HONG KONG, China (CNN) -- It is commonly said that we know more about the Moon than the deep blue sea.
A catch from an illegal bottom trawler in Ivory Coast. The practice of bottom trawling can have hugely damaging environmental consequences.
Despite the fact that the sea takes up 95 percent of the world's living space, just 7 percent of it has been properly studied and sampled, according to the United Nations Environment Program (UNEP).
We don't even know how many species of marine life even live in the world's oceans. But the fish we do know about, we are particular keen on catching to eat.
The problem, we are told, is we are catching too many of them, and we have a finite time period available to us to fix the problem before it is too late. In the past 20 years, the UN says we have managed to double both the percentage of fish stocks facing collapse -- from 15 percent in 1987 to 30 percent last year -- as well as the amount that are overexploited, from 20 per cent to around 40 percent.
UNEP's report, "In Dead Water" released in January, says as much as 80 percent of the world's main fish catch species have now been "exploited beyond or close to their harvest capacity". We are now being told that if we carry on fishing at the rate we do, by 2048 all of the species that we currently fish for food will have disappeared.
In words not to be taken lightly, UNEP is now warning that unless governments around the world enforce some radical changes right now, we could be in the process of witnessing "a collapsing ecosystem".
Should that happen, it would mean nothing short of a catastrophe, with far reaching consequences for marine life -- and human life. One billion people around the world rely on fish as their main source of protein, while 2.6 billion of us get at least 20 percent of our animal protein intake from it.
Too many boats, not enough fish
There are several problems with how we catch fish.
For starters, the World Wildlife Fund (WWF) says the global fishing fleet is 2.5 times bigger than "what the oceans can sustainably support" - i.e. there are too many boats catching too many fish, and not giving fish stocks enough time to replenish them.
One living example of this can be found off the coast of Canada. In the early 1990's, cod stocks in the rich fisheries of the Newfoundland Grand Banks collapsed -- some to as little as 1 percent of their historical levels -- because of over fishing. A decade on, they have yet to recover.
The United Nations Food and Agricultural Organization (FAO) puts the number of fishing vessels at around 4 million with a staggering 86 percent of them operating in Asian waters.
But, according to the World Conservation Union (IUCN) just 1 percent of these vessels are big enough to substantially threaten global fisheries, with the "capacity to take around 60 percent of all the fish caught globally".
These large vessels have been largely kept in business by governmental subsidies, say non-governmental organizations like the WWF which has been urging the World Trade Organization (WTO) to do something about them.
The worldwide fishing industry employs around 200 million people, generating $80 billion a year. But a hefty chunk of the industry's revenues come from subsidies, which are currently estimated at around $34 billion a year. Those most responsible for subsidizing the fishing industry are Japan (spending $5.3 billion a year), the European Union ($3.3 billion) and China ($3.1 billion), according to activist group Oceana.
The increase in illegal fishing hasn't helped matters either, representing a fifth of all catches worldwide, a figure that came out of a recent meeting between the World Bank and the IUCN earlier this year. The business for pirate ships "flying flags of convenience from landlocked nations has boomed", says the New Scientist.
And it's not surprising why. As much as 64 percent of the world's oceans have no national jurisdiction. That means anyone can fish there, as they are deemed to be international waters. They are known as the "high seas" and they cover 50 percent of the Earth's surface.
In 2004, the most recent year statistics are available, the industry caught a record 106 million tons of fish.
The FAO says that, taking into consideration population growth, we will need an additional 37 million tons of fish a year to feed us all by 2030.
It says the only way to do this is through controlled fish farms. The "free-for-all" approach must be curtailed.
Bottom trawling and by-catches
It's not just a problem of where we fish, or even how many we catch -- it's how we go about doing it too.
The IUCN estimates that due to negligent fishing practices, we get as much as 20 million tons of fish that aren't supposed to be there literally caught in the nets each year. They are known as by-catch, and one of the most ubiquitous by-catches around are sharks.
Oceana estimates that 50 million sharks are caught "unintentionally" a year, getting snagged up in gillnets, long lines or trawls. These types of practices -- along with intentional shark hunts for the meat or the fins -- have led to 135 species of sharks being placed on the IUCN's infamous "Red List" of endangered or near extinct species.
By-catch has also been to blame for preventing parts of the Grand Banks from replenishing its cod stocks. In 2003, for examples, a breathtaking 90 percent of the southern Grand Banks' remaining cod population was lost to by-catches, reports trade site Fish Update.
But it's not just the fish that get in the way-- the way we fish is destroying entire ecosystems, perhaps something that is even greater cause for concern.
UNEP's "In Dead Water" report notes that, "over 95 percent of damage and change to seamount ecosystems is caused by bottom fishing".
Bottom trawling is generally accepted to be by far the worst kind of fishing around, with UNEP putting the damage its responsible for "exceeds over half of the sea bed area of many fishing grounds".
According to World Watch Institute, millions of marine creatures and their habitat, including coral reefs, are destroyed by bottom trawling practices. This has been arguably buoyed by depleting fish stocks, as ships seek to go deeper into the ocean in their pursuit of catches.
Bottom trawling can also exacerbate the by-catch issue, with some forms of this practice resulting in 20 pounds of by-catch for every single pound of targeted catch, reports Environmental News Service wire.
Fortunately an increasing awareness of the damage bottom trawling causes is taking hold. And last year, more than 20 South Pacific nations came to an agreement in Chile to restrict bottom trawling in the South Pacific high seas.
The UN General Assembly is now considering imposing some form of moratorium on bottom trawling on the High Seas.
It's about time, some say. Greenpeace says that bottom trawling has already "extinguished" 10,000 species. And such is the extent of the practice still, that the sediment that rises to the surface as a result of dragging weighted nets across the seabed can now be seen from space. E-mail to a friend
(Sources: The Guardian; The Independent; World Conservation Union; New Scientist; World Wildlife Fund; United Nations Environment Program; United Nations Food and Agricultural Organization; Oceana; Fish Update; The Times; ENS-Newswire; Greenpeace)