Alaska | MARINe

Southcentral Alaska

Southcentral AK sites

Southcentral Alaska sits at the northern arc of the Gulf of Alaska, between the Alaska Peninsula and the Alaska Panhandle, and encompasses both temperate rainforest and boreal forest, as well as numerous grasslands, bogs, fens, and wetlands. Distinct coastal features of the region include the Prince William Sound, the Kenai Peninsula, and the Cook Inlet. This rugged and often mountainous coastline is characterized by numerous islands, bays, and fjords. Cook Inlet experiences some of the largest tidal ranges in North America, whereas other areas in the region have less extreme tides. The coastline includes a diverse array of rocky intertidal, cobble/sandy beach, river delta, mudflat, and saltmarsh habitats. 

SC Alaska regional image

The Southcentral Alaska region is dominated by downwelling and water column stratification that is seasonally intensified by extreme changes in temperature and salinity. However, a number of processes (e.g., topographic steering, eddies, and localized upwelling) introduce macronutrients into the system, making it highly productive. Glacial meltwater also plays an important role in many nearshore ecosystems. High precipitation and meltwater coastally emerge as a freshwater film that underpins seasonal stratification of coastal waters and contributes to the fortitude of the influential Alaska Coastal Current.

The region serves as a hub for many branches of the Alaskan economy, namely the fishing industry, tourism industry, and the oil and gas industry, distributing Alaskan derived products both nationally and internationally. Some ports in Southcentral receive a high volume of cruise ship traffic, raising concerns about potential pollution, invasive species, and wastewater discharge. As of 2019, a natural gas liquefaction facility is slated to be established on the Cook Inlet to export North Shore extracted natural gas, and add a gas line that follows the existing Trans-Alaskan Pipeline System. The Trans-Alaskan Pipeline System runs 800 miles, transferring crude oil from the North Shore to Valdez, a distribution point at the north end of Prince William Sound. Consequently, the region experiences heavy shipping traffic. In 1989, the oil tanker, Exxon Valdez, grounded in the northern sound and released 42 million liters of crude oil, contaminating at least 1990 km of shoreline. The slick reached as far as the Alaska Peninsula, about 750 km to the west, resulting in mass mortalities of macroalgae, benthic invertebrates, marine mammals, and seabirds. Heavily oiled intertidal areas were hosed with high pressure hot water, leading to physical removal and further harm to intertidal organisms. Since the Exxon Valdez oil spill, intertidal community recovery surveys have shown the long term presence of oil in subsurface sediments in some areas.  

SC Alaska regional image

Although a network of Alaskan MPAs has yet to be established, an array of protections exist in Southcentral Alaskan waters under the jurisdiction of Alaska Department of Fish and Game, U.S. Fish and Wildlife Service, NOAA National Marine Fisheries Service, and the Western and Central Pacific Fisheries Commission. Funds from the Exxon Valdez oil spill settlement have been used to establish intensive, long-term monitoring of intertidal, nearshore, and offshore ecosystems in the region including Gulf Watch Alaska (, and the Northern Gulf of Alaska Long Term Ecological Research program (  MARINe Biodiversity and Long Term Monitoring Sites have not been established in the region, but citizen science sea star monitoring surveys were established in 2014. The Center for Alaskan Coastal Studies monitors these sea star sites in Kenai Peninsula Borough, Alaska.

The MARINe sites located within Southcentral Alaska are listed below (arranged north to south):

Otter Rock; Peterson Bay

Otter Rock; Peterson Bay ST

Peterson Bay Lagoon

China Poot

China Poot ST

Southeast Alaska

Southeast AK sites

Southeast Alaska is a coastal temperate rainforest called the Alaskan Panhandle and is wedged between British Columbia and the Gulf of Alaska.  Canada lies to the south, east and north with the landmass consisting of a narrow stretch of mountainous mainland and over a thousand islands of various sizes collectively known as the Alexander Archipelago. These islands, spanning 300 miles, are steep sided, densely forested, and receive hundreds of inches of rain annually.

Alaska regional image

This high volume of freshwater transports nutrients and sediments from the forest to the ocean creating a rich, productive marine environment.   Mixing occurs as a result of strong currents, high winds from winter storms, and large tidal ranges. Southeast Alaska connects the marine environments of British Columbia to the waters of the northern Gulf of Alaska, likely maintaining a biological integrity within these marine ecosystems.

The inside islands and waterways, called the Inside Passage, are separated by deep channels and fjords and are relatively protected from large waves.  The western shorelines of the islands located along the exposed outer coast are directly adjacent to the Gulf of Alaska.  This area receives tremendous wave action along the rugged, rocky coastline. The water is constantly agitated; weather is uniform; seldom varying from cool, wet, foggy and windy.  Animals living anywhere in the intertidal are exposed to spray and surf, hence the distribution animals based on zonation is less defined along the exposed outer shores, compared to the inside waters where there is less wave action.

In 1932, a team led by Ed Ricketts and Jack Calvin explored and collected specimens along the Inside Passage and ended in Sitka, on the wave-swept shores of the outer coast in Sitka Sound.  These surveys were included in Between Pacific Tides, a seminal volume on intertidal biology and the relationship of the animals within a tidepool.  Sitka was the home of Calvin who had moved there a few years earlier from the Monterey Bay area where he was a colleague of Ricketts. Here they found Sitka Sound an ideal location to compare wave action impacts on different habitats within the intertidal.  Three sites were surveyed within the waters of Sitka Sound by the Ricketts and Calvin team.  In 2012, two of these sites were reestablished using the Biodiversity Survey Protocol: Pirates Cove and Kayak Island. We also re-established a monitoring site on Sage Rock adjacent to the Sitka Sound Science Center, first sampled by Dr. Molly Ahlgren in 1995.

Alaska regional image

Sitka is a commercial fishing village and many residents make their living from the sea and depend on marine resources for subsistence including traditional hunting and gathering. Although the area remains largely untouched by development the area is at risk from oil spills, invasive species, and natural destructive events such as tsunamis. The Gulf of Alaska is also being impacted by climate change and changes in ocean acidification. Monitoring of key sites in Sitka Sound is important to document changes in the ecosystem through time and intertidal communities provide a good indicator of change.

Biodiversity surveys have been done in this region since 2003, and Long-Term Monitoring sites were established in 2011.

The MARINe sites located within Southeast Alaska are listed below (arranged north to south):

Graves Harbor

Point Louisa


Port Mary

Sage Rock

Kayak Island

Pirates Cove

Puffin Bay

Coronation Island