Gulf of Alaska Integrated Ecosystem Assessments

 

 

The Gulf of Alaska Integrated Ecosystem Assessment program (GOA IEA) is providing ecosystem science and management advice necessary for marine natural resource managers to effectively manage the Gulf of Alaska marine ecosystem. The GOA IEA supports Ecosystem-Based Management through a partnership with coastal communities, commercial and recreational fishermen, and natural resource managers. GOA IEA products are currently informing the North Pacific Fisheries Management Council and the Community of Sitka, Alaska.

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Gulf of Alaska Ecosystem

The Gulf of Alaska (GOA) ecosystem is a predominantly downwelling system that is generally characterized as being a high-nutrient, low-chlorophyll environment. It features high coastal freshwater input from drainages and rivers, strong winds, and complex topography, with many large and small islands, deep seamounts and narrow to broad shelf areas. A combination of cyclonic winds, freshwater input, and alongshore transport in conjunction with a shelf edge contributes to the formation of mesoscale eddies that propagate from east to west. These eddies transport coastal water over the shelf out to the deep basin of the GOA, causing episodic upwelling from tidal mixing and complex bottom topography. The three major currents in the GOA are the Alaska Current (AC), Alaska Coastal Current (ACC), and the Alaska Stream (AS). The AC is the northward-turning portion of the North Pacific Current as it approaches the North American continent. The ACC is a buoyancy-driven current located close to shore, although it is not a continuous feature in the eastern GOA. The AC becomes the AS as it passes into the western GOA, as a continuous feature that is located further offshore than the ACC. The complex environment supports a diverse food web, including large biomasses of groundfish, salmon, seabirds, and marine mammals.


Informing management

Process for ecosystem science informing fisheries quotasFisheries management in Alaska has a long history of including ecosystem information into management decisions. Over the last 25 years, the North Pacific Fisheries Management Council (Council) has actively engaged in Ecosystem-Based Fisheries Management through the development of annual ecosystem status reports that are presented to the Council alongside stock assessment to provide ecosystem context for management decisions on commercial catch limits, the use of climate- and ecosystem-informed stock assessments, the inclusion of IEA team members on Council plan teams and other review boards, and through ongoing NEPA analyses.

In 2014, the Council adopted a vision statement for management to include “Environmental variability and uncertainty, changes and trends in climate and oceanographic conditions, fluctuations in productivity for managed species and associated ecosystem components, be based on best available science, including local and traditional knowledge, and engage scientists, managers, and the affected public.”

The Council stated their ecosystem-based management goals are:

  • Maintain biodiversity consistent with natural evolutionary and ecological processes, including dynamic change and variability
  • Maintain and restore habitats essential for fish and their prey
  • Maintain system sustainability and sustainable yields for human consumption and non-extractive uses
  • Maintain the concept that humans are components of the ecosystem