February 17-19, 2018
Crowne Plaza Convention Center, Portland, OR
The Ocean Carbon & Biogeochemistry (OCB) Program is working with a scientific organizing committee to plan the 4th U.S. Ocean Acidification Principal Investigators meeting in conjunction with the 2018 Ocean Sciences Meeting, where there will be numerous relevant sessions on changing ocean chemistry and ecosystem response. We hope to use the new research presented in these sessions as a springboard for more synthetic discussions at the OA PI Meeting afterward.
The goal of this meeting is to bring funded and newly emerging PIs together to share ongoing research on ocean acidification and co-stressors, discuss progress of the field over past 5-10 years, and develop new collaborations for the future. The outcomes of the meeting will be participant-driven, including new papers, projects, etc. Based on our initial polling of the community, there is interest in the following topical areas:
Applications for this meeting were due November 6. Applicants will be notified shortly after Thanksgiving.
More information is available on the meeting website.
OCB is currently seeking nominations for new Scientific Steering Committee (SSC) members, including a new early career SSC member. To qualify for the early career slot, a nominee must have completed a PhD within the last 4 years; both postdoctoral researchers and 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 the other information listed below.
The following SSC members are scheduled to rotate off at the end of 2017:
However, nominations need not be limited to the expertise listed above. If you wish to nominate someone, please submit your nomination to the OCB Project Office by November 1, 2017 with the following information about your nominee:
OCB SSC members serve a term of 3 years. For more information on the OCB SSC, including a list of current and previous SSC members, the SSC charge and terms of reference, and links to the past year of SSC minutes, please visit the SSC page of the OCB website.
How will phytoplankton respond to climate changes over the next century in the Ross Sea, the most productive coastal waters of Antarctica? Model projections of physical conditions suggest substantial environmental changes in this region, but associated impacts on Ross Sea biology, specifically phytoplankton, remain unclear.
In a recent study, Kaufman et al (2017) generated and analyzed model scenarios for the mid- and late-21st century using a combination of a biogeochemical model, hydrodynamic simulations forced by a global climate projection, and new data from autonomous gliders. These scenarios indicate increases in the production of phytoplankton in the Ross Sea and increases in the downward flux of carbon in response to environmental changes over the next century. Modeled responses of the different phytoplankton groups to shoaling mixed layer depths shift the biomass composition more towards diatoms by the mid 21st century. While diatom biomass remains relatively constant in the second half of the 21st century, the haptophyte Phaeocystis antarctica biomass increases as a result of earlier seasonal sea ice melt, allowing earlier availability of low light, in which P. antarctica thrive.
The projected responses of phytoplankton composition, production, and carbon export to climate-related changes can have broad impacts on food web functioning and nutrient cycling, with wide-ranging potential effects as local deep waters are transported out from the Ross Sea continental shelf. Future changes to this ecosystem have taken on a new relevance as the Ross Sea became home this year to the world’s largest Marine Protected Area, designed to protect critical habitat for highly valued species that rely on the Ross Sea food web. Continued coordination between modeling and autonomous observing efforts is needed to provide vital data for global ocean assessments and to improve our understanding of ecosystem dynamics and climate change impacts in this sensitive and important region.
For other relevant work on observing phytoplankton characteristics in the Ross Sea using gliders, please see: https://doi.org/10.1016/j.dsr.2014.06.011.
And for assimilation of bio-optical glider data in the Ross Sea please see: https://doi.org/10.5194/bg-2017-258.
Daniel E. Kaufman (VIMS, College of William and Mary)
Marjorie A. M. Friedrichs (VIMS, College of William and Mary)
Walker O. Smith Jr. (VIMS, College of William and Mary)
Eileen E. Hofmann (CCPO, Old Dominion University)
Michael S. Dinniman (CCPO, Old Dominion University)
John C. P. Hemmings (Wessex Environmental Associates; now at the UK Met Office)
In the subtropical North Atlantic, dissolved inorganic phosphorus (DIP) concentrations are depleted and might co-limit N2 fixation and microbial productivity. There are relatively large pools of dissolved organic phosphorus (DOP), but microbes need an enzyme to access this P source. One such alkaline phosphatase (APase) enzyme requires zinc (Zn) as its activating cofactor. This has been known for almost 30 years. However, recent crystallography studies revealed that two other widespread APase enzymes contain Fe. Via this requirement, Fe availability could regulate microbial access to the DOP pool.
As detailed in a recent publication in Nature Communications (Browning et al. 2017), this hypothesis was tested on a cruise across the tropical North Atlantic by adding Fe and Zn to incubated seawater and monitoring changes in bulk APase using a simple fluorescence assay. Adding Fe significantly increased APase activity in seawater samples collected in areas that were far-removed from coastal and aerosol Fe sources. Despite seawater Zn concentrations being much lower than Fe, it appeared not to be limiting.
DIP is depleted in surface waters of the tropical North Atlantic because inputs of North African aerosol Fe stimulates N2 fixation and leads to microbial drawdown of DIP. If the modern ocean is a good analog for the past, the lack of APase stimulation following experimental Zn addition could reflect limited evolutionary selection for Zn-containing APase. In general, DIP is only substantially depleted where there is enhanced Fe input fueling N2 fixation; it therefore follows that any significant requirement for APases might be restricted to these relatively high-Fe, low-Zn waters.
On a shorter timescale, growing anthropogenic nitrogen input to the ocean relative to phosphorus could result in more prevalent oceanic phosphorus deficiency. Corresponding iron inputs might then serve as an important control on phosphorus availability for microbes in these regions.
Tom Browning (GEOMAR Helmholtz Centre for Ocean Research, Kiel, Germany)
Eric Achterberg (GEOMAR)
Jaw Chuen Yong (GEOMAR)
Insa Rapp (GEOMAR)
Caroline Utermann (GEOMAR)
Anja Engel (GEOMAR)
Mark Moore (Ocean and Earth Science, University of Southampton, Southampton, UK)
A recent study by Pohlman et al. published in PNAS showed that ocean waters near the surface of the Arctic Ocean absorbed 2,000 times more carbon dioxide (CO2) from the atmosphere than the amount of methane released into the atmosphere from the same waters. The study was conducted near Norway’s Svalbard Islands, which overly numerous seafloor methane seeps.
Methane is a more potent greenhouse gas than CO2, but the removal of CO2 from the atmosphere where the study was conducted more than offset the potential warming effect of the observed methane emissions. During the study, scientists continuously measured the concentrations of methane and CO2 in near-surface waters and in the air just above the ocean surface. The measurements were taken over methane seeps fields at water depths ranging from 260 to 8530 feet (80 to 2600 meters).
Analysis of the data confirmed that methane was entering the atmosphere above the shallowest (water depth of 260-295 feet or 80-90 meters) Svalbard margin seeps. The data also showed that significant amounts of CO2 were being absorbed by the waters near the ocean surface, and that the cooling effect resulting from CO2 uptake is up to 230 times greater than the warming effect expected from the methane emitted.
Most previous studies have focused only on the sea-air flux of methane overlying seafloor seep sites and have not accounted for the drawdown of CO2 that could offset some of the atmospheric warming potential of the methane. Phytoplankton appeared to be more active in the near-surface waters overlying the seafloor methane seeps, which would explain why so much carbon dioxide was being absorbed. Physical and biogeochemical measurements of near-surface waters overlying the seafloor methane seeps showed strong evidence of upwelling of cold, nutrient-rich waters from depth, stimulating phytoplankton activity and increasing CO2 drawdown. This study was the first to document this CO2 drawdown mechanism in a methane source region.
“If what we observed near Svalbard occurs more broadly at similar locations around the world, it could mean that methane seeps have a net cooling effect on climate, not a warming effect as we previously thought,” said USGS biogeochemist John Pohlman, the paper’s lead author. “We are looking forward to testing the hypothesis that shallow-water methane seeps are net greenhouse gas sinks in other locations.”
John W. Pohlman (USGS Woods Hole Coastal & Marine Science Center)
Jens Greinert (GEOMAR, Univ. of Tromsø, Royal Netherlands Institute for Sea Research)
Carolyn Ruppel (USGS Woods Hole Coastal & Marine Science Center)
Anna Silyakova (Univ. of Tromsø)
Lisa Vielstädte (GEOMAR)
Michael Casso (USGS Woods Hole Coastal & Marine Science Center)
Jürgen Mienert (Univ. of Tromsø)
Stefan Bünz (Univ. of Tromsø)
The Ocean Carbon and Biogeochemistry (OCB) Program is soliciting proposals for OCB activities that will take place during the 2018 calendar year. We seek proposals for OCB-relevant scoping workshops and smaller group activities as follows:
Please visit the OCB website to learn about previous workshops and other OCB activities. OCB has recently been involved in numerous workshops and scientific planning activities that have generated guidelines and recommendations for future research in OCB-relevant research areas. OCB also encourages proposals that strengthen collaboration with partner programs such as SOLAS, IMBeR, US CLIVAR, IOCCP, and GEOTRACES. Please note that due to US federal funding sources, the OCB Project Office must prioritize support for US-based activities and scientists.
Please submit workshop proposals electronically to the OCB Project Office (firstname.lastname@example.org) by December 1, 2017 for consideration by the OCB Scientific Steering Committee (SSC). The OCB SSC will discuss and rank all proposals based on the following criteria: 1) Scientific merit (40%); 2) programmatic relevance (20%); 3) potential community impact (20%); and 4) timeliness with regard to OCB’s current scientific priorities and previous activities (20%). Decisions will be announced by end of calendar year 2017.
Current OCB Research Priorities
Proposals should be a maximum of 5 pages in length and should explicitly address
All proposals should include the rationale for and detailed description of the activity, a budget, and a budget justification. No salary may be included in the budget.
Scoping workshop proposals should include preliminary logistical information, including potential time frame and venue, and workshop outcomes (reports, special journal volumes, etc.) and their benefits to the OCB community as a whole. The maximum budget for scoping workshops is $65,000.
Other proposed activities should be a maximum duration of 2 years with a total target budget of $20,000-$30,000 to cover travel, analytical costs, shipping and publication costs, etc. We will consider larger budget requests if adequately justified. If the activity is a follow-on from a previous OCB activity, this connection should be explicitly made and PIs should address how this activity will serve the OCB community and further advance the scientific ideas put forth in the initial activity. Proposals should also include a draft time line for the activity with target dates for products and outcomes, as well as anticipated OCB Project Office scientific and/or logistical support needs.
This workshop, which is co-sponsored by OCB, US CLIVAR, MBARI, and Ocean Mixing Processes (OMIX), aimed to develop an interdisciplinary research community that will facilitate a better understanding of carbon uptake and storage in western boundary current regions, with an emphasis on the Kuroshio Extension.
The extent to which the return of major and minor elements to the dissolved phase in the deep ocean (termed remineralization) is decoupled plays a major role in setting patterns of nutrient limitation in the global ocean. It is well established that major elements such as phosphorus, silicon, and carbon are released at different rates from sinking particles, with major implications for nutrient recycling. Is this also the case for trace metals?
A recent publication by Boyd et al. in Nature Geoscience provides new insights into the biotic and abiotic processes that drive remineralization of metals in the ocean. Particle composition changes rapidly with depth with both physical (disaggregation) and biogeochemical (grazing; desorption) processes leading to a marked decrease in the total surface area of the particle population. The proportion of lithogenic metals in sinking particles also appears to increase with depth, as the biogenic metals may be more labile and hence more readily removed.
Findings from GEOTRACES process studies revealed that release rates for trace elements such as iron, nickel, and zinc vary from each other. Microbes play a key role in determining the turnover rates for nutrients and trace elements. Decoupling of trace metal recycling in the surface ocean and below may result from their preferential removal by microbes to satisfy their nutritional requirements. In addition, the chemistry operating on particle surfaces plays a pivotal role in determining the specific fates of each trace metal. Teasing apart these factors will take time, as there is a complex interplay between chemical and biological processes. Improving our understanding is crucial, as these processes are not currently well represented by state-of-the-art ocean biogeochemical models.
Philip Boyd (IMAS, Australia)
Michael Ellwood (ANU, Australia)
Alessandro Tagliabue (Liverpool, UK)
Ben Twining (Bigelow, USA)
GEOTRACES Digest: Iron Superstar