Wired For The Future -- Coded Tags Help Scientists Learn More About Fish

SHAW ISLAND, San Juan County - The biggest export from this sleepy Northwest isle is also its smallest - a stainless-steel wire about the size of a 2-day-old whisker. A thousand of them barely cover the bottom of a small pill bottle.

Yet this all-but-invisible wire is quietly revolutionizing the science and management of fisheries, from Pacific salmon to Atlantic striped bass and Japanese shrimp.

For a million or so Northwest sports fishermen, "coded-wire tag" technology is fast becoming a fact of life, prodded in large part by federal protections for depleted salmon runs.

This year 18 million baby coho and chinook salmon will be released into the ocean from Washington hatcheries, and each fish will be essentially branded by an ingenious machine that implants a coded wire in its nose and clips a tiny, unused fin on its back. Months or years later, the branding will provide critical information about their life cycles.

"This technology has absolutely changed the way we manage fisheries," says Dan Thompson, a state fisheries biologist who is busily tagging thousands of juvenile coho at the Green River Hatchery just outside Auburn. "And now it should allow us to rebuild the weakest runs."

All of this comes from a single-story building on Shaw Island, where about 20 people work full time for a little-known but wildly successful company called Northwest Marine Technology. Founded by Edmonds native Keith Jefferts, the company holds a virtual monopoly on the coded-wire technology that has spread around the world.

Over one billion sold

Over the past 25 years, the company has sold more than 1 billion tags, plus the sophisticated devices needed to implant them and then detect them months or years later.

Their biggest customer has been the state of Washington, whose taxpayers have spent millions on coded-wire technology and will spend millions more in the effort to restore troubled salmon runs.

The tags are a response to a fundamental problem of world fisheries: The ocean is essentially a black box, inaccessible to scientists. Pacific salmon begin and end their lives in shallow streams but spend most of them in a vast, opaque environment.

As a result, managing salmon and other fish has been mostly guesswork. Scientists try to take samples of sea life and then make educated guesses as to where fish are migrating and how many can be harvested without depleting stocks.

Since political pressures favor more fishing, not less, the history of fisheries management is largely a history of bad guesses with terrible consequences. Salmon, for example, suffer in large part because depleted wild fish swim in the same waters as abundant hatchery fish; fishermen can't tell which is which.

"Too many fish are caught without knowing where it comes from and whether it is endangered," explains Guy Thornburgh, a biologist and chief executive at Northwest Marine Technology.

"Without good data, the burden of proof is on science to prove that a resource is threatened. Good data place the burden on fishermen to prove that it is not."

Other methods haven't worked

There have been attempts to mark fish with metal tags or dyes, but none worked well. Biologists say external tags tend to affect movement, or make fish more vulnerable to predators or infection.

Scientists were desperate for better data - some way of marking fish so they could be tracked in the ocean.

Along came boyhood friends Jefferts and Pete Bergman.

"We grew up poaching trout from the creeks in Edmonds," says Jefferts. "In the early '60s, I was in grad school and Pete was a fisheries biologist, charged with collecting data on salmon. Pete was frustrated because he knew the data he was collecting was meaningless, and it was being used anyway!"

Jefferts, a physicist with a background in magnetism, and Bergman understood the need for an internal tag. "So we sat down one Saturday afternoon and invented one," Jefferts said.

Their idea was a tiny wire that could be notched and magnetized to record basic information - age, size, origin, etc., - much like bar codes that identify merchandise in stores. The magnetism could be detected with a sensitive machine.

There were complications. Jefferts had to find a way to magnetize surgical stainless steel, then devise machines to mark and cut the wire with extraordinary precision, implant it in fish, detect it later and read the code. His company's solution remains a tightly held trade secret.

Then fish managers had to agree on a common digital language for the tags.

First fish tagged in 1970

Washington tagged its first salmon in 1970 and retrieved a few hundred of them, enough to provide a glimmer of data from the black box. Last year, scientists retrieved about 250,000 tags, providing a wealth of information.

Scientists retrieve only a fraction of the tags. Their objective is 20 percent, enough to assemble a statistically significant glimpse of the species. In several cases, they've achieved that goal.

Coded-wire tags have traveled around the world. Northwest Marine Technology has sold tags and detectors for use with Atlantic striped bass and Maine lobster, trout and salmon in the Great Lakes, paddlefish in the Missouri River, frogs and salamanders, even marine worms and banana slugs.

The Japanese have tagged 900,000 hatchery shrimp with company tags made from 22-karat gold wire.

"We don't know of a creature that can't be tagged," says Thornburgh.

The great majority of coded-wire tags are implanted in salmon from Northwest hatcheries, from California to Alaska.

Their data become even more important this year, as Washington state adopts a controversial policy designed to protect wild salmon runs. Hatchery fish are identifiable by their clipped antipose fins, and fishermen will be required to release any salmon that still has the fin indicating it is a wild fish.

Catch sampled

To gather data, state officials check commercial- and sports-fishing docks, sampling 20 percent of the catch. When they detect coded wires, they cut off the heads of the fish and record where in the ocean and when they were caught.

"Where and when" are the critical information. Tag data and harvest data are fed into computers, which extrapolate information on migration patterns.

The biggest drawback is cost. Tagging by hand, eight people can tag about 30,000 juvenile fish in an eight-hour day. State biologists are testing a new Northwest Marine Technology machine that tags and clips salmon automatically: A 2-inch fish swims into the machine, where it is clipped and tagged, and swims out. With this device, two people can tag 50,000 fish in the same eight-hour day. But it is expensive. This year, the state plans to buy 150 handheld detectors costing about $6,000 each and 50 larger detectors at $20,000. In addition, the state will use four of the automatic-tagging machines worth a total of $200,000.

Scientists and entrepreneurs continue to look for other ways to track fish. Northwest Marine Technology and other companies have experimented with fluorescent dyes injected into fish. They have "archival" tags that are inserted into the stomachs of larger creatures, recording their movements for months or years.

But these alternatives are less practical and far more expensive than the coded wires.

"We don't see any marvelous breakthroughs on the horizon," says Thornburgh.

Which means the best view into the black box remains via a pricey, stainless-steel wire that is itself almost invisible.

Ross Anderson's phone message number is 206-464-2061. His e-mail address is: rand-new@seatimes.com