OceanSOS Deploys Deep-Sea Mooring at Agulhas Plateau to Track Carbon Export

8 September 2026

Prof. Andrew Sweetman (SAMS) and Dr. Sheveenah Taukoor (UCT) preparing the mooring system for deployment. (Credit: OceanSOS)

The fieldwork team aboard the SA Agulhas II has confirmed the successful deployment of OceanSOS's first long-term deep-sea oceanographic mooring as part of the Marion Island relief voyage off the southeastern coast of South Africa.

Led by Prof. Andrew Sweetman (SAMS) and Dr. Sheveenah Taukoor (UCT), this deployment represents a core operational step for Work Package 2 (Physical Oceanography & Climate Change) and Work Package 3 (Biological Carbon Pump).

Deployment Details

Location: On the Agulhas Plateau (Agulhas Current System)
Seafloor Depth: 2,379 meters
Mooring Design: 500-meter tall instrumented array
Target Ecosystem: Mesoscale eddy-influenced seamount & adjacent abyssal plain
Planned Deployment Duration: 9 months

The Agulhas Current System is one of three core study regions of OceanSOS with globally significant eddy kinetic energy strength. High-energy mesoscale eddies pass over underwater topography like the Africana Seamount, driving exceptional biological productivity. OceanSOS wants to investigate how the Africana Seamount is impacted by the strong upstream variability of the Agulhas Return Flow, and how this variability modifies local seamount dynamics bentho-pelagic coupling and carbon export. However, capturing how these physical forces transport carbon and nutrients requires continuous, in situ monitoring.

To achieve this, the team deployed a specialized 500-meter deep-sea mooring equipped with:

Technicap Sediment Traps: Positioned in the water column to collect sinking particulate organic carbon over a 9-month period, measuring the strength and composition of the biological carbon pump.
Nortek Acoustic Doppler Current Profilers (ADCPs): Tracking current speed, direction, and hydrodynamic flow dynamics upstream of the Africana Seamount.

Schematic diagram of the 500 m OceanSOS deep-sea mooring array. (Credit: OceanSOS)

Connecting Field Observations to Earth System Models

The data collected from this 9-month deployment will serve multiple work packages across the OceanSOS consortium:

Validating Fine-Scale Physics (WP2): Ocean current measurements will validate sub-mesoscale hydrodynamic simulations using the CROCO (Coastal and Regional Ocean Community) model.
Quantifying Carbon Demands (WP3): Sinking particle fluxes collected by the sediment traps will provide empirical baseline data to calibrate Linear Inverse Models (LIMs) of pelagic and benthic carbon demand.
Supporting Regional Governance (WP5): Empirical evidence of bentho-pelagic coupling upstream of the Africana Seamount will feed directly into risk assessments and regional Safe Operating Space (SOS) frameworks for Areas Beyond National Jurisdiction (ABNJ).

Next Steps

This deployment was carried out by Dr. Sheveenah Taukoor (UCT) during the Marion Island relief voyage 2026 aboard the SA Agulhas II. The mooring will remain on the seafloor for 9 months, gathering continuous data before the planned recovery in 2027.

moreresearch

North Pacific Sea Surface Temperature Dipole Unlocks Reliable Cold Surge Forecasts for East Asia

PRODIGY Field School Gives Graduate Students Hands-On Ocean Mooring Experience

Kelp Forest Losses Dwarf Restoration Gains as Climate Threat Grows

latestnews

latest edition

issue III

From the Pacific tuna grounds to the Chesapeake Bay to the shallows of Florida’s coastline, applied marine science is rethinking who collects ocean data and how that data builds toward long-term coastal stewardship and a stronger ocean economy.

read now