Recently, it has become a regular occurrence that another piece of debris with attached marine species arrives on the shores of Washington and Oregon as a result of the 2011 Japanese tsunami. These reports are fascinating from several perspectives: dispersal of marine species following natural events, a glimpse at Pacific species, and the effect of transatlantic travel on species distribution. Four large docks were washed away from Misawa, Aomori Prefecture, Honshu. One was found in Japan, two have arrived in the United states, and one is still unaccounted for. It will be interesting to learn how this process unfolds in comparison to the much different process of marine species on ships that travel from port to port. Their time at the shore was limited because they took a few days to permanently wash ashore and because they were immediately cleaned and removed from the area. These docks had their greatest potential to impact the open coast because marinas and bays are relatively few in number or protected from the open coast.
The first dock arrived in Oregon on June 4th, 2012, at Agate Beach, Newport. This was a large dock densely covered with attached algae and marine invertebrates. Coincidentally, Newport is the home of the Hatfield Marine Science Center of Oregon State University and The Oregon Coast Aquarium. It was a ideal situation for documenting the species and studying their impact on the surrounding areas. Since then, another floating dock was reported washing ashore December 16-18, 2012, in a remote location along the Washington coast near Mosquito Creek on the Olympic Peninsula. The docks had followed the predicted path of debris from Japan based on prevailing currents, winds, and storms, but they arrived at North America slightly ahead of schedule.
Several research groups and experts are participating in identifying the species on the docks, especially the Agate Beach dock which has over 150 species and was densely covered. Each list is posted on the web and is periodically updated (see LINKS). It will be worth following during the upcoming months to see what species appear as the story unfolds. Several Gulf of Maine MIS species were also seen on the docks including Styela, Didemnum, Grateloupe, and Caprella. Some invasive species were also seen that are already on the West Coast, including the bryozoan Watersipora subtorquata and the Mediterranean mussel Mytilus galloprovincialis. Several encrusting and upright bryozoans were identified. Cryptosula pallasiana and Watersipora subtorquata are encrusting forms with distinctly different enclosures from Membranipora or Electra (see links and images below), and Tricellaria sp and Scruparia sp are beige branching forms structurally different from our Bugula species.
Perhaps one of the
most interesting findings from my perspective was the presence of numerous
stalked, pelagic gooseneck barnacles that settled on the dock during the trip
across the Pacific. Pelagic barnacles are normally found attached by their
flexible stalks to floating timber, the hulls of ships, piers, pilings, and
seaweed. Lepas
anatifera has a cosmopolitan distribution and is found in tropical
and subtropical seas worldwide. Because it is attached to floating objects
carried by oceanic currents, it is ofter found in colder seas where the waters
are too cold for them to reproduce. It will be interesting to learn what other
species were acquired during the trip, whether species that were established on
the docks were lost or diminished in density during the journey, or whether
other species became more dominant due to more advantageous conditions.
Location of the Floating Dock on Agate Beach, Newport, Oregon
Satellite view of Western Oregon over Newport, Oregon showing location of the Misawa dock represented by the yellow rectangle. Red star: location of Hatfield Marine Science Center and Oregon Coast Aquarium.
Predicted Path of Debris From the 2011 Tsunami Around the North Pacific
NOAA's OSCURS (Ocean Surface Current Simulator) is a numeric model for ocean surface currents that predicted the movement of marine debris generated by the Japan tsunami. Debris drifted more rapidly than anticipated, reaching Alaska first and then Oregon in 2012. The model shows that once the debris reaches the eastern Pacific, it can either pass through the California current and reach the coast, or get caught in the current and travel south. More southerly, the current turns west and debris moves west traveling back to the west Pacific. Time sequence progresses as follows: Red, Orange, Yellow, Turquoise, Magenta.
Japanese Floating Dock on Agate Beach, Newport, Oregon
The Misawa dock came to its resting place on a long sandy beach.
(Credit: David Appell)
Marine Growth on the Dock at Agate Beach
An initial survey found a variety of species of barnacles, starfish, urchins, anemones, amphipods, worms, mussels, limpets, snails, solitary tunicates and algae. This section shows numerous mussels (Mytilus galloprovincialis ) and brown algae.
M. galloprovincialis also occurs on the West Coast of America.
(Credit: David Appell)
Marine Growth on the Dock at Agate Beach
An initial survey found a variety of species of barnacles, starfish, urchins, anemones, amphipods, worms, mussels, limpets, snails, solitary tunicates and algae. This section shows numerous mussels (Mytilus galloprovincialis ) and brown algae.
M. galloprovincialis also occurs on the West Coast of America.
Chart of Marine Organisms on the Agate Beach Oregon Floating Dock
Chart of several of the species found on the Agate Beach Floating Dock. A large diversity of species was found. The solitary tunicate on the left looks like a pair of Styela clava. Encrusting and pelagic barnacles are shown in the upper right.
Japanese Floating Dock near Mosquito Creek, Olympic Peninsula, WA
Pelagic barnacles settled on the dock during transport across the Pacific. The side looks nearly covered with the single species, Lepas anatifera.
Lepas anatifera Pelagic Barnacles
Body divided into two parts: the capitulum which bears the body of the animal and a flexible stalk called the peduncle. Capitulum has five large calcareous plates. Plates on the capitulum are smooth or at most finely marked. Upper left, specimens with the cirri withdrawn showing external features - the plate-covered capitulum and the leathery,brown peduncle. Upper right, collected specimens with cirri showing morphological diversity. Bottom, underwater image showing orange tissue-lined pearly white plates and fully extended cirri ready for feeding.
LINKS:
Oregon
Oregon State Japanese Tsunami-Generated Floating Docks Website. Gives updated information on the research and species list. http://blogs.oregonstate.edu/floatingdock/
ANS (Aquatic Nuisance Species) Task Force. http://anstaskforce.gov/Tsunami.html
Flicker Photostream. Oregon's Tsunami Floating Dock's Photostream.
Agate Beach Tsunami Dock Species List. Gives updated species information.
Tsunami
Floating Dock
Preliminary
Species List : As of January 1, 2013
Marine
Organisms Found Living on a Floating Dock from
Misawa,
Aomori Prefecture, Japan Dislodged by the 2011 Tōhoku Earthquake and Tsunami and Washing Ashore on June 4, 2012 at Agate Beach, Lincoln County, Oregon
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Washington
Washington Tsunami Debris: Olympic Peninsula Dock. Huffington Post Report.
Washington Coast Tsunami Dock. NOAA web report.
Species List Washington Misawa Tsunami Floating Dock. Gives updated information.
Tsunami Floating Dock: Misawa 3
Olympic National Park
(JTMD-BF-8)
Species List: As of January 15, 2013
Marine Organisms Found Living on a Floating Dock from
Misawa, Aomori Prefecture, Japan, Washed Out to Sea on March 11, 2011,and
Washing Ashore December 16-18, 2012 near Mosquito Creek, Jefferson County,
Olympic National Park, Washington
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Bryozoa
Encyclopedia of Life (EOL): Cryptosula pallasiana. Overview of the species.
The Exotics Guide: Non-native Marine Species of the North American Pacific Coast. Watersipora subtorquata. Detailed description of the taxonomy, structure, and distribution of the species.
Watersipora subtorquata is an invasive species that has also spread to the US Pacific coast. Top, View of an orange colony from San Francisco Bay (Luis A. Solórzano). Bottom left, Closeup of Watersipora subtorquata zooecia showing the black opercula and the fine black lines where the zooecia join (California Academy of Sciences). Bottom right, SEM image showing fine structural detail.
Encyclopedia of Life (EOL): Tricellaria. Genus overview.
Tricellaria inopinata D'Hondt & Occhipinti Ambrogi, 1985
and upright chains of zooids
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Mussels:
Wonham, NJ. Mini-review distribution of the Mediterranean mussel Mytilus galloprovincialis (Bivalvia: Mytilidae) and hybrids in the Northeast Pacific. J Shellfish Res, 23: 535–543, 2004.
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PelagicBarnacles:
MarLIN: Common Goose Barnacle: Lepas anatiferaEOL Encyclopedia of Life: Lepas anatifera.
