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nmt history


About the time of WWII, two grade school boys were fishing buddies in Shoreline, WA (on Puget Sound between Seattle and Everett). One of them, Pete Bergman, went on to earn his Ph.D. from the University of Washington in fisheries and became a senior salmon manager for Washington Department of Fisheries.

The other, Keith Jefferts, earned his Ph.D. in physics, also from the University of Washington. In 1968 Keith worked at Bell Laboratories with astrophysicists Robert Wilson and Arno Penzias who discovered cosmic background radiation, which earned them the Nobel Prize for substantiation of the Big Bang Theory. The three went on to publish their detection of the presence of carbon monoxide in the Orion Nebula in 1970.  Their use of millimeter-wave spectroscopy proved the molecular gas was in the interstellar medium and lead to a new branch of astronomy.

Meanwhile, the childhood fishing buddies stayed in touch and in the early 1960's worked together to solve the dilemma of tagging salmon. No one had been able to effectively tag juvenile salmon and then track them throughout their life cycle in the vast Pacific Ocean. The existing practice of fin clipping (excision) had serious biological drawbacks, offered very limited "code" capacity, and yielded data of questionable value. This meant that salmon management in those days consisted of harvesting populations of unknown origin.

In 1963 Pete and Keith published  "A Coded Wire Identification System for Macro-Organisms" in Nature.

Frustrated by lack of progress of other people's attempt to produce a good coded wire tagging system, Keith Jefferts left the team at Bell Laboratories in 1974 and relocated his family to tiny Shaw Island, Washington. There, Keith invented the magnetic stainless steel binary Coded Wire Tag that could be cleverly implanted into juvenile salmon and then magnetically detected in the fish after it was captured as an adult. The process to magnetize stainless steel; the technique to microscopically mark the tags; the technology to implant the tag; and the method to detect the tiny magnetic tag (1mm long and 0.25 mm in diameter) were all protected intellectual property of the new Northwest Marine Technology, Inc.

The scheme revolutionized salmon management. Now salmon managers in Japan, Russia, Canada, and West Coast of the United States of America could begin to tell where the fish were coming from and how many from specific locations were being caught.

Today, over a billion Coded Wire Tags have been sold throughout the world and used in hundreds of types of fish and other vertebrates. Thanks to laser technology, tags today are coded in easy to read decimal digits.

NMT's commitment to the problems of fisheries management is ongoing. When NMT identified the need for a tag that could be seen with the naked eye, we undertook the necessary physical and biological research to meet the need. That work led to the novel idea of implanting biologically inert material underneath transparent and translucent tissue. The result was the VI family of products.

NMT has patented several versions of Visible Implant tags used for the identification of fish ("internal" tags are implanted within the fish, as opposed to other techniques of attaching external tags with internal anchors which have foreign material that penetrates through the external surface of fish). These tags differ from the Coded Wire Tag because their code can be read externally by the naked eye.

NMT specializes in developing and manufacturing sophisticated mechanical and electronic tools and equipment for fisheries research and management. Most recently, NMT has revolutionized the handling of live fish by developing a machine that automatically tags and fin clips immature salmon.

Fish processed by the AutoFish System are never touched by human hands; are not anesthetized; are presorted to within 1mm length by a new sorting technology invented for this purpose. The salmon have their tiny adipose fin mechanically removed; and have a Coded Wire Tag automatically injected into their snout. Only one human operator is required to operate an AutoFish trailer, which contains six of these complex processing lines made up of high-tech computer, vision, and robotic engineering.

The company has its corporate office on Shaw Island, WA with satellite offices in Anacortes and Tumwater, WA.

In keeping with Keith's philosophy and the Company's mission, NMT strives to make the technology available as widely as possible, no small task for a very small company. To this end NMT  entered into a partnership with Tanaka Sanjiro Company, a 125 year old Japanese company, located in Ogori-City, Japan, to represent NMT's product line in Asia.


This chronology is a work in progress. Contributions and corrections will be gratefully welcomed. Please address correspondence to the web editor.




  • Pete Bergman (Fish Biologist) identifies the need to tag large numbers of small hatchery fish to conduct experiments and for overall fishery management.
  • Keith Jefferts (Physicist) brings a new science into the realm of fish management and together, Pete and Keith, developed the CWT technology.
  • Products invented:
    • Color Coded Wire Tags
    • Binary Coded Wire Tag (CWT)
    • MK 0.0
    • CWT Detector


  • Northwest Marine Technology, Inc. established in New Jersey then relocated to Shaw Island, WA.
  • Large scale CWT tagging programs begin in the Pacific Northwest.
  • Products invented:
    • MK I and MK II
    • QCD
    • X-Ray Tag


  • Biological Services Division opened in Olympia, WA.
  • Products invented:
    • MKIV
    • Visible Implant Alpha Tag
    • Sequential CWT


  • Asian branch office opened under Tanaka Sanjiro Company.
  • CWT format is enhanced by changed from binary coding to decimal coding.
  • WDFW, BPA, USFWS, and NMT partner to develop automated mass marking machine (AutoFish System) in response to management decision to mark all hatchery fish.
  • AutoFish Division opened in Anacortes, WA.
  • Pacific Northwest implements mass marking (adipose clip) of all hatchery fish. The adipose fin is no longer sequestered as the CWT indicator in the Pacific Northwest and large scale electronic sampling for CWT is established.
  • Products invented:
    • Coded Wire Tags
    • Handheld Multishot Tag Injector
    • Handheld Wand Detector
    • Visible Implant Elastomer Tag
    • R-Series Detectors


  • WDFW and USGS evaluate the processing of fish within the AutoFish System and determine the fish are unharmed.   
  • Large scale marking and tagging programs becomes automated as California, Idaho, Oregon, and Washington utilize the AutoFish System as their preferred processing method. Over 500 million fish processed on the west coast.
  • Products invented:
    • AutoFish System
    • CWT Illuminator
    • CWT MagniViewer
    • T4 Detector
    • T13 Detector
    • Individual Fish Counter


  • All eight Great Lake States and the Province of Ontario implement the Mass Marking Initiative using the AutoFish System technology.
  • Products invented:
    • New Visible Implant Alpha Tag
    • Adult Fish Counter
    • T-Wand Detector


Northwest Marine Technology would like to acknowledge the passing of Keith Jefferts. Keith was the founder of NMT and the inventor of the Coded Wire Tag. During his life Keith contributed to science and to helping others. He will be missed by everyone here at NMT. Read Keith's full obituary here.


Obituary for Dr. Peter K. Bergman