Creation of an international laboratory network towards global microplastics monitoring harmonisation.

Infrastructure is often a limiting factor in microplastics research impacting the production of scientific outputs and monitoring data. International projects are therefore required to promote collaboration and development of national and regional scientific hubs. The Commonwealth Litter Programme and the Ocean Country Partnership Programme were developed to support Global South countries to take actions on plastics entering the oceans. An international laboratory network was developed to provide the infrastructure and in country capacity to conduct the collection and processing of microplastics in environmental samples. The laboratory network was also extended to include a network developed by the University of East Anglia, UK. All the laboratories were provided with similar equipment for the collection, processing and analysis of microplastics in environmental samples. Harmonised protocols and training were also provided in country during laboratory setup to ensure comparability of quality-controlled outputs between laboratories. Such large networks are needed to produce comparable baseline and monitoring assessments.

Regional and global impact of CO2 uptake in the Benguela Upwelling System through preformed nutrients.

Eastern Boundary Upwelling Systems (EBUS) are highly productive ecosystems. However, being poorly sampled and represented in global models, their role as atmospheric CO2 sources and sinks remains elusive. In this work, we present a compilation of shipboard measurements over the past two decades from the Benguela Upwelling System (BUS) in the southeast Atlantic Ocean. Here, the warming effect of upwelled waters increases CO2 partial pressure (pCO2) and outgassing in the entire system, but is exceeded in the south through biologically-mediated CO2 uptake through biologically unused, so-called preformed nutrients supplied from the Southern Ocean. Vice versa, inefficient nutrient utilization leads to preformed nutrient formation, increasing pCO2 and counteracting human-induced CO2 invasion in the Southern Ocean. However, preformed nutrient utilization in the BUS compensates with ~22-75 Tg C year-1 for 20-68% of estimated natural CO2 outgassing in the Southern Ocean's Atlantic sector (~ 110 Tg C year-1), implying the need to better resolve global change impacts on the BUS to understand the ocean's role as future sink for anthropogenic CO2.

Meso- and microplastics monitoring in harbour environments: A case study for the Port of Durban, South Africa.

An investigation into the abundance and distribution of meso- and microplastics within the Port of Durban was conducted using a static immersible water pump and particle filtration system to collect meso- and microplastics from the water column, microplastics from sediment samples and corresponding CTD. Microplastics were detected in all samples under investigation. Results suggest that sewage overflow, stormwater drains, port operations, followed by rivers are input areas for mitigation to focus on. Identifying meso- and microplastics inputs, baselines and distribution allow for long term monitoring and management in a harbour environment. This can potentially contribute to the control and regulation of small plastics particles in harbours, and the subsequent transport of these pollutants via dredged material into other ecosystems.