I grew up on the beaches of Pembrokeshire in south-west Wales. Visits to Tenby were my family’s summer ritual: sand between our toes, paddling in rockpools, strawberry syrup on ice cream.
But 30 years ago, I vividly remember walking along Tenby’s North Beach with my mother and grandmother. No crowds. No laughter. Just the hush of waves sliding over dark, tar‑smudged sand. The holiday postcards had gone grey.
At about 8pm on February 15 1996, the Sea Empress oil tanker missed her tug escort into port by minutes. The ship veered inside the mouth of Milford Haven and struck rocks near St Ann’s Head.
Over the next stormy week, it grounded and re‑grounded many times, creating more damage to the hull each time. About 72,000 tonnes of North Sea crude oil were spilled. This was Britain’s worst coastal oil disaster in a generation.
The fightback was messy. Weather worsened. Control systems to manage the spill were strained. Nine separate releases of oil stained the sea as wind and tide shoved a wounded tanker around the edges of the Pembrokeshire Coast national park.
Aircraft spread dispersants to try to break up the oil spill. Rough seas helped break oil into smaller droplets. This kept oil suspended in the water (not just floating on the surface), which can increase exposure and toxicity for sea and plant life, even as the visible surface layer declined.
At the same time, because the spilled oil contained a lot of relatively volatile petrol components and the weather was windy and the sea choppy, an estimated 35-45% evaporated in the first two days.
Scott Grant, CC BY-NC-ND
In all, 11,000-16,000 tonnes of water-in-oil emulsion are estimated to have reached the shore – far less than the 72,000-120,000 tonnes of emulsion that could have beached. But even so, more than 120 miles (190km) of coastline were oiled. Birds, shellfish, marine and coastal habitats and the local tourism industry all took a hammering.
The UK government’s Marine Accident Investigation Branch found the immediate cause was pilot error – compounded by weak training, poor use of leading marks to help the tanker’s navigation, and no agreed master–pilot plan.
Salvage overseen by the Marine Pollution Control Unit (part of the UK Coastguard Agency) unfolded amid a stormy week. Muddled control was an issue alongside insufficient tug power and limited expert knowledge of the tidal streams. When big ships are in trouble, authority must be clear and tugs must be strong.
What’s changed since the disaster?
A lot has improved since the Sea Empress disaster.
The line of command is now much more direct. The UK created a single, empowered decision-maker – the secretary of state’s representative – to cut through competing interests in a major maritime emergency. The role dates from 1999 and exists because of lessons from the Sea Empress.
There’s also a clearer response plan in place. The national contingency plan for marine pollution incidents sets out who does what from the first call to the last waste bag. It links government, ports, regulators and science advisers, and outlines how to quickly set up a joint response centre for a coordinated approach to complex incidents.
Prevention of oil spills is high on the agenda. The UK government has identified marine environmental high-risk areas, including Pembrokeshire, to warn where a mistake can become a catastrophe.
Ships have also evolved to reduce the risk of big spills like this happening again. After the 1990s, single‑hull tankers were phased out under an amendment to international and national laws. New tankers had to be double‑hulled – designed with two completely watertight layers of steel – to reduce the risk of oil spills as the result of an accident.
By the mid‑2010s, single‑hull tankers were effectively gone from mainstream trade – a quiet revolution that prevented countless spills.
But not everything moved forward in a positive way.
In the 2000s, the UK stationed powerful government‑funded tugs around the coast. But in 2011, this fleet was axed on cost grounds, with a limited Scottish provision later restored and extended. A 2020 government‑commissioned study acknowledged that commercial towage hasn’t filled every gap, and that some sea areas are still at high risk of an oil disaster.
Risk has shifted, not vanished. Milford Haven is now one of Europe’s key liquefied natural gas (LNG) gateways. The South Hook and Dragon terminals, opened in 2009, can together meet up to a quarter of UK gas demand on peak days. That keeps homes warm and industry running. It also concentrates critical energy infrastructure in the same magnificent but exposed seascape that the Sea Empress scarred.
Scott Grant, CC BY-NC-ND
Lessons learnt
Three aspects of the handling of this disaster still guide my thinking as an environmental scientist today.
Hitting the oil hard at sea – and early on – can make a big difference. With the Sea Empress’s cargo of light crude in winter, rapid evaporation and dispersant‑aided dilution reduced shoreline oiling dramatically. It is often better to keep oil off beaches than have to scrape it off later – but you need surveillance, and then aircraft and trained people to be ready immediately.
Scott Grant, CC BY-NC-ND
Coasts need to be cleaned in a methodical way, for as long as it takes. Buried oil re‑emerges. Heavy machinery can drive residues deeper if you rush. Quiet persistence beats flashy photo ops.
The government’s Sea Empress environmental evaluation programme found that, while many habitats recovered faster than feared, some wildlife communities – from limpets to cushion stars – needed continued protection.
Prevention always costs less than compensation. Fines, funds and court cases don’t restore trust or nature quickly. Investing upfront – in trained pilots, rehearsed joint command, powerful tugs in the right places, modern kit and transparent science – is cheaper than rebuilding a reputation for clean beaches, safe seafood and thriving wildlife. That was true in 1996. It is truer now.
Thirty years on, I still see Tenby’s empty beaches when they should have been busy. I can still picture the sad faces of Pembrokeshire’s people. Wales has deep ties to the sea: trade, holidays, food, fun.
With better ships, clearer command and smarter plans, the risk of major oil spills can be minimised. But complacency is a fair‑weather friend. LNG cargoes, bigger vessels, tighter budgets and busier coasts all raise the stakes. Anything can happen after dark in a gale, when radios crackle, information is scarce, and decisions must be made quickly.
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