Posted on 03/25/2003 11:20:58 AM PST by Willie Green
For education and discussion only. Not for commercial use.
BAHIA DE ACHOTINES, Panama (Reuters) - Scientist Kurt Schaefer slices a small hole in the side of a wriggling yellowfin tuna and inserts a tiny computer.
Quickly he sews the slit back up, allowing just enough space for a thin fiber optic wand to protrude from the fish's side, before transferring the animal to a large seawater tank.
"We like to joke we have remote control fish. It surprises the visitors," says Schaefer, pulling off a surgical glove.
Working to protect the tuna from becoming an endangered species in the eastern Pacific Ocean, Schaefer is part of a group of U.S marine biologists from the Inter-American Tropical Tuna Commission (IATTC) studying the yellowfin in Panama.
Little is known about the early life history of the fish, making it vulnerable to over-fishing because of its status as a favorite dish in restaurants from Japan to the Netherlands.
"Fishing stocks worldwide are under pressure," says Vernon Scholey, director of the IATTC's facilities in Panama known as Achotines and based on the southern tip of the Azuero Peninsula in central Panama.
"With the knowledge we gather here, we hope to aid the fishing industry judge how much tuna it can catch without depleting the species," adds Scholey.
Tuna is the world's most commercially traded fish, generating $4 billion in revenues in 2002, the IATTC said. There are 21 species of tuna and five are commercially important including the yellowfin, bluefin and skipjack, which is the variety commonly sold as canned tuna.
The fish is most popular in Japan, where a 444-pound bluefin tuna was auctioned for a record $173,600 in January 2001, according to the Guinness Book of Records.
While yellowfin does not fetch such high prices, it is one of the most important fishes of the eastern Pacific. A tuna steak sells for up to $30 in U.S restaurants.
Yellowfin tuna is not yet at risk from depletion, but catches in the eastern Pacific are increasing.
Between January and September 2002, the catch size rose to 321,000 metric tons, up 35 percent compared with the same period in 1997, according to IATTC figures.
To keep yellowfin stocks stable, the commission provides commercial tuna catchers every year with a suggested quota.
In 2002, instead of putting forward a quota, the IATTC closed the eastern Pacific to tuna fishers for one month, commission Director Robin Allen said.
"We send out observers on vessels to maintain the seas free of tuna fishers from California to Chile, going as far east as Hawaii and French Polynesia," says Allen, from the IATTC's headquarters in La Jolla, California.
COMPUTERIZED TUNA
In an effort to better understand and protect the tuna, the IATTC member governments, including Mexico, France, Japan and the Unites States, set up the Achotines lab in Panama. Since 1993 it has been studying the yellowfin.
The center is now one of the few places in the world to keep tunas alive in a controlled environment. It is also the world's only land-based lab with tuna spawning several million eggs almost daily.
"Through our experiments we try to find small differences in how the eggs might survive in the open ocean," said Scholey.
The lab is still about five years away from making its first recommendations to the IATTC, but an ambitious experiment using tiny 16 megabyte computers inserted into 17 tunas aims to significantly further the Achotines research.
One of the key uses of the computers is their ability to detect changes in the tuna's body temperature.
"We know the tuna changes temperature when it is feeding. We want to know if it does so too when spawning. With that information we would be able know about the tuna's behavior in the open sea, estimating its reproduction rate and its position in the ocean," explains Scholey, an Irish-born biologist from Seattle who has studied tuna fish in Japan.
At a cost of $1,500 each, the computers in the tunas can record up to five years of information about a tuna's life.
According to Schaefer, the Achotines lab is still testing to see if they affect a tuna's growth or development rate.
"We are trying to find out if tuna can spawn with the computers inside," says Schaefer.
UNDERSTANDING THE OCEAN
Aside from the high technology of the embedded computers, the lab's success in enabling 15 other tuna to spawn eggs in captivity allows it to test whether days-old tunas can survive ocean water turbulence, as well as changes in temperature.
In the future, daily ocean data matched with the information steadily gained at Achotines should enable the IATTC to estimate the survival rate of young tuna.
"Ideally, we will be able to advise fishers not to fish at certain times when the tuna is most vulnerable," asserts Scholey.
Gives a whole New World Order meaning to the term "Fish and Chips".
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