The Science of Microplastics in the World Ocean

We would like to invite you to participate in a three and a half-day workshop to evaluate the state of science and technology in understanding the fate and impacts of plastics in the ocean.  Microplastics and Nanoplastics (collectively referred to as MP) have been reported in the marine environment worldwide, from surface waters to deep-sea sediments, even in areas far from human activities such as in polar waters.  All environmental matrices appear contaminated: surface waters, the water column, sediments and marine organisms from microplankton such as ciliates to mesoplankton such as copepods and larval and adult fish.  MP are now found in all five of the world’s subtropical gyres and remote areas including the Marianas Trench, Arctic and Antarctic sea ice, and once pristine tropical islands.  The fate of microplastics is only starting to be revealed, but understanding their fate is fundamentally an oceanographic issue since their distribution is a function of both large and small scale mixing, microbial colonization and degradation, ingestion by a variety of suspension feeders both in the water column and in the benthos, and nucleation of marine snow particulates, which may accelerate export of MP and carbon to the deep sea.  The recent GESAMP Working Group 40 workshop reported that “an increasing number of experts and leading societal thinkers see plastic pollution in the ocean and on land as a threat to our future, comparable to climate change, land use changes, and species extinction.  Science and technology can quantify the extent of plastic pollution and understand the impact of reducing the stock of plastics in the ocean.”  Noting that the “field” of MP research is changing rapidly, this workshop will summarize where we are at the moment and deliver recommendations through a science and technology 10-year roadmap as a peer reviewed manuscript.

High level goals

• To build consensus within the scientific and industrial communities on the critical issues, questions and directions that science should proceed in order to understand the magnitude and impact of microplastics on the ocean environment.
• To come away with a written document that, after additional editing, may be submitted to a peer reviewed journal (e.g., Frontiers in Marine Science) that details the critical issues and develops and a five-to ten-year plan for addressing rigorous science-based research and goals for funding such research.

The detailed goals of this workshop are to:

• Assess the state of best-practices and standards in MP research, sampling of all matrices (biota, sediment, water column), classification, reporting and to articulate recommendations going forward, including ASTM and ISO standards.
• Assess hurdles to quantifying the “missing” plastic and create a global ocean budget using current technology and to propose novel approaches for sampling and classifying MP in all matrices. This includes NP as a particular challenge.
• Assess the fate of plastics in the ocean and processes responsible for creating MP from macroplastics, including the role of UV, abrasion and colonization on fragmentation.
• Assess impacts of MP on ocean ecosystems from neuston to benthos and littoral, neritic, and mesopelagic to abyssal.
• Evaluate the role of numerical modeling in understanding the fate of MP.
• Assess human and socioeconomic impacts of MP in the ocean.
• Develop a report/peer reviewed manuscript describing results of the workshop and a critical scientific research agenda for the next five years.

To address these goals, the following questions will be posed during the breakout groups following each morning of plenary talks:

1. What standards are necessary to allow for consistency in sampling, classifying and reporting?
2. What technologies exist to sample neuston, mid-water, density interfaces (pycnocline), and sediment and how effective are they?
3. How should samples be processed from pelagic, sediment, and biota?

Where are all the Plastics?

4. What are the major sources and sinks of primary and secondary MP?
5. How common and homogeneously distributed are MP?
6. Where do we find MP and at what concentrations?
7. What additional technology and information do we need to gauge the ubiquity of microplastics in littoral to deep sea environments?

What are the impacts?

8. What are the possible effects of microplastics on aquatic habitats and living resources (e.g., scallops, clams, oysters, fish, whales, seabirds)?
9. What are the knowledge gaps and where do we need more data?
10. What policy and management tools are or should be used to address the impact of MP? How effective have they been? Could these tools be emulated elsewhere? Are there additional tools we can recommend?
11. How can funding be maximized and directed at the most critical questions?