Seen from space the Earth is covered in a blue mantle. It is a planet on which the continents are dwarfed by the oceans surrounding them and the immensity of the marine realm.
A staggering 80 percent of all the life on Earth is to be found hidden beneath the waves and this vast global ocean pulses around our world driving the natural forces which maintain life on our planet.
The oceans provide vital sources of protein, energy, minerals and other products of use the world over and the rolling of the sea across the planet creates over half our oxygen, drives weather systems and natural flows of energy and nutrients around the world, transports water masses many times greater than all the rivers on land combined and keeps the Earth habitable.
Without the global ocean there would be no life on Earth.
It is gravely worrying, then, that we are damaging the oceans on a scale that is unimaginable to most people.
We now know that human activity can have serious impacts on the vital forces governing our planet. We have fundamentally changed our global climate and are just beginning to understand the consequences of that.
As yet largely unseen, but just as serious, are the impacts we are having on the oceans.
A healthy ocean has diverse ecosystems and robust habitats. The actual state of our oceans is a far cry from this natural norm.
A myriad of human pressures are being exerted both directly and indirectly on ocean ecosystems the world over. Consequently ecosystems are collapsing as marine species are driven towards extinction and ocean habitats are destroyed. Degraded and stripped of their diversity, ocean ecosystems are losing their inherent resilience.
We need to defend our oceans because without them, life on Earth cannot exist.
Dead oceans, dead planet
We need to defend them now more than ever, because the oceans need all the resilience they can muster in the face of climate change and the potentially disasterous impacts this is already beginning to produce in the marine world.
The Greenpeace Defending our Oceans campaign sets out to protect and preserve our oceans now and for the future by setting aside swathes of the global oceans from exploitation and controllable human pressure, allowing these areas the respite they so desperately need for recovery and renewal.
Building on a protection and recovery system established to manage land based over-exploitation, Marine Reserves are the ocean equivalent of national parks.
Marine Reserves are a scientifically developed and endorsed approach to redressing the crisis in our oceans which work alongside a range of other measures designed to ensure that the demands we make of our oceans are managed sustainably.
Beyond Marine Reserves we need to tackle a great many threats to the oceans' viability and find better ways of managing their resources. To this end, while Greenpeace campaigns for Marine Reserves, we also campaign against the acts which have brought the oceans to this point - we expose the countless pressures, reveal the threats, confront the villains and point to the solutions and measures necessary to create sustainable oceans.
The key threats we address are:
Giant ships, using state-of-the-art equipment, can pinpoint schools of fish quickly and accurately. These industrial fishing fleets have exceeded the ocean's ecological limits. As larger fish are wiped out, the next smaller fish species are targeted and so on. (Canadian Fisheries expert Dr Daniel Pauly warns that if this continues our children will be eating jellyfish.)
Simply put, more and more people are competing for less and less fish and worsening the existing oceans crisis.
Modern fishing practices are incredibly wasteful. Every year, fishing nets kill up to 300,000 whales, dolphins and porpoises globally. Entanglement is the greatest threat to the survival of many species. Moreover, some fishing practices destroy habitat as well as inhabitants. Bottom trawling, for example, destroys entire ancient deep-sea coral forests and other delicate ecosystems. In some areas it is the equivalent of ploughing a field several times a year.
As traditional fishing grounds in the north have collapsed, fishing capacity has increasingly turned to Africa and the Pacific. Pirates that ignore regulations and effectively steal fish are denying some of the poorest regions of the world much needed food security and income, and those fleets fishing legally are only giving a small percentage of the profit to African or Pacific States.
Aquaculture (fish and shellfish farming) is often put forward as the future of the seafood industry, but it is not a solution to overfishing. Many modern aquaculture practices emphasise the unsustainable production of species for high-value export markets. Rapid expansion of intensive aquaculture has resulted in widespread degradation of the environment and the displacement of coastal fishing and farming communities.
Shrimp aquaculture industry is perhaps the most destructive, unsustainable and unjust fisheries industry in the world. Mangrove clearances, fishery destruction, murder and community land clearances have all been widely reported.
The salmon farming industry also proves farming is no solution - it takes approximately 4kgs of wild caught fish to produce 1kg of farmed salmon.
The ocean and its inhabitants will be irreversibly affected by the impacts of global warming and climate change. Scientists say that global warming, by increasing sea water temperatures, will raise sea levels and change ocean currents. The effects are already beginning to be felt. Whole species of marine animals and fish are at risk due to the temperature rise - they simply cannot survive in the changed conditions. For example, increased water temperatures are thought to be responsible for large areas of corals turning white and dying (bleaching).
Another significant impact of human activity on the marine environment is pollution. The most visible and familiar is oil pollution caused by tanker accidents. Yet despite the scale and visibility of such impacts, the total quantities of pollutants entering the sea from oil spills are dwarfed by those of pollutants introduced from other sources. These include domestic sewage, industrial discharges, urban and industrial run-off, accidents, spillage, explosions, sea dumping operations, mining, agricultural nutrients and pesticides, waste heat sources, and radioactive discharges.
Defending our oceans
Fundamental changes need to be made in the way our oceans are managed. This means that we must act to make sure that human activities are sustainable, in other words that they meet human needs of current and future generations without causing harm to the environment. Accordingly, governments must set aside 40 percent of our oceans as marine reserves. Marine reserves can be defined as areas of the ocean in which the exploitation of all living resources is prevented, together with the exploitation of non-living resources such as sand and gravel and other minerals.
For more information, visit //www.greenpeace.org/international/campaigns/oceans