As part of the food chain, we humans are not only the culprits of the whole ocean pollution problem, but also its victims. We talked to Dr Lydia Koehler, Associate Professor at the University of Plymouth and Consultant in Marine Biology, about pollution and what can be done about it.
We managed to get an exclusive interview from her on the subject, touching on yachting and sailing among other things.
The problem of marine pollution is increasingly worsening and has caught the attention of the international community and the public. What are the sources of this problem?
It is a fact that marine pollution originates on land. For example, plastic gets washed into rivers, which then carry it into the ocean. Ships may also discard rubbish at sea and wind carries plastic into the water. There are multiple sources of how plastic enters the ocean. Once plastic enters the marine environment, it remains and disintegrates into microplastic, causing harm to marine life.
Is it possible to track this catastrophic situation with numbers (including the source)?
Yes, several scientists are working on determining the extent of marine pollution. They use, for example, data from satellites to determine where plastic occurs. See, for example, the work by Martinez-Vicente.
Marine pollution is produced on land.
One of the most alarming forms of plastic pollution is microplastic. These tiny particles, less than 5 millimetres in size, are often overlooked, yet they are the ones that have a devastating impact on marine creatures. Why? And how acute is this threat?
The full extent to which microplastic harms marine life is not yet understood, but increasing research is showing impacts on marine life from ingestion of microplastic. For example, I would mention this research from 2015.
What the direct consequences of microplastic ingestion is, is still not fully understood, but it raises concerns about food web accumulation and diseases and intoxication of marine life.
What are ways to improve or solve the problem of marine pollution?
This is a difficult question, and the answer is complex. The problem starts with everyone using plastic. At an individual level you can reduce your own personal use of plastic and switch to more sustainable alternatives. For example, do not buy vegetables or fruits wrapped in plastic and carry a cotton bag with you instead of using plastic shopping bags. At a larger, economic scale, we need to change the way we use plastic – meaning that, instead of single use plastic, we need to recycle more efficiently and create a circular economy, where plastic and other garbage does not enter the environment and is reused or repurposed. Our society has to transform its behaviour and how we deal with plastic and other forms of garbage. To improve the situation for our oceans, we have to do more to avoid plastic entering the marine environment, otherwise all efforts of ‘cleaning up the ocean’ will remain useless.
Lydia Koehler in her research work. Credit: Lydia Koehler, courtesy of
What programs exist and what are they aimed at?
There are several, expanding research programmes on marine pollution. At international level, Member States of the United Nations have agreed on a resolution to end plastic pollution and are in the process of developing a legally-binding instrument on this problem, with the aim of being concluded by the end of 2024.
How well is awareness-raising working and in which countries is the situation worse and why?
This question is difficult to answer, as it would require knowing what happens in every country, which is a challenge. The problem of ocean pollution is a global one, that does not affect just one country, although, in general, a lot of plastic enters the ocean in developing countries with large coastlines, an extensive fishery, and high tourism.
Plastics pose the greatest danger. They enter the oceans from land.
What exactly are you, as a recent PhD graduate, focusing on in your work? And how do you personally view the problem?
My work concentrates on policy and legal aspects of ocean governance and how we preserve marine life. I have a special interest in sharks and their relatives. My personal view on marine pollution is that it is a massive problem that requires urgent action with the cooperation of multiple countries and economic sectors, and a societal change. It is time to act now and not procrastinate or hinder innovation and change in the way we use plastic.
Do activities such as sailing or yachting also have an impact on the environment and the sea?
I think the problem is the increasing pressure on marine life from all human activity. Yachting has massively increased and contributes through the use of fuel to climate change and ocean pollution. There is also a considerable threat from garbage being dumped. However, this being said, there are ways to improve the sustainability of this recreational sector by using alternative fuels, ensuring no rubbish is dumped over board, they do not anchor on sensitive habitats, and follow principles of sustainable tourism.
In which countries have you worked as a marine biologist and where do you think the situation is worst? What have you seen with your own eyes?
I personally worked in Egypt, the Maldives, Brunei Darussalam, Malta, and the United Kingdom on different aspects of marine conservation and fisheries management. I have seen pollution impacts on coral reefs and beaches full of rubbish, especially in locations where tourism, shipping, and fishing are happening in the same place. What became clear to me is that there is no region or ocean that is not impacted by the problem.
Thank you for the interview.
Are you more interested in the topic of ocean pollution? Read more from United Nations here.