It Came from Across the Pacific!

Just in time for Halloween, something scary has washed across the Pacific ocean, landing on the shores of Seaside, Oregon.  The object is approximately 6 x 3 x 2 feet, with a cement exterior.  However, it isn't the object itself that is scary; it is the creatures on it!

A 'mini' floating dock washed up in Seaside, Oregon on the morning of October 8th. The float was host to a plethora of live (and dead) organisms including limpets, chitons, mussels and the Japanese oyster Crassostrea gigas.  These animals are non-native to Oregon and definitively originate from Japan.  Evidence of layering noted by Dr. John Chapman of Oregon State University suggests multiple generations of organisms have survived the journey across the Pacific.

A small dock float washed up in Seaside, Oregon [Photo: Seaside Aquarium]

The dock was reported to the Seaside Aquarium, and sampled by members of ODFW.  The samples were sent to Dr. Chapman, and relayed to other experts in invertebrate identification.

Mussels, barnacles and limpets abound. [Photo: Seaside Aquarium]

Dr. James Carlton, of Williams College (MA) and the Williams-Mystic Maritime Studies  Program (Mystic, CT) has identified several of the organisms, including:

Live members of the mussel species Septifer virgatus, which he notes as an indicator species for Honshu debris:

Photo: Marinbio.org

Lithophaga curta, another Honshu species:

Photo: nmr.pics.nl

and Crepidula onyx, an introduced slipper limpet species in Japan- ironically enough, historically originating from California!

Gastropods.com

The species of chitons and limpets are yet identified, but I will be sure to post information as soon as it is available! The importance of the live organisms washing up on debris will likely not be fully apparent for years, but the animals could have significant impacts as invasive species on North American shores- a scary consequence that could cost billions of dollars due to ecological impacts.


Thanks to Drs. John Chapman and James Carlton for their valuable input and information!