Glacier Bay National Park and Preserve is a marine wilderness park. Here there are opportunities for adventure, a living laboratory for observing the ebb and flow of glaciers, and a chance to study life as it returns in the wake of retreating ice. Amidst majestic scenery, Glacier Bay offers us now, and for all time, a connection to a powerful and wild landscape.
The Land EmergesThe present-day National Park and Preserve, expanded to its current boundaries in 1980, encompasses an extensive and diverse north Pacific coastal biome. Steep, sculpted peaks and scoured, rock-strewn valleys exemplify glacial activity and mark advances and retreats that have occurred since before the Wisconsin ice age. High montane ice fields, expansive river and stream systems and a dozen tidewater glaciers influence the terrestrial and marine environments. The sheltered waters of Glacier Bay ebb and flow with the region's huge tides, while ocean waves pound the beaches of the wild and remote Gulf coast. Between the bay and the coast, the lofty, snow-clad peaks of the Fairweather Range spawn the Park's largest glaciers. The mountains that surround the bay descend into newly deglaciated foothills and outwash plains, rapidly turning green as the ice age retreats. A mature spruce and hemlock forest blankets the shorelines and creeps up the slopes of the lower bay. New islands emerge from the waters as the weight of the glaciers lifts from the earth's mantle, and beaches continue to rise and expand.
The Ocean ProvidesMarine waters make up nearly one fifth of the Park, and with no point of land more than 30 miles from the coast, the terrestrial and marine environments are closely intertwined. The proximity of the sea creates the cool, moist climate with abundant precipitation that enhances glaciation and largely defines the biota. The combination of large seasonal runoff and tidal turbulence generates an upwelling of nutrient-rich waters, forming the basis for a productivity that resonates through the entire ecosystem. Stimulated by long hours of spring sunlight, phenomenal phytoplankton blooms nurture krill and other invertebrates. Rich intertidal and subtidal zones establish thriving communities of marine organisms, which expand in complexity as they increase in distance from the glaciers. These food sources are exploited by a variety of animal life, both terrestrial and aquatic, and account for much of the biodiversity found in the Park.
Sea Life Flourishes
Over 200 species of fish swim in Park waters, including all 5 species of Pacific salmon. Dungeness, king and Tanner crab as well as clams, scallops and shrimp have been harvested by the region's human occupants for centuries. Intertidal communities include barnacles, mussels, seastars, urchins, sea cucumbers, sea anemones, and a variety of crabs, worms, snails, chitons, and seaweeds. This zone is a significant feeding and refuge area for commercially valuable marine species and an important nursery area for some as well. Many fishes are associated with subtidal benthic communities, and several sustain important fisheries such as Pacific halibut, rockfish, lingcod, Pacific cod, sablefish, and pollock. Small schooling fishes in the pelagic zone include capelin, sandlance, herring, juvenile walleye pollock, juvenile salmonids, and myctophids (lanternfish).Marine Mammals Thrive
The productivity of these waters is funneled up the food chain by these aquatic prey, and Glacier Bay is an important foraging ground for marine mammals. Several cetacean and pinniped species feed extensively in the bay, including the endangered humpback whale and the threatened Steller sea lion. Thousands of harbor seals breed and nurture their pups on the floating ice in Johns Hopkins Inlet and among the reefs of the Beardslee Islands. Minke and killer whales as well as harbor and Dall's porpoises feed in the Park's productive, near-shore waters. Sea otters are colonizing the bay as well as Park waters in Icy Strait and Cross Sound. Many of these marine mammals ply the more turbulent gulf coast waters as well, where they mingle with gray whales and the occasional beluga whale or other cetaceans less common to the region.
The Forest Returns
Glacier Bay is blanketed with a mosaic of plant life, from a few pioneer species in recently exposed areas to intricately balanced climax communities in coastal and alpine regions. Mosses, lichens, dryas, horsetail and fireweed are among the first plants to appear near the terminus of the retreating glaciers. As soil accumulates, these pioneer communities usually develop into dense thickets of nitrogen-fixing alder and cottonwood, which enrich the soil and provide shelter for other colonizing species. Furthest away from the glaciers in time and space, the lowlands near the mouth of Glacier Bay have become cloaked in spruce and hemlock rain forest and lush, spongy tracts of muskeg. In the surrounding mountains, the alpine hills and meadows are carpeted with thick mats of flowers and heath. All of these communities support expanding populations of animals, birds and insects as the years pass and the ecosystems grow in complexity.
Avian Species Prosper
About 220 bird species or over 25% of the total number of species in all of North America have been recorded in the Park. Thousands of seabirds nest on cliffs and rocky shores within the bay or on the Park's outer coast, where they flock after abundant aquatic prey. Molting or migrating geese and sea ducks find refuge in quiet arms of the bay, and bald eagles nest along much of its shoreline. Such arctic breeders as the arctic tern and parasitic jaeger find barren outwashes perfect for raising their young. Recently vegetated hillsides support great numbers of nesting songbirds, including several neotropical migrants in a mostly predator-free environment.. The shallow waters and gently sloping beaches of the Beardslee Islands are important foraging and breeding areas for shorebirds and waterfowl and a migratory stopover for many species as well.Mammals Reinvade
The Park hosts healthy populations of land mammals. The mountain goat and brown bear, both highly mobile, have roamed the area for thousands of years and were relatively quick to reinvade after the glaciers' retreat. The coyote, moose and wolf have moved in more recently, but are now well established in the Park. Black bears prowl the forested portions of the lower bay, and the blue or glacier bear, a rare color phase of the black bear, makes occasional appearances. The river otter is widespread, along with marten, mink and weasel, while the scarcer wolverine is present though rarely sighted. Lush vegetation and abundant insects have attracted a variety of rodents including marmot, porcupine and several species of voles, shrews and mice. The Alsek River delta is home to lynx, snowshoe hare and beaver, species that have reached the coast from the interior down the river corridor.
Lessons for the Planet
As have the human inhabitants for centuries, most land mammals and birds utilize some component of the marine environment, and the ocean tides are the pulse of the entire ecosystem. The waters and shorelines are also the main avenue for visitors to explore the Park, and the zone where most contact between humans and the Park's many creatures occurs. Glacier Bay National Park is one of the few protected areas in the world that includes extensive saltwater habitat within its jurisdiction. Proper management of the Park's resources can preserve this unique and vulnerable ecosystem, while still allowing it to instruct and inspire both the scientist and the visitor. Rediscovery of Glacier Bay's significance to the culture and traditions of the Tlingit people could yield lessons for better stewardship of our natural resources. And finally, knowledge gained from this great natural laboratory and wilderness may prove indispensable to the preservation of other areas, and to the maintenance of the planet's ecosystems upon which all life depends.
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