Gignoux-Wolfsohn et al., New framework reveals gaps in US ocean biodiversity protection, OneEarth (2023), https:// doi.org/10.1016/j.oneear.2023.12.014. (accompanying fact sheet)
Gignoux-Wolfsohn et al., New framework reveals gaps in US ocean biodiversity protection, OneEarth (2023), https:// doi.org/10.1016/j.oneear.2023.12.014. (accompanying fact sheet)
The National Science Foundation, on behalf of the National Science and Technology Council Subcommittee on Ocean Science and Technology (SOST), requests input from all interested parties to inform the development of a National Ocean Biodiversity Strategy (Strategy), covering the genetic lineages, species, habitats, and ecosystems of United States (U.S.) ocean, coastal, and Great Lakes waters. Learn more and submit input by Feb. 28.
Amidst a heightened focus on the need for both drastic and immediate emissions reductions and carbon dioxide removal to limit warming to 1.5°C (IPCC, 2022), attention is returning to ocean iron fertilization (OIF) as a means of marine carbon dioxide removal (mCDR). First discussed in the early 1990s by John Martin, the concept posits that fertilization of iron-limited marine phytoplankton would lead to enhanced ocean carbon storage via a stimulation of the ocean’s biological carbon pump. However, we lack knowledge about how OIF might operate in concert with an ocean responding to climate change and what the consequences of altered nutrient consumption patterns might be for marine ecosystems, particularly for fisheries in national exclusive economic zones (EEZs). Tagliabue et al. (2023) addressed this in a recent study using state-of-the-art climate, ocean biogeochemical, and ecosystem models under a high-emissions scenario.
The study’s findings suggested that OIF can contribute at most a few 10s of Pg of mCDR under a high-emissions climate change scenario. This is equivalent to fewer than five years of current emissions and is consistent with earlier modeling assessments. This estimate is based on the modeled representation of carbon and iron cycling and a highly efficient OIF strategy that may be difficult to achieve in practice. Enhanced surface uptake of major nutrients due to OIF also led to a drop in global net primary production, in addition to that due to climate change alone. By then coupling a complex model of upper trophic levels, the projected declines in animal biomass due to climate change were amplified by around a third due to OIF, with the most negative impacts projected to occur in the low latitude EEZs, which are already facing increasing pressures due to climate change.
This work highlights feedbacks within the ocean’s biogeochemical and ecological systems in response to OIF that emerged over large spatial and temporal scales. Associated pressures on marine ecosystems pose major challenges for proposed management and monitoring. Restricting OIF to the highest latitudes of the Southern Ocean might mitigate some of these negative effects, but this only further reduces the minor mCDR benefit, suggesting that OIF may not make a significant contribution.
Authors
A. Tagliabue (Univ. Liverpool)
B. S. Twining (Bigelow Laboratory)
N. Barrier & O. Maury (MARBEC, IRD, IFREMER, CNRS, Université de Montpellier, France)
M. Berger & Laurent Bopp (ENS-LMD, Paris, France)
IPCC. Summary for Policymakers. in Climate Change, 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (eds. Shukla, P. R. et al.) (Cambridge University Press, 2022).
The ultimate goal of marine carbon dioxide (CO2) removal (mCDR) is to sequester more atmospheric CO2 in the ocean than the ocean already does today. As such, any mCDR deployment must lead to quantifiably more CO2 sequestration in the ocean than would have happened without the deployment. This requirement is referred to as “additionality.”
To understand how additionality of CO2 removal is relevant for Ocean Alkalinity Enhancement (OAE) we need to recall what OAE seeks to do. Essentially, OAE accelerates a natural process (weathering) that absorbs protons (H+) in liquid media through geochemical reactions. This anthropogenically enhanced “buffering” results in fewer freely available protons and thus a shift in the marine carbonate system away from CO2 and towards carbonate ions (CO32+), a shift that enables oceanic uptake of atmospheric CO2. However, the anthropogenically buffered protons are then no longer available to be absorbed by natural weathering processes (e.g., calcium carbonate dissolution). Therefore, anthropogenic buffering of seawater pH partially replaces natural buffering (and associated CO2 sequestration) that would have occurred in the absence of OAE. A recent paper (Bach, 2024) describes this “additionality problem” in the context of OAE, and through a series of incubation experiments that emulate a high-energy wave zone (constant mixing), the author investigates how different forms of anthropogenic alkalinity (e.g., sodium hydroxide, steel slag, and olivine) interact with natural alkalinity sources (beach sand) and the subsequent impacts on atmospheric CO2 drawdown. While many questions will require more targeted study, this study represents a foundational baseline for future OAE experimentation and provides preliminary insights on siting and methods of anthropogenic alkalinity addition.
Author
Lennart Bach (Univ. Tasmania)
The Ocean Atmosphere OCB Subcommittee focuses on ocean atmosphere interactions and their role in marine biogeochemical cycles. For our mission statement, previous activities, and recently written US-SOLAS science report, see our website. Our committee meets remotely once a month to lead initiatives, plan activities, interact with international SOLAS, etc. For more details, see our charge and terms of reference.
The Ocean-Atmosphere Interaction committee is seeking nominations for at least three new members, including one or more early-career members. Self-nominations are encouraged. We are especially interested in filling the expertise gaps of
For the early career position, any research relevant to air-sea interaction is welcome. An early career nominee must have completed a PhD within the last 4 years; both postdoctoral researchers and new faculty members are eligible. For the early career nominees who are currently postdocs, a letter of support from the nominee’s postdoctoral advisor is required in addition to filling out the nomination form. This letter of support should be sent to hbenway@whoi.edu.
The Ocean Atmosphere Interaction Committee and SOLAS would like to invite everyone to the Courtyard Brewery, a location near the Ernest N. Morial Convention Center with food and drinks, on Wednesday, Feb. 21 starting at 6:30 PM. Enjoy some appetizers on us while you chat with old friends and make new ones. This is open to all, so please feel free to bring partners, colleagues, and friends.
WHEN: Wed. February 21, 2024 starting at 6:30 pm
WHERE: Courtyard Brewery, 1160 Camp St., New Orleans.
Marine carbon dioxide removal (mCDR) has exploded in popularity this Ocean Sciences Meeting. Are you curious and want to learn more? Are you thinking about engaging in an mCDR research project? Want to partner with industry or learn what’s happening in the environmental NGO space? Join co-hosts Ocean Carbon & Biogeochemistry (OCB), Carbon to Sea, Exploring Ocean Iron Solutions (ExOIS), [C]Worthy, and Ocean Visions for an mCDR networking event on Monday, February 19 from 6:30-9:30 pm at the Audubon Aquarium (1 Canal Street, New Orleans, LA). All are welcome to come by for a few minutes, an hour, or the whole evening to peruse the mCDR landscape. The sponsoring organizations will offer welcome and introductory remarks at the beginning, and then we will mingle over food and beverage! We aim to convene a diverse group of multisector stakeholders to share information and explore new collaborations. Hope to see you there!
Save the date: Thursday, February 22, 12-2 pm
2024 Ocean Sciences Meeting – Convention Center Room 224
Join Federal Program Managers to share what you think are the grand challenges facing the Biogeochemical Observing and Modeling Communities and discuss opportunities for improved connectivity between observing and modeling efforts.
Biogeochemical observing networks and models are developing at an unprecedented pace. This workshop will provide space for biogeochemical modelers and observers to make connections, ensure observing networks are addressing critical modeling data needs, and inform federal research priorities. Participants will split into topical or regional groups and move between tables to discuss what data are currently available for models and what data and data products will be needed in the future. Workshop outcomes may include a report on regional observing data gaps and recommended improvements to data products that feed into biogeochemical models.
Please indicate your interest in attending this workshop by responding to this short google form
Reach out to the organizers with any questions: Erica Ombres, Liza Wright-Fairbanks (NOAA Ocean Acidification Program), Alyse Larkin (NOAA Global Ocean Monitoring & Observing Program)
Ellen Park (Woods Hole Oceanographic Institution)
Title: Quantifying biological carbon pump parameters from the global Biogeochemical Argo float array
Abstract: The ocean is a large sink for carbon dioxide and thus plays an important role in regulating the Earth’s climate. This uptake occurs at the air-sea interface through a combination of physical and biological processes, which are commonly referred to as carbon pumps. The biological carbon pump (BCP) transfers carbon against its concentration gradient via the sinking and transport of particulate organic matter that is produced in the surface ocean. In the modern ocean, the BCP is thought to remove an estimated 6-12 Pg C from the surface ocean annually, which is approximately equivalent to total annual anthropogenic carbon dioxide emissions. The magnitude and variability of the BCP’s drawdown of atmospheric carbon dioxide have large uncertainties due to limited measurements across both space and time and the fact that the ocean has varying ecosystem compositions and physical dynamics. Here, we leverage floats with optical backscatter sensors from the global Biogeochemical Argo float array to quantify BCP metrics across different biomes in the global ocean. The particulate backscatter signals can be decomposed into a large, fast sinking particle signal and small, slower sinking particle one. These values are used to estimate BCP metrics such as particulate matter attenuation coefficients and transfer efficiencies. Quantifying these metrics across time and biomes is important for reducing uncertainties in the BCP, improving model parameterizations, and ultimately better constraining the global carbon cycle.
Adam Stoer (Dalhousie University)
Title: Estimating marine phytoplankton biomass and productivity from Biogeochemical-Argo floats
Abstract: Knowledge on the biomass and productivity of ocean phytoplankton is fundamental to our understanding of life on Earth. Phytoplankton are autotrophic microbes at the base of the marine food web, that, through photosynthesis, produce organic matter that sustains higher trophic organisms. In this talk, I estimate the biomass and productivity of phytoplankton by using the fleet of Biogeochemical-Argo floats. In the first part of my talk, I describe a method for estimating net primary productivity using daily cycles of particulate carbon constructed from float profiles distributed across the ocean. This method provides depth-resolved estimates of productivity that are representative of large swathes of ocean, and which are comparable to satellite models. In the second part of this talk, I use the global array of floats to estimate Earth’s stock of phytoplankton biomass, as well as their seasonal and geographic distribution. I also compare the seasonal cycles between carbon biomass stocks and chlorophyll-a concentrations at the surface, a metric commonly-used as a proxy for biomass, and show how surface chlorophyll-a cannot accurately identify the timing of the peak annual bloom in three-quarters of the ocean. Using these observations, I demonstrate how the Biogeochemical-Argo array can provide a more accurate, holistic view of ocean phytoplankton ecology.
Carter, B.R., Sharp, J.D., Dickson, A.G., Álvarez, M., Fong, M.B., García-Ibáñez, M.I., Woosley, R.J., Takeshita, Y., Barbero, L., Byrne, R.H., Cai, W.-J., Chierici, M., Clegg, S.L., Easley, R.A., Fassbender, A.J., Fleger, K.L., Li, X., Martín-Mayor, M., Schockman, K.M. and Wang, Z.A. (2023), Uncertainty sources for measurable ocean carbonate chemistry variables. Limnol Oceanogr. https://doi.org/10.1002/lno.12477
Learn more about OCSIF here.
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Funding for the Ocean Carbon & Biogeochemistry Project Office is provided by the National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA). The OCB Project Office is housed at the Woods Hole Oceanographic Institution.