The volume of plastic being dumped and discarded in the marine environment has grown exponentially. A few decades ago, Cape beaches were largely free of plastic pollution—never immaculate, but not the crisis we see today. Yesterday, at low tide, I walked the stretch between Dalebrook and Kalk Bay Reef and was taken aback by the sheer amount of plastic washed up on the shore. Bottles, fragments, ropes, nets. It is everywhere.
And this is only what the tide reveals. The real extent of plastic pollution lies offshore, suspended in the water column or circulating in vast marine currents. A marine specialist who rescues vessels once showed me his live monitoring app. He asked me to guess how many ships sit around South Africa’s coastal waters at any one time. I thought perhaps 2,000. That night, the number was 5,000.
But it’s not only ships. It’s people. The Western Cape coastline today carries pressures unimaginable fifty years ago. The number of people fishing alone has grown dramatically. Visitors pour onto the beaches, and many—too many—have no qualms about tossing plastic into the sea. I’ve seen fishermen do it with my own eyes. The result is predictable: the sea becomes a dumping ground, and society pays the cost.
And that cost is far larger than most people realise.
Who Pays for Marine Pollution?
The uncomfortable truth is simple: the public pays, even when the polluter is nowhere near our shores.
A ship travelling from Taiwan or China that dumps plastic overboard is long gone by the time the debris washes up on Muizenberg or Kalk Bay. But the clean-up costs are paid by South Africans through taxes, municipal budgets, and economic losses. The sea itself “pays” through degraded ecosystems, collapsing fish stocks, and the growing burden of microplastics within the marine food chain.
The true economic cost? It is extraordinarily difficult to calculate, but global estimates now run into the trillions of dollars.
This is the essence of an externality—specifically a negative externality: a cost imposed on society that is not reflected in the market price of the product or activity that caused it. Plastic is cheap precisely because the staggering cost of its waste is pushed onto the public.
A Macroeconomic View: Marine Litter as a Public Cost
Economists classify marine litter as a public bad—the opposite of a public good. It is non-excludable (everyone is affected) and non-rival (one person suffering its effects doesn’t reduce the burden on others). The result is a clear market failure: polluters do not bear the costs of the harm they cause.
Here, the classic formula from environmental economics captures the full burden:
Social Cost of Pollution
Economists use this formula to capture the full societal burden of pollution, combining direct industry losses, the cost of cleaning up the damage, and the long-term health and environmental impacts carried by communities.
Marine plastic pollution affects major sectors of the economy:
1. Tourism
Beaches covered in litter drive visitors away. Coastal towns lose revenue. Local businesses—from restaurants to guesthouses—suffer.
2. Fisheries and Marine Harvesting
Plastic debris damages gear, reduces fish stocks through habitat destruction and “ghost fishing,” and undermines the long-term profitability of fishing communities.
3. Shipping and Transport
Floating debris fouls propellers, clogs intakes, and increases vessel maintenance costs.
4. Public Health
Microplastics and contaminants move through the food chain. The cost to healthcare systems and productivity will rise sharply as evidence accumulates.
5. Natural Capital Loss
Marine ecosystems provide food, climate regulation, storm protection, and cultural value. When polluted, their ability to provide these services weakens, producing long-term economic losses often invisible in national accounts.
How Economists Calculate the Cost of Litter
There is no single formula, but economists rely on established valuation methods to quantify the Total Economic Cost. These include:
1. Clean-Up Cost Approach
Direct municipal and government spending on beach cleaning, harbour clearing, and waste disposal.
2. Damage Cost Approach
Costs borne by industries:
• lost tourism revenue
• damaged fishing gear
• lower fish stocks
• shipping delays or repairs
3. Health Cost / Cost-of-Illness
Medical expenses and lost productivity due to pollution-related illnesses.
4. Productivity Loss / Broader Economic Modelling
GDP impacts from tourism decline, reduced ecosystem productivity, and employment losses.
5. Willingness to Pay / Contingent Valuation
Surveys measuring how much individuals value cleaner beaches or healthier marine ecosystems. This captures the intangible: aesthetics, well-being, cultural attachment, and the desire for pristine nature.
6. Total Economic Value (TEV) Framework
Economists sometimes combine these measures as:
A Practical Example: Kalk Bay
To illustrate the concept, imagine calculating a localised annual cost:
• Clean-up operations: Additional coastal cleaning around Kalk Bay and St James may cost hundreds of thousands of rands a year.
• Tourism impact: Even a modest decline in visitor numbers has significant spillover effects on cafés, shops, and accommodation.
• Fisheries: Ghost nets and plastic debris lower catch volumes and damage gear.
• Non-use value: South Africans value the idea of a clean Kalk Bay Reef—even if they never visit it. That value can be measured.
The combined public cost becomes enormous, quickly outstripping what any private polluter would ever pay voluntarily.
The Key Insight
Marine plastic pollution is not an unfortunate by-product of modern life—it is an economic burden hidden in plain sight. The market price of plastic fails to account for the damage it inflicts. Unless these costs are internalised through policy—such as extended producer responsibility, plastic taxes, or deposit-return schemes—the burden will continue shifting onto taxpayers and future generations.
When plastic washes up on Kalk Bay Reef, we pay.
Not the companies that produced it,
not the consumers who discarded it,
and not the ships that dumped it offshore.
We pay.
Academic and Journal Sources
1. Marine pollution research in South Africa: a status report.
https://journals.co.za/doi/pdf/10.10520/EJC97668
2. Marine Pollution – Emerging Issues and Challenges.
https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2022.918984/full
3. Are there gaps in our understanding of marine plastic pollution in South Africa?
https://www.plasticsinfo.co.za/wp-content/uploads/2020/06/SAJS-116_5-6_MPD-reviews.pdf
4. International trade and plastic waste in oceans: legal and policy challenges.
https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1627829/full
5. The economic impacts of marine plastic debris in South Africa.
https://www.sciencedirect.com/science/article/pii/S0025326X24014383
6. Plastic pollution in the marine environment (global review).
https://pmc.ncbi.nlm.nih.gov/articles/PMC7475234/
7. Reducing Oceanic Pollution.
https://www.theregreview.org/2024/09/07/reducing-oceanic-pollution/
8. ASSAf: South African research on marine pollution.
https://sajs.co.za/article/view/7695/10086
9. The economic impact of marine plastic debris in South Africa (CSIR Technical Report).
https://wasteroadmap.co.za/wp-content/uploads/2023/07/043-CSIR_Final_Technical-Report_Nahman_The-economic-impact.pdf
10. Sustainability, externalities and ocean grabbing.
https://www.sciencedirect.com/science/article/pii/S0308597X25000132
11. Frontiers article on global externalities.
https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1549424/full
