Marine oil spills

What is a marine oil spill?

A marine oil spill is an actual or probable release, discharge or escape of hydrocarbon oil that enters or is likely to enter marine water., whether it is the sea, a harbour, estuary, or other coastal waterway. Spills can range from a small fuel leak from a recreational boat to a large discharge from a commercial vessel or an onshore transfer facility.

When a hydrocarbon enters the water, it typically spreads across the surface as a slick. A spill can appear as a dark slick, rainbow sheen, silvery sheen, brown/orange mousse or a combination of these. Hydrocarbons can behave differently depending on what type it is and just a small volume of some lightweight hydrocarbons may cover a vast area. Over time, sun, wind, and waves can break oil down or harden it into tar-like clumps that wash up on shore.

Most spills in New Zealand happen close to the coast or inside harbours, meaning oil can reach shorelines, beaches, and tidal flats within hours, depending on wind, currents, and tides.

When oil enters the water, it typically spreads across the surface as a slick, which can appear as a dark, oily sheen. Over time, sun, wind, and waves can break oil down or harden it into tar-like clumps that wash up on shore.

Why are oil spills harmful?

Oil is toxic to marine life and can cause serious and long-lasting damage to our coastal environment.

Marine animals and birds are particularly at risk. Seabirds can become coated in oil, which destroys the waterproofing in their feathers, leaving them unable to fly or regulate their body temperature. Marine mammals can suffer damage to their eyes, airways, and skin. Fish, shellfish, and other sea creatures can be harmed or killed through direct contact or by ingesting oil that has entered the food chain.

Coastal habitats, including rocky reefs, estuaries, seagrass beds, and sandy beaches can be severely affected. Oil can smother organisms living in sediment and stay in sheltered areas for a long time. Recovery of some species and ecosystems can take many years.

People and communities can also be affected, with fishing grounds, aquaculture operations, and recreational areas potentially closed during and after a spill.

Hawke's Bay's coastline is home to many sensitive and ecologically important areas, including Cape Kidnappers / Te Kauwae-a-Māui gannet colony, the Ahuriri Estuary, and a variety of marine habitats that support commercially and culturally significant species. Protecting these environments from oil spills is a key part of our work.

New Zealand's three-tier response system

New Zealand uses a nationally coordinated, three-tier system to manage marine oil spills, set out under the Maritime Transport Act 1994.

• Tier 1 – Industry response: Businesses and operators at oil transfer sites and on commercial vessels are required to have their own contingency plans and must respond to spills on their own sites.
• Tier 2 – Regional Council response: We are responsible for responding to marine oil spills in our coastal marine area that go beyond what a Tier 1 operator can manage. Our trained response team can be deployed to contain and clean up spills using equipment held within the region.
• Tier 3 – Maritime New Zealand response: For large-scale spills that exceed our regional capacity, Maritime New Zealand leads coordination of the response. They can draw on national resources and, if needed, international support.

How we prepare for oil spills

We maintain a Regional Marine Oil Spill Contingency Plan, which is approved by Maritime New Zealand every three years. The Plan identifies sensitive environmental sites around our coastline, outlines response strategies for different types of spills, and details the roles and responsibilities of our response team and partner agencies.

Our preparedness work includes:

• Maintaining oil spill response equipment within the region
• Training our response team in containment, clean-up, and wildlife recovery
• Carrying out regular exercises to test our readiness
• Working with Maritime New Zealand, Department of Conservation, iwi, and other agencies to ensure a coordinated response.

View our Regional Marine Oil Spill Contingency Plan

What to do if you see an oil spill

If you spot oil in the water, on a beach, or in a harbour — report it to us immediately.

Call our 24-hour pollution hotline on 0800 108 838.

When you call, try to provide:

• Your location (or the location of the spill as accurately as possible)
• A description of what you can see (colour, size, source if known)
• Your contact details so we can follow up

You can also report spills to Maritime New Zealand on 0508 22 55 22.

What you shouldn't do if you see an oil spill:

• Do not attempt to clean up an oil spill yourself. Oil can be hazardous to your health, and incorrect clean-up can make the situation worse or spread the oil further.
• Do not handle oiled wildlife unless you have been asked to by response staff.
• Do not use household detergents or degreasers on oil in the water. These can be toxic to marine life.

• Do not enter or approach the affected area. Keeping clear helps protect your safety and allows response teams to work effectively.

What happens after you report a spill?

Once a spill is reported, we assess the situation and, where necessary, deploys our Marine Oil Spill Response Team. Our team will work to:

1. Identify the source and stop further discharge if possible
2. Contain the spill using booms and other equipment to prevent the oil from spreading
3. Recover and clean up the oil from the water and shoreline
4. Protect sensitive areas such as wildlife habitats, estuaries, and beaches. If wildlife is affected, trained specialists will assist in the assessment and care of oiled animals.
5. Coordinate with other agencies including Maritime New Zealand, the Department of Conservation, and iwi as required
6. Investigate circumstances around spills and, where appropriate, seek costs that relate to the recovery. 

More information

• HBRC Regional Marine Oil Spill Contingency Plan
• Maritime New Zealand – Responding to spills
• Maritime New Zealand – Oil spill response strategy