Study: 90 percent of the world's large predatory fish have disappeared in the past 50 years

Other Fish in The Ocean, But For How Long?

From Earth Policy Institute
Friday, July 18, 2003

Janet Larsen

A recent review of marine fisheries concluded that a startling 90 percent of 
the world's large predatory fish, including tuna, swordfish, cod, halibut, 
and flounder, have disappeared in the past 50 years. This 10-year study by 
Ransom Myers and Boris Worm at Canada's Dalhousie University attributes the 
decline to a growing demand for seafood, coupled with an expanding global 
fleet of technologically efficient boats.

Once thought to be inexhaustible, the world's fisheries are now showing their 
vulnerability. The United Nations Food and Agriculture Organization (FAO) 
estimates that three quarters of the world's oceanic fisheries are being 
fished at or beyond their sustainable yields. The innovations that have 
allowed us to pull more fish out of the oceans--larger and more powerful 
boats (some with on-deck processing facilities), improved fishing gears, and 
navigational and fish-finding technologies--may undermine the oceans' 
presumed resilience.

Data show that once large boats target a fishery, they can deplete 
populations in a matter of years. Within 15 years, some 80 percent of the 
large fish are lost. Smaller species may initially flourish, but often their 
populations soon crash too, either because of a limited food supply, 
overcrowding, and disease or because they become targets for those who are 
"fishing down the food web." The average size of top predatory fish is now 
only one fifth to one half that in the past, in part because the fish left to 
breed are the ones small enough to escape from nets. Another problem is that 
slow-maturing fish are often caught before they are old enough to reproduce.

Fishing gears are frequently indiscriminate. Trawlers drag enormous nets over 
a vast area, virtually clearcutting the seabed, destroying marine habitat, 
and taking up untargeted species. Worldwide, almost one fourth of the fish 
catch is discarded dead at sea, either because the fish are not marketable or 
because fishers have exceeded their catch allotment. Whales, dolphins, and 
porpoises also become part of this collateral damage. In certain fisheries, 
like the Gulf of Mexico shrimp fishery, the weight of this "bycatch," as it 
is known, may exceed that of the profitable take by 10 to 1.

After growing steadily for decades, the world fish catch has stalled between 
85 million and 95 million tons since 1986. (See graph at 
www.earth-policy.org/Updates/Update25_data.htm). In 2001, the world's fishing 
fleets landed some 92 million tons of fish, according to FAO data. An 
analysis by Reg Watson and Daniel Pauly at the University of British Columbia 
reveals that overreporting by China, the world's largest fisher, and 
climate-related fluctuations in Peruvian anchoveta populations may have 
masked an actual decline in the global catch of some 660,000 tons per year 
since 1988.

From 1950 to 1988, the world fish catch climbed from 19 million to 89 million 
tons. This fivefold expansion dwarfed the growth in global beef production 
during that period (from 19 million to 54 million tons). In per capita terms, 
the annual fish catch per person peaked at 17 kilograms in 1988, up from 8 
kilograms in 1950. For most of the last half-century, we could count on a 
steadily growing oceanic catch to help meet the growing demand for animal 
protein. That era is over.

Prospects for the 1 billion people throughout the world who rely on fish as 
their primary source of protein and the 200 million involved with fishing and 
fish-related industries rest on careful management of wild fish stocks and 
farms. Ecologists liken fish stocks to a bank account. With a certain balance 
preserved in the bank, we can live off of the interest. But if we continue to 
dip into the principal, eventually we are left with an empty account. 

The collapse of the Newfoundland cod fishery is a case in point. For 
centuries it was one of the world's most productive fisheries, yielding 
800,000 tons of fish and employing 40,000 people at its peak in 1968. Then 
its stocks plummeted as a result of overharvesting and habitat damage. In 
1992, the fishery was closed in an effort to save it. But it may have been 
too late: a decade has passed, but stocks have not recovered.

This collapse was local in scale, but the issue is much larger. Fisheries 
operating over the entire North Atlantic Ocean now catch half as many of the 
popular species?such as cod, tuna, flounder, and hake?as 50 years ago, 
despite tripling their efforts. Cod stocks in the North Sea and to Scotland's 
west are on the verge of collapse. In a 2001 report entitled Now or Never: 
The Cost of Canada's Cod Collapse and Disturbing Parallels With the UK, 
Malcolm MacGarvin urges Europe to avoid the same fate as Newfoundland's 
fishers.

The deterioration of oceanic fisheries can be reversed. Granting fishers an 
ownership stake in fish stocks is one way to help them understand that the 
more productive their fishery is, the more valuable their share. For example, 
fishers in Iceland and New Zealand have used marketable quotas, allowing them 
to sell catch rights, since the late 1980s. The upshot is smaller but more 
profitable catches and rebounding fish populations. The classic "tragedy of 
the commons" problem is averted.

Because of the complexity of marine ecosystems, some scientists are pushing 
for management of whole ecosystems rather than single species. In addition, 
studies have shown that well-positioned and fully protected marine reserves, 
known as fish parks, can help replenish an overfished area. By giving fish a 
refuge to breed and mature in, reserves can increase the size and total 
number of fish both in the reserve and in surrounding waters. For example, a 
network of reserves established off St. Lucia in 1995 has raised the catch by 
adjacent small-scale fishers by up to 90 percent. Preservation of nursery 
habitats like coral reefs, kelp forests, and coastal wetlands is integral to 
keeping fish in the sea for generations to come.

Consumers can promote healthy fishery production by eating less fish and 
buying seafood from well-managed, abundantly stocked fisheries. The Seafood 
Lover's Guide from Audubon's Living Oceans program is one valuable reference. 
Chilean seabass, for example, makes the list of fish to avoid because stocks 
are on the verge of collapse and illegal fishing abounds. The list also 
distinguishes between wild Alaska salmon, which comes from a healthy fishery, 
and farmed salmon, which is fed meal made from wild fish and thus does not 
relieve pressure on marine stocks. Proper labels are needed to allow 
consumers to make wise purchasing decisions. The Marine Stewardship Council, 
a new independent international accreditation organization, has thus far 
certified seven fisheries as being sustainably managed with minimal 
environmental impact.

The capacity of the world's fishing fleet is now double the sustainable yield 
of fisheries. Myers and Worm from Dalhousie University believe that the 
global fish catch may need to be cut in half to prevent additional collapses. 
Reducing bycatch, creating no-take fish reserves, and managing marine 
ecosystems for long-term sustainability instead of short-term economic gain 
are all policy tools that can help preserve the world's fish stocks. If these 
are coupled with a redirection of annual fishing industry subsidies of at 
least $15 billion to alternatives such as the retraining of fishers, there 
could be a big payoff. It is difficult to overestimate the urgency of saving 
the world's fish stocks. Once fisheries collapse, there is no guarantee they 
will recover. 



For more information, contact:
Reah Janise Kauffman
Vice President
Earth Policy Institute
rjkauffman@earth-policy.org

Web site: 
www.earth-policy.org