Stream Communities and Ecosystems

There are seven National Wild and Scenic Rivers in ARCN, including the Noatak, Salmon, Kobuk, Alatna, John, Tinayguk and North Fork of the Koyokuk rivers. The Kobuk and Noatak rivers are the largest rivers in northwest Alaska and together drain an area of 63,654 km2. More than two hundred turbid headwater streams originate from glaciers in the Brooks Range; however, the majority of streams in ARCN run clear. Due to the stabilizing effect of permafrost on soils, relatively low topographic relief, and low levels of precipitation, average sediment loads in many ARCN streams and rivers are low compared to sediment loads in other Alaskan rivers. There are several spring streams, including tributaries of the Reed River, Kugrak River, and Alatna River. Traditional knowledge indicates these springs do not freeze solid during winter and are an important habitat for overwintering resident and anadromous fish species. The Noatak River, which originates in GAAR, flows into NOAT, where the river and its surrounding watershed have been designated as an internationally recognized Biosphere Reserve (UNESCO).

Potential global stressors on flowing waters in ARCN include wet and dry deposition of contaminants and climate change. Climate change models predict that the magnitude of climate warming in the northern polar regions will be substantially greater than the global average. At the watershed scale, the cumulative effects of warming may lead to a wide range of cascading effects. For example, increased air and water temperatures may lead to degradation of permafrost and increasing soil permeability may cause ground water tables to fluctuate. In some areas small streams and large rivers may cease to flow above ground and increased rates of solifluction and erosion may occur. Changes in the timing and extent of glacial and snowmelt water contributions and precipitation regimes are also likely to occur, according to climate projections. Fire is likely to increase in frequency and magnitude, which would significantly alter riparian habitat, active layer depth, thermokarsting, hydrological patterns, and nutrient cycling in both terrestrial and aquatic systems. These ecosystem-level changes are likely to affect water quantity and quality and species diversity within these systems.

Data and Resources

Additional Info

Field Value
ISO Topics biota, inlandWaters
Primary Contact Jon O'Donnell
Primary Organization National Park Service
Funding Organizations National Park Service
Other Organizations University of Alaska Fairbanks
Organization Types Academic, Federal
Geo-keywords Alaska, North Slope
Start Date 2009-01-01
Created February 23, 2016, 01:39 (AKST)
Last Updated October 1, 2021, 10:03 (AKDT)