and excessive growth or ‘blooms’ of algae. When these algae blooms die and undergo bacterial decomposition, the bacteria remove large quantities of dissolved oxygen from the water. Blooms occur mainly as a result of high levels of organic matter, such as nitrogen and phosphorus, getting into the water. These nutrients come from urban sources like waste water treatment facilities, as well as runoff from fertilized lawns, and fertilized croplands. The intense rainstorms projected to increase across the region will flush this untreated agricultural or urban run-off, into regional waterways. The resultant blooms, combined with warmer water temperatures, create ideal conditions for “dead zone” events.