Over 70% of the Earth’s surface is covered by the ocean

The ocean is the largest exchangeable carbon reservoir on the planet.  While the oceans have taken up the CO2 and heat from the atmosphere and softened cushioned the warming impact, they have turned more acidic as a result. Experts concur that the international response to ocean acidification and seawater stratification poses a significant threat to commercial mollusc production, ecosystem health and coral formation.

Billions of people worldwide who rely on healthy oceans for food, employment, and climate regulation.  Yet, our oceans, the lifeblood of our planet, are under unprecedented threat due to rising temperatures, increasing acidification, declining biodiversity, and nutrient displacement that are putting marine ecosystems at risk.  These changes matter, for example the sargassum seaweed tides and many harmful algal blooms are both an economic and ecological burden. Disrupted ecosystem can rapidly become a source of carbon emission, reducing the capacity of the ocean to absorb CO2.

Our Contribution to Ocean Health  

Enhanced Marine Biodiversity: For every one unit of seawater that passes through our system, we deacidify the equivalent of ten units of seawater back to pre-industrial levels. This rebalancing allows shell-forming organisms - crucial players in marine ecosystems - to flourish. By aiding these creatures in their growth, we indirectly help restore local marine ecosystems, enhancing biodiversity and strengthening the resilience of our oceans.

With every ton of CO2 we  remove from the atmosphere, and every unit of seawater we deacidify, we contribute to a healthier, more vibrant ocean. The ripple effects of seawater improvements and environmental restoration extend far beyond the immediate vicinity of our operations.  By fostering more robust marine ecosystems, we're promoting healthier oceans, fisheries and, by extension, a healthier planet.

Sebastian Hennige

Senior Lecturer & expert on Ocean Deacidification

Dr. Hennige’s research centers around the impact of climate change and pollutants on marine organisms and ecosystems, with particular focus on tropical and cold-water coral reefs and seagrass meadows. Sebastian studied Marine and Environmental Biology at the University of St. Andrews before taking a PhD at the University of Essex. Following this, he went to the University of Delaware (USA) and Heriot-Watt University in Edinburgh (UK) before moving to the University of Edinburgh in 2016. Hennige has spoken at COP 26 and 27 on the impacts of ocean acidification to vulnerable marine ecosystems, highlighting the role of ‘coralporosis’ in future deep-sea coral reef loss. Hennige has been a contributing author to the Intergovernmental Panel on Climate Change (IPCC) Special Report on the Ocean and Cryosphere in a Changing Climate (SROCC), a contributing author to the 2nd World Ocean Assessment (UNESCO), and lead editor of a United Nations Convention on Biological Diversity (CBD) report on the Impacts of Ocean Acidification on Marine Biodiversity.

What is ocean acidification and why is it a problem?

Ocean acidification is when the ocean becomes more acidic that it is now. When carbon dioxide in the air dissolves into the seawater, it reduces the pH from about 8.1, to levels which may approach 7.8 at the end of this century. This is a big problem to many ocean organisms that make their shells and skeletons from calcium carbonate such as bivalves, corals and tiny pteropods (small snails that get eaten by lots of different fish). As pH levels approach 7.8, unprotected shells and skeletons of these organisms can start to dissolve.

Can you discuss the urgency of addressing ocean acidification, particularly as it impacts coral reefs?

Ocean acidification is a problem now, and not something that will only start in the future; we can see the impacts already and can easily track how much the pH has decreased in recent years. In the ocean, there is a depth where seawater becomes corrosive to the calcium carbonate that corals use to make their skeletons. At these depths, exposed coral skeletons (i.e. dead corals) will start to dissolve. This is a big problem for cold-water coral reefs that form spectacular habitats for a wide range of organisms, and can live down to 3000m. The depth where the ocean becomes corrosive to coral skeletons is becoming shallower due to ocean acidification, meaning that most cold-water coral reefs will be exposed to corrosive seawater by the end of the century.

How much time do we have to act on the increasing acidification levels in our oceans? 

Since the industrial revolution, the oceans have absorbed around a third of the carbon dioxide released into the atmosphere, and its pH has decreased by around 0.1. This may not sound like much, but as the pH scale is logarithmic, this represents around a 30% increase in ocean acidity compared to what it was. As the amounts of carbon dioxide released into our atmosphere increase yearly, so too does the amount that absorbs into our oceans. We know from the historic record that it takes thousands of years for ocean acidification to reverse, so we need to focus on preventing ocean acidification rather than focussing on reversing it.

What are some challenges or advancements in the field of ocean acidification that could influence our work at Brilliant Planet?

We now know how important it is to consider multiple ecosystems at once when considering ocean health, as many systems are connected. We know that seagrass meadows can reduce local impacts of ocean acidification to nearby shallow coral reefs by removing carbon dioxide from the water. In such a way we can see how the process of how reducing acidity locally, which is something that the Brilliant Planet process aims to do, can benefit associated ecosystems.The other challenge for ocean acidification is monitoring changes in seawater pH levels and understanding natural variability, particularly in coastal regions. Brilliant Planet have the opportunity to collect high resolution monitoring of this, both in terms of the input water and the outflow water following algal growth to understand local dynamics.

What are your research interests and how are you helping to push the field forward?

My research interests focus on the impacts of ocean acidification to marine ecosystems. This often focusses on tropical corals, deep sea corals, and seagrass meadows. Importantly, all these ecosystems host a large diversity of other organisms, so their success directly impacts lots of organisms (including us!). My work focusses on field measurements, experimentation in laboratories where we simulate future ocean acidification conditions, and in predicting how ecosystems and their associated biodiversity will change over time in response to climate change.

Can you describe how the UN Convention on Biological Diversity is helped by environmental restoration?

At the heart of the Convention on Biological Diversity is the aim to conserve biodiversity, ensure its sustainable use and make sure that there is equitable sharing of benefits. In addition to directly conserving environments and biodiversity through management and practices, ecosystem restoration will help recover degraded habitats (both current ones and in areas where habitats have been lost over time). With this in mind, the Convention on Biological Diversity initiated the UN Decade of Ecosystem Restoration (2021-2030) with the purpose to prevent, halt and reverse the degradation of ecosystems worldwide.


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