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highlighting other research and ocean news
Research Article
June 2025
Antarctic glaciers export carbon-stabilised iron(II)-rich particles to the surface Southern Ocean
This research from the West Antarctic Peninsula (WAP) reveals the growing importance of glacial iron inputs to the global marine iron cycle in the context of accelerated glacial retreat. WAP glacial meltwaters export high concentrations of potentially bioavailable iron(II)-rich particles to the Southern Ocean. As this iron source extends beyond nearshore zones, it may also contribute to long-term iron cycling through sedimentation and resuspension. These findings have significant implications for the Southern Ocean carbon pump and ecosystem dynamics.
Read more about this interesting research here
Jones, R. L., Hawkings, J. R., Meredith, M. P., Lohan, M. C., Moore, O. W., Sherrell, R. M., ... & Annett, A. L. (2025). Antarctic glaciers export carbon-stabilised iron (II)-rich particles to the surface Southern Ocean. Nature Communications, 16(1), 1-10.
News Article
May 2025
“the ocean can recover faster than we had ever imagined; it can bounce back to life”
“The documentary takes viewers on a breathtaking journey through diverse marine ecosystems, including coral reefs, kelp forests, and the open ocean. It highlights the critical role oceans play in sustaining life on Earth and stabilizing the climate. Attenborough delves into the alarming impacts of industrial fishing practices, such as bottom trawling, which he likens to bulldozing underwater rainforests, and the overexploitation of krill in Antarctica.”
Sir David Attenborough releases his new film Ocean on his 99th birthday
Watch the official trailer here
Read more about this important documentary here
Credit: Silverback Films, Open Planet Studio, Altitude, National Geographic
Research Article
May 2025
Coupling Between the Subantarctic Seasonal Iron Cycle and Productivity at the Southern Ocean Time Series (SOTS)
Using 27 years of data from the SOTS south of Australia, a composite seasonal cycle of dissolved iron was constructed to examine its relationship with primary productivity. Three distinct phases emerged, where in the first phase, during the early growing season, light availability appeared to be the dominant control on phytoplankton growth. As the water column stratified and the system transitioned into the second phase, dissolved iron become the primary limiting factor, leading to rapid biomass accumulation and a near-complete drawdown of available iron. In the final phase, despite increased iron supply, productivity declined and the system shifted toward net heterotrophy, where community respiration exceeds primary production. These findings highlight a strong seasonal transition from biological carbon uptake to carbon release, providing a robust framework for understanding iron-driven productivity and carbon cycling, informing improved climate models.
Read more about this comprehensive research here
Traill, C. D., Rohr, T., Shadwick, E., Schallenberg, C., Ellwood, M., & Bowie, A. (2025). Coupling between the subantarctic seasonal iron cycle and productivity at the Southern Ocean Time Series (SOTS). AGU Advances, 6(3), e2024AV001599.
News Article
March 2025
“High Court victory for the Critically Endangered African Penguin” - SANCCOB
South Africa’s Pretoria High Court has issued a crucial order – a lifeline, so to speak – approving a settlement between two conservation NGOs, BirdLife South Africa and SANCCOB, and the country’s sardine and anchovy purse-seine fishing industry, aimed at helping protect the endangered African Penguin.
“The order provides for the delineations of no-take zones for the commercial sardine and anchovy fishery around six key African Penguin breeding colonies that lie within coastal areas where this commercial fishery operates. The six closures work together to secure biologically meaningful foraging areas for African Penguins in each of the west coast, southern Cape and Algoa Bay regions to help bring the species back from the brink of extinction.”
Heather Forrer
Read more about this excellent news here
Credit: SANCCOB
Research Article
February 2025
Observed declines in upper ocean phosphate-to-nitrate availability
Climate change is increasing ocean stratification, which limits the upward flow of nutrients needed to support marine life near the surface. However, direct measurements are challenging because nutrient levels at the surface are often below detection. Using global data from 1972 to 2022, this research suggests that the depth of phosphate-rich waters (the phosphacline) is getting deeper (by about 20 meters), while nitrate-rich layers (the nitracline) have stayed mostly stable. These findings were supported by Earth System Models, which suggest that reduced iron stress is driving nitrogen fixation, supporting the maintenance of nitrate levels. Meanwhile, phosphate is declining, suggesting a growing phosphorus limitation in surface waters. These changes have important consequences for future phytoplankton, marine food webs, and nutrient cycles.
Read more about these nutricline trends here
Gerace, S. D., Yu, J., Moore, J. K., & Martiny, A. C. (2025). Observed declines in upper ocean phosphate-to-nitrate availability. Proceedings of the National Academy of Sciences, 122(6), e2411835122.
Research Article
February 2025
Climate-driven shifts in Southern Ocean primary producers and biogeochemistry in CMIP6 models
This study examines how climate-driven changes in the Southern Ocean may reshape global ocean productivity by altering phytoplankton dynamics. Under a high-emission scenario, CMIP6 models project a ~30% increase in Antarctic primary productivity by 2100, primarily due to reduced light limitation from declining sea ice. However, large uncertainties occur from limited representation of phytoplankton ecophysiology, nutrient cycling, and grazing pressure. While model differences in simulating phytoplankton functional types underscore the importance of iron and light in structuring communities, key limitations include sparse observations and simplified assumptions. To enhance predictive capacity, the study highlights the need for targeted data collection in dynamic regions and improved modeling of biogeochemical-ecological feedbacks, especially under combined stressors like warming, acidification, and freshwater input from ice melt.
Read more about this informative study here
Fisher, B. J., Poulton, A. J., Meredith, M. P., Baldry, K., Schofield, O., & Henley, S. F. (2025). Climate-driven shifts in Southern Ocean primary producers and biogeochemistry in CMIP6 models. Biogeosciences, 22(4), 975-994.
News Article
November 2024
South Pacific: World’s largest coral discovered
In a groundbreaking discovery, researchers from the National Geographic Society’s Pristine Seas team have identified the largest known individual coral on Earth. Found in October during an expedition to a remote region of the southwest Pacific Ocean, the colossal coral measures approximately 34 m wide, 32 m long, and stands 6 m tall - making it longer than the average blue whale.
This extraordinary specimen, a Pavona clavus or “shoulder-blade coral” named for its distinctive ridged structure, is estimated to be over 300 years old and was built by nearly a billion tiny stony coral polyps. Unlike coral reefs, which are composed of many individual colonies, this massive organism is a single, continuous structure.
It surpasses the previously largest known coral, the 22-m-wide "Big Momma" in American Samoa, by a significant margin.
Credit: National Geographic Pristine Seas
News Article
October 2024
“World’s next generation of marine scientists present cutting-edge research on Kaua‘i”
The Dissertations Symposium in Chemical Oceanography (DISCO) offers recent or soon-to-be PhD graduates in chemical oceanography a platform to present their dissertation research to professional peers and build lasting professional relationships that support their future research and academic careers.
This year, DISCO XXIX was held in Kaua’i where 27 early career researchers gathered to share their cutting-edge research!
Credit: Scott Yunker
Research Article
September 2024
Antarctic krill sequester similar amounts of carbon to key coastal blue carbon habitats
This research highlights the major role Antarctic krill play in global carbon sequestration. Each summer, their sinking faecal pellets sequester ~20 million tonnes of carbon - comparable to coastal blue carbon systems like mangroves and seagrass. Although the carbon density is lower, the vast area of the Southern Ocean compensates, making krill-derived sequestration globally significant with an estimated value of this ecosystem service ranging from USD $4 to 46 billion. However, krill face increasing threats from climate change and fisheries. Given their unique efficiency in transporting carbon to depth, protecting krill habitats is essential for sustaining this ecosystem service and should inform future climate and ocean management strategies.
Read more about krill blue carbon stores here
Cavan, E. L., Mackay, N., Hill, S. L., Atkinson, A., Belcher, A., & Visser, A. (2024). Antarctic krill sequester similar amounts of carbon to key coastal blue carbon habitats. Nature Communications, 15(1), 7842.
Research Article
July 2024
Observational and Numerical Modeling Constraints on the Global Ocean Biological Carbon Pump
This study assessed ocean biological carbon pump metrics as part of the RECCAP2 project by comparing outputs from a global ocean biogeochemical model ensemble to satellite, sediment trap, and geochemical observations. The analysis focused on spatial patterns and global rates of particulate organic carbon production and sinking flux. Although variable, model outputs generally aligned with large-scale observations, where ensemble-mean export production at 100 m (6.08 ± 1.17 Pg C yr⁻¹) and the export ratio (0.154 ± 0.026) were at the lower range of observational estimates. This suggests a potential underestimation of biological CO₂ drawdown in productive regions. These results highlight the value of standardized metrics for evaluating model performance and improving predictions of climate-driven changes in ocean carbon cycling.
Read more about this interesting study here
Doney, S. C., Mitchell, K. A., Henson, S. A., Cavan, E., DeVries, T., Gruber, N., ... & Primeau, F. W. (2024). Observational and numerical modeling constraints on the global ocean biological carbon pump. Global Biogeochemical Cycles, 38(7), e2024GB008156.
Research Article
April 2024
Relationships Between Plankton Size Spectra, Net Primary Production, and the Biological Carbon Pump
This study investigates how the size structure of plankton communities influences oceanic carbon cycling. Using consistent methodologies across five ocean regions, researchers quantified biomass size spectra spanning heterotrophic bacteria to metazoan zooplankton. Although ecological theory suggests that larger organisms enhance carbon export efficiency, results revealed only a weak relationship between size spectra and export efficiency. Large organisms were associated with higher primary production, and both plankton size structure and carbon export tended to increase with overall ecosystem productivity. However, among ecosystems with similar productivity levels, those dominated by larger plankton did not export significantly more carbon than those dominated by smaller organisms. These findings suggest that while plankton community size structure reflects system productivity, it does not independently determine the efficiency of carbon export to the deep ocean, underscoring the complexity of biological processes governing carbon sequestration.
Read more about these significant findings here
Stukel, M. R., Décima, M., Kelly, T. B., Landry, M. R., Nodder, S. D., Ohman, M. D., ... & Yingling, N. (2024). Relationships between plankton size spectra, net primary production, and the biological carbon pump. Global Biogeochemical Cycles, 38(4), e2023GB007994.