1. Never dispose of toxic materials, chemicals or oil down the street drain

If you dispose of toxic materials, chemicals or oil down the street drain they will end up in the waterways, maybe even in Sydney Harbour.

Toxic materials and chemicals in the water will enter the food chain when marine organisms eat them or absorb them through their bodies. These poisons can have a whole range of affects on marine plants, animals and birds such as stopping them from growing properly or reducing their ability to reproduce. Toxic materials and chemicals can even result in death.

Sometimes a small amount of these poisons bioaccumulate in the leaves or bodies of marine organisms. Bioaccumulated poisons move up the food chain so when bigger animals eat smaller animals or plants any bioaccumulated poisons are consumed too. The poison then bioaccumulates in the bigger animal's body. So creatures at the top of their food chains - sharks, dolphins and humans - are most vulnerable to bioaccumulated poisons as they consume the greatest amounts.

Oil is also harmful if ingested by marine animals. Oil accumulates on the surface of the water to create a floating film of pollutant that smothers surface dwellers such as marine birds. A film of oil floating on the surface also reduces the amount of oxygen and sunlight that can enter the water: both of these elements are essential for marine organisms to remain healthy.

2. Clean your car on your lawn using the least amount of detergent

Washing your car on the lawn using the least amount of detergent is a good way of keeping Sydney Harbour clean and looking after marine organisms. Marine plants and animals that consume or absorb detergents can become ill or die. Detergents also harm fish by making them vulnerable to parasites.

Most detergents contain a substance called phosphorus. An increase of phosphorus in marine environments can cause a tiny, rootless marine plant called algae to rapidly increase in numbers, a situation called an algae bloom.

By washing the family car on the lawn you make it harder for the detergent to reach waterways including Sydney Harbour. Also your garden plants, grass and trees will use the phosphorus contained in the detergent for their own growth so that less of this substance reaches the water.

3. Prevent your car from leaking petrol and oil through regular maintenance

All liquids that leak from your family vehicle will find their way into stormwater drains, creeks and other waterways and so into the ocean or Sydney Harbour. This includes fuel such as petrol or diesel and engine oil.

Petrol is very dangerous to marine organisms. Petrol is made of compounds that are highly toxic if consumed or absorbed and can also damage plants and animals by smothering them. Petrol can slow growth, shorten lives and cause the death of marine organisms.

Oil is also harmful if ingested by marine animals such as fish and dolphins. Oil accumulates on the surface of the water to create a floating film of pollutant that smothers surface dwellers such as marine birds. A film of oil floating on the surface also reduces the amount of oxygen and sunlight that can enter the water: both of these elements are essential for marine organisms to remain healthy.

Each individual vehicle may only release small amounts of petrol or oil per year, but imagine how much is released by all the vehicles on the road. Petrol and oil released from many cars, trucks, motorbikes and even boats accumulates in the waterways to cause problems for marine organisms. Keeping vehicles in top mechanical shape will reduce the amount of petrol and oil in our waterways.

4. Prevent garden waste from entering stormwater drains

When garden waste goes down stormwater drains it can cause all kinds of problems that are harmful to the environmental well being of Sydney Harbour.

Household gardens often contain plants that are actually weeds. When garden waste is disposed of down stormwater drains the seeds from weeds are spread into waterways and the water spreads them far and wide. When these seeds establish themselves in areas of natural bushland they can become a big problem. Weeds crowd out native plants but do not provide the same food and shelter to native animals, birds and insects that native plants provide.

Excess plant matter from incorrectly disposed garden waste also increases nutrient levels such as nitrogen in the water. An increase in nutrient levels in marine environments can cause a tiny, rootless marine plant called algae to rapidly increase in numbers, a situation called an algae bloom.

Another problem with garden waste entering waterways is that as it decomposes it uses up oxygen in the water resulting in less available oxygen for marine organisms. This is especially dangerous in still or slow moving bodies of water that are not able to easily renew their oxygen levels.

So you can see there are a whole swag of reasons not to allow garden waste to go down storm water drains.

5. Place all litter in a bin

Putting your rubbish in the bin instead of dropping it on the street is the easiest way you can help Sydney Harbour. Any rubbish you drop within the Sydney Harbour catchment could end up in the harbour, either by entering stormwater drains or being blown by the wind.

Rubbish in the harbour looks horrible and is very harmful to plants and animals. Litter can take years to break down in the water. Plastic bags can last for over 100 years and cigarette butts take 5 years to decompose! As rubbish breaks down it releases toxic chemicals that can harm marine organism's growth, reproduction and lifespan.

Marine wildlife can mistake rubbish for food or get tangled up in rubbish. Marine mammals such as whales and dolphins have died from swallowing plastic bags, which they have mistaken for food: think how much a plastic bag floating in the water looks like a jellyfish! Birds, turtles and other sea animals have all been found with cigarette butts in their stomachs. Marine wildlife also gets caught up in plastic bags and other plastic rubbish resulting in injury and sometimes death.

We all love going to the beach and hope that it will be clean and free of litter when we get there. And we are all responsible for keeping marine environments clean by carefully placing our rubbish into bins or taking it home if no bins are available.

6. Use biodegradable detergents around the house

When we use cleaning products around the house we finish off by rinsing everything, including the detergents we used, down the drain. But many detergents are made with compounds that do not break down naturally in the environment.

If you have ever seen a frothy foam on top of a creek after rain you have seen the effect of detergents released into our waterways. Think what it must be like for fish and other marine animals to have to breath water that is full of detergent!

By using biodegradable detergents around the house you will reduce the amount of harmful substances that reach our waterways and Sydney Harbour. However even excessive amounts of biodegradable detergents can harm the environment so try to use the smallest amount possible.

7. Don’t put fats and oils from the kitchen down the drain

Pouring kitchen fats and oils down the drain can damage your house's plumbing in addition to damaging the environment. Continually pouring fats, oils and greases down the drain will eventually result in blocked kitchen pipes and an expensive plumber's bill.

Kitchen fats, oils and greases released into the environment clogs up slow moving creeks and reduces the quality of habitats for all marine organisms. Kitchen oil joins with other oils from vehicles to create a floating film of pollutant that smothers surface dwellers such as marine birds. A film of oil floating on the surface also reduces the amount of oxygen and sunlight that can enter the water: both of these elements are essential for marine organisms to remain healthy.

You can stop kitchen fats, oils and greases escaping into the environment by pouring them into newspaper and disposing them with your normal rubbish. Give the pan a wipe with a kitchen paper towel to remove even more fats, greases and oils: it will make cleaning the pans easier too!

8. Reduce the amount of chemicals and pesticides used in your garden

Householders like to keep gardens full of colourful plants and use a range of chemicals to keep everything looking good. Unfortunately these chemicals harm marine environments when they are washed into stormwater drains after rain.

Gardeners often use chemical fertilisers that contain nitrogen and phosphorus. But when these elements get washed into waterways they can cause a tiny, rootless marine plant called algae to rapidly increase in numbers, a situation called an algae bloom.

Gardeners also use pesticides to kill pests such as the insects that eat their plants. But pesticides are dangerous to all animals, including humans if we breathe them or sometimes even if we get them on our skin. Pesticides from many gardens are washed into waterways and can harm or even kill a whole range of marine organisms that are not pests at all, especially not to gardeners!

A simple way of looking after Sydney Harbour is to reduce the amount of chemicals and pesticides used in your garden. This can be achieved by planting a wide variety of native plants that require fewer chemicals and have a natural defence against insects.

9. Clean up after your dog

Dog droppings don't only look horrible; they also pose a threat to marine environments. Like anything else dropped in the catchment, dog droppings will end up in waterways and the harbour after heavy rain.

Dog droppings contain harmful bacteria and high levels of nitrogen. Increased levels of nitrogen in the water can cause a tiny, rootless marine plant called algae to rapidly increase in numbers, a situation called an algae bloom.

Make sure you clean up after your dog and place the droppings in bins provided for this purpose of bury them in your garden.

10. Take all discarded fishing line with you when you leave

A tangle of fishing line is annoying for a fisher, but potentially lethal for many forms of marine wildlife. Birds, fish and turtles are just a few of the sea creatures that can get caught up in discarded fishing line. Injuries include loss of movement, inability to feed, cuts that lead to infection and many more unpleasant and dangerous conditions.

By taking your old fishing tackle home including tangles of fishing line, bait bags, weights and hooks you will be doing a good job of looking after all the marine animals that make our Harbour so great.

Marine organism: Any living thing in salt water environments such as oceans, harbours and estuaries. Marine organisms include seaweeds and seagrasses, fish, dolphins, turtles, crabs, shrimps, octopus, seastars, crayfish, squid, cuttlefish and many, many more. All marine organisms depend on a healthy marine environment for their well being.

Algae bloom: Excess nitrogen and phosphorous in the water allow algae numbers to rapidly multiply and result in an algae bloom. During an algae bloom there are so many of these small plants that they use all the oxygen in the water and block sunlight from reaching other plants and animals resulting in lower growth rates or even death in extreme situations.

Bioaccumulates: the process by which poisons build up in the tissues of organisms due to eating contaminated food, drinking contaminated water or due to absorption through the organism's body.

Biodegradable: Substances that can be broken down in the environment through natural processes such as through micro organisms, bacteria and fungi activity. Wood and paper are biodegradable but plastics generally are non-biodegradable.

Nitrogen and phosphorus: Elements that occur naturally and are essential for plant growth but are harmful to marine ecosystems in increased quantities.

Nitrogen is used by farmers as a fertiliser and is found in manure and sewerage. Phosphorous is also used as a fertiliser and is found in many household detergents.

Nutrients: Substances that promote growth and are absorbed or consumed by organisms. Nitrogen and phosphorous are 2 common plant nutrients.

Weeds: Weeds are simply plants that are growing in the wrong place. This includes plants that are not native to Australia and plants that are native to Australia but not to the region of Australia they have been brought to.