AFTER THE DELUGE
In the northern Great Plains, waters are receding from one of the worst flood seasons on record, and residents’ health and safety are no longer at risk. But for the National Wildlife Refuge System, the hard work is just beginning.
One of the Refuge System’s northernmost stations, the Devils Lake Wetland Management District Complex, which manages a 10,000-square-mile district containing 253,000 acres of wetlands and waterfowl production areas, now, faces wildlife management tasks greatly exacerbated by the spring flooding.
Bypassing submerged roads and repairing broken dikes, levees and fences is just the start. “From the Devils Lake headquarters to Lake Alice refuge, it’s normally17 miles. Now it’s 56 miles,” said Roger Hollevoet, project leader at Devils Lake Complex
High waters have transported potential contaminants and sediment into wetlands, fundamentally changing their ecology. Once-shallow marshes that served as nesting areas for waterfowl, herons, ibis, egrets, grebes, terns and other wetland-dependent birds are now submerged in water too deep for birds to nest. Siltation is spurring the growth of non-native cattails that can choke out native plants. Hollevoet and his staff are working to restore some of these habitats to improve conditions for many wetland-dependent species.
In other areas, new or expanded lakes now teem with non-native carp and bullhead that compete with the birds for food, such as snails, scuds and mosquito larvae. “It may be 10 years until some of wetlands dry out to the point where they can no longer support these fish,” said Ron Reynolds, project leader for the U.S. Fish and Wildlife Service’s Habitat and Population Evaluation Team in the Dakotas. The U.S. waterfowl production is likely to drop in the meantime. Half of the waterfowl production comes from the Prairie Pothole Region of the Dakotas and Montana.
In upland areas, many grasses won’t survive months of being under water. In their place, Tom Koerner, project leader at Lacreek National Wildlife Refuge in South Dakota, who’s been serving as North Dakota branch director for flood relief efforts, expects an invasion of noxious, choking weeds, such as Canada thistle and hybrid cattail.
Timing, crucial in managing wildlife habitats, will be off this year. By the time uplands dry off, it will be too late to seed native grasses or stage controlled burns. “A lot of things we need to have happen will be lost for up to a year,” said Hollevoet.
Refuge managers draw hope from knowing they’re part of a historic geological cycle. “In the prairie, wetlands get wet, they go dry, they get wet, they go dry,” said Koerner. “What’s different this year is just the magnitude of the flooding, which was well above anything these refuges have seen before. There are a lot of unknowns about how quickly things will recover and how quickly wildlife will be able to move back in.”
Contact: Roger Hollevoet, Devils Lake Wetland Management District at 701-662-8611 or Roger_Hollevoet@fws.gov.Tom Koerner, Lacreek National Wildlife Refuge at 605-685-6508 or Tom_Koerner@fws.gov.