Marine ecology & environmental sciences

More than two decades ago, I studied physics because of my strong interest in understanding phenomena in the natural world. At that time, the subject of ecology was practically non-existent, and the environment was subject of a highly charged political debate.

Today, environmental sciences have developed into a natural science research field, with a sound basis in biology, chemistry, physics and climate/ocean science. During the past three years, while finalising my projects in the Emmy Noether research group on starburst clusters, I studied Environmental Sciences and Protection in the University of Rostock's long-distance study programme. It was a challenge to lecture, supervise, and learn at the same time, but I quickly realised that this natural science-based ecology course was exactly what I needed to get a sound background in environmental sciences.

Although I followed many of the research areas in environments closely from a public perspective, my main interest lies in ocean protection and the science of the marine environment. The anthropogenic influence in the world's Oceans, in my view, causes four major areas of concern.

• Overfishing - which is extensively discussed in the environments community and in political contexts
• Eutrophication - the influence of nitrogen-enrichment through agricultural practices causing algal blooms is also a matter of hot debate
• Species transport & climate change - the related aspects of changing wheather patterns and water temperatures are of major concern both to the natural ecosystems and their biodiversity as well as to the human coastal living environment
• Plastic pollution - the omnipresence of plastics on the remotest beaches and in the deepest sediment layers of ocean trenches implies that plastic reaches all layers of the marine food web at the present time

All of these issues are imminent and need further quantification and research to understand the depth of the problems and define measures for releave.

• Coastal communities living on the natural resources of the Sea are particularly vulnerable to marine pollution, and are directly affected by flood, increasing storm events, coastal degradation and rising sea levels from climate change.
• Marine animals provide the major protein source for many nations and peoples, yet at the same time fishing has become a mega-industry depleting marine ressources without regard for bycatch and respect for biodiversity and species not caught to provide food for humans.
• Industrialisation in fishing has become an emerging concern to ecologists, as radar detection methods allow the catch of entire large schools of fish at ocean layers several thousand meters deep, causing a severe concern for deep ocean depletion.
• Ocean plastics have become a major concern for the marine food web, as plastic fragments of all sizes are found in almost all water and sediment samples. Macroplastics can have sizes from a centimeter to tens of meters in the case of derelict fishing nets. Microplastics are defined to capture particles and fibres smaller than 5 millimeters (Arthur et al. 2009). The most frequent microplastic particles are smaller than 100 micrometers (0.1 millimeter), mimicking plankton species in size and hence may be mistaken for food by plankton feeders and juvenile fish (e.g., Moore et al. 2001, Thompson et al. 2004).
• Plastics are found throughout Oceans, coastal seas and on the remotest islands, where it is transported by wind drift and ocean currents. A global map of all microplastic detections until early 2013 may be found in do Sul & Costa (2013). Even remote Pacific islands are heavily affected by plastic accumulation (McDermid & McMullen 2004, Hidalgo-Ruz & Thiel 2013). Hence, marine plastic debris is not a local problem caused by local people. It is a global concern caused by the unhealthy combination of weather-exposed landfills and waste mismanagement, increasing plastic packaging and production, with the majority of plastics produced for one-time use without recycling, slowly degrading synthetic netting deployed by the fishing industry, and many other factors.
• The origins of macroplastics in the Oceans, and of microplastics from macroplastic fragmentation, can be traced to fisheries, the shipping industry, plastic production and recycling, and landfills. Landfills were recently estimated to provide a large amount of possibly 5-13 Million metric tons of plastic waste to the Oceans each year (Jambeck et al. 2015). Because the origins are so diverse, it is difficult to trace back individual plastic items and claim responsibility from the polluter.
• The wide-spread distribution of marine plastics and the diversity of possible sources render the plastics problem one of the most difficult marine conservation issues. If the responsible industry, such as the packaging industry or the cosmetics industry, can be defined, there is hope to reduce and possibly even remove the source of plastic pollution. California and New York State, banning plastic bags and cosmetic peeling fragments, are two excellent examples where the overwhelming microplastic contamination could be tackled at the source. Without clear knowledge of the potential contributors as well as the fragmentation and transport processes of plastics in the marine environment, however, responsibility is difficult to convey and mitigation measures are hard to define.

In recent years, I followed the debates on overfishing and bycatch most closely, as I have a special interest in ocean mammals and sea turtles. However, while these issues are slowly, and with large resistence from the fishing industries of various countries (including my own), but increasingly addressed by international and European law, ocean plastics as a research subject is just beginning to emerge. More than a decade has passed since Captain Charles Moore brought the existence of large amounts of plastics in the midst of the Pacific Ocean far from any human civilisation into the public attention, and yet today is the amount of plastics and its spatial distribution in the marine ecosystem known only in exceptional locations.

As a physicist and natural scientist, it is my sincere believe that a problem has to be understood quantitatively to trace back its origins and choose the best ways to solve it at its roots. On the political and industrial stage, proof is needed to provide convincing arguments for new laws, international agreements, and for changes in the production and waste management policies. Without knowing the main sources of macro- and microplastics in the marine environment, no one can be made responsible and solutions will not be found. Only if we understand the major origin, the transport mechanisms, and the effects of plastics in the marine food web, can efficient measures be defined to decrease the plastic entry into rivers and seas, and to relieve the marine world from plastic pollution.

With these issues in mind, I have engaged in a Master project on Microplastic Contamination along the German Baltic coast.

References:

With the rising awareness for the scale of the problem, the number of publications on marine plastics, and especially on microplastics, has increased dramatically in the past few years. Numerous publications are available on the web, are partially freely accessible, and easily found with simple web searches. Because of the shear wealth of publications, only a few of the most connected references are selected here.

Arthur, C., Baker, J., Bamford, H. (eds). 2009: Proceedings of the International Research Workshop on the Occurrence, Effects and Fate of Microplastic Marine Debris, Sept 9-11, 2008, NOAA Technical Memorandum NOS-OR&R-30

Jambeck, J. R., Geyer, R., Wilcox, C., Siegler, T. R., et al. 2015:
Plastic waste inputs from land into the ocean, Science, 347, 6223, 768-771

Hidalgo-Ruz, V., Thiel, M. 2013: Distribution and abundance of small plastic debris on beaches in the SE Pacific (Chile): A study supported by a citizen science project, Marine Environmental Research, 87-88, 12-18

McDermid K. J., McMullen T. L. 2004:
Quantitative analysis of small-plastic debris on beaches in the Hawaiian Archipelago,
Marine Pollution Bulletin, 48, 790-4

Moore, C. J., , Moore, S. L., Leecaster, M. K., Weisberg, S. B. 2001:
A Comparison of Plastic and Plankton in the North Pacific Central Gyre
Marine Pollution Bulletin, 42, 1297-1300

Thompson, R. C., Olsen, Y., Mitchell, R. P., Davis, A., et al. 2004:
Lost at Sea: Where Is All the Plastic?
Science, 304, 838

General references:

Californians against Waste [access date: April 2015]:
State of the legal prohibitions against plastic shopping bags.
http://www.cawrecycles.org/issues/plastic_campaign/plastic_bags/local

New York State Microbeads-free water act [access date: April 2015]:
http://open.nysenate.gov/legislation/bill/A5896-2015

Convention on Biological Diversity 2012:
Impacts of Marine Debris on Biodiversity: Current Status and Potential Solutions