(This post is part of the Plastics theme for 2020)

IEEE/MTS OCEANS’19 was held in October 2019 in Seattle, USA, with approximately 1700 attendees, 300 technical papers and 120 exhibitors. Given the interest that OCEANS conferences generate, combined with the rapid ongoing deterioration of our marine ecosystem, it was not  surprising to me that the conference theme was “Blue Sea, Blue Sky, Blue Tech”. During the conference, I was motivated to attend a session on “Plastics in the Ocean: Observation and Mitigation Methods” to know about the latest research on plastic pollution in our Oceans, and mitigation methods.

The oceans are a critically important component of the Earth, supporting its ecosystems and biodiversity. They regulate the weather and climate, are essential for producing freshwater, and soak up carbon. They also provide food and other resources, trade and migration routes. Our Oceans cover 71% of the Earth. They contain 96% of the Earth’s living space, and 80% of living organisms. Additionally, Ocean plants produce almost half of the oxygen we breathe, and the Oceans hold an estimated 80% of the Earth’s mineral resources. Unfortunately, our Oceans are under severe threat; 60% of the world’s major marine ecosystems have been significantly degraded or are unsustainably used [1]. We have reached a stage where the Ocean health needs to be carefully monitored and attribution analysis comprehensively performed, if we wish to save our planet.

Of all the major reasons for degradation of the marine ecosystems, plastic debris is probably one of the most damaging and critical ones [2, 3]. What makes the issue even more disturbing is that in recent times, this problem has been increasing at its fastest rate ever. In the past few decades, plastics have emerged as the most dangerous pollutants that are rapidly accumulating in the Oceans.

About 8 million tonnes of plastic enter the sea every year, and at this rate we face a future with more plastic in the Ocean than fish by 2050 [4]. This plastic leads to countless marine birds and animals ending up dead by entanglement or poisoning, and even leads to chemical contamination of the fish we eat.

Plastic has been found in more than 60% of all seabirds and in 100% of sea turtles species, that mistake plastic for food. When animals ingest plastic, it can cause life-threatening problems including reduced fitness, nutrient uptake and feeding efficiency - all vital for survival. From the tiniest plankton to the largest whales, plastics impact nearly 700 species in our Ocean.

Marine animals and birds are often the victums of plastic pollution.

The vast swirls of plastic rubbish visible on the sea surface – horrifying as they are – represent just the tip of the iceberg [5]. What lies beneath are the masses of micro beads and broken-down particles of plastic that are easily ingested by sea creatures, and impossible to remove. The urgently needed solution calls for a combination of enhanced awareness, reduced plastic use, and massively improved waste management. The most effective way to have less plastic in the Ocean is to use less plastic in the first place. While the governments plan and legislate less use of plastic, we discuss some interesting ideas that can help us detect, map and manage the plastic that we have already contaminated our Oceans with. There were five very interesting talks focusing on this, at OCEANS 2019, Seattle. The five presentations I allude to are:

1. Plastic Pollution in the Coastal Oceans: Characterization and Modeling, by Abhinav Gupta from MIT [6].

2. Identification of Marine Plastics using Raman Spectroscopy, by Emilie HyrumDahl from NTNU/AMOS [7].

3. A state of art on plastics in the oceans: Observation and Mitigation Methods, by Marco Trapanese from the University of Palermo [8].

4. Zero-fuel open-ocean going tugs, and applications for the large scale collection of ocean plastics, by Danny Golden of Dublin Offshore Consultants Ltd [9].

5. Mineral Accretion: An Environmentally Alternative to Plastic for Oyster Restoration, by Kelli Hunsucker from Florida Institute of Technology [10].

This session on Plastic in the Oceans: Observation and Mitigation Methods was held on Tuesday, October 29, 2019 and was chaired by Stephanie Jaeger. The presentation on oyster population restoration using an environmentally friendly material in place of plastic [10] brought to light an interesting situation. Traditional methods for oyster population restoration and natural water filtration lead to a situation where solving one problem leads to another. The talk showed how electricity provided to a steel mesh can provide an environmentally friendly alternative to plastics.

In another interesting talk, "Identification of Marine Plastics using Raman Spectroscopy" [7] , the presenter discussed the use of Raman spectroscopy in detection of micro-plastics. Micro-plastics are mistaken as food by marine animals and can adversely and sometimes severely impact the health of these animals. Raman spectroscopy can extract the chemical structure of an object, and this property has been analysed for efficacy in identifying the specific types of micro-plastics in water.

Identifying the micro-plastics and possibly their concentration is one critical task for enabling clean-up of marine plastics. The other equally important task is modeling plastic transports in time and space. To accomplish this task, the talk on "Plastic Pollution in the Coastal Oceans: Characterization and Modeling" [6] presented a new partial differential equation based methodology for improved modeling of plastic transports. Movement of plastics originating from four sources was simulated and compared with existing plastic data. The authors also illustrated some new insights that resulted from this study.

It was illuminating to attend this technical session on plastic in the Oceans. It was disturbing to be brought face-to-face with the harm we are causing to our environment. Our planet is the only abode we have, and it appears that we are behaving irresponsibly and not taking care of it. Thankfully, the session was also a beacon of hope. It was heartening to note that some of the brightest minds are working on correcting some of the wrongs that we might have committed. I certainly came out of the session a more responsible citizen of this lovely planet.

References:

[1] UNEP, 2011, accessed: 1 Feb. 2020. [Online]. Available: http://www.unesco.org/new/en/natural-sciences/ioc-oceans/focus-areas/rio-20-ocean/blueprint-for-the-future-we-want/marine-biodiversity/facts-and-figures-on-marine-biodiversity/
[2] IUCN, “Issues brief: Marine plastics,” Accessed: 1-2-2020, https://www.iucn.org/sites/dev/files/marine plastics issues brief final 0.pdf .
[3] C. C. S. J. e. . Thevenon, F., “Plastic debris in the ocean: The characterization of marine plastics
and their environmental impacts, situation analysis report,” 2014, gland,Switzerland: IUCN.
[4] Q. Unite, “Key issues: Marine plastic pollution,” Accessed: 1-2-2020, https://www.oceanunite.org/issues/marine-plastic-pollution-2/.
[5] Marine Plastic Pollution-Ocean Unite, http://www.oceanunite.org/wp-content/uploads/2016/03/FINAL-Plastic-Talking-points-print.pdf
[6] P. F. J. Lermusiaux et al., "Plastic Pollution in the Coastal Oceans: Characterization and Modeling," OCEANS 2019 MTS/IEEE SEATTLE, Seattle, WA, USA, 2019, pp. 1-10, doi: 10.23919/OCEANS40490.2019.8962786.
[7] E. M. H. Dahl, A. Ø. R. Stien, A. J. Sørensen and E. J. Davies, "Identification of Marine Plastics using Raman Spectroscopy," OCEANS 2019 MTS/IEEE SEATTLE, Seattle, WA, USA, 2019, pp. 1-8, doi: 10.23919/OCEANS40490.2019.8962613.
[8] A. Viola, V. Frazitta and M. Trapnese, "A state of art on plastics in the oceans: Observation and Mitigation Methods," OCEANS 2019 MTS/IEEE SEATTLE, Seattle, WA, USA, 2019, pp. 1-4, doi: 10.23919/OCEANS40490.2019.8962849.
[9] D. Golden, J. Fitzimons, T. Doyle and D. Hayes, "Zero-fuel open ocean-going tugs, and applications for the large scale collection of ocean plastics," OCEANS 2019 MTS/IEEE SEATTLE, Seattle, WA, USA, 2019, pp. 1-5, doi: 10.23919/OCEANS40490.2019.8962741.
[10] K. Hunsucker, A. Melikov, M. Gilligan, H. Gardner, R. Weaver and G. Swain, "Mineral Accretion: An Environmentally Alternative to Plastic for Oyster Restoration," OCEANS 2019 MTS/IEEE SEATTLE, Seattle, WA, USA, 2019, pp. 1-5, doi: 10.23919/OCEANS40490.2019.8962694.