Classifying connectivity to guide aquatic habitat management in an arctic coastal plain watershed experiencing land use and climate change

Abstract

Habitat connectivity supports life history requirements of many arctic fish species during periods of flowing water. However, aquatic habitat connectivity is susceptible to change due to climate factors and land use, particularly in the 4,600 km2 Fish Creek Watershed (FCW) located in National Petroleum Reserve in Alaska. Varying degrees and mechanisms of connectivity between overwintering habitat and summer foraging habitat motivated us to assess and classify aquatic habitat connectivity to help inform management. Using geospatial analysis and field methods we classified processes affecting connectivity within riparian corridors and upstream channels. Results show the dominant geomorphic process affecting connectivity varied among river systems, providing general and catchment-specific guidance as to the distribution of important migratory fish habitat. Barriers to fish passage caused by subsurface flow were more common along river corridors with high channel migration rates, whereas wetland flowthrough was the most common barrier in upstream catchments throughout the FCW. Coupling both riparian and catchment connectivity showed that 28 percent of catchments were classified as having fish-passable connectivity, indicated by no barriers present in the riparian zone or upstream channels. Future work should evaluate how well this classification predicts fish habitat, is useful to resource management, and is applicable to other arctic watersheds.

Keywords

• arctic
• hydrology
• geomorphology
• connectivity
• catchment