The global fishing fleet is currently 2.5x larger than what the oceans can sustainably support(1) - meaning that humans are taking far more fish out of the ocean than can be replaced by those remaining. As a result:
52% of the world's fisheries are fully exploited, and 24% are overexploited, depleted, or recovering from depletion(2)
Seven of the top ten marine fisheries, accounting for about 30% of all capture fisheries production, are fully exploited or overexploited
As many as 90% of all the ocean's large fish have been fished out(3)
Several important commercial fish populations have declined to the point where their survival is threatened
Unless the current situation improves, stocks of all species currently fished for food are predicted to collapse by 20484.
Why is this happening?
Many fishers are well aware of the need to safeguard fish populations and the marine environment.
However, the greed and waste of some large commercial fleets combined with modern developments in fishing technology have had an enormous effect on fishing worldwide. Contributing factors to the current level of overfishing include:
Technological advances that have made large-scale fishing easier
Subsidies that keep too many boats on the water
Unfair Fisheries Partnership Agreements that allow foreign fleets to overfish in the waters of developing countries
Pirate fishers that don't respect fishing laws or agreements
Massive bycatch of juvenile fish and other marine species
Destructive fishing practices
A lack of sound fisheries conservation and management
From the coast to the deep sea
As coastal and pelagic (open ocean) fisheries around the world have collapsed, fishing effort has shifted to the deep sea and previously unexploited fish species. Here, overfishing can quickly deplete local fish populations - even within a single season. Some newly fished populations, such as monkfish, Patagonian toothfish, blue ling, and orange roughy, have already collapsed in some areas.
There is insufficient data on other populations to determine what level of fishing is sustainable. At present most deep-water species are likely to be over-exploited - and as many as 40% of the world's fishing grounds are now in waters deeper than 200m.
The impacts of declining fish catches are being painfully felt by many coastal fishing communities around the world.
Newfoundland in Canada provides a sobering example of what happens to communities when fish populations are fished to commercial extinction. For centuries the cod stocks of the Grand Banks seemed inexhaustible. In the early 1990s, 110,000 people were employed in the fishing and fish processing industry.
But in 1992 the cod fishery was finally deemed to have collapsed - and some 40,000 people lost their jobs overnight, including 10,000 fishermen. More than 10 years later, the cod have still not recovered. And the latest science indicates that the ecosystem has now substantially changed, meaning that the cod may never make a comeback.
Similarly, in Senegal fishers no longer catch prized barracudas and red carp. Instead they must go after smaller and less appetizing kobos (a small coastal pelagic fish) because most of the time there is nothing else.
Other marine species are also being left with few fish to eat, including seals, sea otters, seabirds, whales, and dolphins. Humpback whales in Canada's Bay of Fundy, for example, appear to be suffering from lack of food due to competition with fishing fleets for herring.
(1) Porter, G. (1998). Estimating overcapacity in the global fishing fleet. WWF
(2) FAO (2004) State of World Fisheries and Aquaculture (SOFIA) - SOFIA 2004. FAO Fisheries Department
(3) Myers, R.A., and Worm, B. (2003) Rapid worldwide depletion of predatory fish communities. Nature, 423: 280-283
(4) Worm, B. et al (2006) Impacts of biodiversity loss on ocean ecosystem services. Science, 314: 787
Directly quoted from WWF
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More on overfishing:
Understanding the problem
More resources on overfishing
In this chapter:
Destructive fishing practices
Also in this section:
The importance of a coral reef ecosystem
What is a coral?
Elements that influence a coral reef ecosystem
Threats to coral reef
Coral reef and global warming
Why do we try to protect the coral reef?
Indigenous knowledge of the marine ecosystem on Balobaloang
Knowledge and practice of sustainable fishing on Balobaloang
Academic works and research on Balobaloang
Global fish trade and the environment