This includes collecting information on currents, temperature, ocean productivity, habitats, fish and human populations.
This is part of a major research effort to predict what the Western Indian Ocean (WIO) will look like from now until 2100.
Prof Roberts heads the UK-SA Bilateral Research Chair in Ocean Science and Marine Food Security. This is jointly hosted by Nelson Mandela University in South Africa and the University of Southampton in the United Kingdom.
He explains that all ocean data collected will be used to check the accuracy of the world-first digital twin of the ocean – the largest ever computer model of the world’s oceans – that aims to predict what the Earth’s (Global) Ocean will look like until the end of this century. He is interested in the western part of the Indian Ocean, that includes South Africa, Mozambique, Madagascar, Tanzania, Kenya, the Seychelles, Mauritius, Comores and Somalia. “The WIO was chosen because we have the second largest population in the world, some 60 million people, who are directly dependant on the Indian Ocean for their food security and livelihoods,” says Prof Roberts.
He explains that the computer model is being developed by the European Union Horizon programme – the EU’s key funding programme for research and innovation – and South Africa, with support from the UK, is part of it. “The digital twin is a digital replica of the oceans that draws on vast amounts of data, models and artificial intelligence to provide high-resolution, multi-dimensional descriptions of all marine systems, with forecasting periods ranging from seasons to multi-decades.”
The digital twin of the ocean gives scientists, policymakers, fisheries, all marine businesses and citizens the power to understand what would happen to the oceans, fish and other marine life, along with people living on the coast “if issues like climate change, overfishing and pollution continue unabated”.
The European Commission is investing €13 million for the development of the prototype European Digital Twin Ocean (EDITO) by a European Union consortium that will release the initial data at the end of this year. EDITO complements the €19 million project, Iliad, funded under the Green Deal Call for research proposals to pilot the digital twin ocean concept. “We work closely with EDITO and are part of the Digital Twin Ocean pilot,” says Prof Roberts.
“This high-end research is expensive, but fortunately, the UK BEIS Tactical Fund has rallied behind us and financially helped kickstart this new WIO phase of the digital twin ocean. Initial funding will be used to support start-up strategic activities and multilateral work with international parties.”
Using the EDITO model with regional data, and an ecosystem model called ECOSPACE that Nelson Mandela University and the University of Cape Town are developing, scientists will be able to credibly predict what the WIO’s future will look like until 2100.
“Importantly, we need to identify the tipping points of the WIO ecosystem; when these will happen and how this will impact the future of the region’s fisheries. We have already started the work, but once we have EDITO’s initial data, we can really move on this.”
The end goal of the digital twin is to help countries in the WIO understand and develop ways to mitigate and adapt to climate change and work at restoring healthy marine and coastal habitats. This will help support a sustainable blue economy (including subsistence, artisanal and industrial fisheries, marine ecotourism, industry and aquaculture) and achieve marine food security.
“Marine food security depends on the health of marine ecosystems, and this directly affects the 60 million people in the WIO who depend on the ocean for food and livelihoods,” Prof Roberts explains. “As climate change warms the WIO, or some areas of it, so the ecosystems will change, becoming less productive in terms of plankton – the very foundation of the food web. A lean food web means fish species higher up will be impacted through a process called recruitment. Recruitment entails the success of fish larvae feeding on plankton, and therefore surviving to become adults. A lean plankton biomass implies less food for the fish, and hence, less fish.”
Fish abundance projections based on his team’s work already demonstrate the amount of fish in the region, as well as species diversity rapidly declining as a result of overfishing, ocean warming, pollution and population growth.
The change will not be the same everywhere in the WIO. The oceanography differs throughout the region so some areas will warm more than others, and some might even cool over the next 80 years. These hot and cool spots will impact ocean productivity, hence the survival of fish larvae, as well as the distribution of species. “To understand this future, we have to use models – big, very powerful models, like the digital twin to determine how the areas are going to respond. But validation of these is equally critical.”
Prof Roberts adds, “We have abundant research that points to most fisheries in the WIO becoming negatively impacted by climate change. The flagship for our digital twin modelling will be South Africa’s squid population, which is completely reliant on the dynamical ecosystem of the Agulhas Bank (the widest shelf area on the African continent), and has huge spinoffs for the whole of South Africa’s fisheries and the many species that prey on it, including rays, sharks, seals and fish. It is important to mention here that the squid fishery (SASMIA1) is uniquely strongly supporting this research.”
His research found that regime shifts in the Agulhas Bank ecosystem, possibly as result of climate change, resulted in the squid fishery collapsing in the Eastern Cape in 2001 and 2013. Over 2 400 squid fishermen lost their livelihoods, with about 35 000 family dependants being affected. “We need a huge model in the form of the digital twin of the ocean to help us anticipate future shifts and if or when the squid fishery crash could happen again,” says Prof Roberts.
His team is developing a policy brief that they aim to put on the 2023 agenda of the United Nations World Food Security Committee. This is to raise the issue of marine food security in the WIO, and to catalyse planning and action. He added that, “WIO governments and the international community urgently need to collaborate on understanding the rate at which changes in the ocean are manifesting and, critically, mitigation measures need to happen. Time is running out quickly!”
Sixty million people in the WIO directly depend on the ocean for food and livelihoods. Photo Credit: Courtesy of FishFORCE