Ocean acidification: our changing seas

  • Other species
Years funded
  • 2009, 2010, 2011, 2012, 2013, 2014
  • Archived
Project type
  • Research

Our planet is warming and the chemistry of ocean waters is changing. Jason wants to know what this means. He is studying underwater volcanoes to see how increased levels of carbon dioxide affect marine ecosystems.

Ocean acidification: our changing seas

Jason Hall-Spencer

Project leader
About the project leader

As a professor of marine biology, I have always been fascinated by ocean life – and there is still so much to discover. Growing up by the sea meant that I spent much of my childhood in rock pools or out on boats. Some years later, a highlight of my career, and of my life, was diving in a two-man submarine in the Arctic. At depths of perpetual darkness we found a giant coral reef teeming with large fish and a riot of colourful animals – nobody even knew that coral reefs could occur in the Arctic! Also, I have...

Related Blogs
By Jason Hall-Spencer, 8th October 2015
How to act on ocean acidification: an important new report
A new publication entitled Acting on ocean acidification: improving prospects by planning ahead has been launched at the Our Ocean Conference in Valparaiso, Chile. The document calls for a forecasting system and a global monitoring network. It also emphasises the importance of scientific research into…
By Jason Hall-Spencer, 8th April 2015
It will take more than seaweed to prevent ocean acidification
Ocean acidification is causing biodiversity loss and altering ecosystems. There is currently much concern over how this will affect us and what can be done to lessen the effects of rising carbon dioxide (CO2) levels in our oceans. This past week, we published a study…
By Jason Hall-Spencer, 9th March 2015
Testing the Waters
Ocean acidification – also known as the other CO2 problem – is now affecting the ecosystems of the Mediterranean. The scientific project MedSeA (Mediterranean Sea Acidification in a changing climate), funded by the European Community, has been studying the impacts of the phenomenon throughout the…
By Jason Hall-Spencer, 12th December 2014
Looking through a window into the future
Energised by the endorphins released from a Sukhumvit Road-style Thai foot massage, I am wide awake in my hotel room at 3 am. Despite the jet lag, or because of it, I’m inspired to let you know about my week ahead. I have just taken…
By Jason Hall-Spencer, 16th October 2013
“State of the Ocean” Report on Acidification Video
The second ‘State of the Ocean’ report by the International Programme on the State of the Ocean (IPSO) and IUCN was released on October 3rd 2013. The report confirms the IPCC’s recent findings that the ocean is bearing the brunt of climate change, but says…
By Jason Hall-Spencer, 3rd August 2012
Sea anemones may thrive in a high CO2 world
Save Our Seas Supported Project Leader Jason Hall-Spencer recently (co-) authored several interesing papers. One of them describes increased growth in sea anemones because of the higher CO2 content in seawater. The abstract of the paper tells us: Increased seawater pCO2, and in turn ‘ocean…
By Jason Hall-Spencer, 25th July 2012
Jason Hall-Spencer speaks about ocean acidification
Save Our Seas Supported Project Leader Professor Jason Hall-Spencer is an authority on ocean acidification. Our seas currently absorb over 25 million tons of CO2 every day. This has caused surface waters to become 30% more acidic since wide-spread burning of fossil fuels began. As…
By Jason Hall-Spencer, 27th February 2012
Ocean Acidification in the News
Save Our Seas Supported Scientist Dr. Jason Spencer-Hall’s work is frequently in the news. The huge amounts of atmospheric CO2 being absorbed by the world’s oceans is making them more acidic than they have been for tens of millions of years. Coral Reefs provide habitat…
Project details

Assessing the ecosystem effects of ocean acidification

Key objective

Studying sites with naturally high levels of carbon dioxide (CO2), such as those near underwater volcanic vents off Italy, will enable us to form a better understanding of the consequences of allowing the oceans to become increasingly acidic.

Why is this important

Our seas currently absorb more than 25 million tonnes of CO2 every day. This has caused surface waters to become 30% more acidic since widespread burning of fossil fuels began. We need to understand the effect this will have on marine communities.


Our seas currently absorb more than 25 million tonnes of CO2 every day. This has caused ocean surface waters to become 30% more acidic since widespread burning of fossil fuels began. As well as lowering pH, increased CO2 levels alter the ocean’s chemistry. Falling levels of carbonate are a major conservation concern since these are the building blocks for shells of marine organisms from tiny coccolithophores to giant coral reefs. Current research into ocean acidification is mainly being carried out using short-term-shock experiments whereby CO2 levels are manipulated in aquaria and enclosures over short time scales.

This project seeks to facilitate fieldwork and to publicise a new approach to determine the ecosystem-wide responses to long-term changes in ocean pH. The effects will be studied in marine communities around underwater volcanic vents in the Mediterranean, which release millions of litres of CO2 per day causing seawater acidification. Impacts on marine life include a 30% reduction in biodiversity in areas where average pH has dropped by 0.4 units compared to areas at normal seawater pH (8.2). Natural CO2 vents will be used to test modelling and laboratory predictions, and bring much needed high-profile publicity to the problem of ocean acidification.

Aims & objectives

The broad aim of this project is to provide a wake up-call to raise public awareness about the problems associated with ocean acidification and to get people to think about the consequences of unabated CO2 emissions. The results that this project generate will be used as a platform for educating children and adults alike, they will be publicised using interactive public lectures, on websites and through the media.

The objectives of this project to:

  • Create as much publicity as possible for preliminary findings from CO2 vent areas showing the dramatic ecosystem tipping points that occur when the pH of seawater is lowered to the levels expected by the year 2100 if current emissions continue unabated.
  • Obtain better video images of the CO2 vent sites, visit more such sites and engage with the specialist scientific community at conferences to sell the idea that this project shows the way for a larger, fully resourced international programme designed to harness naturally acidified areas to refine our understanding of the conservation consequences of ocean acidification under the various emissions scenarios predicted by the Intergovernmental Panel on Climate Change.