Marine Invasive Species Program - What's New

What's New?

Chinese Mitten Crab Watch

Report Chinese Mitten Crab Sightings(opens in new tab)

An image of the Chinese mitten crab Eriocheir sinensis
Imagine courtesy of the Smithsonian Environmental Research Center(opens in new tab)
We need your help to solve a mystery! The Marine Invasive Species Program is collaborating with Smithsonian Environmental Research Center to find out if the invasive Chinese Mitten Crab is gone from the San Francisco Bay and the Delta or, if they are just in low abundance and hard to detect. Please help us detect live mitten crabs by reporting any sighting in North America to the Mitten Crab Watch website. We are especially interested in collecting sightings from San Francisco Bay, the Delta, Chesapeake Bay, Delaware Bay, Hudson River --- where the crab has been common in the past.

The website contains all the information you'll need to submit your crab sighting, but if you see a crab, remember:

  • Do not throw it back alive!
  • Take a close-up photo.
  • Note the precise location where the animal was found.
  • Freeze the animal, keep on ice, or as a last resort preserve it in rubbing alcohol.
  • Please report a mitten crab by submitting information and photos(opens in new tab) or email SERC will reply to each report and may also ask about any specimens that you may have collected.
  • For other questions, you can also contact the Mitten Crab Hotline at (443) 482-2222.

New Sea Squirts Arrived in San Francisco

3 new tunicates to San Francisco Bay

According to SERC’s Marine Invasions Lab(opens in new tab), three new non-native sea squirts traveled over 500 kilometers north of their previously recorded range. Marine biologists discovered three new non-native species (Microcosmus squamiger, Styela canopus and Molgula ficus), in San Francisco Bay, that where previously established in Southern California estuaries. The lab suspects these sea squirts (a.k.a. ascidians or tunicates) hitched a ride on boats that were traveling up the coast of California. A multiyear marine heat wave called “The Blob” might have given them the perfect conditions to establish in their new home. Going forward, we will watch closely to see how these species fare and what (if any) havoc they wreak. Read more about the new invaders in an article in BioInvasions Records(opens in new tab).


Anthony Rietl
Phone: (916) 341-6958

Last update : 3/20/2023 3:52:09 PM

Contact Us

California Department of Fish and Wildlife (CDFW)
715 P Street, Sacramento, CA 95814
Mailing: P.O. Box 944209, Sacramento, CA 94244-2090
(916) 445-0411 for General CDFW Information

Office of Spill Prevention and Response
Mailing: P.O. Box 944209, Sacramento, CA 94244-2090
(916) 375-8580 for OSPR Information

Report Oil Spills
(800) 852-7550 or (800) OILS-911

Email OSPR | Office Locations

Facebook  Twitter  YouTube  Instagram  Flickr