Assessment of coastal water resources and watershed conditions: Kenai Fjords National Park

Nagorski, Sonia; Hood, Eran; Pyare, Sanjay

This assessment of coastal water resources and watershed conditions in Kenai Fjords National Park (KEFJ) is provided in response to the National Park Service (NPS) Natural Resource Challenge. KEFJ is part of the Southwest Alaska Network (SWAN). The 669,983 acre Kenai Fjords National Park is located along the southeastern side of the Kenai Peninsula in southcentral Alaska. The coastline is characterized by extensive fjords, numerous offshore islands and sea stacks, and abundant marine wildlife. The park lies along an active continental margin, making it highly prone to earthquakes, sudden sea level changes, and resulting tsunamis. KEFJ includes a large portion of the Harding Icefield, which covers large portions of the eastern slope of Kenai Mountains and is the second largest icefield entirely within U.S. borders. Most of the glaciers in KEFJ have been retreating since the end of the Little Ice Age (~250 yrs ago) and continue to retreat today. Coastal streams terminate in bays, fjords, and lagoons that deeply indent the southwest to northeast-trending coastal boundary of the Kenai Peninsula. Most of the watersheds are at least partially of glacial origin, and some include substantial lakes. KEFJ has a maritime climate characterized by frequent cloudiness and precipitation, strong winds, and relatively mild temperatures. Most streams in KEFJ are unnamed, short (<5 km), and either carry glacier runoff or drain small, rugged coastal watersheds that rim the fjords and bays. Watersheds extend from sea level to greater than 1,500 m (~5,000 ft) in elevation on the Harding Icefield. Several dozen small lakes dot the coastal landscape.Inventories completed in 2001 listed 660 vascular plant species (136 confirmed as present), 40 fish species (30 confirmed as present), 210 bird species (188 confirmed as present), and 54 mammal species (42 confirmed as present) as occurring in KEFJ. Several of the marine mammal species, including Steller sea lions and harbors seals that haul out in and near the park, have experienced precipitous population declines. Coastal KEFJ hosts abundant seabird populations that include tufted and horned puffins, black-legged kittiwakes, glaucous-winged gulls, common murres, Kittlitz’s murrelets, and many others. In recently deglaciated watersheds or those with actively retreating glaciers, a predictable sequence of vegetative succession occurs along age gradients of newly exposed soils.Water, sediment, and biologic quality in marine waters was surveyed in 2002 by the State of Alaska as part of the nationwide Environmental Monitoring and Assessment Program, which showed that water and sediment quality conditions in the Gulf of Alaska region were very high. Generally, all water quality and biologic investigations showed the streams to be within normal ranges for glacial streams.Climate warming is amplified at higher latitudes, and Alaska’s climate has warmed by approximately 2.2 ºC (4º F) since the 1950s and is projected to rise an additional 2.8–10 ºC (5–18 ºF) by 2100. The environment and water resources of KEFJ are highly susceptible to climate change in large part because more than half of KEFJ is covered by glacial ice and permanent snowfields, the volume and extent of which are diminished by climate warming. Glacial runoff strongly influences the physical and biological characteristics of streams within and around KEFJ; thus changing glacial coverage has important implications for freshwater and marineecosystems.Visitor use of KEFJ has increased nearly twenty-fold since 1982 and is concentrated in the Exit Glacier area. Glacier and wildlife cruises are becoming an increasingly popular way of exploring the coastline, with numerous tour boats departing from Seward daily during the summer. The majority of visitors to the park do not overnight, although the campground and public use cabins are in high demand. Winter snowmobiling at the Exit Glacier area is growing in popularity as well.

Assessment of coastal water resources and watershed conditions: Kenai Fjords National Park

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