* Study looks at environmental impact of fishing industry
* Taste for predator fish increases impact on ocean
* Global overfishing a growing concern (Figures in U.S. dollars unless noted)
By Allan Dowd
VANCOUVER, Sept 22 (Reuters) - China is the largest consumer of seafood, but the environmental impact of countries like Japan and the United States is magnified by a taste for fish at the top of the food chain, such as tuna or salmon, according to a report on Wednesday.
Consumers worried about the oceans need to consider not just how much fish they consume, but what that fish ate before it was caught, and where it came from, according to Canadian research published in October's National Geographic magazine.
The researchers at the University of British Columbia in Vancouver said their SeafoodPrint Study tried to measure the impact that different countries had on the oceans by looking at not only how much fish they consumed but also what type of fish it was.
A large tuna at the top of the food chain must eat the equivalent of its body weight every ten days, so it may devour as many as 15,000 smaller fish each year. Those smaller fish in turn consumed other fish and seafood, and smaller organisms such as zooplankton.
"The SeafoodPrint allows us to directly compare a sardine fishery with a tuna fishery, because each is measured according to the primary production it represents," lead researcher Daniel Pauly said in a written statement.
The full study has not yet been released.
China, with the world's largest population, has the largest impact on the oceans. It leads all other countries in the amount of fish caught and consumed annually, and its demand continues to grow, according to the report.
Japan is the second-largest consumer, but it relies on imports to meet much of its demand. Peru ranked second in fish production, but most of the catch is small fish exported for industrial uses such animal feed.
China consumes about 694 million tonnes of ocean resources each year, compared with 582 million tonnes by Japan and 349 million by the United States -- which ranked third for production and consumption.
The preference of consumers in Japan and the U.S. for top predator fish such as tuna and salmon means their consumption has a relatively larger impact on the ocean environment, according to the report
The researchers say using imports to meet rising demand also increases a country's impact by promoting overfishing around the globe and pushing boats into areas of the oceans that had previously not been harvested.
Fisheries contribute between $225 billion and $240 billion to the world economy annually, according to a series of economic studies published last week by researchers at the University of British Columbia.
Those studies also warned that decades of overfishing have deprived the food industry of billions of dollars in future revenue and eliminated fish that could have helped feed undernourished countries. (Reporting Allan Dowd; editing by Rob Wilson)
Our Standards: The Thomson Reuters Trust Principles.
