Marine pollution overview

Find out what the major causes of marine pollution are, such as oil, antifouling paints, detergents, garbage, noise and sewage, and what you can do to protect our coastal environment in Western Australia.

Western Australia's coastal environment is among the most spectacular in the world. With over 13,500 km of salt marshes and temperate ocean, it has a rich biodiversity of marine life that cannot be found anywhere else in the world, including several species of corals, mangroves and seagrasses.

The Department of Transport protects our marine environment through:

  • Public education programs.
  • Enforcing marine pollution regulations.

Individual offenders could face fines of up to $50,000 while companies could be fined $250,000.

  Oil pollution overview

Oil pollution and the environment

The chart below shows the oil that enters the environment each year, according to the Australian Petroleum Production and Exploration Association.

Oil that enters the environment each year:

37% - industrial discharge and urban runoff
33% - general vessels
12% - tanker accidents
2% - oil/gas industry

Oil can often contain toxic chemicals which could kill marine animals that ingest it. Even if there are no immediate or visible effects, reproduction may be affected, and survival rates of their young may be reduced.

As oil weathers and disperses over time, its toxicity generally falls.

Marine life that becomes coated or smothered in oil may suffer from:

  • Burning or skin irritation.
  • Dehydration.
  • Inability to regulate body temperature.
  • Physical injury.
  • Other effects from the sheer weight of the oil.

Preventing oil pollution

The best way to protect the environment against oil pollution is to adopt good preventative habits.

General tips on preventing oil pollution:

  • Fix any oil leaks from your car and boat immediately.
  • Keep a supply of oil-absorbent rags at hand to wipe up any spills or leaks.
  • Clean and service your boat engine regularly.
  • Dispose of used oil or oil-soaked materials at appropriate oil recycling facilities.
  • Be familiar with the procedures and facilities of the harbours you use.
  • Install an oil absorbent pad in your bilge and check it regularly.

When refuelling your boat:

  • Refuel on land rather than over water (if possible).
  • Check the capacity of fuel tanks before refuelling, and do not overfill.
  • Fully insert the nozzle before starting the pump, and do not remove until fuel has stopped flowing (watch the breathers for signs of blow-back or overflow).
  • Do not wedge the hand-piece open and leave the nozzle unattended.
  • Use a cloth to clean any spills up immediately.

What to do if you spill some oil

Report any spilled oil immediately.

If a marine oil spill kit is available, mop up the spill with absorbent pads and dispose of it using the container provided.


It is an offence to pour degreaser or dispersant onto the oil without permission, as it makes clean-up harder and could further damage the environment.

Opens in a new window Australian Petroleum Production and Exploration Association (APPEA)

  The impact of oil on the environment

The environmental impact of oil depends on:

  • Chemical and physical properties of the oil.
  • Effect of weathering on the oil.
  • Exposure to marine life.

Chemical and physical properties

Oil can often contain toxic chemicals which could kill marine animals that ingest it. Even if there are no immediate or visible effects, reproduction may be affected, and survival rates of their young may be reduced.

Effect of weathering

As oil weathers and disperses over time, its toxicity generally falls.

Exposure to marine life

Marine life that becomes coated or smothered in oil may suffer from:

  • Burning or skin irritation.
  • Dehydration.
  • Inability to regulate body temperature.
  • Physical injury.
  • Other effects from the sheer weight of the oil.

Oiled wildlife

Even slight oiling can have major effects. Birds exposed to oil can lose their water resistance, resulting in hypothermia when water comes in contact with the skin. This may cause the bird to preen excessively in an attempt to remove the oil, resulting in ingestion of the oil, which can have lethal consequences.

The Department of Parks and Wildlife is responsible for the care and treatment of oiled wildlife, and works closely with the Department of Transport in responding to oil spills that may affect marine life.

For more information, please refer to the Oiled Wildlife Response Plan, which is part of the State Hazard Plan

Opens in a new window Department of Parks and Wildlife

  Antifouling paints

Some marine organisms that attach themselves to vessels can affect its performance, damage its equipment and contaminate marine life at another location. Antifouling paint is applied to the hulls of boats to prevent such organisms from attaching themselves.

Use of tributyltin is now restricted worldwide. Western Australia also restricts the use of any antifouling paint that contains copper or tin.

Effect on the marine environment

Antifouling paint can be released as a result of hull cleaning, chipping or scraping. Application and removal of antifouling paint should only take place in a controlled environment.

Biocides are toxic and can kill marine life.

What you can do

  • Use Teflon or silicon-based antifouling paints as they are more environmentally friendly.
  • Apply or remove antifouling paint in areas where runoff can be contained and collected for disposal, such as a designated area at a boat-lifting facility.
  • Collect all paint residue after sanding or scraping the hull and disposing of them appropriately.
  • Ensure all antifouling paints are stored and disposed of correctly.

Please also refer to the Antifouling page of the Federal Department of the Environment which also includes a Code of Practice.

Opens in a new window Department of the Environment

  Aquatic biosecurity

To help prevent the introduction of new pest species into Western Australia and to prevent those already here from spreading, regular vessel maintenance and effective antifouling is required.

Aquatic biosecurity is about protecting our oceans, rivers, lakes and dams from the spread of aquatic pests and diseases.

Find out more about good vessel maintenance, and what you can do to keep your vessel clean to make sure it won't be a biosecurity risk for Western Australia.

Opens in a new window Department of Agriculture
Opens in a new window Department of Fisheries: Aquatic biosecurity
Opens in a new window Marine pests: The marine pest threat

  Detergents and boat cleaning products

Many products used to clean boats contain phosphates, ammonia, chlorine or other chemicals that may be toxic to aquatic life.

Cleaning in or around waterways may release chemicals into the marine environment either directly or through drainage systems.

What impact does it have?

Detergents containing phosphate increase the nutrient levels, which could lead to algal blooms. This reduces the amount of oxygen in the water, and kills fish and other marine life.

Phosphates can also accumulate in the sediment and be released again when disturbed.

Some cleaning products can also coat the gills of fish and cut off their oxygen supply, while other products may contain toxic chemicals that accumulate in the food chain and have a domino effect.

What you can do

  • Always remove your boat from the water to do any hull cleaning.
  • Use minimal cleaning products - cleaning your boat with fresh water and scrubbing brushes after each use will reduce the amount of chemicals needed.
  • Not use bleach or products containing chlorine.
  • Use phosphate-free, biodegradable cleaning products.
  • Use environmentally-friendly alternatives where possible.

Detergents and boat cleaning products

Product Alternative
Bleach (chlorine) Borox or hydrogen peroxide
Chrome cleaner Apple cider vinegar to clean, baby oil to polish
Copper cleaner Lemon or lime juice in salt
Degreasers Citrus or water-based products
Drain cleaner Boiling water and plunger
Fibreglass stain remover Baking soda paste and water
Scouring powders Baking soda and elbow grease
Shower cleaner Baking soda, scouring cloth and warm water and a final wipe with lemon juice
Windows and mirror cleaner Vinegar and lemon juice mixed in warm water
Wood polish Olive oil or almond oil for interior wood
Detergent and soap Elbow grease
Floor cleaner White vinegar in warm water
Mildew remover Paste using equal parts lemon and salt
Toilet cleaner Baking soda
Plastic and glass cleaner Lemon juice and salt solution
Deck cleaner Vinegar and warm water
(To clean aluminium) Cream of tartar and water
(To clean stainless steel) Undiluted white vinegar

  Garbage (marine environment)

Garbage is sometimes dumped overboard from vessels, even though this is not acceptable practice. It could also be released by accident through boating and land-based activities. Garbage may also take a long time to disintegrate, creating a danger for a prolonged period.

Turtles, whales, fish and sea-birds may mistake this garbage for food and try to eat it. As they do not have the ability to regurgitate the ingested rubbish, it could block the digestive system and starve them to death.

Garbage can also entangle marine animals, causing them to starve or drown.

What you can do

  • Not throwing any waste overboard, store it in a secure area onboard.
  • Collect any garbage you come across, either in the water or on land.
  • Dispose of all waste at a proper waste disposal facility on shore.

It is against the law to dump the following in our oceans:

  • Oil.
  • Plastics thrown into the sea at all;
    • Synthetic ropes,
    • Plastic garbage bags, and
    • Synthetic fishing lines and nets.
  • Garbage discharged within 12nm from the nearest land;
    • Food waste,
    • Paper products,
    • Rags,
    • Glass or
    • Metals, etc.

Remember the simple saying: 'Stow it, don't throw it'. View the AMSA brochure for more information.

Australian Maritime Safety Authority (AMSA): Marine pollution response

  Noise (marine environment)

People and wildlife who live near the shore can find loud noises disturbing. Please ensure that you check you boat's motor to ensure that it is not too loud, and also control the volume of music players and other devices that you have on board.

  Pollution and sewage

Another major cause of marine pollution is sewage discharge from vessels, offshore platforms, and coastal facilities.

Find out more about Pollution and sewage regulations in Western Australia.

Page last updated: Tue Jul 12 2022 2:07:56 PM