The third session within the Marine and Antarctic Research Strategy research theme: Oceans and marine ecosystems under global change chaired by Suzanne Fietz of Stellenbosch University. The presentations resort under the title ‘Southern Ocean productivity: drivers and consequences. The session was introduced by Susanne Fietz and the alignment to MARS. (Above: group photo – Photo credit Suzanne Fietz)
Above (l-r): Liam Quinlan, Emtia Wium, Johan Viljoen, Asmita Singh, Jared Walsh (Stellenbosch University)
Liam Quinlan: Characterising phytoplankton communities: A Southern Ocean case study of environmental coupling. (Abstract)
Amelia Deary: Early community development at the Southern Ocean Marginal Ice Zone. (Abstract)
Sadiyah Rawat: The role of the island mass effect in enhancing productivity and carbon export in the Subantarctic Ocean. (Abstract)
Emtia Wium: Impact of metals in aerosols and dust on marine phytoplankton: South Africa. (Abstract)
Sina Wallschuss: The seasonality and origins of nitrous oxide in the Atlantic sector of the Southern Ocean. (Abstract)
Faith February: Observations of Southern Ocean marine aerosols in Simon’s Town, False Bay. (Abstract)
Susanne Fietz: General discussion
Mhlangabezi Mdutyana: Nitrification in the Southern Ocean: controls, kinetics, and biogeochemical implications. (Abstract)
Susanne Fietz: Trace metals and phytoplankton. (Abstract)
Sarah Fawcett(left) could not attend, but her and Dr Katye Altieri (right)students gave presentations during this session. Sarah Fawcett (abstract): Nanoplankton: the dominant vector for carbon export across the Atlantic Southern Ocean in spring.
Suzanne Fietz and the Stellenbosch University Earth Sciences team submitted an excellent e-poster Asmita Singh(e-poster) and Johan Viljoen (abstract) and Jared Walsh(abstract) were not able to attend the symposium in person.
The second session within the Marine and Antarctic Research Strategy research theme : Oceans and marine ecosystems under global change was chaired by Sandy Thomalla and Sarah Nicholson from Southern Ocean Carbon- Climate Observatory (SOCCO). The session title, “The Southern Ocean’s sensitivity to a changing climate: insights from a seasonal cycle approach” were presented through oral presentations and e-posters from SOCCO. (Left Sandy Thomalla, Right Sarah Nicholson, above SOCCO group photo)
Above (l-r): Tesha Toolsee, Tommy Ryan-Keogh, Thapelo Ramalepe, Thato Mtshali.
Sarah Nicholson: The impact of storms on CO2 and heat exchange across the Southern Ocean.
Tesha Toolsee: The complex role of storms in modulating intra-seasonal air-sea CO2 fluxes in the sub-Antarctic Southern Ocean.
Sandy Thomalla: Trends in Southern Ocean Phytoplankton bloom phenology.
Sifiso Mpapane: Understanding photo acclimation effects on Chl:C ratio in the Southern Ocean: modelling considerations and insights into seasonal assemblage composition. (E-poster)
Tommy Ryan-Keogh: Multi-decadal trend of increasing iron stress in the Southern Ocean phytoplankton.
Thapelo Ramalepe: Exploring the seasonal processes governing manganese supply in the Southern Ocean.
Thato Mtshali: Winter-time distributions and dissolved iron mixed layer budget in the south Atlantic sector of the Southern Ocean.
Miranda Sitofile: Investigating seasonal variability of dissolved iron in the South Atlantic sector of the Southern Ocean: Insights from the winter and spring SCALE 2019 cruises. (e-poster)
Lillina Ruiters: Variability of phytoplankton photo physiology in the Southern Ocean: an analysis of assumptions and uncertainties. (e-poster)
Above(l-r): Sifiso Mpapane, Miranda Sitofile, Lillina Ruiters
More about the South African Weather Service team on the recent Gough Island takeover expedition.
L-R: James Joubert Burns, Velelo Mazele, Samkelisiwe Thwala, Khuliso Collen Maphaha, Fulufhelo Brenda Khobo and Kelcey Maewashe.
The South African Weather Service (SAWS) has been part of the South African National Antarctic Programme (SANAP) from the beginning, when the first team was appointed to stay on Gough Island. The metkassies (meteorological overwintering team members) continue to contribute to a long history of data collection on Gough Island. This includes an automatic weather station that measures temperature, wind speed and direction, humidity, and pressure.
What can the new overwintering team on the island look forward to?
The metkassies when on shift do visual observations which includes cloud height and type, horizontal visibility, precipitation type, weather present and past and sea temperature. Formal observation is done every hour from 06:00GMT until 15:00GMT and then every 3 hours during night shift. This is done every day of the week.
Research team on the recent Gough Island takeover expedition.
Phytoplankton are microscopic plants that live in the ocean, and just like plants on land they need to have enough food to grow and be happy. However, some places in the ocean don’t have enough food for them whereas some places do. The Southern Ocean Carbon & Climate Observatory (SOCCO) team based at CSIR, Trace Metals team based at Stellenbosch University (TracEx) and the Department of Forestry, Fisheries and the Environment: Oceans and Coasts team are trying to figure out where those places are (in the Southern Ocean).
During the Gough Island takeover expedition:
The Trace Metal Biogeochemistry research teams sampled upstream and downstream of Gough Island to look at how the Antarctic Circumpolar Current (ACC) interacts with the island to resuspend sediments from the seafloor. This resuspended sediments acts as a source of trace metals to the surface mixed layer in support of phytoplankton blooms. The team used a 12 bottle mini-CTD rosette system (see image below, right) to sample for dissolved trace metals, particulate trace metals and organic trace metal chemistry.
TEAM
Trace Metal Biogeochemistry
Projects Name
Seasonal Iron speciation in the Southern Ocean, from open ocean environments to naturally fertilized sub-Antarctic Islands (Marion and Gough Island)
Principal Investigator
Dr Thomas Ryan-Keogh
Senior Researcher at the Southern Ocean Carbon-Climate Observatory (SOCCO), CSIR South Africa
Co-Principal Investigator (On board DFFE team leader)
Dr TN Mtshali
Department of Forestry, Fisheries and the Environment (DFFE)
Including all ship-based scientists sampling for trace metals
The project in more detail:
The Southern Ocean (SO) is one of the largest high-nutrient low-chlorophyll regions in the World’s Ocean, where primary productivity is limited by iron bioavailability, thereby impacting the strength and efficiency of biological carbon pump. There are, however, exceptions with large phytoplankton blooms persistently observed downstream of the sub-Antarctic Islands. While extensive research has focussed on iron-biogeochemistry around Kerguelen and Crozet islands, no such studies have been conducted at Marion and Gough islands.
Furthermore, whilst our previous studies have made substantial advances toward addressing the gaps in seasonal data coverage through the Southern oCean seAsonaL Experiment (SCALE) 2019 winter and spring expeditions, there is still a paucity of dissolved iron data in the SO, especially from autumn to late spring. This is severely hampering our understanding of the full seasonal biogeochemical iron cycle and its impact on primary production. This project aims to continue its focus on seasonality by expanding seasonal coverage of iron measurements to include autumn (Marion) and late-spring (Gough) expeditions for more comprehensive coverage of the SO seasonal cycle, with a particular focus on quantifying biogeochemical cycling of iron-pool around these understudied islands.
This project is funded by: The National Research Foundation, South African National Antarctic Programme funding (NRF-SANAP).