Natural shifts in oxygen levels within coastal waters could be the key to helping marine species better tolerate threats associated with climate change and contamination, according to a new study led by scientists at Newcastle University.

Investigating the effects of deoxygenation on coastal environments, the authors of the new study have highlighted the urgent need to rethink how we understand and measure oxygen in our ocean as a means to protect the marine life within it more effectively.

Key oxygen producing habitats such as kelp forests, coral reefs, seagrass meadows, mangroves, and some microbial communities all help to fight oxygen loss within the ocean to create rich and healthy environments. The paper states that protecting these habitats is therefore essential for keeping coastal marine life thriving in the face of climate change.

Published in the journal Trends in Ecology and Evolution, the work proposes a new conceptual framework to help demonstrate how natural shifts in oxygen levels could help marine species better tolerate the kind of threats associated with climate change. 

This involves – states the paper – a ‘new way of thinking about oxygen, not just as something species need, but as resources they may compete for, depending on how much is available, how fast it is provided, and how crowded the environment is.’

By studying how marine organisms react to changing oxygen levels, the paper has argued, we can better plan for the future, protect biodiversity, and support ocean health.

Dr Marco Fusi, senior lecturer in marine biology at Newcastle University’s School of Natural and Environmental Sciences and lead author of the study, said: “We often think of oxygen in marine ecosystems as stable and unchanging. But for marine life, oxygen levels are constantly shifting. Understanding this dynamic “oxyscape” is key to improving how we measure oxygen, assess deoxygenation, and evaluate ecosystem health.”

“When animals are exposed to natural oxygen fluctuations, they can build tolerance to stressors like heatwaves and pollution,” continued Dr Fusi. “However, to truly grasp how marine life responds, we must move beyond a human-centred view and consider what marine organisms actually experience, especially in coastal environments where oxygen levels can vary dramatically.”

Dr Fusi argues that conditions that seem mild to humans “may be extreme for fish, corals, and other sea life”, using this perspective to compound the argument for the adoption of a new approach of measuring oxygen at the scale and frequency that animals experience it.

“This will help us design better experiments, develop smarter conservation strategies, and build more accurate climate models,” he said.

It’s hoped that by considering this dynamic nature of oxygen in coastal waters, researchers will be able to make improved predictions of how species will respond to climate change. This could – according to Dr Fabrice Stephenson, a senior researcher at the University of Newcastle – provide a more robust forecast for important target species in fisheries, as an example.

Dr Simone Baldanzi from University of Valparaiso in Chile, added: “It is fundamental to investigate how marine coastal species, including economically important resources, perceive and respond to changes in oxygen at scales that matter for the functioning of the coastal ecosystem. This will help to improve the management of fisheries and reduce the effects of ongoing global ocean deoxygenation.”

Importance now rests, argue the paper’s authors, on protecting the oxygen-producing habitats responsible for generating natural oxygen fluctuations – those like seagrasses and mangroves – which not only support biodiversity but also maintain coastal ecosystems.

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