Prince William Sound

History
Exxon Valdez Oil Spill
Ecosystem
Subsistence
Maps
Resources & Links

Ecosystem

Forests
Sources for this information include the Alaska Department of Fish and Game, Alaska Department of Natural Resources, Anchorage Daily News, Alaska Fisheries Science Center, EarthJustice, ExxonValdez Oil Spill Trustee Council, Marine Mammal Science, National Wildlife Federation, NOAA, Prince William Sound RCAC, State of Alaska, United States Fish and Wildlife Service, United States Forest Service and the Union of Concerned Scientists.

More than three thousand shore land miles of bays, coves and deep fjords comprise the prized seacoast region of Alaska's famous Prince William Sound. Exceeding the combined area of Massachusetts, Connecticut, and Rhode Island, this sheltered waterway contains the greatest diversity of habitats found along the entire Eastern Pacific Coast, including the world's northernmost temperate rainforest.

Sharp, up thrusting mountains created by volcanic activity enclose bays, fjords, channels and myriads of islands. Scattered among the timbered slopes are muskeg meadows dotted with fresh water melt ponds and cascading waterfalls.

Prince William Sound contains some of the last remaining boreal rainforests left in the world. Most of the forested land found within Prince William Sound is owned by regional Native Corporations whose shareholders are the traditional landowners and inhabitants, or, part of the Chugach National Forest. The Chugach National Forest is the second largest National Forest in the United States. The primary species are Sitka and white spruce. Cottonwood, hemlock, and black and Lutz spruce are also found.  Under story species include alder, willow, salmonberry, and blueberry. 

Timber resources are hard to extract in the steep and difficult environment, yet logging has occurred since the early 20th century.  Today, spruce bark bee tle infestations are affecting parts of Prince William Sound, although not as heavily as on the Kenai peninsula and other parts of the state.

Fish and shellfish
Prince William Sound’s fish resources include five species of salmon, herring, hooligan, halibut and sablefish; and shellfish including Dungeness, Tanner and king crabs, razor clams and spot shrimp.

Salmon
Commercially harvested since the 1880’s, Copper River and Prince William Sound salmon include all five species of Pacific Salmon (King, red, silver, chum and pink). Pacific salmon are anadromous meaning that they hatch in fresh water, spend part of their life in the ocean and then spawn in fresh water. Chinook, or king salmon, is Alaska’s state fish. All salmon are born in fresh water and depending upon the species may spend up to several years in the river or lake system of their origin before outmigrating to the ocean for their adult life stages. Returning anywhere from 2 to up to five years from the ocean to the streams, rivers and lakes of their birth to spawn. While Copper River king, red and silver salmon are the hallmark of the region, 85% of the Sound’s salmon are pink salmon. Pink salmon are the smallest of Pacific salmon. They mature in 2 years. Prince William Sound has the largest salmon hatchery program in North America, releasing more than 500 million pink salmon fry each year from five hatcheries. It is estimated that wild salmon runs total 2-5 million fish annually, while hatchery returns since 1995 have varied between 10-25 million fish. Historically Chum salmon have been important to subsistence users who dry the fish for winter use. In recent years the commercial demand for chum salmon has grown with the development of markets for fresh and frozen chum salmon has emerged in Japan and northern Europe.

Halibut
Young Pacific halibut, up to 10 years of age, are highly migratory and generally move in a clockwise direction east and south throughout the region. Halibut in the older age classes tend to be much less migratory using both shallow and deep waters over the annual cycle. Once hatched, free-floating larvae float for up to six months and are transported up to several hundred miles by current of the North Pacific eventually beginning their life as bottom dwellers in shallow nursery grounds where they live for five to seven years.  As the fish mature and gain their “flatfish” appearance they migrate to deeper waters. Halibut can live up to 30-40 years and weigh as much as 500 lbs.

Halibut fishing in Prince William Sound is supported by entirely wild stocks. It is an important component in both the commercial and sport fishing industries and subsistence diets. Recent concerns over the health of the fishery have led to action on the part of the charter industry and the federal government. In 1999, the charter boat industry for Prince William Sound requested a moratorium on new operators saying that the existing fleet was too big for the fishery. In 2007, due to concerns regarding overfishing, the federal government set a 2 fish bag limit for some areas outside of Prince William Sound in southeast Alaska. Also in 2007, while all salmon tested low, the Alaska department of Health and Social Services announced its first public safety advisory regarding mercury levels in fish, advising the public that eating halibut over 50 pounds (and shark, lingcod, yellow eye rockfish and spiny dogfish) in large quantities might not be ok for pregnant women and small children and suggested that consumption be restricted to one meal per week. The state indicated that halibut caught by the commercial fisheries and commonly sold to restaurants and grocery stores poses minimal risk for consumers because average weights of commercial landings are about 25lbs. However, the larger, older fish that are prized by sport fisherman carry more mercury. The source of the mercury is thought to be deposition of airborne mercury from distant industrial sources such as coal fired power plants. While Prince William Sound’s halibut fishery remains strong, these recent concerns point to possible issues for the future.    

Herring
Pacific herring are a keystone species for the ecosystem of Prince William Sound, an important prey species for 40 different species of mammals and birds such as the endangered Stellar Sea lions and humpback whales, salmon, brown and black bear, black-legged kittiwakes and eagles. Herring are also fished commer cially for food, bait, sac-roe and spawn on kelp. Alaska’s commercial herring fishery began in the late 1800’s producing herring for salting and pickling, and herring reduction canneries that produced herring meal and oil. During the 20th century herring have been harvested for salting, pickling, meal, oil, bait and also sac roe harvested primarily for a Japanese market.

Upon reaching sexual maturity at 3 or 4 years of age, herring begin to spawn annually in shallow, vegetated areas in the intertidal and subtidal zones. Adults move offshore to feed on zooplankton, copepods and crustatceans. Prince William Sound herring have an average life span of 8 years.

Prior to the 1989 ExxonValdez oil spill, Prince William Sound’s herring population was increasing with record harvests. However, in 1993 there was an unprecedented population crash. Since that time, herring in Prince William Sound have failed to reach the minimum sustainable biomass. Tests indicate that a significant contributing factor is the presence of Viral Hemorrhagic Septicemia (VHS), a naturally occurring virus. Older healthy herring are believed to develop immunity to VHS through exposure to low level exposure at a young age. However, a 1999 sampling of herring in Prince Willi am Sound indicated a decline of 40% in age-3 and age-4 herring. Some researchers believe that expos ure to residual oil from the 1989 EVOS has compromised normal disease resistance in juvenile herring.  Scientists are also studying the possible relationship between herring biomass decline and decline in Stellar sea lion populations. In 2006, the state and the EVOS Trustee Council acknowledged the need for more attention to the restoration of Pacific Herring in Prince William Sound.

Shellfish
Prince William Sound’s shellfish resources include scallops, shrimp, crab, clams and mussels. The commercial fishery for razor clams was destroyed when the 1964 earthquake uplifted Cordova razor clam beds. Small fisheries exist for scallops, sidestripe shrimp (trawl) and spot shrimp (pot). Commerical fisheries for dungeness, golden king and tanner crab in Prince William Sound started closing in the 1980’s due to overfishing. Subsistence harvesting for some species has also been restricted.   

Although clams are no longer part of the commercial fishery in Prince William Sound they still represent a substantial part of subsistence use for residents.  Clams are widely distributed across th e Sound in a variety of substrates and are most abundant in the lower intertidal and subtidal zones. Clams are an important prey for various fish and wildlife resources including sea otters, some sea birds and sea ducks. A 2006 study by the ExxonValdex Oil Spill Trustees Council indicates that clam populations in spill areas continue to be impacted. Additionally, exposure of clams to oil could result in contamination of predators know n to forage on clams such as sea otters and birds.

Mussels are a keystone species in the nearshore environment of Prince William Sound and are locally important for subsistence users. The provide prey for harlequin ducks, black oystercatchers, juvenile sea otters, river otters and other species. Mussel beds are also an important component of intertidal habitats because they provide physical stability and habitat for other organisms in the intertidal zone. Following the ExxonValdez oil spill, oiled mussel beds were purposely not cleaned since hot water high pressure washing methods would certainly have killed mussels and habitat. The primary route by which mussels accumulate oil is through ingestion of petroleum hydrocarbons in the water. The ExxonValdez Oil Spill Trustees Council measures recovery of mussels in oiled regions based on mussel populations and hydrocarbon contamination of predators such as harlequin ducks, Barrow’s goldeneye and black oyster catchers.   Because of the high concentration of petrochemicals present in many mussel beds in the spill region, subsistence use of blue mussels has significantly declined.

Mammals

Terrestial and marine mammals are perhaps the second most recognized symbols of Alaska after wild salmon. The Prince William Sound experience is often represented by photos of sea otters, Stellar sea lions, killer whales, porpoises, minke whales; and brown and black bears, dall sheep, mountain goats, and moose.

Native to southeast Alaska and British Columbia Sitka blacktail deer were released to into the Sound in the early 1900’s to support subsistence hunting. The population of blacktail deer in PWS has now expanded to cover most of the coastal mainland and almost all of the various islands from Cordova to Jackpot Bay. Today, the Sitka Blacktail deer is the most abundant large terrestrial mammal in the Sound. 

Sea Otters
Sea otters were once found throughout the north Pacific. However, sea otters were aggressively exploited by Russian and English fur traders from the time of Vitus Bering’s expedition to Alaska in 1742. As early as 1880, records show that sea otter populations had been over harvested and, by 1890, only Natives were permitted to hunt otters for subsistence purposes. It is estimated that by 1911, when the North Pacific Fur Seal Convention banned commercial hunting of sea otters, as few as 2,000 total sea otters existed. Today, Alaska’s charismatic sea otters account for 75 percent of the world’s sea otter population. Unlike seals, sea otters rely on air trapped between their body and their exceptionally dense fur to maintain body temperature. If the fur becomes matted or soiled, it looses its insulation qualities. This explains why sea otters can often be observed meticulously grooming themselves and why Sea otters were heavily hit by the 1989 ExxonValdez oil spill with acute mortality rates as high as 40%. Continuing studies of mortality rates suggest that sea otters continue to experience poor survival rates. According to some researchers, it may take another 15 to 25 years for sea otters to fully recover assuming that are no new threats to their survival. Healthy sea otter populations can be an important part of a balanced ecosystem. Eating 25 percent of their body weight each day, sea otters diet includes mussels, clams and sea urchins. Appropriate populations of sea otters help to keep urchin populations balanced thereby maintaining abundant and diverse kelp forests.

Continued research on sea otter mortality has found that besides the ongoing issues of contamination potentially lowering immune functions, boat strikes seem to be biggest threat to sea otters.    

Orcas
There are approximately 160 Orcas, or killer whales, in eight resident (fish eating) pods in Prince William Sound. Additionally, transient (marine mammal eating) groups are also known to be present in the Sound.  Orcas are members of the dolphin family. They are called killer whales because (transient groups) attack and consume whales or other large prey such as seals and sea lions. Orca’s live in groups called pods and are matrilineal. Pods typically consist of a female and her offspring of both sexes. Orcas live long lives and reproduce slowly. The individuals which comprise the pod change very little. They are very vocal and each pod has it own unique type of calls. One of the Sound’s resident populations, AB pod, is known to diet primarily on salmon, preferring coho, as well as herring and halibut. Population of the AB pod declined following the ExxonValdez oil spill from 36 in 1989 to 22 in 1990. During that time no young were recruited into the population. The transient ATI group, feed  exclusively on marine mammals including habor seals, Dall’s porpoises, Stellar sea lions, and harbor porpoises. The AT1 population of 22 resident orcas declined by over 50 percent since the ExxonValdez oil spill. Researchers attribute this decline to the impacts of direct oiling and eating oiled seals. Research on contaminants in killer whales in the Sound also indicates that individuals in the AT1 group are carrying elevated levels of PCB’s, DDT and DDT metabolites in their blubber. Although the presence of these contaminants is not related to the oil spill, presence of these contaminants at these levels can cause reproductive problems in marine animals.  In 2004, in response to concerns over population declines and exceedingly high levels of toxic contaminants, the AT1 pod’s remaining 9 whales were listed as depleted under the Marine Mammal Protection Act. As with all marine mammals, it is illegal to shoot killer whales.   

Harbor seals
Harbor seal populations had declined by 40% prior to the ExxonValdex oil spill. In the past two decades, their decline has increased by 60% to 80%. Today, only 5,000 seals live in Prince William Sound. The Sound’s harbor seals are largely resident throughout the year and have limited movement and interbreeding with subpopulations in the northern Gulf of Alaska. Harbor seals depend on herring and other forage fish which have steeply declined and seals now compete with commercial fisherman for the Pollock fishery. Because they regularly haul out on rocky shorelines that were heavily oiled by the ExxonValdez oil spill, and other coastal areas used by humans, habor seals are very susceptible to human impacts. Harbor seals are often the nuisance of Prince William Sound fisherman. Able to dive to depths exceeding 600 feet and remain submerged for over 20 minutes, harbor seals are notorious for raiding salmon from gillnets and wrecking gear in the process. Harbor seals reach sexual maturity between 3 and 7 years and give birth to single pups between from May to July. Pups are weaned at about one month. Harbor seals have been estimated to live from 26 years for males to 32 years for females. 

Steller Sea Lions
Also known as the Northern sea lion, this largest of the eared seals was one of several animals named after the German botanist, explorer, zoologist, physician Georg Wilhelm Steller who participated in the Vitus Bering Second Kamchatka Exploration of Alaska.  They are named “sea lions” because of the males large neck and shoulders covered with course, thick hair resembling African lions.  The average adult male can weigh over 1,000 lbs with a body length of 10 feet or more.  Females weigh about half the size and grow to be abo ut 8 feet in length. 

Preferred prey for sea lions is off-bottom schooling species such as pollock, herring, caplin, cod and salmon.  Transient killer whales and large sharks are thought to be the significant predators of Stellar sea lions. Haulouts and rookeries are traditionally used throughout the Sound to bear and raise pups, escape from predators and bask in the sun during the summer. Sea lions will rarely haul out in the winter as the water is warmer than the ambient air temperature. Since being protected by the Marine Mammal Protection Act of 1972, hunting is only allowed for native subistence and traditional use.  Steller sea lions populations are below historic numbers, and remain on the Federal Endangered Species list.

Bears
Brown and black bears can be found on the mainland surrounding Prince William Sound and on some of the larger islands such as Montague and Hichinbrook Islands. Brown bears are the less reclusive of the two and can typically be spotted along shorelines and rivers in the spring and early summer when bears forage for fish, and in the forests in late summer and fall as berries ripen. Data to determine population sizes and trends is limited. It is estimated that brown bears in the Sound number 300. Black bears are common throughout the Sound. Salmon returns, berry crops and deer populations are all significant factors that contribute to the health of brown and black bears in the Sound. 

Birds
219 species of birds have been recorded in Prince William Sound, 111 of which are primarily water related.  The Copper River Delta, which lies just to the southeast of PWS, is a major migratory bird route.  In the spring millions of migratory birds filter through this natural corridor into and through PWS.  The annual Cordova Shorebird Festival has become one of the areas most popular spring events attracting hundreds of birders from around the world to watch the spectacle.

Eagles
Bald Eagles are Alaska’s largest resident bird of prey with a wing span of up to 71/2 feet. Claims by fox farmers and fishers of eagle depredations caused the Alaska Territorial Legislature in 1917 to impose a bounty on eagles. These claims were later found to be mainly false, but over 100,000 eagles were killed before the bounty was removed in 1953. With statehood in 1959, the Bald Eagle received federal protection under the Bald and Golden Eagle Protection Act of 1940. This made it illegal to kill or possess an eagle, dead or alive, or to possess any part of an eagle, including feathers. The widespread use of DDT after World War II caused eagle populations to plummet toward extinction. When DDT washed into waterways it was absorbed by aquatic plants and animals. When eagles ate the contaminated fish they absorbed DDT which in turn prevented the proper formation of calcium necessary to produce strong eggshells. Widespread reproduction failure and population decline followed. As a result, the Bald Eagle was protected in 1967 under a precursor to the Endangered Species Act. Today, Bald Eagle populations have rebounded from a low of 417 nesting pairs in 1963 to an estimated high of 9,789 breeding pairs today. Bald Eagles are more abundant in Alaska than anywhere else in the United States and it is est imated that 6,000 seasonal and year-round bald eagles live in Prince William Sound. In June of 2007, the US Fish and Wildlife Service removed the Bald Eagle from the endangered species list. However, the Bald Eagle continues to be protected by the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. Threats to Alaska’s Bald Eagle population are the destruction of nesting habitat and nesting disturbances. Nests are typically built in the largest oldest trees or in treeless areas on rock pinnacles or the ground.

Marbled murrelets
Marbled murrelets are mysterious, shy and elusive. They were the last bird in the United States to have its nesting site discovered in 1974. Murrelets don’t actually build nests, they nest high up in depressions of large moss-covered old-growth tree limbs. Murrelet pairs return to the same forest each year and sometimes nest repeatedly in the same tree. They spend their days on the ocean feeding on juvenile herring, capelin, sand lance and juvenile Pollock. Murrelets come off the water at dawn and dusk and are estimated to fly between 60 – 90 miles per hour. Females lay only one egg per year. Marbled Murrelets have declined drastically along their range from California to Alaska, and are l isted as threatened in California, Oregon, Washington and British Columbia. The primary threat to their existence has been loss of old-growth forest to clearcut logging. Prince William Sound has also seen a large decline resulting from the 1989 ExxonValdez oil spill which impacted habitat and forage species; such as herring and sand lance. Approximately 300,000 marbled murrelets bred in the Sound in 1972; a 2000 survey estimated only 52,377. Mortalities from the gillnet fisheries are also considered a contributing factor in population dynamics. 

Black oyster catchers
Over half the world’s population of black oystercatchers lives in Alaska, and about 20% of Alaska’s total population lives in Prince William Sound. Black oystercatcher’s are long-lived (15+ years) and territorial, occupying nests in rocky areas close to intertidal zones and returning in successive years to nest again in the same vicinity. They are fully dependent on the nearshore environment and forage exclusively on invertebrate species along shorelines. In summer they live in pairs defending their territory and chicks tenaciously. Shoreline development, intertidal contamination and disturbance from human activity are their greatest threats. Black oyster catchers in Prince William Sound were heavily impacted by the ExxonValdez oil spill. In add ition to direct mortalities, breeding activities were disrupted and clean-up activities diminished habitat and productivity. Current research indicates that Black oyster catchers continue to be exposed to persistent oil in sediments along shorelines. 

Shorebirds
Each spring five to seven million shorebirds migrate to the mud flats and shorelines of the Copper River Delta to feed on tiny crustaceans, clams, aquatic insects and plants. Flocks of thousands of tiny sandpipers, sanderlings and dunlins twist and turn along the flats like enormous velvety brown Chinese festival dragons. Least sandpipers and golden plovers can be found in the grasses feeding on insects and worms. Red-necked phalaropes hang out in ponds feeding on aquatic insects and invertebrates. Thirty-six different species have been recorded arriving from South, Central and North America.