He returned to UCT to complete a PhD in physical oceanography. He received the DTi-NRF award for Scientific Excellence in Innovative Technology Development and the DEA: Oceans & Coasts "Award for Individual Excellence" both in 2010. He has been chief scientist on more than 30 cruises and Principal Investigator (PI) of over 36 research projects ranging from national NRF, fishing industry and government projects to large international projects including the ASCLME (Agulhas Somali Currents Large Marine Ecosystem), MESOBIO (Influence of mesoscale dynamics on biological productivity at multiple trophic levels in the Mozambique Channel), SAMOC (South Atlantic Meridional Overturning Circulation) and the Agulhas System Climate Array (ASCA).

Of the 32 national/international committees he previously/presently resided on ─ possibly the most significant are the IIOE2 SCOR Science Development Committee and the Sustained Indian Ocean Biogeochemical Ecosystem Research (SIBER) – the latter of which he is co-chair.

He has established 3 research groups/schools: Physical and Applied Oceanography Group (MCM); Centre for Operational and Observational Oceanography (www.cfoo.com) (DEA), and recently the Regional School of Technical Oceanography (SOTO) at the V&A Waterfront (CPUP). Academic experience includes the publication of over 90 articles and reports, lecturing physical oceanography and ecosystem functioning at UPE, RU, and UCT, and supervising 55 postgraduate students.

Relevance of research

The Indian Ocean has many pressing and escalating societal pressures ─ mostly driven by the massive population (2 billion people) which lives around the equatorial and northern rim and islands. India’s population alone increased more than 75% between 1970 and 2000, reaching 1.3 billion people in 2014. The declining state of both artisanal and industrial fisheries raises serious concerns about food security in this region especially in light of climate change and a changing global ocean. Indeed, the Indian Ocean is one of the fastest warming ocean basins and convincing evidence now exists that demonstrates climate change is impacting ocean upwelling ─ one of the most fundamental and powerful mechanisms in ocean dynamics that underpins the critical supply of nutrients to sustain ecosystems and marine food resources.

Current research interests

Current research investigates the underpinning processes that sustain food security (i.e. ecosystem functioning) with a strong focus on how climate change and a changing global ocean will impact marine upwelling systems in the western Indian Ocean. Investigation of these upwelling systems and their links to food security requires a full multidisciplinary approach from physics to fish to forecasts (security), and encompasses and couples the fields of physical oceanography, biogeochemistry, plankton, trophic ecology, fisheries and food resources ─ all quantified by end to end ecosystem and socio-economic modelling. Prof Roberts’ research program called the Western Indian Ocean Upwelling Research Initiative (WIOURI) totally embraces this approach and moreover uses modelling not only to understand, couple and quantify processes, but also to streamline the avenues of multidisciplinary investigation making the research program more focused on the ultimate deliverable ─ how and by how much is climate change and a changing ocean going to impact food resources in the WIO. Great emphasis is placed on linking and transferring these research outputs into ocean governance and food security structures including national governmental departments, SAPHIRE, ESPA, Nairobi Convention and the FAO. Indeed, the FAO is thoroughly involved in WIOURI as its EAF−Nansen program is a core partner.

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2019 - 2020

Novel Research on Seamounts for MADRidge Project

The seamounts around Madagascar are marine biodiversity hotspots and yet very little was known about them, putting them at great risk of damaging exploitation.

A major research project called MADRidge, completed in 2019/20, focused on three submarine seamounts around Madagascar in the Western Indian Ocean (WIO) to begin to understand these biodiversity hotspots.

“Seamounts, with their special shape and depth, are biodiversity hotspots, attracting top predators such as tuna, billfish and sharks near their summits,” says marine specialist scientist Professor Mike Roberts, who heads the South African Research Chairs Initiative in Ocean Science and Marine Food Security. MADRidge is one of six major research initiatives that Prof Roberts is rolling out in the WIO.

The Chair is jointly hosted by Nelson Mandela University in Port Elizabeth, the University of Southampton and the Southampton-based National Oceanography Centre – the United Kingdom’s leading marine science research and technology institutions.

The Ocean Sciences Campus at Mandela University

The Chair is also partnering leading French marine research institutions, notably the Institut de Recherche pour le Développement in Marseille and the Université de Bretagne Occidentale in Brest. MADRidge is part of this partnership.

”Seamounts, which are essentially reef systems, are exceedingly important for marine food security as the vertical movement of deeper, nutrient-rich water against the abrupt topography induces regular upwelling which stimulates primary production in the upper layer of the ocean,” says Prof Roberts.

Based on these considerations, an international team of scientists from France and South Africa, undertook three research cruises, one to each of the most prolific seamounts in this region – MADRidge (240m below the surface), Walters Shoal (18m below the surface) and La Pérouse (60m below the surface).

“Understanding one of the least known marine hotspots in the world required an intensive multidisciplinary team effort that has built and strengthened the network between the partnering institutions in France, South Africa, the UK and Madagascar.

The research is being used to involve international bodies in trying to protect the fisheries around the seamounts, which are in the open ocean and classified as Areas Beyond National Jurisdiction. Because no one is policing, these fisheries have been plundered since the 1970s by European, Russian and Asian fleets, and since the 1990s by others operating out of Réunion.

The slow growth, late maturity and low fecundity of many of the deep-sea species fished here contributes to their decimation.

Added to this is the emerging threat of mining. These threats have raised a number of questions, such as the legal status of seamounts – both within and beyond national jurisdiction – which laws apply, and who will implement the legislation at these faraway isolated sites. This brings into focus important bodies like the International Seabed Authority.

The multidisciplinary nature of the MADRidge project, combined with the research cruises, provides an excellent setting to develop early career researchers and postgraduate students – especially for those from South Africa and the WIO who do not have access to world-class research infrastructure and technologies. The team approach with senior scientists has not only provided mentorship, but strongly assisted them in publishing their first results.

The extensive MADRidge research is being published in August 2020 as 13 articles in a special issue of the international journal, Deep Sea Research, titled Bio-Physical coupling around three shallow seamounts in the South Western Indian Ocean, with regional comparisons based on modelling, remote sensing and observational studies.

 

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Marine Food Security

The Western Indian Ocean (WIO) region, extending up the eastern coast of Africa, has the most serious food security problem on the planet. It is estimated that 60 million people in the region directly depend on the ocean for their livelihoods, at a time when the indications are that the WIO is warming faster than the world’s other oceans, impacting all levels of the marine food web. Overfishing, destructive fishing practices and high levels of pollution are causing the WIO marine environment to deteriorate further. What is Africa doing to address this? “We are pursuing intensive research to understand and address the key questions of what sustains marine food security, what the underpinning ecosystems are and how do they function in this era of climate change and changing global oceans,” says Prof Roberts.

 

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Marine Robotics Unit

 

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2018 - 2019

What is Africa doing about its oceans?

Increasing sea temperatures, destructive fishing practices and high levels of pollution are impacting the Western Indian Ocean (WIO), which extends from South Africa all the way up the eastern coast of Africa, where an estimated 60 million people depend on the ocean for their livelihoods.

The Indian Ocean is the least researched and understood of the world’s oceans, so in an initiative jointly hosted by Nelson Mandela University, the University of Southampton (UoS) and the Southampton-based National Oceanography Centre (NOC), the SARChI Chair in Ocean Science and Marine Food Security is investigating what sustains marine food security and the underpinning ecosystems in the WIO.

New Frontier PhD and Early Research Career (ERC) programme

The New Frontier programme is part of the Chair’s Innovation Bridge – Regional Hub (IB-RH) research engagement mechanism. It is building partnerships between top institutions in Africa and top, well-resourced institutions in the Global North to tackle ocean science challenges in the southern hemisphere that have global implications. “Together with our French partners, the joint Mandela University-UoS–French PhD and Early Career Research (ECR) programme is growing the postgraduate ocean sciences pipeline in South Africa and the WIO to over 100 students, and we already have 15 master’s, PhDs and ECRs registered,” says Professor Mike Roberts, holder of the SARChI chair.

 

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South African squid fishery collapse 2013

Nelson Mandela University researchers are investigating the causes of the squid fishery collapse in the Eastern Cape between 2013 and 2014 that affected many thousands in the Eastern Cape dependent on the fisheries for their subsistence.

Prof Roberts explains how the source of the problem may lie further away in the WIO:  “The South Equatorial Current that flows across the Indian Ocean from east to west induces mesoscale eddies – large, swirling masses of water – in the Mozambique Channel and the Agulhas Current. This turbulence is responsible for significant ocean production, but further south on the edge of the Agulhas Bank, it can cause substantial loss of shelf waters. We don’t know whether the turbulence is increasing and therefore whether this kind of fishery crash could be more regular, and what this means for livelihoods and food security.”

Satellite observations and ocean models suggest that the “cold ridge”, an oceanographic feature of the Agulhas Bank that is believed to be responsible for much of the ocean productivity here, was absent in 2012. This would explain the fishery crash in 2013. “Ultimately, we believe there has been a regime shift in the Agulhas Bank ecosystem, probably as a result of climate change. If this is the case, we need big, powerful models to help us anticipate future shifts and to predict if or when this will happen again.”

 

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East African marine ecosystems

The Chair’s partner institutes in Kenya and Tanzania are carrying out case studies on the northern Western Indian Ocean (WIO), where there has been limited scientific research on marine ecosystems, how these are changing and how this is impacting the ocean food resources.

Prof Roberts explains: “Coastal communities in Zanzibar and mainland Tanzania coastal communities depend on the monsoon-related small pelagic fish (anchovies, sardines, mackerel, threadfin and herring) for food and income. Hundreds of small, locally built boats venture out to fish at night using nets and lamps. Fluctuations in the supply of these fish varies from year to year, depending on the strength of the monsoon and the resultant degree of coastal upwelling that brings nutrients into the surface waters.

“In July 2018, our partners from the Tanzanian Institute of Marine Studies and the UK National Oceanography Centre deployed a series of satellite-tracked ocean drifters in the Pemba Channel to identify the complexity of flow in the lee of Pemba Island, north of Zanzibar, during the South-East monsoon season, the most energetic period for this part of the Western Indian Ocean (WIO). This information was augmented by a 10-day ship and ocean glider survey in July 2019 to collect data under the sea’s surface.

 “In synopsis, we know ocean productivity is decreasing in the tropical WIO as a result of warming seas. The research aims to determine if this coastal region of the WIO is changing too, how this is affecting the food web, and importantly, to use computer modelling to forecast the future. We strongly suspect a decrease in food production in the future. This will require engaging with the respective governments to initiate policies to mitigate this challenge.”

The French Connection

A major collaboration with French partners in the Innovation Bridge-Research Hub – notably the Institut de Recherche pour le Développement (IRD) in Marseille and the Université de Bretagne Occidentale (UBO) in Brest – has focused on a seamount 200km south of Madagascar. Seamounts play a special role in the global ocean, as their special shape and shallow depth provide biodiversity “stepping stone” hotspots. They attract top predators such as tuna, billfish and sharks near their summits and are as important as continental shelves.

Roberts says: “To date, we have had three cruises using French research vessels with scientists and students from Nelson Mandela University, France and Madagascar onboard. We will be publishing an 18-paper special issue for December 2019’s volume of the journal Deep-Sea Research II, with recommendations that may play an important role in helping Madagascar formulate ocean conservation measures.”