Invasive species from the Japanese dock: “We really don’t know how bad it might get. We really don’t!”
Hatfield Marine Science Center Marine Biologist Dr. John Chapman says the Japanese Tsunami-tossed dock that came ashore at Agate Beach in early June carried, from their observations and calculations, an estimated five tons of biological plants and critters across the north Pacific. But when it came ashore, only two tons remained attached. Chapman told the MidCoast Watersheds Council Wednesday night that although scientists and state parks personnel successfully scraped two tons of material off the dock at Agate Beach and buried it in a deep “mass grave” uphill from the water, “Three tons of invasive species successfully made the 5,000+ mile trip and are now lingering on our beaches and along the Oregon Coast’s inter-tidal zone. When asked if some of the more aggressive species of crabs, starfish and seaweed may eventually kick a big dent in our native intertidal ecology, Chapman said “Nobody knows. Invasive species can have very long fuses. We won’t know until they start popping up, if they pop up at all.”
Within a few hours, scientists gathered from the dock samples of barnacles, starfish, urchins, anemones, amphipods, worms, mussels, limpets, snails, solitary tunicates and algae – and there are dozens of species overall. Chapman said, “This was a unique geologic event in that an extremely well built method of transport (the dock) offered safe passage for Japanese plants and animals to a new world. The dock’s vibrant plant and animal communities were able to breed many generations during their 15 month journey, something that is probably unparalleled in recent history. The fact is, they’re here. Will they survive and thrive? Only research and time will tell us.”
Chapman said nearly 90 species of flora and fauna were discovered on the dock, which was one of four floating docks that were ripped from their moorages in the fishing village of Misawa, Japan, just north of Tokyo. He said one dock was found washed up on shore, so counting the one in Newport, there are two more of these 130 ton behemoths possibly floating around in the north Pacific. Chapman said that based on the algae growth pattern on the Agate Beach dock, it was floating at about a 25 degree angle with about 25% of one end protruding above the surface. He said because the dock remained upright over during the catastrophic tidal surge and on the long journey to the U.S., it made it possible for the many species of plants and animal to endure the journey since they had enough sunlight to keep them alive.
Chapman said he and his fellow scientists are anxious to travel to Misawa to tabulate all the flora and fauna that are common in the bay there. He said they want to compare what’s there to what survived the journey to the U.S. to get a feel for the veracity of what they’re dealing with.
Chapman said the biggest threats to Oregon’s shoreline may be from a particular sea weed, star fish and crab that they found in abundance on the dock. “But again,” he added quickly, “they could do well here, or they might not. Only time will tell, and it could be a very long time before we do find out.”