Blue Carbon: What a scientist wants you to know about seaweed
We spoke to seaweed expert Dr. Ana Queirós about kelp conservation and the questions guiding blue carbon research in the Orkney Islands
Photo by Faine Loubser
Dr. Ana Queirós is a mother, climate scientist, benthic ecologist (someone who studies the bottom of the ocean) and an international expert on seaweed carbon storage. Through her work at Plymouth Marine Laboratory, she’s currently studying kelp sequestration and the carbon storage potential of seaweeds, focussing on the Orkney Islands in the Northern Isles of Scotland. We recently caught up with Dr. Queirós after Ross Edgley’s record-breaking 52-hour, 39-minute swim in Loch Ness — a spectacle of human endurance completed in support of research to better understand and protect underwater forests.
Seaweeds can reportedly sequester up to 20 times more carbon than terrestrial forests, but where does this carbon get stored and eventually end up? Dr. Queirós’ and her team are conducting ground-breaking research to quantify blue carbon on the seafloor and strengthen conservation efforts. Here, she shares the questions guiding her research, and what keeps her optimistic that we can still create a better future for the next generation.
Q&A with Dr. Ana Queirós
What's the first thing you tell people about seaweed?
The contribution of seaweed to the regulation of the global climate system has been largely overlooked until recently. They have great capacity to absorb CO2 and are home to a large number of species of commercial and conservation value. Facing both a climate change emergency and a biodiversity crisis, it is our job (in the scientific community) to make sure we fully understand the potential capacity of seaweed to mitigate each of these issues.
What is known about the climate benefits of sea kelp and kelp forests?
Seaweeds are thought to occur on around a quarter of the global coastline. Kelp is a major group within that, and responsible for the amazing giant kelp forests of the temperate ocean that house a large number of species we want to protect, and those we want to eat. From within the marine macrophytes (large marine plant group), seaweed are thought to absorb the most CO2 , turning it into their living biomass. By absorbing CO2, seaweed take away some of that increased rate from the atmosphere, and sink it in the ocean.
This is part of the enormous value that the ocean has in the regulation of the global climate system, and potentially the slowing down of climate change (“mitigation), because CO2 is a key greenhouse gas (gasses whose increased presence in our atmosphere due to our excess emissions is leading to global warming).
The tricky aspect with seaweed is that - much like trees in the forest shedding leaves in Autumn - seaweed also shed much of their living biomass over the course of the year (both as fragments and as chemicals that dissolve in the sea). So in themselves, seaweed do not keep the CO2 for long enough (>100 years) to slow down climate change.
What we still need to work out is how to make sure we hold on to those fragments and the dissolved chemicals that hold the carbon that seaweed produces in the ocean, away from the atmosphere. That is what the scientific community is now very focused on. We have an idea of how to do it, and some of the tools to do it – now we need to apply it at larger scales to demonstrate its broader climate benefit. Some of it will have to do with how we design marine protected areas in future, so that we protect kelp habitat, but also other areas in the ocean where their shed carbon ends up. That’s what this project is about.
Can you talk us through your method? How does one measure and map the carbon storage potential of macroalgae?
We need to measure how much CO2 kelp absorbs (macroalgae), and then follow the carbon it sheds to potential sinks (in the seabed and the deep water column). That involves the use of the latest scientific approaches, including the use of particle tracking models and eDNA tracing.
What questions are guiding your research in the Orkney islands now?
What we know is that the Orkney islands host these beautiful kelp forests that provide a myriad of benefits, both for the local biodiversity, the local fisheries and ultimately, through their carbon fluxes. Our main question is where is the kelp carbon ending up in the long term? In this project, we are deploying the latest scientific tools to pursue that question. Our long-term goal is to provide this information to local and national level ocean managers to find out how best to protect those long-term sinks.
What is 'marine spatial planning' and why is it important for climate adaptation and the protection of the world's kelp forests?
A key missing piece of the puzzle when we talk about ocean conservation is that we often think of conservation as either an isolated effort within the ocean policy landscape, or indeed, one at odds with other users of the ocean, such as fisheries. What marine spatial planning (or MSP) provides, is a policy tool that allows us to manage all the different uses of the ocean together, through a platform that brings different users together in an integrated way, with a particular focus on the co-existence of activities (i.e. when an area of the ocean can be allocated to several uses, e.g., conservation and energy generation).
This is a fundamental approach to ensure that conservation goals are met (conservation being a key policy within UK Nations MSP and around the world), whilst being realistic about the challenges involved in allocating space to conservation in the real world, where many sectors compete for space as part of the Blue Economy (the ocean based economy). MSP is already part of global ocean management, and the Orkney Islands have their own regional plan, which is then supra-regulated at the Scottish level, and more broadly, at the UK level. What we are doing in this project, is tapping into the valuable partnerships we already have with the Orkney planning community (through the MSAPCE project) to make sure the information we uncover in this project is used to help protect Orkney’s kelp and its potential climate change benefits.
Meeting the ambitions of the conservation sector, and those of the many other users of ocean space, means that a key focus of MSP is the need to make sure any approaches implemented are climate-resilient -that is, that they work not just for now but also in the future, as climate change unfolds. Looking at kelp conservation specifically, what that means, is protecting areas where kelp and its carbon sinks will be located not just at present but also in the future. That may mean including a degree of recommendation about climate-adaptiveness when we consider potential locations for these sites - that is, recommendations that take into account how the distribution of kelp and its broader ecosystem will change spatially, as climate change affects each individual region.
How do kelp forests bolster biodiversity in Scotland and beyond, and what can we do to better protect them?
Beyond serving as food to a number of species, kelp fall in the group of species we call “ecosystem engineers”, much like beavers. That means they create habitats for other species because they: reduce wave impacts, provide shelter and shading that keeps predators away for some species including fish, increase habitat complexity that promotes the co-occurrence of more species than could otherwise occur in these rocky areas. Shelter provision is especially important for the young of many species, making them important nursery areas. Because they soak up nutrients from the water, seaweed in general are thought to increase water quality and reduce the local effects of both eutrophication and ocean acidification. All of these effects and more lead to increased local biodiversity.
Kelp are sensitive to physical abrasion (e.g. from fishing gear, but also from stormy weather) so both fishing and weather patterns affect them. Because they are photosynthetic, kelp depend on light being able to penetrate the water column to reach them, up to depths of 40m in the UK but deeper in areas of less nutrients, such as Madeira. Pollution in coastal areas, and shading arising from seabed disturbance (e.g. via dredging and bottom contact fishing gears) impact kelp populations.
Kelp are also known to be particularly sensitive to global warming, and to the increase of extreme events, such as heatwaves and storms. Protecting kelp into the future will therefore require the maintenance of good coastal water quality, protection from physical disturbance, and the identification of suitable habitat areas where kelp can continue to maintain healthy populations despite climate change.
When did you know you wanted to be a scientist?
As a child, I was fascinated by the American space programme, by the images of our blue planet floating in space, which stimulated in my young mind questions about how everything is connected, and a deep sense of wanting to help nature conservation.
What is your mission as a benthic ecologist?
As a benthic and climate change ecologist at Plymouth Marine Laboratory, I am interested in uncovering answers that help us manage the ocean sustainably; that help us identify and protect refuges from climate change for ocean species – those seedbanks that will help us protect ocean life as climate change unfolds. I am also aware of the vast capacity of the ocean for regulating the global climate system and want to work with others to find solutions that allow us to maximise that capacity in a safe and effective way.
What's your personal connection to the oceans?
Growing up in Portugal, the ocean was a constant presence in my life, and a deep connection with marine life emerged from a young age - from the rockpools, to the joy of swimming in the wild and playing in the surf. To this day, the ocean continues to be an important presence: a place of happiness whilst paddleboarding; a shared playground for my family and friends.
What's the significance of collaboration in your work - for example, why is it important to bring art and science together?
Many scientists recognise the similarities between the creative process in science and art. Working with artists is thus a great way to explore our own scientific understanding deeply, conceptually. Art also touches people in a very personal way, so art-science crossovers are also a great vehicle to communicate scientific understanding in a way that touches the public, a great way to raise awareness of issues using emotion, which people resonate with, and which is completely removed from scientific communication.
As a mother and scientist in these crucial months for climate action - what gives you hope for our future on this fast-changing planet?
Attending the last UNFCCC COP 26 in Glasgow last year, I was buoyed by the increased level of engagement of all levels of society in our ambition to limit climate change. We had hundreds of people outside the main arena every day. This gives me hope that the public is watching the scientific community and environmental policy, and raising the pressure on this issue because we all want a better outcome for all of us. This hopefully spurs our political structures to help us achieve the necessary level of ambition and delivery on climate change mitigation. As a mother, this gives me hope that we may still pass on a thriving planet to our kids.
Thank you, Ana! Read more about Dr. Queirós’ work with Plymouth Marine Laboratory here.
Dr. Ana Queirós is an internationally recognized expert on seaweed blue carbon and climate change ecology, with expertise in field, laboratory and modeling based approaches.
Ana is working specifically on helping to manage ocean habitats through the advancement of our understanding of global blue carbon capacity and the identification of ecosystem-level climate signals. She recently published the first field-based quantification of sedimentary seaweed carbon sequestration in the wild, highlighting the need for joint conservation of seaweed and sedimentary habitats.
Plymouth Marine Laboratory’s research in the Orkney Islands is a collaborating initiative of Forests of the Sea — our ongoing program with Mission Blue and Sea Legacy. The work received funding and support from Talisker x Parley, in part through awareness raised with Ross Edgley’s record-breaking Loch Ness swim.
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