Explore the Issues
Plastic pollution is the juggernaut of ocean environmental disasters. It sweeps down sewers, stormwater drains, falls from garbage trucks or trash cans, carries in the breeze to the sea where it clogs our waterways, damages ecosystems, entangles our marine life, poisons animals and enters the food chain.
Humans are polluting the seas at an alarming rate with 8 million tons of plastic being dumped in the ocean every year. This is the equivalent to a dump truck of plastic every minute.
As plastics break down, it makes its way to the very base of the food chain. Plankton, the smallest of all marine creatures, suck in water to feed and particles of polystyrene accumulate in their tissues. Plankton, full of plastic, is then eaten by larger and larger creatures, until it’s sitting on our dinner plate.
Plastic kills hundreds of thousands of sea creatures every year. Animals eat plastic or get trapped and strangled by plastic. Turtles and dolphins confuse plastic bags for jellyfish; plastic pellets look like floating fish eggs and kill fish; filter feeders such as lugworms and mussels gobble up microplastic particles on the seabed. Even corals are consuming plastic.
Microplastics act like sponges sucking up toxic chemicals in the ocean. Plastic pellets collected from Japanese coastal waters had toxin concentrations up to a million times that found in the surrounding seawater.
We don’t understand the full impact of microplastics on marine ecosystems and the potential human health risks yet. But early research suggests plastics may disrupt endocrine function, which may lead to cancers, birth defects, immune system suppression and developmental problems in children.
There are no longer ‘too many fish in the sea’.
Fish populations of some key species have been reduced to only 10% of what they were in the 1950s.
The scale of the modern fishing industry has become enormous. Nets large enough to haul a dozen 747 aeroplanes, trawl behind factory fishing vessels, scooping up anything in their path. A huge amount of by-catch (unwanted species such as endangered sharks, turtles and dolphins) are thrown back into the sea – dying or dead.
Industrial-scale methods used to catch the fish are destroying habitats and devastating marine life. Bottom trawlers rake the sea for scallops and prawns, leaving wide swaths of seabed desolate as deserts. Long lines, hundreds of kilometres in length and baited with thousands of hooks swing enticingly, indiscriminately ensnaring any kind of wildlife.
Illegal fishing vessels are operating all over the world, fishing in prohibited territories.
Changes can be made to improve conditions. People who eat seafood can demand sustainable fish. Vessels can implement smart fishing practices that eliminate by-catch, waste and overfishing. Governments can reduce harmful subsidies and crack down on unregulated fishing.
‘Sustainable seafood' is seafood which reaches our plates with minimal impact on fish populations and the marine environment. It can be wild-caught or farmed in aquaculture. But very few fisheries are actually certified as sustainable throughout the world.
So what should I eat?Choose small fast-growing sustainable species. Avoid top predators, such as swordfish, sharks and tuna. These animals can accumulate unhealthy levels of mercury, but are also slow growing and reproduce less often, meaning fish are slower to reproduce.
Know what you're eating:
SUSTAINABLE SEAFOOD GUIDE
Check out the Australian Marine Conservation Society's Sustainable Seafood Guide and make informed seafood choices.
The guide gives you an insight into the sustainability of around 90 seafood species commonly found at our fishmongers supermarkets, fish and chip shops and restaurants. It includes assessments of Australian and imported fish species.
You can find important information about Australia's seafood industry, seafood and your health, seafood labelling, some of the common seafood myths and much more.
Overseas you can rely on these guides:
Declining Marine Life
In the last forty years half of all marine life has disappeared. Industrial scale fishing can be blamed for the massive quantities of fish being plundered from the ocean but we are responsible for the destruction of the marine habitats.
We have created ocean pollution, coastal development and the greenhouse gas emissions which increase water temperatures and promote acidification, destroying coral reefs where one quarter of marine life live.
Human behaviour and cultural customs are also putting species at risk. Just like the Ivory trade – many species are subject to poaching and exploitation through international wildlife trade. Tortoise shell is still sold in many Pacific island communities for tourism trinkets. Killing sharks for their fins is still rampant in parts of the world. Manta Rays are killed for their gills, which are sold as a health tonic.
Destruction of Habitats
We have national parks on land, it’s time our ocean and marine life receive the same respect. Areas where sea creatures and their homes are protected from extractive industries, such as fishing and oil and gas exploration, are vital for ocean health.
Only 5% of the ocean surface is classified as Marine Park, despite scientists believing 30% is necessary.
A network of global marine parks would reduce stress on marine ecosystems and allow the whole of the ocean to bounce back. Like green lungs, these sanctuaries filter pollutants and act as a breeding ground for marine life stretching across the world. They enable the ocean to cope with the pressures already facing her, like insurance policies for damage that has occurred and will occur in other parts of her waters, creating a healthier ocean and a healthier planet.
The ocean plays a major role in regulating the Earth’s climate. It produces half the oxygen we breathe and absorbs vast amounts of carbon dioxide and excess heat from the atmosphere. And just as climate change climate is effecting our land, climate change is effecting our oceans.
Oceans are becoming warmer, sea levels are rising and the increase in carbon dioxide has started a process of acidification in our ocean.
The blue truth is, the process the ocean uses to protect us (absorbing carbon dioxide and heat) is destroying it.
For decades, the ocean has been acting as a buffer, soaking in the carbon dioxide dumped into the atmosphere by burning fossil fuels. It has absorbed most of the extra heat produced by elevated atmospheric carbon dioxide levels.
Ocean heat not only determines sea surface temperature, but also affects sea level and currents. It affects flooding, which becomes more frequent as sea levels rise. Changes in sea temperature affect habitats and the behaviour of marine life as they are forced to adapt or die.
Blue carbon is carbon captured by oceans and coastal ecosystems. Ocean plants take in carbon dioxide and give off oxygen, just like land plants, but they are even more effective. Ocean vegetation can absorb four times more carbon than forests. Blue carbon sinks - mangroves, saltmarshes, seagrasses and estuaries - capture 1 billion metric tons of carbon every year.
If not for the ocean, we’d be choking on our own CO2. Yet we are destroying its ability to help us combat these ever increasing CO2 levels by degrading wetland ecosystems, prioritising instead urban expansion and coastal development. This will accelerate climate change.
Unsustainable infrastructure (such as port expansion) in marine sensitive areas creates the double whammy- increasing CO2 levels by pumping fossil fuels into the air and destroying the ecosystems which could absorb it. Big business is giving us the disease and denying us the cure.
To date, we have lost 27% of the world’s coral reefs. If present rates of degradation continue, it may be too warm for coral reefs to exist.