Oil Slicks And The Marine World: A Sticky Issue

The little bird struggled towards the shore, her wings pinned to her side with a thick, sticky substance. The taste of oil burns her throat and she panics, unable to fly away as the ice cold water penetrates her feathers and soaks her skin. If not found soon, it won’t be long until she is overcome by hypothermia. It’s a race against time.


On the 15th February 1996, the oil tanker Sea Empress hit rocks in the middle of the Cleddau estuary on her way into dock at Milford Haven. She began to release 130,000 tones of light crude oil into the sea and, despite the hard work of salvage teams, 70,000 tonnes entered the water devastating the local environment. Home to 35 sites of Special Scientific Interest, 2 potential European Special Areas of Conservation and Britain’s only coastal marine park, the Pembrokeshire coast was teeming with marine life and so it was clear that the impact of this disaster was catastrophic. 7,000 sea birds either covered in oil or dead were admitted to a makeshift hospital run by volunteers, a very small percentage of those involved. Lobster and shellfish populations were badly damaged as was the local fishing economy and the habitat of a rare breed of starfish was severely affected in West Angle Bay, one of the first areas to be hit. It was a deadly disaster.

Oil spills have a lethal effect on our environment but what exactly does this entail and do they have the same effect each time?

Well, different kinds of oils have different impacts. Light oils such as gasoline and fuel oils, for example, disperse relatively quickly however they are also very toxic, killing plants and animals they come into contact with and can even ignite. Heavy oils, on the other hand, like bunker oils form thick, black layers on the surface and can remain in the environment for a considerable amount of time but although they can kill they are actually less toxic and sometimes even harden over time reducing their impact. Oil is a sticky issue. There are both short term and long term effects which vary hugely in atrocity depending on a number of factors and a good example of this is the Sea Empress disaster. When it occurred, the wind actually pushed 87% of spilled oil away from the coastline preventing further shoreline casualties and as a lighter oil, when combined with the success of dispersants, it was relatively easier to treat and disperse. Likewise, had the incident happened a few weeks later then there would have been a higher seabird mortality rate as they came into shore for the breeding season. These are all positives in terms of the prevention of an even bigger disaster but to those affected, it was no consolation.

Approximately 20,000 seabirds were thought to have been involved in the Sea Empress oil spill. For those lucky enough to be treated at the makeshift hospital, their survival rate after release was still limited to a very slim 9 days and it’s thought that half of the West Carmarthen Bay population of Common Scoter duck was decimated. When a bird comes into contact with oil, a number of things happen. The bird’s feathers are coated with the glutinous material stripping them of their waterproof properties with the feathers being forced to separate and are subsequently unable to lock together. At this stage there is a real danger that the bird will contract hypothermia. In order to rectify this, the bird may try to preen itself to remove the oil only to ingest it and suffer from internal exposure. It’s a painful and agonising way to die and sadly birds weren’t the only ones in distress.

Other animals ,including the resident cetacean and grey seal populations, were affected. Despite some being treated for exposure and a lack of solid evidence that they suffered any direct effects, it can be presumed that they were still threatened by the impact after creatures further down the food chain were. Seaweeds were coated in the substance which left them unable to photosynthesise. Bivalves and crustaceans were contaminated as they accumulated toxins and in rare cases fish were also affected. Progressing through the food chain, the effect that the oil had on different species of both plants and animals varied hugely but were equally as devastating.

20 years later and the effects of the Sea Empress disaster can still be felt both along the Pembrokeshire coast and around the world. Oil is still evident on the affected Welsh beaches and some reports suggest that the lobster and shellfish populations are still only in the early stages of recovery.  After the initial incident workshops and training schemes were organised to educate people of the dangers and prevention of oil spills, emergency contingency plans were put in place and 4 Emergency Towing Vessels were established around the UK. Scientific studies were organised to further understand the use of dispersants and the effect such incidents have on marine life and whilst it has enhanced our knowledge of oil spills, more action needs to be taken globally with statistics suggesting that a least 1 large oil spill occurs in our oceans each year. 

One of the last major reported oil spills occurred 6 years ago in 2010 when an undersea BP oil well exploded in the Gulf of Mexico releasing 200 million gallons of oil. Despite massive clean up operations, 1,100 miles of coastline were affected and fish, birds and turtles washed up coated in a thick layer of oil . Before this there was the catastrophic Exxon Valdez oil spill in Alaska in 1989 where 11 million gallons of oil were leaked into the waters of Prince William sound reaching beaches 650 miles away and killing eagles, otters, sea birds and cetaceans such as killer whales, two of whom’s populations have not recovered. More recently, in 2011 the Rena ran aground on the Astrolabe reef  in New Zealand spilling 350 tonnes into the ocean and at the beginning of 2016, 3,000 barrels of oil have leaked from a pipeline in Peru, threatening the local wildlife and indigenous people. Oil affects everything and everybody no matter how much or whereabouts it is spilled. From the smallest of creatures at the bottom of the food chain to those at the top, we are all affected and something needs to be done.

The remnants of oil still languish on our beaches and in our wildlife but so does the passion of volunteers for protecting the environment and as long as that remains, something can be done. With the developments of oil dispersals and the progressive knowledge of it’s effects, it is hoped that more will be done in the prevention of repeat disasters but with such high shipping traffic, it’s a race against time before another major incident takes place. Oil is a sticky issue and we need to be prepared.