Did you know that our oceans naturally contain trace amounts of toxic metal elements such as lead, mercury, arsenic and cadmium? This sounds a little worrying. However, these trace elements usually do not pose a problem. However, human activities such as industry and agriculture contribute significantly.

Worse, new research has revealed that climate change is already affecting how these elements distribute and accumulate in our seas. This could have significant consequences as we move forward.

Understanding changes in the ocean

We know all too well the effects of climate change on our oceans: rising temperatures, increased acidity and loss of oxygen. But the newest development in this story is how climate change affects pollution in our seas. The research was led by Dr. Dr., a marine chemist at the GEOMAR Helmholtz Center for Ocean Research in Kiel. Rebecca Zitun and Dr. Ružer Bošković Institute in Zagreb. It was conducted by Saša Marcinek.

Lead, mercury, cadmium and other metals don’t enter our oceans only through industrial activities or the burning of fossil fuels. It turned out that the natural sources of these elements change depending on climate factors such as rising sea levels, overflowing or drying of rivers, and melting of sea ice and glaciers. Conclusion? Increased flux and mobilization of pollutants.

Metal pollution in the ocean

The study is the product of a working group of the United Nations Joint Panel of Experts on Scientific Aspects of Marine Protection (GESAMP) focusing on metal pollutants in the oceans.

Professor of Marine Mineral Resources at GEOMAR and former head of the Laboratory for Marine Environmental Studies at the IAEA in Monaco. Sylvia Sander initiated this working group. Another member of this group is German co-author Christoph Felker from AWI.

Dr. “Our working group focused on the effects of climate change and greenhouse gases on pollutants in the ocean,” Sander explained.

The main reason for this increase is the melting of glaciers, permafrost melting and coastal erosion. These increases in mercury pose a significant risk to communities dependent on artisanal fishing due to the accumulation of mercury in the food chain.

Contribution of human activity

“Human activities have increased the global flow of toxic metals such as lead and mercury by three to seven times compared to pre-industrial levels,” Dr Sander said. “Toxic elements such as silver are increasingly being detected in coastal waters due to coal burning and the increasing use of silver nanoparticles in antibacterial products.”

Not only these elements, but even silver is increasingly found in coastal waters, thanks to coal burning and the increasing use of silver nanoparticles in antibacterial products.

Plastic distribution and transportation has further exacerbated this problem. They can enter the food chain by binding heavy metals such as copper, zinc and lead. Human contribution of these heavy metals may increase further as ocean use increases.

Climate change and metals

Climate changes such as rising sea temperatures, ocean acidification, and oxygen depletion affect micronutrients in a variety of ways. For example, water temperature directly affects the bioavailability and uptake of trace elements such as mercury by marine organisms.

At higher temperatures, metabolism increases, oxygen solubility decreases, and gill ventilation improves, causing more metals to enter organisms and accumulate in their bodies.

Additionally, as our oceans absorb more of the CO2 emitted by humans, their pH decreases, increasing the solubility and bioavailability of metals such as copper, zinc, and iron. This can be particularly harmful to copper, which is highly toxic to many marine organisms at high concentrations.

Changes in ocean pollution

Human activity has a dual impact on the amount of pollutants in our coastal areas. There are direct effects when we release pollutants into the environment, and climate change also has indirect effects on the natural resources of these elements.

Worryingly, there is a significant lack of data on how climate change affects pollutants in the ocean.

The task force argues that we need more research on new and understudied pollutants. They also highlight the need for better models, as well as the need to update legislation controlling the impact of pollutants in the seas.

Problems that arise

The twin threats of climate change and environmental pollution represent a major challenge that requires innovative solutions and collaborative strategies. One emerging area of ​​research is the development of advanced models that provide a comprehensive understanding of the interaction between climate variables and polluting behavior in marine ecosystems.

Such models will allow scientists to predict changes in the distribution of pollutants and, more importantly, to develop mitigation strategies that prioritize environmental and human health. In addition, the integration of satellite technology and big data analytics offers unprecedented opportunities to improve our understanding and monitoring of marine pollution on a global scale.

Saving oceans from toxic metals

“To better understand impacts on ecosystems and human health, we need to address knowledge gaps on interactions between pollutants and climate change and develop standardized methods that provide globally comparable data,” Dr Zitun said.

While we still have much to learn, the importance of strengthening sea defenses and developing sustainable solutions for sensitive coastal areas cannot be underestimated. Climate change and pollution are complex issues, but addressing them is vital to protecting our oceans. The study was published in the journal Contact Earth and Environment.