Without marine life, atmospheric carbon dioxide levels could be up to 50% higher. Our understanding of how marine life achieves this and, in particular, how this may alter in response to climate change has major gaps. The BIO-Carbon NZOC Science Mission is an exciting and strongly complementary collaboration with the ongoing NERC Net Zero Ocean Capability (NZOC) initiative to bring cutting-edge, low-carbon approaches to bear on important science questions relevant to the wider societal debate around ‘net zero’ and whether we should deliberately manipulate the ocean to remove carbon dioxide from the atmosphere.
HM: As the Champion for the BIO-Carbon program, what are some specific questions that you personally hope to answer and/or investigate?
AM: As the Champion for BIO-Carbon, my role is focused on ensuring that the overall aims of the program are delivered. The three main challenges are understanding how marine life affects the ability of seawater to absorb carbon dioxide, how the carbon dioxide in seawater is then converted into living organisms, and what happens to the carbon making up those organisms when it inevitably decays back into carbon dioxide. Together, answering these challenges would help us understand how marine life stores carbon in the ocean and how this may change. In practice, this means I spend my time coordinating fieldwork and collaboration between the component projects (involving researchers from across the UK and their international collaborators) that will provide the scientific breakthroughs and insights we seek.
Dr. Adrian Martin, BIO-Carbon champion from the National Oceanography Centre.
HM: Does the autonomous fleet require ship-based operations, or can they operate from coastal ports?
AM: The NERC autonomous underwater vehicle (AUV) fleet is flexible, as you would expect. There is already considerable use of autonomous vehicles like Autosub Long Range (aka Boaty McBoatface) and gliders deployed from research vessels. The exciting extra dimension offered by the BIO-Carbon NZOC science mission is in offering additional funding to support shore-launched vehicles as a powerful extra tool to tackle the BIO-Carbon science challenges. This is more challenging than it may sound, as the areas that scientists want to study may be 500 km or more from land.
HM: What kinds of measurements and sensors are on board the autonomous robots?
AM: Understanding how carbon is stored in the ocean is a truly interdisciplinary challenge. It requires knowledge of the physical and chemical environment as well as the nature of the living (and dead) material. Hence, the range of sensors that scientists may choose to make use of, and which can be fitted to AUVs, is very wide, from standard sensors for temperature, salinity, and oxygen abundance to more recent technology, such as sensors that can do ‘wet’ chemistry in situ, others that can probe the health of the organisms turning carbon dioxide into living material, cameras capable of resolving organisms less than a hair’s width in size and water samplers that can bring water back for analyses that are still currently only possible in the laboratory.
HM: Are the sensor packages on board provided by other companies, or are they made in-house?
AM: BIO-Carbon is a NERC program, so there is no ‘in-house’. Which sensors will be used will depend on what is requested by the scientists currently writing their proposals to be involved in the program’s fieldwork in the North Atlantic next year. The sensors are likely to come from a range of sources. Some will be standard ‘off-the-shelf’ sensors, while others may be ones developed by or in collaboration with the UK research community, but these will hopefully be the off-the-shelf sensors of the future.
HM: What policies and technologies do you think are still needed to ensure the possibility of Net Zero ocean exploration?
AM: My personal view is that the potential of net zero ocean exploration has already been demonstrated. The questions are how we get there and how quickly. To assist in that, several things are needed. From a technological point of view, the endurance of AUVs is an ongoing and important focus. Additionally, the need for, and difficulties associated with, integrating diverse sensors on an AUV to sample in a consistent way and to cross-calibrate them across different vehicles remains a major challenge that shouldn’t be underestimated. We can learn a lot from the biogeochemical ARGO float program in this regard. It is also necessary to fully engage the scientific community. Technological advances are essential, but unless the science community is aware of them and embraces them as tools to answer the questions they are interested in, progress will be slower than it might be.
HM: What are some of the biggest data and knowledge gaps in the carbon realm that need to be addressed?
AM: BIO-Carbon was careful to tackle this question right at the start. The first group of projects included one that had the specific task of identifying the major gaps in our knowledge. This project is called BRICS (Biology’s Role In ocean Carbon Storage) and, as anticipated, found many significant gaps. Rather than try and summarize their findings in a sentence, I would recommend anyone interested to check out their preliminary report on the project webpage (https://bio-carbon.ac.uk/projects/brics). As an appetizer, we are, for example, still unable to answer the fundamental question of whether the total amount of carbon dioxide converted to living material in the ocean each year—which supports the entire marine ecosystem—will increase or decrease in the future.
HM: Can you share what some of the greatest difficulties are when obtaining data related to ocean carbon storage?
AM: The difficulties facing BIO-Carbon are, to a large extent, common to many areas of marine science and can be broadly characterized as paucity and sparsity of data. We know that key processes can be ephemeral and intermittent, so you must be lucky to capture them, particularly if on a short research cruise that is constrained in time. Seasonality is also significant. Much of the surface ocean has a seasonal cycle characterized by spring bursts of life, like on land. What might be more surprising is that the effects of these ‘blooms’ can be seen hundreds of meters deeper in the ocean. Obviously, that comes with challenges for observing the key processes at such depths, particularly if we want to see what happens before or next if it takes us into periods that may be challenging for research cruises, like winter. AUVs are clearly going to be increasingly valuable tools in addressing these difficulties.
HM: Are there any other upcoming projects or topics you wish to share with us?
AM: I would strongly encourage a look at our existing six projects which already tackle the role of organisms from bacteria to fish in storing carbon in the ocean. You can find information on these projects on our program webpage—bio-carbon.ac.uk. We are also waiting to receive proposals from the science community for our field program, which will hopefully take place next year. Selected proposals will appear on our webpage towards the end of the year—so please keep checking.
