Marine pollution incidents kill thousands of seabirds – and it could be legal!

Guillemot in peril. Image courtesy of Portland Bird Observatory.

A PIB-covered Guillemot struggles to come ashore. Image courtesy of Portland Bird Observatory.

Between 29 January and 6 February 2013, more than 500 seabirds, mainly guillemots, were killed or rendered helpless by a mystery substance from a pollution event off the south coast of England.
For every bird rescued we knew there were many more that had perished at sea.

Shockingly, these deaths and injuries may have resulted from legal shipping activity. The substance was subsequently identified as a man-made synthetic polymer known as polyisobutene, or PIB. This same substance has also caused the deaths of thousands of other seabirds in recent years in the Irish and North Seas.

Although it is illegal to discharge mineral oil directly into the seas (most major incidents of oil pollution now relate to shipping `accidents’, such as the MSC Napoli off Devon in 2007), it is still legal with conditions to discharge hazardous noxious chemicals, such as PIB, directly into the sea when washing out cargo tanks.

There is growing evidence, however, that some of these chemicals have highly damaging impacts on the marine environment, of which seabirds are the most obvious victims, but which are not currently considered by existing regulations. This has to change.

The latest sticky business

These birds were coated with a whitish or transparent, glue-like substance, so adhesive that it stuck their wings to their bodies, and even stones and rocks to the birds themselves. The hotspot was between Chesil Bank and Portland, Dorset but smaller numbers of similarly affected birds were reported from Devon and Cornwall.

Staff and volunteers from conservation and welfare NGOs recorded casualties. The RSPCA collected live casualties: 286 guillemots and 24 razorbills, and smaller numbers went for treatment elsewhere. Sadly, 53 of these casualties have subsequently died or had to be euthanized. Approximately 200 dead birds were recorded at Chesil/Portland in total. Many birds were emaciated, indicating they had not been able to feed for some days.

Marc Smith, Dorset Wildlife Trust, was one of the first to witness the scale of the tragedy; he and his colleagues worked with RSPCA staff to retrieve affected birds. “It was heart-breaking seeing the birds washing up along the shore. Some were so covered in this horrible substance they were literally stuck to the beach – still alive but unable to move. Others only had a small amount on them but you could see they were in distress. Exhausted, freezing and emaciated - they were the lucky ones. For every bird rescued we knew there were many more that had perished at sea. Dead birds littered the beach. What really sticks in your throat is knowing this was preventable”. 

For every bird rescued we knew there were many more that had perished at sea.

Of the affected birds, 90% were guillemots, 10% were razorbills and other victims included at least one cormorant, one fulmar, one gannet, one kittiwake and one puffin. Guillemots are usually not found close inshore in numbers during the winter and at the time of this incident large numbers of razorbills were present off Portland, indicating that the pollutant was first encountered further offshore.

The species involved, their poor body condition, the timing and widespread distribution of birds washed ashore and the weather conditions at the time all suggests the pollutant was released at some location offshore in the Channel, possibly south of Cornwall, some days before birds were found. To date, however, despite investigations by the Maritime and Coastguard Agency, no shipping incident or source of the pollutant has been identified or may ever be in future.

The nature of PIB

With confirmation by the Environment Agency and the University of Plymouth of PIB as the pollutant, the incident changed from being a tragic, one-off event to just the latest in a series of mass seabird mortalities caused by discharges of this noxious substance into the sea.

PIB alone is believed to have been responsible for thousands of seabird deaths in at least four incidents around European coasts in recent years. Such numbers are potentially just the tip of the iceberg though, as many more seabirds are affected out to sea than ever wash ashore.

Alec Taylor, the RSPB’s Marine Policy Officer, said: "PIB is used to make many products including sealants, chewing gum, cosmetics and adhesive tape, and millions of people safely come into contact with it every day. However, PIB in its raw state is hydrophobic; when mixed with sea water, it becomes glue-like and can be lethal for seabirds, covering them in a sticky goo and preventing them from feeding and flying, causing immobilisation, hypothermia, starvation and eventually death."

It is not known how much PIB is released into our seas, as the IMO does not require systematic recording of this. However, given global consumption of PIB is over 850,000 tonnes per year, a fifth of which is produced in Belgium and France, and that this figure is expected to increase by 40% to 1.2 million tonnes in 2017, which is predominantly transported by ships, it is feared many more seabirds will continue to suffer and die until the regulations are changed.

A five point plan for preventing another disaster

It is clear that lessons about the discharge of PIB and other similar substances have not been learnt, leading to the tragic scenes witnessed along the south coast of England this year. This is in large part due to a lack of detailed knowledge and monitoring for incidents relating to so-called noxious liquid substances under Annex II of the MARPOL Convention, and the lack of enforcement against illegal discharges. Given the current and projected increase in the use and transportation of PIB, there are imperative and compelling reasons to act now to prevent any further similar incidents. 

In order to do this, the RSPB has proposed a five point plan, which requires:

1. An urgent review of the hazard classification of PIB and other legally dischargeable substances, in relation to their impacts on the marine environment (including seabirds).

2. The testing of Annex II substances for their effects in more realistic marine conditions, which takes into account the effects of changes in consistency, time to degrade, toxicity if ingested and in-combination effects when mixed with other substances.

3. The establishment of a formal monitoring protocol and collated central database for recording pollution incidents involving Annex II substances.

4. Commitment to further scientific research on the effects of contaminating noxious substances on wider aspects of marine ecosystems, in addition to charismatic megafauna such as seabirds and cetaceans.

5. The strictest possible enforcement and prosecution of illegal discharges of any polluting substance.

The RSPB asked the IMO to review the hazard rating of PIB after the 1994 incident. Now, nearly 20 years, and at least three incidents later, we are all still waiting for the IMO to make discharge of PIB into the sea illegal, by upgrading its hazard rating under MARPOL to prohibit its release into the marine environment.

If you agree that this scandal in our seas must stop, please support the RSPB in its efforts to protect our marine environment and its precious wildlife:

Further Reading

The legal discharge of PIB and other substances into the marine environment

Polluting discharges at sea are regulated by the International Maritime Organisation (IMO) through the global MARPOL Convention. In relation to Annex II of MARPOL, in the mid 1990s more than 800 substances were evaluated to reassess their risks and hazards to the marine environment and consequently a revised MARPOL Annex II was adopted in 2004 and took effect in 2007.

Due to its perceived hazard to the marine environment, PIB is classed as category Y, i.e. “substances presenting a hazard to either marine resources or human health and therefore justifying a limitation on the quality and quantity of discharge into the marine environment.”

This is the higher of two categories of hazardous substance considered to have a potentially harmful effect if discharged, but which is legal to do so. Importantly, however, this classification is only based on the persistent floating properties of PIB, and does not consider wider potential environmental impacts.

The risk criteria for polluting substances are decided by the UN Advisory body to MARPOL known as GESAMP (Group of Experts on Scientific Aspects of Marine Environmental Pollution). The last major GESAMP review of noxious substances was in 2002 to feed into the revision of Annex II, but did not appear to consider previous PIB related seabird mortalities.

It is therefore perfectly legal for cargo ships to discharge category Y substances into the sea when washing out their empty cargo tanks, with some restrictions according to pre-discharge treatment of the substance, the ship age, ship speed, water depth and distance from shore.

The English Channel, wintering auks and marine pollution

The English Channel is the busiest shipping lane in the world and its waters, particularly Lyme Bay, host thousands of wintering auks. A conservative estimate of 25,000 razorbills was recorded off Portland at the time of the incident. Most of these breed further north in the UK and Scandinavia but some affected guillemots were already in breeding plumage so likely included local birds that would have bred later along the cliffs of Dorset and Devon.

Auks are gregarious in all seasons; they typically raft in large groups on the surface of the water and dive repeatedly into the sea to catch fish. As such, they are particularly susceptible to contamination from oil and other pollutant substances floating on or just under the surface of the water. Guillemots and razorbills are frequently the major casualty in marine pollution incidents.

Helene Jessop is an RSPB SW England Conservation Assistant and was involved in the RSPB response to the incident. Alec Taylor is an RSPB Marine Policy Officer and the organisation’s national lead on marine planning and marine pollution issues.

Contact for correspondence: 

The RSPB acknowledges the efforts of all individuals and organisations involved in recording, retrieving and treating birds affected by this incident, particularly staff and volunteers from Abbotsbury Swannery, Chesil Bank & Fleet Nature Reserve, Dorset Wildlife Trust, RSPCA and South Devon Seabird Trust.