Plan Sea: Ocean Interventions to Address Climate Change
Plan Sea is hosted by Wil Burns, Co-Director of the Institute for Responsible Carbon Removal at American University, and Anna Madlener, Senior Manager for monitoring, reporting, and verification (MRV) at the Carbon to Sea Initiative.
As co-hosts, Wil and Anna invite guests to the podcast each episode to discuss potential ocean-based climate solutions, particularly approaches that lead to carbon dioxide removal (CDR) from the atmosphere. The podcast scrutinizes risks and benefits of these options, as well as matters of governance, community engagement, ethics, and politics.
Plan Sea: Ocean Interventions to Address Climate Change
Dr. Lydia Kapsenberg and Dr. Tyler Cyronak discuss research advancements on OAE’s environmental safety
In this episode of Plan Sea, hosts Anna Madlener and Wil Burns dive deep into the new Biogeosciences special issue focused on the environmental safety of ocean alkalinity enhancement (OAE). This episode’s guests are Dr.Lydia Kapsenberg and Dr. Tyler Cyronak who helped edit the special issue. Compiling more than 20 studies, the special issue serves as a “one-stop shop” of the latest peer-reviewed science on the environmental safety of OAE — ranging from responses of micro algae and corals, to the influence of biogeochemical cycling and trace metals. Tune in as we unpack what insights these studies collectively suggest and discuss what it means for next steps in environmental safety research for OAE.
The volume of OAE research has grown dramatically in recent years — increasing four-fold over the last five years. The Biogeosciences special issue shines a light on this rapidly evolving landscape and offers a tool for researchers, funders, regulators, and other partners to access centralized information on potential ecological risks, environmental monitoring standards, and feedstock safety related to multiple OAE approaches.
Throughout the discussion, many themes arise, including the question: How important is it to understand both system-wide patterns and local ecological realities? Lydia and Tyler highlight that while the Biogeosciences studies suggest that many phytoplankton species appear to be resilient under expected OAE conditions, local species and ecological contexts must still be factored into any field research design. This is where researchers have an important responsibility to meaningfully engage with communities on what matters most for their local marine ecosystems and align planned environmental monitoring efforts accordingly.
For researchers, policymakers, and communities assessing OAE’s environmental safety as a potential climate solution, the Biogeosciences special issue offers a crucial early evidence base and a clearer picture of what questions come next.
As mentioned during the episode, Carbon to Sea’s Environmental Impact Monitoring Framework is now available for public review and comment here, through December 12th. Carbon to Sea and the Prince Albert II of Monaco Foundation are also currently soliciting proposals for scientific research on the safety of OAE on commercially and culturally valued marine species. You can view the full funding opportunity and submit a proposal by January 16, 2026.
Plan Sea is a semi-weekly podcast exploring ocean-based climate solutions, brought to you by the Carbon to Sea Initiative and the American University Institute for Responsible Carbon Removal.
ACRONYMS / CONCEPTS:
- CDR: Carbon Dioxide Removal
- EPA: Environmental Protection Agency
- MRV: monitoring, reporting, and verification
- OAE: ocean alkalinity enhancement
- OAEPIIP: Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project
Plan Sea is a semi-weekly podcast exploring ocean-based climate solutions, brought to you by the Carbon to Sea Initiative & the American University Institute for Responsible Carbon Removal.
0:13 - Welcome & Episode Overview
Wil Burns (00:13): Hello everyone, and welcome to the latest episode of Plan Sea: Ocean Interventions to Address Climate Change podcast. As always, I'm your host, Will Burns, and I'm co-executive director of the Institute for Responsible Carbon Removal at American University. And I'm joined by my co-host, Anna Madlener, who is Senior Manager for MRV at the Carbon to Sea Initiative. Hi, Anna.
Anna Madlener (00:38): Hello there. What's in store for us today?
Wil (00:39): Well, I'm really excited about today's episode. We're diving, or swimming deeply, into the biogeosciences special issue on environmental impacts of ocean alkalinity enhancement with two of its editors, Lydia Kapsenberg and Tyler Cyronak. This special issue is a collection of peer reviewed articles and preprints all in one place, and it pulls together more than twenty studies, ranging from impacts of OAE on microalgae and corals to biogeochemical cycling and trace metals. What are you looking forward to today, Anna?
Anna (1:17): I'm looking forward to a range of things, I would say. First off, I'd say it's quite a timely publication. I'm curious to hear from Tyler and Lydia what their take is on the systematic overview of where we stand, what we've learned, and what comes next with respect to environmental impact. I'm also interested to talk more about the importance of a special issue itself. I personally didn't really know about the value and role of that type of synthesis or publication. So how about you, Wil?
Wil (1:52): Yeah, you know, as the law person, I'm thinking about field projects that are underway or those that are contemplated in the context of ocean alkalinity enhancement and the fact that regulators are reasonably asking sharper questions now about ecological risk and monitoring standards and feedstock safety. And so I think it'll be interesting to hear how these studies might help to inform that decision-making and what else is needed to be confident at the end of the day, especially as we expand the scope of the field studies, that we can move forward or not move forward to the next stage in terms of this research. So I'm really looking forward to speaking to Lydia and Tyler. And so with that, why don't we bring them in?
Anna (2:44): Let’s do it.
Wil (2:49): Welcome Lydia and Tyler. Let's start with a round of introductions. Lydia, do you want to go first?
Lydia Kapsenberg (2:55) Sure, my name is Lydia Kapsenberg. I work for CEA Consulting, which is a small firm in California. And I help the philanthropic side of the marine carbon dioxide removal community. And I was a guest editor in this special issue and helped kick off this project.
Wil (3:13): Great. Tyler?
Tyler Cyronak (3:14): Hi, I'm Tyler Cyronak. I'm an assistant professor at Georgia Southern University and I'm an associate editor for Biogeosciences.
3:24 - The Scope of the Special Issue & How It’s Being Used
Anna (3:24): Wonderful. Thank you both so much for being here. It's a pleasure to finally have you on. We've been talking about this episode for quite a couple of weeks or months even. I'm excited to chat. I was hoping that we could start off by describing the nature of a special issue, for the non academics in the room or well, in the headphones, so to say. Can you share with us what the goal is of a special issue?
Lydia (3:51): Generally the goal of a special issue is just to bring attention to a particular topic that's current and where a lot of activities are happening, and where there's a lot of papers in the pipeline to be produced, all together within a short period.
Anna (4:09): So the intended audience is primarily academic, or does it go beyond that?
Lydia (4:14): I'd say the peer reviewed papers are, you know, obviously for an academic audience, but a special issue can be utilized by other people. This particular one, we really wanted to draw attention to ongoing work on environmental impacts of ocean alkalinity enhancement. We started this project three years ago, almost to the date. And at the time, there was not very much published research on environmental impacts of ocean alkalinity enhancement, but a lot of work going in the chemistry side and understanding and trying to quantify the potential for this to work at scale. We knew that there were numerous projects underway that were looking at environmental impacts like phytoplankton. And before they were being published, we thought it might be a nice opportunity to set up this special issue and bring this collection of this first phase of work on environmental impacts together. And so that was the premise for the project. We were trying to get ahead of the publications, keep them all together, but also motivate authors potentially to speed up writing processes and the publication process. So the journal that we selected, which is Biogeosciences, allows for preprints, which was a way to help get the data out there faster. And by having a special issue, we thought it might encourage people to present their work through the special issue and because of the preprints, the data and the message and the information and the work would get out to the world a little bit sooner than it might if this was work published in other journals.
Anna (5:57): That's super interesting. Thank you for sharing that. I definitely wasn't aware of the process mechanics behind it and how that also motivates surfacing data sooner, but in particular also producing more papers, and submitting more papers to it. That's really helpful. Can you share a bit more about what the special issue encompasses? Environmental monitoring, or assessing the ecosystem health of ocean alkalinity enhancement projects is of course a very broad issue, if you want to share a bit about which aspects of environmental impacts we're covering in this issue.
Lydia (6:32): Yep. The scope we set is really broad. We didn't want to be exclusive of any study that worked on assessing the environmental impact. So we included, of course, biological processes, ecological processes, also planning type processes or review papers or meta-analyses that drew upon already published work from other fields. The only exclusion we really had for the scope of this was the chemistry studies and modeling studies of the carbon dioxide removal potential, which was primarily the wave of publications at that time. Tyler can share what was submitted.
Tyler (7:09): Yeah, so I think we ended up with sixteen papers total published at the end. And they ranged on topics; most of them were on phytoplankton and dynamics of plankton communities. There were a couple papers that looked at higher trophic organisms. And then there were a couple of review papers as well, as Lydia said.
Lydia (7:32): And a technical note to help standardize a particular approach for phytoplankton studies.
Anna (7:38): And just so that our audience knows, Tyler was deprived of all your notes because of your fire alarm and you're joining us from the car. So I appreciate that you're probably sharing all of this off of the top of your head.
Tyler (7:49): Yes, I have no notes right here, so…
Anna (7:52): Thank you. Yeah, that's a really impressive overview. I'm curious if you want to say a little bit more, Lydia, about the impact and the utility of how you think this issue is going to be used. You mentioned, of course, scientists and academics, but as an interdisciplinary field, ocean alkalinity enhancement spans many different audiences. And yeah, I'm curious if you would just want to add feedback you've also heard so far from others, maybe philanthropies or regulators who've reacted.
Lydia (8:27): Feedback hasn't reached me, but the way that I’ve used this is a tool to help share a one-stop shop for the first big wave of studies on environmental impacts on ocean alkalinity enhancement. It's an easy reference to say, hey, if you want to understand how phytoplankton are reacting to different alkalinity feedstocks, what type of experiments have been done, the range and complexity of what ocean alkalinity enhancement might look like in the field, this is a great place to start looking. I'm not sure how much the original scientific article format lends itself to broader engagement. My hope is that there's other organizations like ocean conservation groups or key communicators in the field that do engage with the primary scientific literature that can use this and then develop other talking points or blogs or podcasts, like you guys are doing.
9:30 - Standout Papers and Research Priorities
Wil (9:30): Okay, so why don't we dive into some of the particulars of the papers in the collection? And I guess one broad question I have at the outset is, were there particular papers that you think are really pertinent to research priorities in the field and and and moving forward?
Tyler (9:52): So I think there's definitely a few papers that stood out. One of the more interesting papers was one that was a meta-analysis looking at the impacts of carbonate chemistry changes from ocean acidification experiments. So looking at data that was generated in the context of ocean acidification. Research on that has been going on since probably the late 90s to early 2000s. So there's a wealth of information about how changing things like pH, generally lowering pH, because that's what ocean acidification is doing, impacts organisms' responses. And so that was really nice to be able to put together an idea of what is going on across a broad range of types of organisms, from things like corals to pretty much any organism that you can think of to higher trophic level things like fish, and trying to understand how we can use those responses and think about how that might influence the responses of ocean alkalinity enhancement when we're changing pH through those pathways.
10:59 - Mimicking OAE in a Lab Setting
Wil (10:59): Yeah, I thought that was particularly important also. I think one of the strengths of the special issue in general was thinking about both proxies and what the optimal ways of measuring some of these things are going to be, right? And there was a lot of good research in that context. Another question is - one of the most common questions around the environmental impacts of ocean alkalinity enhancement is in the context of phytoplankton for obvious reasons, given the importance in the ecosystems as well as their uptake of CO2 themselves. How would you describe the state of knowledge around this topic, at least as captured in these studies, and were there particularly interesting new insights from these studies about ocean alkalinity enhancement and phytoplankton interactions?
Tyler (12:02): Yeah, I think there were quite a few really interesting studies. And one of the thing that relates to your previous question, and one of the neat novel things to come out of the special issue, are the different ways that scientists try to mimic ocean alkalinity enhancement under both the chemical conditions and the real world deployment conditions. So for instance, there was a study that was looking at the impacts of olivine enhancement. And instead of dissolving olivine, they made up a concoction of chemicals dissolved in seawater that would mimic what olivine would release.
Lydia (12:39): I can add something. There was an extreme diversity in experimental design amongst all of these papers, and the papers that have been published over these past couple of years outside of the special issue. And there were numerous alkalinity types that were being tested. There were numerous types of experimental designs, exposure lengths, equilibration of carbon dioxide, yes or no in treatments, the biological responses and indicators that were being measured. And I think the broadest stroke to draw from all these different types of experiments is that phytoplankton do pretty well under some of these exposures, at least under the conditions that are highly applicable for what might be expected for the lasting signature of ocean alkalinity enhancement, the permanent change in seawater chemistry. And I think the field now has to grapple with how to balance broad research on organismal physiology and ecology, but keep research tailored to the real world's conditions. There's going to be a very, very tiny proportion of the ocean, and I mean like teeny, that's going to be exposed to really extreme conditions. And those extreme conditions matter from a biological perspective if you have really critical biological processes happening in that moment that extreme exposure exists. For example, if you could think of some feedstock coming off of a ship, it's a short-term high signature of alkalinity enhancement, and that pH might spike, but then it will dilute very quickly. There was one study that looked at these exposure recovery effects. But of course, this introduces another variable into experimental design. So that gets kind of complex. You don't want all of this work to completely balloon. The other aspect is that the exposures to date have included really extreme exposures. And it's just going to be important to build a lot of evidence of the safe exposures. And that requires, you know, hundreds of papers showing no effect, which is extremely boring science. It's not interesting to publish. It's not motivating for scientific careers to have 20 publications that show no effect, perhaps. And so there is a little bit potentially of a disconnect between what an independent academic scientist might want to study versus the evidence that needs to be built up through independent academic research to allow this field to scale up in research and potentially eventually deployment.
Anna (15:42): I'm wondering if you can say a little bit more also about, as you said, mimicking real OAE or ocean alkalinity enhancement in a lab setting. So there's the question of the actual concentration of alkalinity. Were there studies also focusing on actually mimicking the rate and completeness of dissolution? I think that's also quite a difficult thing to do, right? But I'm curious if that was included in any of the studies.
Tyler (16:15): So the rate of alkalinity addition was, you know, it varied in all of the different studies and was really dependent on the method that was trying to be mimicked and the methods used. So for instance, in the olivine study, it's not going to mimic exactly the slow olivine dissolution process, but is going to tell us thresholds of chemistries that we might not want to approach in the field. Some of the other studies, a lot of the studies, added things like sodium hydroxide, where the alkalinity change is immediate, but some studies were interested in looking at changes to organism responses over a concentration range. And it's really important because you want to be able to predict where bad things are going to happen. And so in some of the more toxicology- aligned studies, you really have to push the organisms to the end to figure out where we don't want to go in the natural environment.
Anna (17:14): Yeah, and it’s super critical to inform real world applications, right, where some mineral alkalinity could potentially be added. And it's important to know exactly for which amount of time organisms may be exposed to which amount of alkalinity. But studying this dissolution of minerals in a lab can't entirely replicate the conditions that exist in the ocean for the mineral to dissolve in the first place. So [it’s a] big area definitely to keep looking at.
17:46 - Co-Benefits and Potential Positive Impacts
Wil (17:46): Yeah, so most of the focus it seemed on these studies was on potential risks associated with introduction of ocean alkalinity enhancement. Were there any studies that focused on potential co-benefits, you know, ranging from impacts on some other organisms as well as at least localized potential benefits in addressing ocean acidification? Because I think in the long term, even though our regulatory regimes are not that conducive to it, in the long term we're probably going to have to engage in comparative risk assessment, right? Given the fact that unchecked climate change obviously has massive impacts on oceans also. Do those studies help us in any way suss out some of those co benefits?
Tyler (18:41): I think a lot of the studies, well, most of the studies really found minimal impacts or minimal effects. But as far as co-benefits go, I don't think anything was really written exactly in those terms, but I do think this is a really important thing that we need to start thinking about. And Lydia and I actually wrote a paper back in 2019, or 2018, where we were thinking about ocean acidification refugia and potential benefits for organisms that might experience high or low pH environments and maybe induce resilience in some of the organisms. And some of those things that we talk about in that paper are really relevant to thinking about co-benefits as far as ocean alkalinity enhancement goes, because the benefit has to directly affect some organismal process, right? And so we have to number one, show that that co-benefit is benefiting the organism you're thinking about. And then it also has to do something that is good for the organism. And so I think for me with co-benefits, the most common thing that I can think of that is a problem with ocean acidification, and then the thing that ocean alkalinity enhancement actually provides a beneficial chemistry for, is enhancing calcification back to before the ocean acidification scenario. So enhancing the calcification of the organisms back to what it was in pre-industrial conditions. The issue with that is now you have to think about the carbon dioxide removal potential that's being lowered by the enhanced calcification. So you lose some of the carbon removal potential; you gain a co-benefit.
Wil (20:25): Right. And some of those studies in here were talking about that too, right?
Tyler (20:27): Yeah, I think maybe a little bit. There was some discussion about it. I don't think there was anything that really fully focused on that, but it is definitely something that could be…I mean, how does a carbon market value those two things, I think is really important in figuring out. But also we still need to do a lot of experiments on different types of organisms to see if there are these benefits out there. And actually, research in my lab – I'm really focused on the ecosystems around me in Georgia. So oysters are a really important commercial species. So I'm interested in - can ocean alkalinity enhancement stimulate oyster calcification and at the same time potentially help oyster farms reduce carbon dioxide or reduce their carbon footprint. And then the other side is coral restoration and thinking about growing corals for outplanting, so planting them back out into the environment and growing them under enhanced alkalinity to support their growth and maybe their resilience. So that's the things that I'm interested in. But those benefits have to be really, I think, carefully aligned with the alkalinity enhancement method and you know, they have to be linked to the chemistry that's being changed in those scenarios.
Anna (21:43): And I think you also really raise an important point about the need for co-benefits to be considered in very local contexts. I mean, I feel like the research community has generally repositioned itself a little bit in terms of ocean alkalinity enhancement and looking at it from a generally more local perspective rather than talking about ocean alkalinity enhancement as the global approach that will globally reduce ocean acidification, but in local conditions. Do you think there has been some indication that it could help? But to your point, the aspect of additionality, so whether a co-benefit reduces the carbon removal potential, needs to be really closely studied. Was there, given everything that you read in the papers, something that stood out to you that would be an obvious next approach?
Tyler (22:37): You know, I think the additionality issue, one, there's more work that just needs to be done with different types of environments and different types of organisms. And thinking about where we're going to apply these processes in the future becomes really critical because it's one thing to go and put alkalinity in the open ocean, right? But if that's not going to be how it's actually done in practice, maybe it's more likely that's going to be in a coastal outfall or maybe it's going to be olivine put on beaches or things like that. I think we really got to match the experimental design with exactly the process that's going to be adding the alkalinity to the oceans, like you said. And with the localized additions, I think that is where you're going to get most of the benefit, compared to this broad scale reduction of ocean acidification, which would be great, but I mean, that's a lot of alkalinity to add to the oceans.
Anna (23:33): And I'm putting you a little bit on the spot, sorry. But it also strikes me as something that's incredibly hard to quantify, right? Like quantifying or assessing carbon removal potential inherently means that we want to understand how much carbon was removed from the atmosphere, which entails quantification of how much potential a feedstock had, or how much alkalinity was added and how much carbon can be removed as a consequence of that. Is it even in the realm of possibility, to quantify a co-benefit in that regard such that you would be able to reduce it or subtract it from your carbon removal potential? Or how would one approach that problem?
Tyler (24:17): Well, I think that just depends on the specific scenario where it's happening. I think it's a lot harder to do in an open system for sure. So in the systems I'm thinking about, like oyster farms and coral restoration facilities, that's more small and closed systems. You can measure the inputs and outputs a little bit more easily. But yeah, I think it becomes harder to measure a co-benefit once you're going out into big open systems. And I don't know what Lydia thinks about this, but that's what we talked about in our 2019 paper. We were talking about how the benefit has to be in these small - it's probably gooing to be localized and in small areas. And this was for ocean acidification refugia, which we were thinking more of natural solutions and not necessarily these alkalinity enhancement solutions.
Lydia (25:10): I will add about co-benefits that there's a strong implied human dimension to it because a co-benefit, what is that? How is that determined? I see it as something that people care about, how you assess if something's a benefit or not. And so there's this localized aspect about co-benefits that's really important in understanding what is the - not just the environmental co-benefits potentially. Neutral may be good enough to get community support, co-benefits helps. There's other types of co-benefits and risks associated with, you know, industrial scale, ocean alkalinity enhancement, and how that human element is brought into project, I think, is really important to set the course for successful research with, you know, place-based engagement and also informing the direction of the research. We cannot endlessly study everything. So we ought to prioritize the things that are most critical to the things that we care about. That might be an ecosystem functioning in a particular place. It might be a particular species or, you know, a particular season or life stage of a species. And yeah, I think aiming for no effect or co-benefit is a great one, but you definitely need that local context to guide the research and a useful and catalytic outcome of the research.
26:49 - Implications for Monitoring in Field Trials
Anna (26:49): Sort of related, good segue into my next question…we're of course seeing early early demonstrations of ocean alkalinity enhancement in practice that come along with environmental impact monitoring regulation and frameworks. There's a handful of specific projects also tackling this. So I don't want to go into too much detail, but I'm curious if from the studies you felt that there were concrete, actionable recommendations that are directly implementable into requirements for how to monitor environmental impact at field trials. Anything that particularly changed or even maybe just sharpened a requirement given how things are being done today?
Lydia (27:37): You know, the focus on the base of the food web remains crucial. So work on phytoplankton, I'm sure, will emerge as a metric across some of these environmental impact assessment frameworks. We had talked previously about this, Tyler and I, and we really came to the conclusion that you really need a baseline and you really need long term monitoring, which means you also need funding for those two things. This may go, you know, beyond the academic research interest – I'm not sure – or capability in some places. It's hard to know if the level and detailed approach of academic research can really scale with the industry scaling. So I do think it's going to be really important to have, maybe not quite academic level, but maybe better than just the basics for environmental impact monitoring on some of these early scaling deployments.
Anna (28:32): I think I'm curious what you think for a quantification of ocean alkalinity enhancement. There's, I wouldn't say a consensus, but there's a bit of a tendency to say one year of a baseline at minimum is what you need in order to characterize a site. You wouldn't really capture variability across different years by only studying one year, but at least for the carbon and chemistry and physics, you're going to get a good idea of yeah, some local conditions, how things change over seasons. Do you have an intuition around how long a baseline needs to be for ecological data? And is that done in good manner at the moment?
Tyler (29:17): Yeah, I think it's interesting thinking about baselines between these two types of measurements. The chemistry, I mean, it just depends what system you're in. And I mean, there might be seasonal variation and then, you know, you get into the above seasonal variation that's going to happen. But for ecological and biological monitoring, I think – I mean, the first baseline that you need is to know what's there, right? What organisms are there, what potential organisms maybe are really resilient or really susceptible to some of the changes and which ones are, you know, both commercially important but also ecologically important. So starting at the base of the food chain I think is really good, as far as thinking about plankton and phytoplankton go.
Anna (30:06): Yeah, I think it's a balance, right? Ideally we would have decades of baseline data for any place that considers doing ocean alkalinity enhancement. And somehow there will have to be a balance between studying, starting things, evaluating things and accepting that there is an imperfect baseline. But that's a bit of a different topic.
Tyler (30:28): And I think thinking about the baseline's important, thinking about what's there and how it could change, but also the monitoring moving forward is probably even more important to make sure that you're monitoring some of these things as you're doing these perturbations to try and see, are there any changes? Are there any biological species, community shifts, things like that that could really potentially only be picked up if you're constantly looking at it?
30:57 - Implications for Regulatory Processes and Permitting
Wil (30:57): Okay, let's talk a little bit about the implications for the regulatory environment and permitting. Which of the papers in this collection, if any, do you think may have particular importance in terms of informing the permitting process for these projects? And were there any insights that would merit adapting current practices and our early small-scale pilots that we're seeing both in terms of companies as well as some academic shops?
Lydia (31:34): Well, I'll take a broad strokes perspective again. All of these experimental design in all these things was so different from study to study that I think the broad stroke for the field is that there's a lot of indication that ocean alkalinity enhancement is probably safe enough to do, you know, a small scale field trial, open system experiments that are short term. Collectively, there's a trend for the, you know, really high perturbations, high pH to trigger some impacts. Phytoplankton community can shift. We still don't really know if those shifts are good or bad. There are some detectable changes, but I think overall this body of work shows that it might be safe enough to just move into the field and do series of field trials and permits. So I'm not sure that any particular individual study can show that, because each study is very particular to its experimental design, the feedstock, the exposure duration, and where that experiment was done. So it's hard to translate those observations into different deployment contexts. So I think with this phase one type research, we can advance decisions based on the broad strokes and then keep a focus on the details in each particular type of study to contribute to modification of that broad stroke or you know, understanding of how to make some conclusions based on particular individual contexts and start to build a body of evidence that you can call a trend or an effect.
Wil (33:26): Yeah. One thing that I thought was particularly interesting was in the Bednaršek and co-authors piece where they indicated that the EPA standard of nine for pH, right, may turn out to be far too lenient, maybe in terms of some of the impacts that they were seeing in these studies, right? And that would have implications. It seems to suggest we're going to need very specialized management regimes for ocean alkalinity enhancement and some of the regulatory approaches that we have right now maybe are not simply honed enough to be able to regulate these things properly. Do you think that's a correct conclusion?
Lydia (34:16): Yeah, I think pH nine, you know, as represented at conferences and conversations in this field, I think is considered quite high and not a place that anyone is trying to maximize operations at. It's also a place where the chemistry becomes unstable. And so, the higher biological risk and the efficacy risk starts emerging. So I think there's general agreement that the smaller perturbation is the better one. But certainly evidence of biological impacts at those higher pH levels is known, you know, that there's a reason that that regulatory threshold exists. And I think there's good reason to think that we should stay much further below it for pH manipulations.
35:04 - What’s Next? Future Research Priorities
Anna (35:04): Given that, Lydia and Tyler, I'm curious to do a bit of foreshadowing. Based on what you've read, based on what we know today, what would you hope to see, let's say, in a special issue two years from now or so? What do you think emerged as the key next scientific focus areas to help refine those findings?
Tyler (35:27): Well, it's funny you asked this because one of the articles that was in our special issue is now leading to another special issue. So the OAEPIIP, the Ocean Alkalinity Enhancement Pelagic Impact Intercomparison Project, which was led by Lennart Bach, where they sent simulated mesocosms out to a bunch of different scientists around the world, and they all did a similar experiment. So we're actually putting together another special issue in Biogeosciences, which is going to report some of the results on that. Now that's all phytoplankton and other plankton dynamics, so none of these higher trophic levels. But I think that's going to bring together some research that has been done in very divergent ecosystems from open ocean to estuarine, and give us a better idea of how that base of the food chain is impacted by ocean alkalinity enhancement.
Wil (36:20): Can I ask you a follow-up on that? I was just curious. When you were talking about some of the research on higher trophic levels, I was thinking about the recent study from Antoni et al. that was talking about impacts of ocean alkalinity enhancement on bacterial assemblages. Do you think we need more research in that context also? Because that study seemed to indicate that there might be some fairly serious impacts in bacterial organisms.
Tyler (36:50): I'm not honestly very familiar with that study. Understanding shifting communities in the microbial world is really important. So even some of the studies in our special issue and other ones that have looked at plankton communities do show some potential shifts in community structure that are occurring. And so I think with those, we want to be careful how to interpret that, but also want to think about what a negative shift looks like, or a positive shift, because it's not necessarily just a change that is the problem. I mean, it could be a beneficial thing if we're getting more phytoplankton that are sinking faster and storing more carbon or something like that. So I think it's just a matter of each individual study and location and thinking about what those organisms do. And bacteria, I mean, they're super important in the global ocean carbon cycle. They basically can recycle organic matter. So keeping that organic matter from sinking out and pushing it back into the system to recycle that carbon. So yeah, we definitely – without knowing the full extent of that paper, I would say we need to know more.
Anna (38:01): In a similar vein, back to the beginning, do you have general recommendations on how we can enable both the sharing but also the application and and and use of such knowledge faster, given the speed at which things evolve?
Lydia (38:18): I think what we learned through this process is that it's quite difficult to speed up the academic scientific process. There are certain steps that just have to be accomplished. I think the use of journals that allow preprints is really helpful. Continued engagement in conferences is helpful. I mean, academia does all of this already. There is a question for how you can strike a balance between something that's not transparent, but something that has to go fully through the scientific peer review. And it's definitely challenging because on any great academic paper, there's a lot of feedback. There's often a lot of peer review critique, and that can be even for the best papers. And so anything less than the best academic lab is also going to be subject to that type of feedback and those errors or feedback. So I think it's a question that we who think about this field a lot, think about. And I just don't think you can speed things up. I think it means that it is ever so important to understand what the priority topic is to study because the process is kind of slow. And so going back to the special issues, I would love to see something on the valued species. Everyone wants to know what happens to their food supply, to livelihoods, to fisheries. Even if bacteria have a super crucial role, it's going to be much harder to communicate that and engage people on [that]. I think we need a whole wave of studies that just look at the investigation on higher trophic levels, ideally with strong scientific hypotheses. So we're not just exposing organisms to a bunch of different conditions, but have a mix of what it is that people care about with strong scientific hypotheses for why there might be an effect or why there might be a risk or a co-benefit to that particular organism.
Anna (40:34): Yeah, and to your point, the fact that the academic peer review is the way it is also lends to its credibility, right? Like that's why we trust science because it's gone through review and it's, again, one of those important balances to strike, considering that things are happening. Super valuable, super interesting to hear your thoughts on all of the above. And for anyone curious to dive deeper into any of these topics and explore the papers that we discussed today, we'll put the link to the special issue in our show notes. Before we close out, I wanted to very quickly allude to two things that may address some of what you just mentioned, Lydia, two opportunities to engage and work with environmental monitoring at Carbon to Sea right now. Firstly, the ocean alkalinity enhancement environmental impact monitoring framework, which was developed in partnership with Plymouth Marine Laboratory and Carbon to Sea, is currently open for public comment until December 12th. So that's definitely highly recommended to add input to. And then secondly, to your latest comment, Lydia, we just announced, together with the Prince Albert II of Monaco Foundation, a request for proposals that will put out two grants studying the effect of ocean alkalinity enhancement on commercially and culturally important species. And this request for proposals is open until January 16th. So hopefully we'll have some more insight on that last point and deliver some cool science.
Wil (42:04): Thanks for that, Anna. And thanks again, Lydia and Tyler, for joining us and sharing your insights and helping us plow through a lot of research here.
Lydia (42:15): Thank you so much for having us.
Tyler (42:16): Thanks for having us.
Wil (42:17): And as always, I want to thank our listeners. If you enjoyed this episode, please leave a comment or a review and share this episode with others. If you want to suggest a specific topic for the pod, feel free to reach out to us either through our LinkedIn page or via our email, which is plansea@carbontosea.org. And with that, we say thank you and hope to see you again in the future.
