Session Chairs: Cathryn Clarke Murray, DFO, Canada; Alexander Bychkov, PICES

This session is dedicated to researchers and managers working on large-scale marine debris issues. This session will highlight many novel advances, applications, and lessons learned from Japanese Tsunami Marine Debris study in the North Pacific that can be used elsewhere.

 The Great East Japan Earthquake and Tsunami of March 2011 resulted in a unique mega-pulse marine debris event that became the subject of many long-term intensive research programs around the North Pacific Ocean. In addition to the sheer magnitude of this event, Japanese Tsunami Marine Debris (JTMD) became an important vector for many Japanese species to reach the shorelines of North America and Hawaii.

This session will focus on exciting advances in marine debris research that have arisen from efforts to characterize and understand JTMD behavior, including higher resolution ocean modeling of marine debris movement, the development of novel surveillance and monitoring tools for marine debris landfall and accumulation, and the application of bioforensics and risk assessments to determine the potential threats from exotic species transported by long-lasting anthropogenic rafts. Although tsunamis and other large-scale natural disasters will remain difficult to predict, lessons learned from the research arising from the 2011 Great Japan Tsunami provide a framework for other mega-pulse events, including predicting the potential fate and impacts associated with the sudden appearance of huge debris fields in the ocean, that can inform management decision-making or policy development around marine debris.

It is estimated that the human population will to grow by 2 billion people over the next 25 years, with approximately 40% living within 100 km of the world’s coastlines, suggesting the amount of anthropogenic material available for ocean-entry will rise significantly in the coming decades. In turn, global climate change is already affecting the frequency and scale of storm activity, including hurricanes, typhoons, and monsoons, which increases the probability and magnitude of future mega-pulse debris events. This session welcomes submissions related to JTMD and other mega-pulse debris events. Further, the trans-oceanic movement of species on marine debris is an emerging issue in invasion research, and submissions on this are also welcome.




Pathways, impacts and fate of marine debris generated by the 2011 tsunami in Japan derived from a synthesis of numerical models and observational reports

presenting: Nikolai Maximenko (University of Hawaii, United States); authors: Nikolai Maximenko (University of Hawaii, United States), Jan Hafner (University of Hawaii), Masafumi Kamachi (Japan Agency for Marine-Earth Science and Technology), Amy MacFadyen (National Oceanic and Atmospheric Administration)

March 11, 2011 tsunami devastated the east coast of Japan and produced millions of tons of marine debris that drifted across the North Pacific. The extraordinary amount and unusual composition of tsunami debris allowed to trace its drift across the ocean and arrivals on remote shores and helped to better understand the pathways of floating marine debris. Synthesized with a suite of ocean models, these observations helped to produce most complete picture of the debris dynamics, pathways, and fate. While observations allowed to optimize such model parameters as windage and source distribution, the models filled large gaps in sparse observations and produced estimates of the total budgets. For example, the study suggests that the original number of boats lost to the tsunami was about 1,000 and more than 100 of these boats may be still floating in the ocean.


Tsunami debris increased risks to navigation and had impacts on shoreline activities in some areas. In addition, floating debris transported Japanese species from Japan to North America and Hawaii and posed on local ecosystems risk of invasion. Here we will present new methods developed to characterize these impacts.


Finding a needle in a debris haystack: surveillance of debris from the Great Japan Tsunami

presenting: Cathryn Murray (Fisheries and Oceans Canada, Canada); authors: Cathryn Murray (Fisheries and Oceans Canada, Canada), Kirsten Moy (Department of Land and Natural Resources), Miguel Castrence (Resource Mapping Hawaii), Brian Neilsen (Department of Land and Natural Resources), Tomoya Kataoka (Tokyo University of Science), Atsuhiko Isobe (Kyushu University)

The devastating Great East Japan earthquake and resulting tsunami in 2011 dispersed an estimated 5 million tons of marine debris into the ocean. An estimated 70% of that debris sank (Ministry on the Environment of Japan, 2011), but the remaining 1.2 million tons were dispersed across the Pacific Ocean and began to appear in North America and Hawai’i in 2012. As a part of the Assessing the Debris-Related Impact of Tsunami (ADRIFT) project, aerial surveys were conducted along the coast of British Columbia, Canada and the eight main Hawaiian Islands, USA to identify potential tsunami items and estimate macro-debris abundances. The resulting imagery was analyzed to identify and quantify visible marine debris on these coastlines. These projects provided a baseline of marine macro-debris densities at a moment in time, and collaborated with the state and provincial authorities to prioritize areas of highest marine debris accumulation, or “hotspots”, in order to provide guidance to citizen cleanup groups, regulatory agencies, and local and federal partners.


How the 2011 Japanese Earthquake and Tsunami Prompted a Marine Debris Monitoring Program in Central California, USA

presenting: Kate Bimrose (Greater Farallones Association, United States); authors: Kate Bimrose (Greater Farallones Association, United States), Kirsten Lindquist (Greater Farallones Association), Jan Roletto (Greater Farallones National Marine Sanctuary)

The March 11, 2011 Japanese earthquake and tsunami amplified the existing global marine debris problem with the input of an estimated 1.5 million tons of debris, some of which landed on U.S. shorelines along the Northeast Pacific Ocean for several years following the disaster. This devastating event and subsequent impacts have become the focus of research and coordination among various levels of government to answer important questions surrounding when, where, and with what impacts does debris hit our shores. In July, 2012 Greater Farallones National Marine Sanctuary (GFNMS) and Greater Farallones Association, joined the NOAA Marine Debris monitoring and Assessment Project (MD-MAP). Participation in the project includes execution of monthly beach surveys at several locations along the California coast. NOAA protocol are utilized to monitor each location and record the presence of debris along with detailed instructions for recording and reporting potential tsunami debris sightings. For the past five years GFNMS, in partnership with citizen science volunteers, has recorded 25,000+ debris items over the course of 300 beach surveys, establishing an important first ever baseline of information on monthly marine debris presence along California shores. This presentation will discuss how the Japanese earthquake and tsunami helped California, and the U.S. west coast, better understand the marine debris problem both locally and regionally. Additionally, the presentation will discuss how findings from data analysis can have national and international implications for the prevention and mitigation of marine debris.


An estimate of the abundance of Japanese tsunami marine debris washed ashore on the west coasts of the North America, based on a combination of webcam monitoring and a particle tracking model experiment

presenting: Atsuhiko Isobe (Kyushu Univ., Japan); authors: Shinsuke Iwasaki (Kyushu Univ., Japan), Atsuhiko Isobe, Shin’ichiro Kako, Tomoya Kataoka, Kei Yufu, Charlie Plybon, Thomas Murphy, Hideaki Maki

Particle tracking models (PTMs) are capable of computing debris motion in the ocean circulation. However, it is difficult to determine by the PTMs alone if modeled particles in the ocean are washed ashore onto the land, because the stranding must be dependent on nearshore processes that might not be resolved in modeled ocean currents (hence, PTMs) sufficiently. Also, re-drifting processes of stranded particles into the ocean should be incorporated into the PTM; otherwise the estimate of debris quantity on beaches remains unreliable. The webcam monitoring on a beach in Newport, OR provides us with a simple scenario of stranding/re-drifting processes: the debris on the beach increased during the downwelling-favoring winds, and rapidly decreased under the onshore-winds at spring tides by re-drifting. The PTM in the present study consists of two models: one is a PTM to reproduce the tsunami-debris motion in the North Pacific using an ocean reanalysis product (ocean circulation) and satellite-derived winds (leeway drift), and the other is a “sub-model” to give the criterion whether the modeled particles are washed ashore on the neighboring land grid cell, and whether they return to the oceanic domain from the land. The satellite-derived winds on the grid cells neighboring the land boundary were used for the criterion in the sub-model. An attempt in the present study is to evaluate the abundance of the modeled particles (which can be approximately converted to tsunami-debris weight) washed ashore on the land during the past five years.


Diving into debris: the biology and ecology of biota transported on Japanese tsunami marine debris

presenting: Jessica Miller (Oregon State University, United States); authors: Jessica Miller (Oregon State University, United States), James Carlton (Williams College), Reva Gillman (Oregon State University), Cathryn Clarke Murray (PICES), Gregory Ruiz (Smithsonian Environmental Research Center), Michio Otani (Osaka Museum of Natural History), Jocelyn Nelson (PICES), Jonathan Geller (Moss Landing Marine Laboratories), John Chapman (Oregon State University)

Nearly 300 coastal marine species collected on >650 debris items from the 2011 Great East Japan earthquake and tsunami have landed alive along the Pacific coast of North America and the Hawaiian Archipelago. We synthesized life history, environmental, and distributional information for 103 of these species and quantitatively compared traits of species with (n = 31) and without (n = 62) prior invasion histories. Tsunami-transported species with invasion histories occurred more frequently on artificial and hardpan substrates, included more boring and fouling organisms, were more common in subtropical and tropical waters, and exhibited greater salinity tolerance than those species with no invasion history. We also identified species with no prior invasion history that overlapped in multidimensional space with known invasive species but are not currently present in the Northeast Pacific or the Central Indo-Pacific to identify candidate species for monitoring. Additionally, we examined the size, reproduction, and growth of an invasive mussel Mytilus galloprovincialis, which was present on >50% of the debris items, to better understand long-distance rafting of a coastal species. The majority of mussels (79%) had developing or mature gametes, and growth rates averaged 0.075 mm/day. Structural and elemental analysis of mussel shells generated estimates of growth in coastal waters, which provides an indication of residence times in waters along North America and the Hawaiian Islands prior to landing. Detailed studies of species can contribute to our understanding of debris as a transport vector and aid efforts to evaluate potential risks associated with marine debris.


The invasion risk of invertebrate species associated with Japanese Tsunami Marine Debris in North America and Hawaii

presenting: Thomas Therriault (Fisheries and Oceans Canada, Canada); authors: Thomas Therriault (Fisheries and Oceans Canada, Canada), Jocelyn Nelson, James Carlton, Michio Otani, Danielle Scriven, Gregory Ruiz, Cathryn Murray

Marine debris from the 2011 Great Japan Tsunami represents a novel transport vector for Japanese species to reach Pacific North America and Hawaii. Over 650 debris items attributed to the tsunami have been intercepted and over 380 species of algae, invertebrates and fish have been identified associated with this Japanese Tsunami Marine Debris (JTMD). Most of the species encountered are native to Japan, not currently present in North America or Hawaii, and their invasion risk is unknown. Thus, it is important to characterize the risk their introduction may pose to North American and Hawaiian ecosystems. Here we characterize the risk of individual invertebrate species associated with JTMD using an established screening-level risk assessment tool – the Canadian Marine Invasive Screening Tool (CMIST). This tool scores both the probability and consequences (impacts) of an invasion for receiving ecosystems to generate an overall risk score that encompasses assessor uncertainty. Although there were some ecoregional differences, well-known global invaders, such as the mussel Mytilus galloprovincialis and the ascidian Didemnum vexillum were higher risk for most ecoregions, while those that have yet to invade many (or any) of the assessed ecoregions like the sea star Asterias amurensis and the shore crab Hemigrapsus sanguineus were also higher risk. However, most of the invertebrate species assessed were considered relatively low to moderate risk, due perhaps in part to a lack of reported invasion history and impacts elsewhere.


Megarafting: The Role of Marine Debris in the Coastal and Transoceanic Transport of Marine Life

presenting: James Carlton (Williams College, United States); authors: James Carlton (Williams College, United States), John Chapman (Department of Fisheries and Wildlife), Jonathan Geller (Moss Landing Marine Laboratories), Jessica Miller (Department of Fisheries and Wildlife), Deborah Carlton (Williams College), Megan McCuller (Williams College), Nancy Treneman (Oregon Institute of Marine Biology), Brian Steves (Department of Environmental Science and Management), Gregory Ruiz (Smithsonian Environmental Research Center)

The amount of anthropogenic non-biodegradable material, especially composed of plastic, on coastal land has increased dramatically over the past half-century. Not surprisingly, the amount of plastic waste flowing into, dumped, or ejected into the world’s oceans from nearly 200 countries has now reached many millions of tons per year. In turn, climate change models predict that cyclonic systems, such as hurricanes and typhoons, capable of effectively sending coastal infrastructure into the sea, will increase in size and frequency. This juxtaposition of situating vast amounts of non-biodegradable materials in great density along coastlines now available to be swept into the ocean at potentially increasing rates appears to have no historical precedent. Studies on the marine debris field generated by the Great East Japan Earthquake and Tsunami of 2011 reveal that the debris fraction still existing after more than 6 years at sea consists solely of plastic material, with wood having disappeared from the debris field in the early years after 2011. On tsunami marine debris we found nearly 300 living Japanese species landing in North America or the Hawaiian Islands. Our work demonstrated that many of these coastal species can survive for years drifting on the high seas, and eventually landing on distant continental shores, due to these ocean rafts being no longer biodegradable. Plastic marine debris is a potentially increasing novel vector for successfully transporting marine invasive species along coastlines and between oceans.