Tsunami-driven rafting: transoceanic species dispersal and implications for marine biogeography

The 2011 East Japan earthquake generated a massive tsunami that launched an extraordinary transoceanic biological rafting event with no known historical precedent. We document 289 living Japanese coastal marine species from 16 phyla transported over 6 years on objects that traveled thousands of kilometers across the Pacific Ocean to the shores of North America and Hawai‘i. Most of this dispersal occurred on nonbiodegradable objects, resulting in the longest documented transoceanic survival and dispersal of coastal species by rafting. Expanding shoreline infrastructure has increased global sources of plastic materials available for biotic colonization and also interacts with climate change–induced storms of increasing severity to eject debris into the oceans. In turn, increased ocean rafting may intensify species invasions.

2011年东日本地震引发的巨大海啸，触发了一场史无前例的跨洋生物漂流事件。我们记录到来自16个门（phyla）的289种存活的日本沿海海洋物种，它们依附于漂流物历时6年穿越太平洋数千公里，最终抵达北美及夏威夷海岸。大部分扩散发生在不可生物降解物体（nonbiodegradable objects）上，这构成了有记录以来沿海物种通过漂流实现的最长跨洋存活与扩散案例。扩展的海岸线基础设施不仅增加了全球可供生物定殖（biotic colonization）的塑料材料来源，还与气候变化引发的日益严重的风暴相互作用，将碎片冲入海洋。反过来，海洋漂流的增加可能加剧物种入侵（species invasions）。