Chinese mitten crab found in Willamette River near Portland; ODFW asks for help to identify invasive species in Oregon’s waters

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SALEM, Ore. – A Chinese mitten crab, a prohibited species in Oregon, was found in the Willamette River near the Sellwood Bridge and reported to ODFW on Nov. 17.

The crab was spotted in shallow water and captured by hand. It was alive and not released back into the river. Mitten crab is a non-native crab species that lives its adult life in freshwater and migrates to brackish water to breed, unlike Oregon's native crab species that live in the ocean, bays, and estuaries.

This recent confirmation is concerning for ODFW as another Chinese mitten crab was found in Oregon waters in April 2025 in a different location – marking the second confirmation of this invasive species in Oregon.

ODFW biologists are working with the U.S. Fish and Wildlife Service, Portland State's Center for Lakes and Reservoirs and the Oregon Invasive Species Council to determine if other mitten crabs are in the Willamette River.

Detection methods include setting up artificial habitats to attract mitten crabs and collecting water and substrate samples to look for environmental genetic markers specific to Chinese mitten crab. PSU initiated a monitoring program for mitten crab in the Columbia and Willamette rivers by conducting shoreline walks and looking for signs of mitten crab including molted carapaces (top shell).

It is unlawful to possess mitten crabs in Oregon, so they are unlawful to sell in Oregon. There is a risk of mitten crabs being illegally imported and sold in the food trade and then released alive into Oregon waters. The agency asks the public to report any suspected unlawful sales.

It is important to correctly identify this species and report it to 1-866-INVADER or report it online via the Oregon Invasive Species reporting hotline form. Photographs can be submitted through the hotline and people are encouraged to do so as crab identification can be difficult and native crabs have been misidentified as invasive.

Chinese mitten crabs are known to burrow into dikes, levees or stream banks which can increase erosion and damage flood control and water supply systems. These medium-sized crabs, about 3-inches wide, prey on native species, consume fish eggs and compete for food, potentially impacting native fish and crayfish populations.

Mitten crabs vary in color from brownish orange to greenish brown and are named for their hairy mitten-like features located on the outside of their claws. They have a notch between their eyes and four spines on each side of the carapace.

When identifying non-native mitten crabs, it is important to note that the hairy shore crab, a native species to Oregon, also have a patch of hair on the inside of their claws.

Photo submitted to ODFW from most recent invasive species report (Nov. 17, 2025).

Visual identification guide for crabs in Oregon – be sure to not harm native species.

Link to Chinese mitten crab identification illustration

ODFW Contact

Adam Baylor, 503-930-7116, adam.c.baylor@odfw.oregon.gov

The Oregon Invasive Species Council (OISC) is seeking nominations for four appointed member seats to serve 2-year terms from January 1, 2026 - December 31, 2027

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Contacts 

Josh Emerson | 2025 Oregon Invasive Species Council Chair |  Joshua.EMERSON@deq.oregon.gov   

OISC Coordinator | coordinator@oregoninvasivespeciescouncil.org  

The Oregon Invasive Species Council (OISC) is seeking nominations for four appointed member seats to serve 2-year terms from January 1, 2026, to December 31, 2027. Could you, or someone you know, be a good addition to the OISC? 

Invasive species have the potential to devastate Oregon’s infrastructure, economy, and natural resources that Oregonians hold dear. The Oregon Invasive Species Council (OISC) acts as a catalyst for the collaborative effort to protect Oregon from invasive species across the network of its members, including state and public agencies, tribes, researchers, land managers, industry leaders, educators, and members of the public. Strong council member nominees will have experience or expertise that relates to invasive species prevention or control or specialize in a related area of interest. 

The Council is seeking to appoint four voting members representing the following categories for 2-year term positions that conclude on December 31, 2027: 

  • Representing an organization or association with the purpose of advocating for Private Industry.

  • Representing an entity in Gilliam, Hood River, Jefferson, Morrow, Sherman, Umatilla, Union, Wallowa, Wasco, or Wheeler Counties

  • Representing an entity in Baker, Crook, Deschutes, Grant, Harney, Klamath, Lake, or Malheur Counties 

  • Representing an entity in Benton, Lane, Linn, Marion, or Polk Counties 

Council members’ primary role is to support the advancement of Oregon’s Statewide Strategic Plan for Invasive Species. Members benefit from multi-agency communication and collaboration that the OISC provides through meetings, committees, events, and communication. Council members are expected to participate in 3 Council meetings per year (in person or by teleconference), multi-day meetings are typically held once a year, rotating around the state, and include a field trip. Appointed council members are allowed to designate an alternate for quorum purposes if they are unable to attend a meeting. Council members are not paid, but may be reimbursed for travel expenses associated with attending Council meetings as budgets allow. 

Additionally, Council members are required to serve on at least one committee and support communication with and/or convening other interested groups to contribute to Council activities. Appointed member service is limited to two consecutive two-year terms. 



The deadline to submit nominations and applications is November 1st, 2025. Fill out the online nomination form here: https://www.oregoninvasivespeciescouncil.org/nominations  

Complete nominations must include submission of the following information: 

  • Name, title, phone, email, and mailing address (self-nominations are encouraged)

  • The seat being applied for

  • A brief description of nominee qualifications. 

  • A statement from the nominee that explains interest, relative experience, and contributions they are willing to make to the Council. 

  • Letters of support for the nominee are not required but are highly encouraged. 

The Council will vote to approve the new appointees at the December 2, 2025, OISC business meeting, and will welcome the new appointees at the 2026 winter OISC meeting (tentatively planned for February/March 2026 in Salem). For more information about OISC meetings, please visit: https://www.oregoninvasivespeciescouncil.org/meetings 


Student Invasive Species Management Projects

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Portland State University students in Dr. Catherine de Rivera’s Ecology & Management of Bioinvasions class created invasive species management projects for community partners: OISC members and other invasive species professionals. The projects focused on invasive species that threaten Oregon’s infrastructure, economy, natural resources, and food & water systems, and those that can impact outdoor recreation opportunities and tourism. Students worked with their community partners to create management products that would be useful in addressing an active invasive species issue.

Below is a list of the 2024 projects that were completed (click the links to learn more about each project):

Pamphlets and Outreach Projects:

Invasive Plant Prevention In Oregon & Washington
Gabriella Johnson, Hannah Roy, Mimi Crosby, Mikel Sunyich, Amesia Ariadne

Mute Swans: What to Know
Dalton Palin, Richard Torres, Cara Smit, Rose Tucker

Invasive Green [5-spined] Crab

Assessing the effectiveness of incentive programs for the control of invasive species: a meta-analysis to inform West Coast European green crab management Beatrice Larson, Devin Forest-Hines, Erin Riley, & Harry Jack

Dredging Risk Assessment for Green Crab Kyle Swanson & Keria Moritsugu-Vandehey

Risk Assessments

Novel Invasive Plant Pest Risk Assessment: Double-Spined Bark Beetle Ips duplicatus (Sahlberg, 1826) Anna Mele

Pest Risk Assessment for Mute Swans (Cygnus olor) in Oregon
Alyson Yates, Aubrey DeBolt, Rose Tucker, Angel Santos

Informational Pamphlets

Invasive Crayfish of Oregon - A guide to identifying Oregon’s native and invasive crayfish
Aaron Deluca, Destiny Hazeri

LOOK OUT! for Flowering Rush (Butomus umbellatus) in Oregon’s Waterways
Aaron Deluca, Destiny Hazeri

The Oregon Invasive Species Council seeks nominations for one open council seat for an organization representing private industry.

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The Oregon Invasive Species Council (OISC) is seeking nominations for one appointed member seat to serve a 2-year term from January 1, 2025 - December 31, 2026. Could you, or someone you know, be a good addition to the OISC? 

Invasive species have the potential to devastate Oregon’s infrastructure, economy, and natural resources that Oregonians hold dear. The Oregon Invasive Species Council (OISC) acts as a catalyst for the collaborative effort to protect Oregon from invasive species across the network of its members, including state and public agencies, tribes, researchers, land managers, industry leaders, educators, and members of the public. Strong council member nominees will have experience or expertise that relates to invasive species prevention or control or specialize in a related area of interest. The Council is seeking the appointment of one member representing the following category for 2-year term positions that conclude on December 31, 2026: 

  • Representing an organization or association with the purpose of advocating for private industry.

Council members’ primary role is to support the advancement of Oregon’s Statewide Strategic Plan for Invasive Species. Members benefit from multi-agency communication and collaboration that the OISC provides through meetings, committees, events, and communication. Council members are expected to participate in 3 Council meetings per year (in person or by teleconference), multi-day meetings are typically held once a year and include a field trip. Council members are allowed to designate an alternate if they are unable to attend a meeting. Council members are not paid, but may be reimbursed for travel expenses associated with attending Council meetings as budgets allow. 

Additionally, Council members are required to serve on at least one committee and support communication with and/or convening other interested groups to contribute to Council activities. Membership is limited to two consecutive two-year terms. 

As the 2025-2026 term is already underway, there is no deadline to submit nominations, and applications will be reviewed on a rolling basis. Fill out the online nomination form here: https://www.oregoninvasivespeciescouncil.org/nominations  

Complete nominations must include submission of the following information: 

  1. The individual’s name, title, phone, email, and mailing address (self-nominations are accepted)

  2. The seat for which they are applying

  3. A brief description of the nominee’s qualifications. 

  4. A statement from the nominee that explains their interest, relative experience, and contributions they are willing to make to the Council. 

  5. Letters of support for the nominee are not required but are highly encouraged. 

The Council will notify appointees as soon as possible and welcome the new appointees at the summer OISC meeting in 2025 (tentatively planned for July 16-17 in the mid-Willamette Valley). For more information about OISC meetings, please visit: https://www.oregoninvasivespeciescouncil.org/meetings 

ABOUT THE OREGON INVASIVE SPECIES COUNCIL 

The Oregon Invasive Species Council’s mission is to protect Oregon's natural resources and economy through collaborative cross-agency participation. As a result, Oregon’s Statewide Strategic Plan for Invasive Species was adopted in 2017 and outlines the long-term and short-term strategies for the state’s invasive species control and includes the following objectives: 1) Prevention; 2) Early Detection & Rapid Response; 3) Control & Management; 4) Education & Outreach; 5) Coordination & Leadership. Council membership includes representation from Oregon’s natural resource agencies, tribes, higher education institutions, federal agencies, private industry, other non-governmental organizations, and the general public from six Oregon regions covering the entire state. For additional information about invasive
species issues in Oregon, see 

https://www.oregoninvasivespeciescouncil.org/threats-and-opportunities-primer  

Report Invasive Species!
1-866-INVADER or https://oregoninvasiveshotline.org