Chinese Mitten Crab Watch
Report Chinese Mitten Crab Sightings
Imagine courtesy of the Smithsonian Environmental Research Center
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 or email SERCMittenCrab@si.edu. 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
According to SERC’s Marine Invasions Lab, 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.
Reports, Publications, and Studies
- NEW 2019 Biennial Report on the California Marine Invasive Species Program (PDF) by Scianni C., et al. Produced for the California State Legislature. California State Lands Commission, Marine Environmental Protection Division, February 2019.
- Dry and wet periods drive rapid shifts in community assembly in an estuarine ecosystem by Chang, A.L., et al. 2017. Global Change Biology. Abstract.
- Invasions in Marine Communities: Contrasting Species Richness and Community Composition Across Habitats and Salinity (PDF) by Jimenez, H., Keppel, E., Chang, A.L., Ruiz, G.M., Estuaries and Coasts pg 1-11, July 25, 2017.
- Settlement plates as monitoring devices for non-indigenous species in marine fouling communities (PDF) byMarraffini, M.L.,et al.2017. Management of Biological Invasions Vol 8, pg 1-8.
- Northward range expansion of three non-native ascidians on the west coast of North America (PDF), by Tracy, B.M., et al.2017. BioInvasions Records 6: 1-7 [PDF] from reabic.net
- 2016 Summary of Spatial and Temporal Analysis of Marine Invasions in California: Morphological and Molecular Comparisons Across Habitats (PDF) by Greg Ruiz and Jon Geller for CDFW, MISP.
- 2016 Spatial and temporal dynamics of ascidian invasions in the continental United States and Alaska (PDF) by Christina Simkanin et al.
- 2016 N.E.M.O. (PDF) by San Francisco Estuary Partnership
- 2016 Contribution of Non-Native Species to Soft-Sediment Marine Community Structure of San Francisco Bay, California (PDF), by Haizea Jimenez, Greg Ruiz, Biological Invasions, April 26, 2016.
In the News
- Rainy winters reduce invasive species in SF Bay's marine life, research finds by Kurtis Alexander, San Francisco Chronicle, January 15, 2018.
- One wet winter can shake up San Francisco Bay's invasive species by Kristen Minogue, EurekAlert!, December 7, 2017.
- How 'white blobs' and other species invaded California's waters by Emily Dugdale, 89.3 KPCC, Environment and Science, September 1, 2017.
- What's the best weapon for battling species invading California waters? by Rachel Uranga, Long Beach Press Telegram, August 19, 2017.