Response to Marine Oil Spills: Introduction to oil spills

Summary

This script delves into the complexities of oil spill response, highlighting the importance of understanding oil types and their behavior in marine environments. From the historical lessons of the Torrey Canyon disaster to the expertise of organizations like ITOPF, it emphasizes the need for well-planned strategies that consider weathering, dispersion, and biodegradation. The narrative illustrates how knowledge of oil's interaction with sea conditions can significantly influence the impact and response to spills, showcasing the evolution of our preparedness since past incidents.

Takeaways

• 🌏 Global oil consumption has reached four billion tonnes annually, highlighting the scale of potential environmental impacts from oil spills.
• 🚢 Oil spills, though rare, can have severe consequences for the environment, livelihoods, and local economies, emphasizing the importance of effective response strategies.
• 🛡 The Torrey Canyon disaster in 1967 marked a turning point, leading to the establishment of ITOPF to provide technical advice on marine spills.
• 📈 ITOPF's experience shows a significant decrease in major oil spills since the 1970s, with a shift towards smaller volume spills from non-tanker ships.
• 🛑 Understanding the type of oil spilled is crucial for planning an appropriate response, as different oils behave differently in the marine environment.
• 🔬 The physical properties of crude oil can vary widely, affecting how it spreads, evaporates, and interacts with the environment after a spill.
• 🌊 Weathering processes, such as spreading, evaporation, emulsification, and dispersion, significantly alter the oil's behavior and must be considered in response strategies.
• 🧪 Experiments simulating ocean conditions are vital for understanding how oil behaves and for preparing effective response equipment and techniques.
• 🌡️ The environmental impact of a spill can vary greatly depending on the oil type and weather conditions, as demonstrated by the contrasting outcomes of the Exxon Valdez and Braer incidents.
• 🌿 Biodegradation by marine microorganisms is a natural process that helps to break down and remove residual oil from the marine environment over time.
• ⏳ The response to an oil spill must be swift and well-planned, taking into account the specific characteristics of the oil and the environmental conditions.

Q & A

How much oil is consumed globally every year?

Globally, we consume four billion tonnes of oil every year.

What was the impact of the Torrey Canyon oil spill in 1967?

The Torrey Canyon oil spill in 1967 resulted in the release of 119,000 tonnes of oil into the sea off the UK coast, threatening livelihoods and causing the death of thousands of sea birds.

What is the role of ITOPF in oil spill response?

ITOPF (International Tanker Owners Pollution Federation Limited) provides technical advice on oil and chemical spills to shipowners, insurers, local governments, environment agencies, and people affected by oil spills.

Why was the response to the Torrey Canyon oil spill ineffective?

The response to the Torrey Canyon oil spill was ineffective because the know-how for dealing with spills on such a large scale did not exist at the time, and in some cases, the authorities made matters worse.

How has the number of major oil spills changed since the 1970s?

The number of major oil spills has dramatically declined since the 1970s, with an average of two spills per year in the last decade compared to around 25 major spills per year in the 1970s.

What challenges do heavier oils, like bunker oil, pose during clean-up?

Heavier oils, such as bunker oil, pose challenges during clean-up because they are thicker and more persistent, staying at sea for much longer, and when they come ashore, they smother things and become very tarry and difficult to clean.

How does the type of oil spilled affect the response strategy?

The type of oil spilled affects the response strategy because different types of oil have different physical properties and behaviors in the marine environment, requiring tailored clean-up techniques to minimize impact.

What is the significance of understanding the weathering process in oil spill response?

Understanding the weathering process is crucial in oil spill response because it involves physical and chemical changes that oil undergoes at sea, such as spreading, evaporation, emulsification, and dispersion, which significantly affect the behavior of oil and the response strategy.

Why was the environmental impact of the Braer oil spill relatively small compared to the Exxon Valdez spill?

The environmental impact of the Braer oil spill was relatively small because the spilled oil was a light crude oil with low viscosity that did not form persistent water-in-oil emulsions, and the force of the winds and waves helped disperse the oil into the water column.

How does biodegradation contribute to the clean-up of oil spills?

Biodegradation contributes to the clean-up of oil spills by involving microorganisms that naturally break down oil into water-soluble compounds. This process accelerates when the oil is dispersed into small droplets, increasing the surface area available for the bacteria to attach and break down the oil.

What is the importance of planning in oil spill response?

Planning is crucial in oil spill response as it saves precious time at the outset when the potential damage is the greatest. It involves understanding the type of oil spilled and predicting its behavior to apply the right blend of techniques that will minimize the impact.

Outlines

00:00

🌏 Global Oil Consumption and Spill Impacts

This paragraph discusses the global scale of oil consumption, highlighting the rarity but severe impact of oil spills on the environment, livelihoods, and local economies. It introduces a series exploring key considerations in oil spill response, including the need for expertise and techniques to minimize impact. The historical context is provided by the Torrey Canyon disaster of 1967, which led to significant environmental damage and a lack of coordinated response. The International Tanker Owners Pollution Federation (ITOPF) is introduced as a not-for-profit organization offering technical advice on marine spills, emphasizing its role in providing support to various stakeholders during incidents.

05:07

🛢️ The Evolution of Oil Spill Response

The paragraph examines the evolution of oil spill response strategies, noting a significant decline in the number and volume of major spills since the 1970s. It points out that while spills are less frequent, the challenges posed by different types of oil, particularly heavier bunker oils, remain significant. These oils are thicker and more persistent, posing unique difficulties in clean-up efforts. The International Tanker Owners Pollution Federation's (ITOPF) role in advising on clean-up strategies and the importance of understanding the type of oil spilled for an effective response are emphasized, along with the technical and emotional challenges of dealing with oil spills.

10:10

🌊 Understanding Oil Behavior in Marine Environments

This section delves into the importance of understanding how different types of oil behave when spilled in the marine environment. It explains the physical properties of crude oil and how they can vary, affecting the oil's behavior in water. The paragraph describes a visit to Cedre, a research center in Brittany, to observe the behavior of different oils, including diesel, medium crude oil, and heavy fuel oil or bunker oil. The differences in viscosity, density, and the potential for evaporation and dispersion are highlighted, emphasizing the need for tailored clean-up techniques based on the type of oil involved in a spill.

15:11

🌪️ Weathering Processes and Their Impact on Oil Spills

The paragraph explores the concept of weathering, which refers to the physical and chemical changes oil undergoes when exposed to waves, wind, and other environmental factors at sea. It describes an experiment in a facility known as the polludrome, which simulates the effects of weathering on oil, such as the formation of water-in-oil emulsions and the natural dispersion of oil into the water column. The importance of understanding these processes for effective spill response planning is underscored, with examples of how different weather conditions can drastically affect the impact of oil spills, as illustrated by the contrasting outcomes of the Exxon Valdez and Braer incidents.

20:13

🌿 Bioremediation and Long-Term Oil Spill Processes

This section discusses the role of biodegradation in the long-term management of oil spills. It explains that oil is a natural material that has been present in the environment for eons, and that certain marine microorganisms have evolved to break down oil into water-soluble compounds. The paragraph describes how these bacteria are attracted to oil spills and begin the process of biodegradation, which can accelerate if the oil is dispersed into smaller droplets. It also touches on other slower processes like sedimentation and the formation of tar mats, and emphasizes the importance of understanding these long-term processes in addition to immediate response strategies.

⚔️ Preparing for Oil Spills: Knowledge and Strategy

The final paragraph emphasizes the importance of preparation and understanding in dealing with oil spills. It reiterates the need to know the type of oil spilled and to be aware of its behavior in the marine environment. The paragraph stresses the value of learning from past incidents, such as the Torrey Canyon, and the continuous process of learning about oil behavior. It concludes by stating that while accidents are inevitable, being prepared with the right knowledge and strategies is crucial to minimize their impact.

Keywords

💡Oil Spill

An oil spill refers to the release of petroleum hydrocarbons into the environment, typically caused by accidents or operational failures in the oil industry. It is a central theme of the video, discussing the environmental, economic, and social impacts. The script mentions the Torrey Canyon and Exxon Valdez incidents as historical examples of oil spills and their consequences.

💡Marine Environment

The marine environment encompasses the oceans, seas, and coastal areas where oil spills can have devastating effects. The video script discusses how different types of oil behave in the marine environment, affecting marine life and ecosystems, as seen in the impact on sea birds and fish farms mentioned in the transcript.

💡Response Planning

Response planning in the context of the video refers to the strategic and tactical preparation for dealing with oil spills. It is crucial for minimizing the impact of such incidents. The script emphasizes the importance of understanding the type of oil spilled and tailoring an appropriate response to effectively manage the situation.

💡ITOPF

ITOPF, or the International Tanker Owners Pollution Federation Limited, is highlighted in the script as a not-for-profit organization that provides technical advice on oil and chemical spills. It plays a significant role in the video's narrative by offering expertise and support during oil spill incidents, as illustrated by Karen Purnell's role and the organization's involvement since the Torrey Canyon spill.

💡Technical Expertise

Technical expertise is essential in the field of oil spill response, as it involves understanding the properties of different oils and how they interact with the marine environment. The script describes the qualifications and skills required by ITOPF's team, including stamina, diplomacy, and a strong scientific background to handle the complex and emotionally intense situations that arise during oil spills.

💡Crude Oil

Crude oil is a naturally occurring substance consisting of hydrocarbons and other organic compounds that is refined to produce fuels and other products. The video script explains that crude oil has varying physical properties depending on its origin and formation, affecting how it behaves when spilled, such as the example of the Amoco Cadiz tanker.

💡Bunker Oil

Bunker oil, also known as heavy fuel oil, is used to power ships and is noted in the script for its thick consistency and persistence in the marine environment. It poses a significant challenge during clean-up operations due to its tendency to smother marine life and form tarry residues that are difficult to remove.

💡Weathering

Weathering, in the context of oil spills, refers to the physical and chemical changes that oil undergoes when exposed to the elements at sea, such as waves, wind, and sunlight. The script discusses how weathering processes like evaporation, dispersion, and emulsification can alter the volume and characteristics of the oil, affecting the response strategy.

💡Biodegradation

Biodegradation is the process by which microorganisms break down complex organic substances, such as oil, into simpler compounds. The video script explains that this natural process can help to degrade and clean up residual oil in the marine environment after human intervention has occurred, as illustrated by the discussion with marine ecologist Jon Moore.

💡Environmental Impact

The environmental impact of oil spills is a key focus of the video, detailing the damage to marine life, coastal ecosystems, and the aesthetic quality of the environment. The script contrasts the effects of different spills, such as the Exxon Valdez and the Braer, to demonstrate how the type of oil and environmental conditions can influence the severity of the impact.

💡Clean-Up Techniques

Clean-up techniques are methods employed to remove oil from the sea and shorelines following a spill. The video script discusses the importance of understanding the type of oil and its behavior to apply the right techniques, such as the use of dispersants or physical removal methods, to minimize the impact of the spill on the marine environment.

Highlights

Global oil consumption has reached four billion tonnes annually, with oil spills from accidents and blowouts posing severe environmental and economic impacts.

The Torrey Canyon disaster in 1967, spilling 119,000 tonnes of oil, highlighted the lack of effective oil spill response strategies at the time.

The International Tanker Owners Pollution Federation (ITOPF) was established in 1968 to provide technical advice on marine oil and chemical spills.

ITOPF's role includes dispatching experts to oil spill sites worldwide to provide immediate assistance and advice.

The number of major oil spills has significantly decreased since the 1970s, with a shift towards smaller spills from non-tanker vessels.

Different types of oil, such as diesel, medium crude, and heavy fuel oil, behave distinctly in the marine environment, affecting response strategies.

Oil spill response must consider the physical properties of oil, which can vary widely depending on its composition and origin.

Weathering processes, including spreading, evaporation, emulsification, and dispersion, significantly alter the behavior of oil in the marine environment.

Experiments in facilities like the polludrome are crucial for understanding how oil behaves under various sea conditions.

Biodegradation by marine microorganisms is a natural process that can help break down oil over time, complementing human response efforts.

The Exxon Valdez and Braer incidents illustrate the varying impacts of oil spills based on oil type and environmental conditions.

The Erika disaster in 1999 demonstrated how heavy fuel oil, when mixed with sea water, can create a viscous emulsion, leading to extensive shoreline contamination.

Sedimentation can occur in shallow waters, where oil droplets mix with sediment and sink to the sea bed, posing a challenge for clean-up operations.

Understanding the advantages and drawbacks of different clean-up techniques is essential for tailoring an effective response to a specific oil spill.

The importance of planning and preparedness in oil spill response is emphasized, as it can save valuable time and reduce damage at the onset of a spill.

Lessons learned from historical oil spills continue to inform and improve current response strategies and techniques.

The documentary underscores the importance of knowing the type of oil spilled to effectively minimize the environmental and economic impact of oil spills.

Transcripts

Globally we now consume four billion tonnes of oil every year.

Oil spills from shipping accidents and offshore blowouts are rare,

but when they happen, the impact on the environment...

..on livelihoods and on the local economy

can be severe.

In this series, we'll be asking the key questions.

What issues do we need to consider?

What expertise and techniques are available?

How do we deliver a well-planned and executed response to minimise impact?

In this film, we'll look at some of the first things to consider

when planning a response.

In particular, how different types of oils behave

in the marine environment.

First, I'm going to find out a bit more

about the history of oil spill response.

The giant tanker Torrey Canyon aground off Land's End.

In 1967, the world watched as the Torrey Canyon tanker

spilled 119,000 tonnes of oil into the sea off the UK coast.

On the Seven Stones Reef, 16 miles off Land's End,

she lies like some stranded ocean monster shedding her lifeblood.

The impact was widespread, threatening livelihoods

and resulting in the death of thousands of sea birds.

At the time, the Torrey Canyon was the biggest-ever oil spill

and the first involving the new breed of supertanker.

The authorities struggled to coordinate an effective response

and in some cases made matters even worse.

Naval vessels joined the fleet, which was shadowing the slick,

bringing in drums of detergent to break it up.

The know-how for dealing with spills on this scale simply did not exist.

Surely it's time for an international effort

to beat the menace before it gets out of hand.

In operation since 1968,

ITOPF is the maritime industry's primary source

of objective technical advice

about marine spills of oil and chemicals.

Set up in the wake of the Torrey Canyon,

it's a not-for-profit organisation funded by the shipping industry.

I want to find out what they're about,

so I'm visiting their headquarters in London

to meet with Managing Director, Karen Purnell.

Karen, tell me about the role of ITOPF.

What exactly do you do?

ITOPF provides technical advice

on oil and chemical spills

and we provide that

to the shipowner and his insurer

and also to the local governments, local environment agencies

and to all of the people affected by the oil spill.

How involved are you in the process? Do you get involved at the beginning?

Yes, if it looks like it's going to be a serious incident,

then we may send one or two people, straight out on the next flight,

and go into the country and be there as quickly as possible.

ITOPF has attended hundreds of spills,

including all the major tanker spills in countries around the world.

Partnership with the global spill response community

has been vital in responding to and learning from every incident.

As well as that experience you have a tremendous amount of expertise here.

What sort of people and qualifications

do you have within your team?

Probably the most important qualification is stamina, diplomacy,

as well as a very strong scientific background

because they're going to have to go and deal

with some very emotionally intense situations

where people are upset about a situation.

They're going to have to apply their science,

but also try and calm the situation and provide reassurance.

Just one of several oil tankers,

which has collided in the world's busy shipping lanes in recent years.

ITOPF's first decade in operation was a baptism of fire.

The 1970s saw around 25 major tanker spills every year...

..with accidents releasing over three million tonnes of oil into the sea.

A black tide of oil from the wrecked tanker Amoco Cadiz

with a cargo of 220,000 tonnes of light Arabian crude.

Within hours the Liberian tanker had disgorged fully half its cargo

of six million gallons of oil, according to coast guard estimates.

But since then the number of major spills per year,

those over 700 tonnes, has dramatically declined.

So back in the 1970s,

we were having 20, 25 large spills from tankers

and the total amount of oil spilt was in the hundreds of thousands.

Now if you look at the last decade, two spills on average

and probably just a few thousand.

If you compare that to the quantity of oil

that's carried by sea each year,

it's a miniscule amount.

So fewer spills and less total volume of oil spilt.

What would be a typical incident today?

We're seeing more spills, probably a smaller volume,

from the fuel oil carried in ships

like container ships and bulk carriers.

Those make up a larger proportion of the spills that we attend.

What challenges are posed by bunker oil or these heavier oils?

The type of oil that's spilled is much thicker and more persistent,

so that oil can stay at sea for much longer.

It doesn't break up like the lighter oils.

When it does come ashore, it tends to smother things,

it can become very tarry and very difficult to clean,

so it's more of a challenge in the clean-up.

So for a smaller volume of oil spilt,

the technical challenges seem to be just as great?

Absolutely, yes, and the same emotional challenges.

Even a small amount of oil through fish farms and seaweeds

can cause a great deal of damage.

As the challenge evolves,

ITOPF continues to advise on clean-up strategies

and the effects of spills on the environment and people's livelihoods.

I want to find out how the lessons learned from previous spills

can help us plan, respond and react to future incidents.

Beginning with one crucial factor.

Following any incident, it is important

to consider the type of oil that's been spilled.

Responders need to establish quickly what they're up against

and tailor an appropriate response.

When it comes to crude oil, the thing to remember

is it's a complex mixture containing many different hydrocarbons.

Their physical properties can vary widely

depending on where they're found and how they were formed.

I've come to Cedre in Brittany, a specialist research centre,

to find out how different oils behave in water.

Sometimes when the public think of oil, they think of one thing,

but it's not quite as simple as that, is it?

No, oils are mainly composed of hydrocarbon,

but actually their properties and composition can vary a lot.

Here you have some samples of three different types of oil.

We'll see how these oils differ in their behaviour,

starting with the lightest, a diesel.

You can see it's a bit like water.

It has low viscosity and low density.

If I pour it into sea water, it will spread really quickly.

- OK. We can see that, can we? - We can see that.

The surface spread can be impressive,

but the volume itself may be quite small.

Just to give you an example, one litre of diesel

can cover up to a football pitch surface, so it's quite...

- Incredible. So a very thin sheen. - Yes.

As diesel is highly volatile, it will evaporate quickly into the atmosphere

and won't persist long in the marine environment,

meaning a clean-up is rarely necessary.

Next up, a medium crude oil,

much more viscous than the diesel

and immediately you can see how it behaves differently.

What's happening, as you can see, is it's spreading a bit,

but not as much as the diesel oil earlier.

Around 20% to 40% of the crude is made of light product, as well.

So this 20% to 40% will naturally evaporate, as well,

reducing the volume of the crude,

but leaving some heavy compound in the marine environment.

And finally, heavy fuel oil or bunker oil.

It's this that's used to power ships

and it can represent a serious challenge for clean-up.

Because it's very viscous,

it won't disperse as much, it will not evaporate.

Usually you have less than 5% of light product.

- It really clings together. - Exactly.

So you see a tiny bit of the light compound evaporating,

spreading a tiny bit, but it's mainly a thick slick.

Fuel like this can persist

as semi-solid material at sea for a long time.

It's clearly a different proposition to the crude and the diesel

and it's crucial for responders to understand these differences

in order to apply the right clean-up techniques.

But understanding the type of oil is only one part of the jigsaw.

You've also got to take into account how it will behave at sea.

At sea most oil will spread rapidly,

potentially covering hundreds of kilometres in just a few days.

As it's subjected to waves and wind,

it'll undergo a range of physical and chemical changes

known as weathering.

Understanding weathering and how the individual processes

affect the behaviour of oil is the cornerstone of oil spill response,

so I want to get to grips with the basics.

This piece of equipment is capable of simulating these processes.

Beakers in a lab are one thing, but this is stepping up the scale.

What's going on here?

Well, we are here in the polludrome

and you can see here on a much smaller scale

what will happen at sea.

You have the waves, you've got the current, the turbulence and the wind

and so it will alter the composition of the oil.

Two days ago, this medium crude oil was placed in the polludrome,

so the effects of weathering could be observed.

You can see it's very different to the one we had in the beaker.

You can see it's much more viscous and the colour has changed.

The reason is because the light compounds have already evaporated

and you have different phenomena that have already started.

The one that has the most action is called water-in-oil emulsion

where you have droplets of water that are mixed in the oil

and that will increase the volume, sometimes up to five times,

and it will give this consistency.

It's a bit like a chocolate mousse.

So the volume of this oil has changed, even in two days,

because the water droplets in the oil increase the volume.

Exactly, and it's going to be much more difficult

to respond to this type of oil than to fresh oil.

Oil will also disperse naturally into the water column,

as this experiment demonstrates.

Larger droplets resurface,

but smaller droplets are kept under the surface by the turbulence.

They're diluted and eventually broken down.

Natural dispersion is a key process for responders to understand.

Just how important are experiments like this

for understanding the behaviour of oil?

It is really important to understand how oil behaves,

so you can be prepared in case of a spill, if a spill occurs,

to have the proper equipment to respond to a particular type of oil.

- There are a lot of variables. - A lot.

That's why this type of apparatus is very useful.

Processes such as spreading, evaporation,

emulsification and dispersion

interplay differently with different oils.

Understanding this is critical

to planning an effective response to spills.

Take a look at this - in 1989, the Exxon Valdez runs aground

in Prince William Sound, Alaska.

A large proportion of the crude oil comes ashore

and the environmental impact, in particular, is severe.

But now look at this.

Four years later the Braer is blown onto rocks off the Shetland Islands

and more than 85,000 tonnes of oil spill into the sea.

That's twice as much as the Exxon Valdez,

so you'd think the impact would be twice as great.

The Shetlands were braced for catastrophe, but it never arrived.

In fact, the economic and environmental impacts

were relatively small-scale

and there was little need for a spill response operation.

The answer to why

rests in understanding the types of oil spilled

and how they interacted with the conditions.

Dr Tim Lunel from ITOPF attended the incident.

Tim, this was a huge spill,

yet the shoreline wasn't too badly affected.

What happened?

It was the fact that the oil that was spilt

was a light crude oil called gullfaks

and that was very low viscosity

and so it didn't form the water-in-oil emulsions,

which can make many oils persistent on the sea surface.

Then added to that, you can see the crashing waves there

and the force of the winds there was force 11 to 12 winds,

gusting 13 to 14, so it was pretty wild out there.

You can see the waves breaking that slick up

and dispersing it into the water column.

If you look around the Braer itself, the vessel itself,

you can see that coffee-coloured plume to it

and that's the visual evidence

to show the oil is being broken up into these really small oil droplets,

really tiny ones, about 70 microns in diameter,

and then just diluted over time.

And you can see the energy of those waves.

How long did those conditions carry on for?

Those conditions carried on for 12 days or more,

so that continued to break the oil up and spread it over a very large area.

The heavy seas also had very fine suspended sediments in the water.

The oil interacted with those

and helped to spread it over a very large area, it interacted

and then the naturally occurring marine bacteria out there

helped to degrade it over time.

What that meant was that there really wasn't a surface slick.

You can see in the area around the vessel, there on the beaches,

these head-high waves crashing in, coming up the beach,

but then washing back out again.

The black waves came in, but came out

without leaving that characteristic strand line.

What that meant was that compared to the Exxon Valdez -

twice the volume of oil at the Braer -

but the environmental impact was pretty minimal.

That's because the fate of the oil

was determined by the process of evaporation and natural dispersion.

But strong seas aren't always good news.

Depending on the oil type,

the churning of the waves can make the problem much worse.

For example, look at this. The Erika in 1999.

Similar sea conditions, but crucially a different oil type.

On this occasion, it was a heavy fuel oil that was spilled.

As we've seen, it's a completely different prospect.

As the Maltese tanker sank off the French coast,

the churning action of the waves

captured droplets of sea water in the slick,

creating a viscous emulsion.

And here's the result.

A shoreline that was heavily contaminated

and a large-scale clean-up operation followed.

So far, we've seen how processes

such as spreading, dispersion, evaporation and emulsification

act on the oil immediately after a spill,

but there are other processes to consider which take a bit longer.

A less frequent process

that can happen in shallow water is sedimentation.

This is when sediment,

stirred up into the water column by intense wave action,

mixes with dispersed oil droplets and then slowly sinks to the sea bed.

When floating patches of heavier oil pick up suspended sediment,

they can also sink to form dense tar mats,

presenting a challenge for the response.

There's another process to be aware of.

It may be slow, but it's one of the main mechanisms

for getting rid of the last traces of oil from the marine environment.

To find out more I've come to Milford Haven

to meet marine ecologist, Jon Moore.

He's attended spills worldwide

and has spent many years studying their impact

on marine organisms and communities.

He's offered to explain how oil in the water

is by no means a modern phenomenon

and how nature has equipped itself with a solution.

Oil is a natural material.

It came from life aeons ago, underground

and in many places it does still seep out.

We're using it and life has adapted to use it over millions of years.

Life has evolved to use it as a foodstuff.

The sea is teeming with microscopic organisms,

some of which are able to break down oil into water-soluble compounds.

It's a process known as biodegradation.

And so when a spill occurs, what happens?

Do these bacteria get to work immediately?

Bacteria that are present in the water in large amounts

are immediately attracted to it.

They will attach to the surface of the oil

and will start to break it down.

Obviously, the larger the surface area there is of oil,

the more bacteria can get on to it

and multiply rapidly and break it down more rapidly.

If the oil is broken up into small droplets into the water column

through natural or chemical dispersion,

this increases its surface area and accelerates biodegradation.

By contrast it's much slower

if the oil is lying in thick layers on shorelines

or if it gets mixed up with sediment on the sea bed.

So this isn't a substitute for removing bulk oil,

but this is a process that sort of cleans up the rest of it

once a lot of the response has happened.

Well, all the oil that remains in the marine environment

that we haven't taken out of the environment in our response

will eventually get degraded by these microorganisms.

We've seen that from the moment oil hits the water

it is influenced by processes.

Some of them take effect immediately,

others like biodegradation can take months or years.

Understanding these processes is crucial.

There are so many factors to consider

and yet the need to deal with spills quickly and effectively is paramount.

We can never know when an oil spill will strike,

but if we understand how different oil behaves at sea,

then we can at least be prepared.

Planning is crucial and can save precious moments at the outset

when the damage is potentially the greatest.

It's essential to know the oil that's been spilt

and to know how it'll behave.

Forewarned is forearmed.

In military terms, it's know your enemy.

Different oils behave differently,

so it's important to know the advantages and the drawbacks

of different techniques,

so you can tailor for that particular spill

the right blend of techniques that will minimise the impact.

We've come a long way since Torrey Canyon

and learned important lessons about the way oil behaves

and of course we're still learning.

Accidents will happen.

What's important is to be ready for them when they do.