Two of the three very large items did not exceed the richness of the medium or large items; Thus, pairwise richness comparisons were made (figs. S4 and S5) only between small, medium, and large objects. We collected or obtained (Materials, Supplementary Materials and Methods) only part of the JTMD field. From discussions with local officials, including county, state and federal beach authorities and with members of the public and conservation groups, it is clear that a large number of objects discovered by the public during and after 2012 and known to be possible related to the tsunami were not officially reported (including removal from the public for private purchases);
Large sections of the coast of North America and the island of Hawaii are relatively inaccessible, and thus not suitable for research. To date, all items that can be linked to a specific location in Japan have come from only one of the four prefectures (Aomori, Iwate, Miyagi, and Fukushima) most affected by the tsunami (3). Holland, District of Ucluelet, British Columbia, manufactured post-and-beam lumber (shear and canopy construction) was identified by Japanese standard dimensions (46).
JTMD-identified items generally supported marine life typical of the colder waters of the Tohoku coast, i.e. the northeastern coast of Honshu north of the Boso Peninsula. Thus, incoming biota represent a largely non-random homogeneous "fingerprint" of the portion of the Japanese coast hardest hit by the Great East Japan Earthquake and Tsunami. Some objects from the Tohoku coast arrived in North America and in the Hawaiian Islands with additional species from south of the Boso Peninsula, indicating that these items either drifted south to obtain warmer water elements, or that southern larvae in the ocean currents are swept north, or both.
Non-JTMD objects could be biologically recognized by having species communities from different regions of the western Pacific (Russia to Southeast Asia), but no such objects were found during the study period. A large, steady stream of waste from the Tohoku coast has not previously been observed arriving in North America or the Hawaiian archipelago. In contrast, in the spring and summer of 2012, a new wave of a wide range of debris (Table S1) began washing ashore from the tsunami source area.
Indeed, items arrived non-randomly according to wind characteristics: items with very high winds (buoys, pallets, some ships (boats), the Ryou-un-Maru ship, and the first Misawa dock) arrived in spring and summer . of 2012; many additional small, lower-wind craft began arriving in November 2012, and items driven primarily by ocean currents (as opposed to surface winds) then began arriving in winter-spring 2013, such as construction timber behind and beams. , and, a little later, trees, posts and beams of heavier wood. Based on detailed knowledge of the specific events surrounding the discovery, acquisition and sampling of a particular object, including the level of knowledge and experience of the sampling person or team, the amount of time available to sample a particular object, the care of inspection potential, and other factors, a subset of 110 objects (starred in Table S1) were identified as having a higher-resolution estimate of onboard macrobiota diversity. There were fewer scientists and lower populations in the Pacific Northwest in the 1890s and 1930s than now, and while it would not be surprising if limited landfall records were discovered from these earlier events, it seems unlikely that a debris field equivalent to that generated by the 2011 Great East Japan Earthquake and tsunami washed ashore in each country and was not recorded.
Species accumulation (raredown) analyzes were done with the specaccum function of the R package "Vegan" version 2.4-3 (59). The post-and-beam pieces discovered in 2016 may represent re-flooding (washed back into the sea after previous landings), rather than being in the sea since 2011. Proportion of all macroinvertebrate and fish taxa in function of the number of objects in which they were present.
Post-and-beam log dates are actual or best-estimated landing dates (sometimes set as a standard date based on forensic evidence and site familiarity).
Japanese species
Oceanic Pelagic (Neustonic) Species CNIDARIA
North East Pacific Nearshore Species Acquisitions ANNELIDA
Oso Altermark Unibersidad ti Artiko ti Norveška, Tromsø, Norveška Teredinidae Claudia Arango Museo ti Queensland, Avstralija Pycnogonida. Fehlauer-Ale Pederal nga Unibersidad ti Paraná, Brazilija Bryozoa Unibersidad ti Kenneth Finger ti California, Berkeley, ZDA Foraminifera Megan Flenniken Unibersidad ti Stony Brook, Nueva York, ZDA Anthozoa. Niels-Viggo Hobbs Unibersidad ti Isla ti Rhode, ZDA Isopoda Leslie Harris Natural a Museo ti Kondado ti Los Angeles.
Hiroshi Kajihara Unibersidad ti Hokkaido, Hapon Nemertea Gerald Krantz Unibersidad ti Estado ti Oregon, E.U.A Halacaridae Elena Kupriyanova Museo ti Australia, Australia Serpulidae Gretchen Lambert Unibersidad ti Washington, E.U.A. Ascidiaceae Robert N. Konstantin Lutaenko Instituto ti Zhirmunsky, Vladivostok, Rusia , E.U.A Artes. Eijiroh Nishi Yokohama Nailian nga Unibersidad, Hapon Annelida Teruaki Nishikawa Nagoya Unibersidad, Hapon Atsushi Nishimoto Nailian nga Instituto ti Panagsukisok ti Panagkalap.
Ronald Noseworthy Jeju National University, Sydkorea Polyplacophora Peter Ng National University of Singapore, Singapore Decapoda Michio Otani Osaka Museum of Natural History, Japan Cirripedia; Generel. Hiroshi Saito National Museum of Nature and Science, Japan Polyplacophora Eric Sanford University of California, Davis, Bodega Marine. Ashleigh Smythe Virginia Military Institute, USA Nematoda Jackie Sones University of California, Davis, Bodega Marine.
Taylor Natural History Museum, London, England Bryozoa Nancy Treneman University of Oregon Institute of Marine.
