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Advancing resilience of Maine’s shellfisheries

Sunrise on a coastal town in Maine
Sunrise on a coastal town in Maine. Credit: NOAA Sea Grant
  • Principal Investigator(s): Katherine Mills, Gulf of Maine Research Institute; Jared Wildwistle, Gulf of Maine Research Institute
  • Fiscal Year Funded: 2025, 2026, 2027

Data synthesis and community engagement to define the scope of a regional ocean acidification vulnerability assessment in Casco Bay

Why we care
Ocean circulation dynamics have contributed to rapid warming and created conditions for enhanced acidification in the Gulf of Maine. Maine’s shellfisheries are an important part of the state’s culture and economy. Since many shellfish have demonstrated sensitivity to ocean acidification, this project assesses the potential risk to the shellfish industry from changing ocean chemistry and is a critical step in advancing resilience in Maine’s shellfisheries. 

What we are doing 
This project aims to enhance the resilience and adaptability of Maine’s shellfisheries, with a specific focus on Casco Bay. The team will bring together wild shellfish harvesters, aquaculture producers, shellfish hatchery operators, scientists, municipal shellfish committee members, and other decision-makers to advance key objectives. First, the group will work to better understand the observed impacts of acidification to the industry, risks of greatest concern, and information needed to support adaptation by shellfish fishery participants in Casco Bay. Next, they will coordinate the synthesis of this information and develop a framework for an integrated resilience assessment for Casco Bay shellfisheries. 

Benefits of our work
Insights gained and groundwork developed through this project will support continued leadership in addressing ocean acidification and preparing coastal industries for the challenges of a changing ocean. The novel resilience assessment framework will support informed risk assessment and decision-making. This work will strengthen the future of Maine’s shellfisheries and the communities that rely on them.

Resources
Casco Bay Estuary Partnership
Friends of Casco Bay / Casco Baykeeper
Northeast Coastal Acidification Network

Investigators
Katherine Mills, Gulf of Maine Research Institute
Jared Wildwistle, Gulf of Maine Research Institute
Carissa Maurin, Gulf of Maine Research Institute
Kanae Tokunaga, Gulf of Maine Research Institute
Emily Whitmore, Maine Aquaculture Innovation Center
Curtis Bohlen, Casco Bay Estuary Partnership
Janelle Goeke, Casco Bay Estuary Partnership
Mike Doan, Friends of Casco Bay
Ivy Frignoca, Friends of Casco Bay
Damian Brady, University of Maine
Kate Liberti, University of Maine
Suzanne Arnold, Island Institute

Advisory Committee
Curtis Bohlen, Casco Bay Estuary Partnership
Cait Cleaver, Colby College
Dan Devereaux, Town of Brunswick
Will Everett, Friends of Casco Bay
Christopher Hunt, University of New Hampshire
Jessica Joyce, Casco Bay Regional Shellfish Working Group
Dana Morse, Maine Sea Grant
Thomas Safford, University of New Hampshire
Ben Wahle, Maine Department of Marine Resources
Emily Whitmore, Maine Aquaculture Innovation Center

Effects of ocean acidification and temperature on Alaskan crabs

Red King Crab
Image credit: David Csepp, NMFS AKFSC ABL

Long-term declines of red king crab in Bristol Bay, Alaska may be partially attributed to ocean acidification conditions. These impacts may be partially responsible for the fishery closures during the 2021–2022 and 2022–2023 seasons. Researchers found that ocean acidification negatively impacts Alaskan crabs generally by changing physiological processes, decreasing growth, increasing death rates and reducing shell thickness. Funded by the Ocean Acidification Program, scientists at the Alaska Fisheries Science Center continue to investigate the responses of early life history stages and study the potential of various Alaska crabs to acclimate to changing conditions. Results will inform models that will use the parameters studied to predict the effects of future ocean acidification on the populations of red king crab in Bristol Bay as well as on the fisheries that depend on them. Fishery managers will better be able to anticipate and manage stocks if changing ocean chemistry affects stock productivity and thus the maximum sustainable yield.

More about this work

Forecasts for Alaska Fisheries

Crab pots and fishing nets in Alaska's Dutch Harbor
Image credit: Michael Theberge

Understanding seasonal changes in ocean acidification in Alaskan waters and the potential impacts to the multi-billion-dollar fishery sector is a main priority. Through work funded by NOAA’s Ocean Acidification Program, the Pacific Marine Environmental Laboratory developed a model capable of depicting past ocean chemistry conditions for the Bering Sea and is now testing the ability of this model to forecast future conditions. This model is being used to develop an ocean acidification indicator provided to fisheries managers in the annual NOAA Eastern Bering Sea Ecosystem Status Report.

ADAPTING TO OCEAN ACIDIFICATION

The NOAA Ocean Acidification Program (OAP) works to prepare society to adapt to the consequences of ocean acidification and conserve marine ecosystems as acidification occurs. Learn more about the human connections and adaptation strategies from these efforts.

Adaptation approaches fostered by the OAP include:

FORECASTING

Using models and research to understand the sensitivity of organisms and ecosystems to ocean acidification to make predictions about the future, allowing communities and industries to prepare

Closeup of oysters cupped in someone's hands

MANAGEMENT

Using these models and predictions as tools to facilitate management strategies that will protect marine resources and communities from future changes

TECHNOLOGY DEVELOPMENT

Developing innovative tools to help monitor ocean acidification and mitigate changing ocean chemistry locally

REDUCING OUR CARBON FOOTPRINT

50 more ways to reduce your carbon footprint >

On the Road

Drive fuel-efficient vehicles or choose public transportation. Choose your bike or walk! Don't sit idle for more than 30 seconds. Keep your tires properly inflated.

With your Food Choices

Eat local- this helps cut down on production and transport! Reduce your meat and dairy. Compost to avoid food waste ending up in the landfill

With your Food Choices

Make energy-efficient choices for your appliances and lighting. Heat and cool efficiently! Change your air filters and program your thermostat, seal and insulate your home, and support clean energy sources

By Reducing Coastal Acidification

Reduce your use of fertilizers, Improve sewage treatment and run off, and Protect and restore coastal habitats

TAKE ACTION WITH YOUR COMMUNITY

You've taken the first step to learn more about ocean acidification - why not spread this knowledge to your community?

Every community has their unique culture, economy and ecology and what’s at stake from ocean acidification may be different depending on where you live.  As a community member, you can take a larger role in educating the public about ocean acidification. Creating awareness is the first step to taking action.  As communities gain traction, neighboring regions that share marine resources can build larger coalitions to address ocean acidification.  Here are some ideas to get started:

  1. Work with informal educators, such as aquarium outreach programs and local non-profits, to teach the public about ocean acidification. Visit our Education & Outreach page to find the newest tools!
  2. Participate in habitat restoration efforts to restore habitats that help mitigate the effects of coastal acidification
  3. Facilitate conversations with local businesses that might be affected by ocean acidification, building a plan for the future.
  4. Partner with local community efforts to mitigate the driver behind ocean acidification  – excess CO2 – such as community supported agriculture, bike & car shares and other public transportation options.
  5. Contact your regional Coastal Acidification Network (CAN) to learn how OA is affecting your region and more ideas about how you can get involved in your community
       More for Taking Community Action