Our oceans are taking major strain

In a sobering new assessment, the 9th edition of the Copernicus Ocean State Report (OSR9) and its companion Starfish Barometer synthesis underscore how the world’s oceans are increasingly strained by rising heat, mounting human pressures and biodiversity loss.

While the report is global in scope, its signals carry urgent implications for Africa and for South Africa, whose long coastline binds livelihoods, climate resilience and food systems to the sea.

At the heart of OSR9’s narrative is the concept of a “triple planetary crisis” — the overlapping threats of climate change, pollution and biodiversity collapse — and how the ocean sits at its centre. The report highlights the following findings:

• In 2024, ocean heat content, sea surface temperature and sea-level rise all reached new high records.
• Sea levels have risen about 23 cm since 1901, placing coastal communities increasingly at risk.
• The extent and severity of marine heatwaves have surged, with warming penetrating deeper into ocean layers.
• Biodiversity stress is acute: of marine species assessed, 1,677 species are now listed as “at risk,” and 37.7 % of global fish stocks are overexploited.
• On the protection side, policies now formally protect about 8.34 % of the ocean surface — a welcome development, but far from sufficient.

Why must South Africa pay attention?

Though the Copernicus report does not dwell in depth on regional breakdowns for every coastline, its broad findings resonate powerfully for African nations, especially those with long coastlines, fishing economies and climate vulnerability.

Many African coastal zones already host dense population centres, ports and fragile ecosystems (mangroves, coral reefs, estuaries). Rising seas and stronger storm surges compound risks of flooding, saltwater intrusion into aquifers and erosion.

In South Africa, key coastal cities, such as Cape Town, Durban and Gqeberha, may face greater exposure to coastal inundation, especially under extreme weather events.

Marine heatwaves and warmer waters shift species distributions, disrupt breeding and food chains and exacerbate the overexploitation challenge.

For communities in West, East and Southern Africa who depend on fish both for nutrition and income, this is more than an environmental issue, it is a livelihood crisis.

With a significant share of fish stocks already overfished globally, the buffer is thin.

Coral reefs, mangrove forests, and other coastal ecosystems are under pressure from warming, acidification and human pollution.

In parts of Africa, along the East African coast, in the Indian Ocean realm, coral bleaching has already been observed.

As biodiversity falters, so does the natural coastal resilience that protects communities from wave action, storms and erosion.

The ocean is a critical moderator of Earth’s climate. It stores heat, regulates weather patterns and absorbs carbon.

As the ocean warms and its circulation patterns shift, the knock-on effects on atmospheric systems, rainfall and regional climate may be profound.

African regions that already face drought pressures or shifting rainfall zones could see amplified volatility.

Given these risks, what does the Copernicus report imply for policymakers, civil society and researchers in Africa, and what steps should South Africa consider?

Strengthened ocean observation and data capacity

OSR9 emphasises that uncertainty remains a major barrier: many ocean processes, especially subsurface warming and regional circulation changes, are still poorly resolved.

For Africa, investing in ocean observing systems, such as buoys, autonomous platforms, coastal sensors, is critical. Enhanced regional datasets would allow better forecasting, adaptation planning and early warning systems.

While 8.34 % of the global ocean is under formal protection, many marine protected areas (MPAs) are “paper parks” which are underfunded, poorly enforced, or simply nominal.

African governments should scale up MPAs in ecologically meaningful ways, backed by management resources, community participation and monitoring.

Cross-border marine cooperation between the East African coast and the West African coast may help in scaling impact.

Reforming harvest regimes, reducing illegal, unreported and unregulated fishing, and investing in aquaculture and alternative livelihoods are crucial.

Africa has the opportunity to leapfrog to sustainable blue economy models rather than repeat exploitative practices of the past.

Coastal adaptation through seawalls, managed retreat and buffer zones, must integrate with ocean health. One cannot build seawalls while degrading the reef that helps dampen wave energy.

South Africa, in particular, could align its coastal development planning, port expansion and marine spatial planning to the new realities of rising seas and shifting marine ecosystems.

The report’s revelations highlight that ocean action is a global public good. Unfortunately, many African countries lack the financial capacity to act at scale.

Thus, global climate and nature finance frameworks must include marine dimensions, and funding instruments such as grants and concessional finance need to support ocean adaptation and conservation in lower-income coastal nations.

A moment of reckoning — and possibility

The Copernicus OSR9 and Starfish Barometer do not merely issue warnings, they also point to opportunity.

The ocean remains humanity’s biggest carbon sink, and healthy marine systems can support sustainable food, energy, economic development and climate resilience.

For Africa and South Africa, the moment requires a pivot: from seeing the sea as a resource to exploit, to stewarding it as part of climate resilience strategy.

South Africa’s long coastline is both a vulnerability and an asset. If managed wisely, it can help buffer climate shocks, support coastal communities and preserve biodiversity.

In the next decade, the action will lie with governments, scientists, communities and financiers working in tandem to translate the global warnings of OSR9 into regional investment, adaptation and governance.

The ocean is not a distant frontier for many African nations, it is integral to food security, climate justice and sustainable development. The Copernicus report makes it impossible to ignore that fact any longer.

• Dr Enock Sithole is the executive director of the South Africa-based Institute for Climate Change Communication.