Facts and Figures

Facts and Statistics on Ocean Threats


Fish and Marine Life

  • 200 years ago the area of the oceans we did not fish or hunt exceeded the area in which we did by 100 to 1. Today it is the other way around. The de facto refuges of old were reservoirs for spawning fish that spilled their bounty into the fishing grounds. Today the only refuges at sea are those we deliberately create.
  • Two-thirds of the world’s major fish stocks that are monitored by the UN Food and Agriculture Organisation have been fished to collapse since 1950.
  • Overfishing is probably the world’s biggest soluble environmental problem. We know what to do and if we were to act decisively, it would take only 15 years to fix most of what has gone wrong.
  • Laysan albatross fly thousands of miles across the Pacific to gather food for their young, only to bring back dozens of pieces of plastic trash. Their chicks are starving on a literal junk food diet.
  • Adelie penguins are freezing to death because the Antarctic has warmed. Their downy feathers insulate when it snows but not when it rains.
  • The world’s most expensive fish — Atlantic Bluefin tuna — reached a new price record in January 2012 when a single fish sold for US$738,000.
Pollution
  • The oceans have absorbed a third of all the carbon dioxide emitted since the Industrial Revolution, sparing us, so far, more extreme warming but causing seawater acidity to rise faster than at any time in the last 55 million years, with unpredictable and potentially disastrous consequences for life.
  • Ocean acidity has risen 30% since the Industrial Revolution, and could rise a further 150% by 2100 unless we curb carbon dioxide emissions. Such acidity increases are making life very tough for creatures like corals, shellfish and key groups of plankton that secrete calcium carbonate — chalk — to make skeletons and shells.
  • In the next 50 years, global warming could intensify upwelling of deep waters, which contain toxic gas rather than oxygen, to the point where the waters off northern California belch toxic gases over coastal towns.
  • Huge increases in the use of agricultural fertilisers mean that levels of nitrogen and phosphorus in the oceans have trebled since pre-industrial times, leading to massive increases in the numbers and expanse of deoxygenated coastal ‘dead zones’. There are well over 500 such zones, and this number is increasing fast, spurred on further by rising sea temperatures.
  • Chemical pollutants such as the flame-retardant chemicals and synthetic musks found in detergents which recent studies have traced in the polar seas.
  • The world’s largest container ships and supertankers each emit more pollution than the world’s smallest countries and they make so much noise they can be heard by marine mammals a day before they pass by.
  • Near population centres every linear metre of beach can be polluted with tens or hundreds of thousands of pieces of plastic most of it so small it looks like sand grains.
  • In the early years of the 21st century, Chinese shrimp ponds released forty-three billion tonnes of effluent into coastal seas, compared to just over four billion tonnes of industrial effluent and sewage from land-based sources. China’s Bohai Sea supports some of the most intensive aquaculture in the world but is also one of the planet’s most polluted seas.
  • The length of all the longlines — fishing lines studded with thousands of hooks — set every night by fishing fleets on the oceans is long enough to wrap around the world 500 times.
  • In the midst of ocean gyres, sometimes dubbed ‘ocean garbage patches’, there can be more plastic than zooplankton. The Great Eastern Garbage Patch in the Pacific Ocean is the size of Texas.
How the Ocean’s Environment has Changed
  • The oceans around us are changing faster than at any time in human history and probably since the cataclysm that destroyed the dinosaurs 65 million years ago, and we are the cause of that transformation.
  • In the last decade, melting of Arctic Sea ice has opened a connection between the Pacific and Atlantic oceans that had been shut for 800,000 years.
  • In just 25 years, repeated disease epidemics have swept the Caribbean, killing 4/5 of its corals. If this occurred to a land species, the reaction would be huge and global.
  • The thickness of the oceans is to the size of Earth as the skin of a peach is to the fruit inside, yet they constitute more than 95% of the living space on our planet and are vitally important to life in the remaining 5%.
  • In 1998, the Indian Ocean became so hot that three quarters of its corals died, yet this sinister forewarning of global warming passed almost unnoticed by the world community. If three quarters of forest trees had withered that year there would be near universal alarm. Yet below water the oceans are out of sight and therefore out of mind.
  • The pace of global mean sea level rise is accelerating: levels rose by approximately 1.8mm per year over the last 50 years, but doubled to 3.1mm per year in the 1990s, and were 2.5mm per year in the period 2003—2007.
  • As coastal sea ice melts in the Arctic, methane geysers have begun to erupt beneath the sea, releasing tens of thousands of tonnes of this potent greenhouse gas to accelerate global warming.
  • European politicians have for the last 25 years set annual fishing quotas a third higher than recommended as safe by their scientists, driving many fish stocks toward collapse.
The Value of the Ocean
  • The UN has calculated that over three billion people depend on marine and coastal biodiversity for their livelihoods, and estimates the market value of marine and coastal resources and industries at $3 trillion per year, or about 5% of global GDP.
  • The global value of fish catches at landing is approximately $100 billion, and the wider economic activities related to fishing reach a value of about $240 billion.
  • Illegal, unreported, and unregulated (IUU) fishing is responsible for the loss of $10 billion to $23 billion a year — the value of the 11 million to 26 million tonnes of fish that are unaccounted for, out of a total world capture of approximately 80 million tonnes.
  • Coral reefs alone have been estimated to provide goods and services worth up to $375 billion per annum; with the economic value of coastal protection from a coral reef calculated at $25,000 per hectare per annum. Reef-based tourism now brings in tens of billions of dollars every year.
Sources: The United Nations, The Stockholm Environment Institute, Professor Callum Roberts
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