On 8 June 2025, the SANAP community celebrates World Oceans Day under the powerful theme: One Ocean, One Climate, One Future – Together. At the heart of this theme lies a call to protect our blue planet through collective research, and deepened understanding of the critical role our oceans play in shaping the Earth’s climate and supporting life.
For the South African National Antarctic Programme (SANAP), this is more than a celebration—it’s a reaffirmation of our mission – Understand, Develop and Conserve. Our Southern Ocean research efforts are driven by the urgent need to understand the links between ocean health, climate change, and the wellbeing of future generations. South Africa, as a gateway to Antarctica and the Southern Ocean, plays a key scientific and logistical role in advancing global knowledge of polar and marine systems.
Sometimes called the lungs of the planet, the Southern Ocean absorbs vast amounts of carbon dioxide and heat, making it one of the most crucial regulators of Earth’s climate. It drives ocean circulation, supports unique ecosystems, and connects all major ocean basins. However, it is also one of the fastest-changing regions due to climate change—warming waters, shifting ice dynamics, and altered ecosystems pose challenges that demand urgent scientific attention.
SANAP’s Research Footprint
Through SANAP, South African researchers from various institutions are contributing world-class science to understand and protect the Southern Ocean:
The University of Cape Town (UCT) leads long-term monitoring programs on carbon fluxes, ocean-atmosphere interactions, and ecosystem responses to warming. MARiS includes the Antarctic MIZ Observations: Interdisciplinary approaches to resolve seasonal sea-ice variability. The SEAmester floating classroom initiative also trains young scientists at sea, combining education with real-time research.
Stellenbosch University contributes cutting-edge work in marine microbiology and ocean biogeochemistry, studying the role of microscopic life in global carbon cycling and nutrient dynamics.
Nelson Mandela University focuses on marine top predators, such as seals and penguins, to track ecosystem health and food web shifts in response to
South African Weather Service project includes the decoding the mercury cycle in the Southern Ocean: in situ observations and advanced modelling
CSIR – Smart Places – SOCCO has two projects focusing on the Southern Ocean Carbon-Heat Nexus: mixed-layer processes & feedback for improved climate projections and emergent constraints on Southern Ocean phytoplankton physiology (ECOSOPHY)
Wayne de Jager – Increased Rotational Coupling Between Antarctic Sea Ice and the Atmosphere Over the Last 30 Years
Sebastiaan Swart – The oceans imprint on air sea fluxes: Drivers of turbulent heat flux over the Agulhas Current
Tarron Lamont – Monitoring Western Boundary Current System variability with satellite altimetry
Riesna R. Audh – Rafting of Growing Antarctic Sea Ice Enhances In-Ice Biogeochemical Activity in Winter
Robyn Verrinder – Antarctic MIZ observation platforms: Interdisciplinary approaches to resolve seasonal sea ice variability
Tamaryn Morris – 1. Sustained ocean observations for the Agulhas Current: Realizing the Benefits of Ocean Knowledge through Co-Design. 2. Capturing a cyclonic eddy, and cross-shelf dynamics, in the Agulhas Bight during an early retroflection of the Agulhas Current.
Magata Mangatane – Intercomparison of Antarctic sea-ice thickness estimates from satellite altimetry and assessment over the 2019 data-rich year.
Sharon Nicholson – The seasonal cycle in Southern Hemisphere Africa
Rutger Marquart – Coupled dynamics and thermodynamics modelling of heterogeneous sea ice and ocean waves
Janine Schoombie – Mapping within-island-scale wind variation on Marion Island
Christopher Reason – Multiyear La Niña events, the Mozambique Channel, and rainfall over eastern Africa
Thulwaneng Mashifane – Trait–Based Adjustments: Key to Improving Bloom Seasonal Cycle in the Subantarctic Zone
Sandy Thomalla – VeGAS-pCO2: Versatile glider, atmospheric and ship high precision pCO2 gas flux analyser
Amber Sneddon – Atmospheric River climatology for the South Atlantic Basin based on modern image-processing-based tracking.
Marcel Du Plessis – Storms regulate Southern Ocean summer warming
Sandy Thomalla -Southern Ocean Observing System for sustained and coordinated observations in a changing world
Thomas Ryan-Keogh – How can we effectively manage the impact of climate change on Antarctic ecosystems?
Sandy Thomalla – Climate-driven change to phytoplankton blooms across the global ocean
Nicolette Chang – Investigating Heat and Carbon Exchange in the Southern Ocean: Insights from a Mesoscale-Resolving
Sarah Du Preez – Environmental influence on zooplankton variability around sub-Antarctic Prince Edward Islands
Sarah-Anne Nicholson – The impact of storms on CO2 and heat exchange across the Southern Ocean
Thato Mtshali – Wintertime distribution and mixed layer dissolved iron budget in the south Atlantic sector of the Southern Ocean
Miranda Sitofile – The seasonal iron supply in the Southern Ocean
Chris Reason – Interannual and intraseasonal variability in the Southern Hemisphere
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
MARIS started the first session on Southern Ocean research within SANAP with focus on SEA ICE. Above: Rutger Marquart, Magata Mangatane, Dylan White, Anand Nair, Wayne de Jager, Leila Nefdt, Safiyyah Moos, Tokoloho Rampai, Marcello Vichi, Robyn Verrinder, Hayley Swait, Riesna Audh, James van Niekerk. (Photo Credit: MARIS)
The first ocean session covered the Antarctic sea ice research field led by the Sea Ice Team from the Marine and Antarctic Research for Innovation and Sustainability (MARiS). The research themes covered in this session were innovation and development, oceans and marine eco-systems under global change and earth systems observations. The presentations and posters under these research theme covered a diverse range of projects from large-scale sea ice observations, tracking and measurements to the small-scale sea ice dynamics, properties and biogeochemistry. Antarctic sea ice research has received a comparatively limited focus compared to its Arctic counterpart. The MARiS sea ice team is constituted of the departments of Oceanography, Electrical and Chemical Engineering at the University of Cape Town, with projects aimed to contribute new insights and push the boundaries within this research domain. The presentation within this session were on a variety of earth system observations models, simulations of sea ice wave interactions, innovative tool development for lab-based experiments and field-based work investigating sea ice dynamics and properties and the ecological impacts of algae and their biogeochemical significance. The session under the MARS theme; Oceans and marine ecosystems under global change was chaired by Principal investigator Tokoloho Rampai and it included an overview of Maris by Robyn Verrinder. The session was done in round table fashion and included posters and oral presentations. Tokoloho concluded the session with a closing statement
Oral presentations:
Robyn Verrinder – Overview of MARIS.
Rutger Marquart – Numerical modelling of sea ice dynamics and thermodynamics in the Antarctic marginal ice zone. (abstract)
Anand Nair – Three-Dimensional Computational Fluid Dynamics Modelling of Pancake Ice on Waves. (abstract)
Safiyyah Moos – Investigating the dynamics and exchanges across the ice-ocean interface in artificial sea ice. (abstract)
Hayley Swait – Investigating Brine and Air Porosity in Sea Ice from the Eastern Antarctic Marginal Ice Zone. (abstract)
Poster Presentations were displayed in the venue during the symposium and presenters gave a quick introduction to their posters during the round-table session.
Wayne De Jager – Sub-daily Antarctic sea-ice variability estimates using swath-based retrieval methods. (abstract)
Dylan White – Discussion on the Premise of, and Challenges in, the Development of a Ship-Based Radar System for the in-situ Measurement of Sea Ice Thickness. (abstract)
Marcello Vichi – Wind- and wave-driven free-drift dynamics in Antarctic Sea ice.(abstract)
Tokoloho Rampai – Sea ice growth dynamics and their influence on the physical, structural and mechanical properties-A discussion on innovation in in situ testing. (abstract)
James van Niekerk – Investigation of the Interactions Between Sea Ice Algae from the Marginal Ice Zone of Antarctica and Artificial Sea Ice. (abstract)
Riesna Audh – Winter biogeochemical activity is enhanced by rafting in growing Antarctic Sea ice. (abstract)
After the session the group took pictures (Credit: Leila Nefdt)
It is with great sadness that we announce the untimely passing of Dr Precious Thembumuzi Mahlalela.
Dr Mahlalela, Research Coordinator of the South African Polar Research Infrastructure (SAPRI) LTO-Ocean Integrated Facility, passed away on 28 November 2023 after a short battle with cancer.
Dr Mahlalela joined NRF-SAEON (host of SAPRI) in May 2023 at the same time as successfully finishing off the corrections for her PhD in Ocean and Atmospheric Sciences thesis, entitled Variability and Trends in Rainy Season Characteristics of the Eastern Cape. She was due to graduate in December.
Upon joining the SAPRI team, she threw herself straight into the adventure, assisting with SEAmester and providing great support at sea. As soon as she was back on dry land she flew to China to learn about moorings. Although this was her first international trip, she approached it like the other challenges she has faced, with a calm and humble attitude, open to learning and new experiences. Upon her return, she insisted on accompanying the SEAON team on a science engagement roadshow in the Western Cape to inspire young minds. She continued to work with the same positive energy and gentle sense of humour that endeared her to everyone.
“In the short time she was with us at SAPRI she became part of our family. Taken from us far too soon, her light will continue to shine through the friendships she made, the individuals she worked with, and the souls she ignited with inspiration. Fair winds and following seas, shipmate. We have the watch now” Prof Juliet Hermes – SAPRI and SAEON Egagasini Manager.
Dear Precious
Your warmth and gentle spirit shone so brightly that any room you walked into lit up with a soft glow. You were an angel on this earth who combined both a bubbly and calming presence and we will miss you more than any words can convey. We were so honoured to have worked with you.
Go gently dearest Precious. With love, from the SAPRI team.
The SAPRI team and SAEON Egagasini team will miss you dearly.
Our deepest condolences to Precious’s family, friends and everyone who had the privilege of meeting her.
Obituary of Precious Mahlalela by Juliet Hermes, Tammy Morris, Anne Treasure, Errol Julies, Anche Louw, Abu Nguna, Rabia Mathakutha and Riesna R. Audh, 30 November 2023.
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).