Alaska AOA Spatial Analysis

NCCOS Spatial Planning Overview

NOAA’s National Centers for Coastal Ocean Science (NCCOS), NOAA Fisheries, and the State of Alaska collaborated on the marine spatial planning analysis for the Alaska Aquaculture Opportunity Area (AOA) identification process within state waters.

Coastal and marine planning plays an important role in sustainable coastal and ocean development. NCCOS works closely with partners to develop spatial models, which incorporate important considerations and provide outputs for easier consumption, enabling more informed, inclusive, and transparent coastal and marine planning efforts. These spatial models include hundreds of data layers for ocean sectors such as transportation, natural resources, national security, fisheries, and other ocean industries.

Spatial modeling is a powerful tool for understanding ocean ecosystems and the interactions of human uses and natural resources. Early and comprehensive spatial planning helps avoid conflicts and minimizes environmental impacts. Spatial suitability modeling provides a mathematical calculation that is understandable, with minimal bias to support siting decisions. Below we walk through the steps NCCOS, NOAA Fisheries, and the State of Alaska took to develop the spatial analysis for the Alaska Draft AOA identification process in state waters including how public input helped shape the process.

Determining Planning Goals

One of the first steps was determining the planning goals for the spatial analysis: to identify suitable areas that may support between three and five commercial-scale aquaculture operations to be considered in the AOA identification process. The Alaska AOA spatial modeling approach was specific to the planning goals of identifying discrete areas:

• up to 4,000 acres per study area for subtidal shellfish and seaweed aquaculture
• up to a 100 acres per study area for intertidal shellfish aquaculture

All locations will occur within Alaska state waters (less than three nautical miles from shore) up to 200 feet (61 meters) depth; and meet identified species environmental tolerances and gear thresholds. The options are of sufficient size (50-2,000 acres) to support multiple aquaculture operations.

The intent was not to analyze all of Alaska state waters, but rather narrow down state waters to specific study areas for more detailed analysis. Initial study area parameters included: 

1. State waters within a 25-mile radius of coastal community population centers (based on 2010 census data) as proxy for needed infrastructure to support aquaculture development in Alaska; and
2. State waters that do not regularly experience significant sea ice cover (based on the 10 year aggregate maximum sea ice reported by the U.S. National Ice Center).

Using these parameters, NCCOS, NOAA Fisheries, and the State of Alaska identified preliminary study areas located off the Southeast, Southcentral, and Southwestern coasts of Alaska.

The Alaska AOA Final Study Areas for spatial analysis were identified using a series of public engagement approaches including a Request for Information published in the Federal Register (88 FR72046; October 19, 2023), Interagency Working Group review, and one-on-one meetings with Alaska Native entities, aquaculture industry members, and constituents.

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Data Collection

NOAA Fisheries and the Interagency Working Group selected 10 final study areas for the next phase of the AOA identification process. These study areas were chosen based on proximity to existing infrastructure, lack of historical ice cover, and public comments submitted (e.g., protected species considerations) during the Request for Information.

The study areas are spread across Southeast, Southcentral, and Southwest Alaska state waters. Geospatial analysis for identification of Draft AOA Options was based on a categorical framework to ensure relevant, comprehensive data acquisition and characterization for spatial suitability modeling. An authoritative spatial data inventory was developed that included data layers relevant to national security (i.e., military), cultural resources, natural resources, industry and navigation, fisheries and aquaculture logistics (i.e., current speed, distance to port, or water depth) and existing use. With over 95 data layers included in this analysis, the maps, models, and descriptions provide the most comprehensive marine spatial modeling in Alaska state waters to date.

Spatial Planning Workshops

NOAA held two AOA Spatial Planning Workshops (February and March 2024) to discuss the ongoing Alaska AOA identification process and discuss available spatial data within the Alaska AOA study areas. 

Over 130 individuals attended the workshops. Participants across both events included Alaska Native community members, fishermen, aquaculture industry representatives, environmental organizations, scientists, and State and Federal agency personnel. 

• Anchorage and Juneau Workshops Spatial Planning Approach for Alaska AOAs Presentation (Feb 26/March 26)
• Alaska AOA Spatial Planning Workshops Summary Report

Building the Suitability Model

 Each model calculates a unique suitability score for each grid cell within a study area using the underlying data that are available. The model then identifies the grid cells with the highest scores, revealing the optimal areas. The team then develops heat maps that identify hotspots of relative suitability and conflict. These spatial modeling products provide new intelligence about the study area, enabling decision-makers to simultaneously consider data from multiple ocean sectors. See Morris et al. 2021, Riley et al. 2021 for example methodology on spatial suitability mapping for the Round 1 identification process.

Identifying Alaska AOA Options

The preliminary result of the marine spatial planning study used a scoring and ranking process to narrow the suitability analysis results to 97 Draft Alaska AOA Options (76 subtidal Options and 21 intertidal Options) that have high relative suitability scores. All Draft Alaska AOA Options occur within Alaska state waters (less than three nautical miles from shore) up to 200 feet (61 meters) depth; and meet identified species environmental tolerances and gear thresholds. Additionally, the study area boundary, originally set at 25 miles linear distance from population centers, was updated to measure a 25 mile transit distance (not just a straight-line distance) from population centers. The marine spatial planning report, An Aquaculture Opportunity Analysis for the Gulf of Alaska summarizes the methods and analysis used to develop the Draft Alaska AOA Options and related suitability efforts that were available for public comment for 30 days in the Draft AOA Options Notice of Availability (90 FR 17051; April 21, 2025). 

The Draft Alaska AOA Options represents a significant reduction from the AOA study areas based on the Interagency Working Group, Alaska Native entities, aquaculture industry members, and public feedback. NOAA Fisheries anticipates future reductions to the Draft AOA Options, while striving to retain sufficient area to meet the States’ aquaculture planning goals. These reductions will be informed by comments received in response to the Notice of Availability, as well as through NOAA’s public engagement efforts.

Additional Information:

• Comments Received: Notice of Availability on Alaska Draft AOA Options (May 2025)
• NCCOS Report: An Aquaculture Opportunity Analysis for the Gulf of Alaska  (April 2025) 

Alaska Opportunity Area Atlas

NOAA considered information received in response to the Notice of Availability to finalize results of the marine spatial planning study and Alaska AOA Options in An Aquaculture Opportunity Area Atlas for the Gulf of Alaska. NCCOS identified 77 Final Options in the Alaska Atlas spanning over 13,000 total acres. This represented a 26 percent reduction in total acreage from draft to final Options. Public comments provided critical information allowing NCCOS to incorporate new data sources, and make model refinements.

The Alaska Atlas provides peer-reviewed geospatial planning information that will be used as one source of information to assist the agency and State of Alaska in developing alternatives for consideration in developing a Programmatic Environmental Impact Statement. 

Mapping Resources: 

• The marine spatial planning study, An Aquaculture Opportunity Atlas for the Gulf of Alaska summarizes the methods and analysis used to develop the Final AOA Options and related suitability modeling efforts.
• The NCCOS Alaska Digital Atlas shows the layers for individual maps contained in the marine spatial planning study as well as the locations of the Final AOA Options.
• The NCCOS StoryMap walks you through the process and the science behind identifying the Final AOA Options in Alaska.

Next Steps

NOAA Fisheries is developing a Notice of Intent to prepare a Programmatic Environmental Impact Statement for the identification of AOAs in state waters. This step will start the environmental review phase of the process. The Alaska Atlas will serve as one source of information to assist NOAA Fisheries and cooperating agencies in developing alternatives for consideration in the National Environmental Policy Act process.

To learn more about the next steps in the AOA identification process and how to be involved, please visit the AOA Roadmap and AOA Public Engagement webpages.