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AFSC Historical Corner:  Technological Methods, Techniques, and Ideas

Early Pioneers
Research and Mgmt.
Canning & Curing
Diving Programs
Tools & Equipment
tagging box
George B. Kelez  takes soundings in Iliamna Lake.
Auke Bay Laboratories photo.

NOTE:  This page is under development,
            pending additional content.

For similar topics check out:  "Tools, Gear, & Equipment"  and the "Research and Management"  pages.

Fishing:  Owing to the severe weather conditions at sea and working around heavy equipment, fishing has always been a very hazardous occupation in Alaska. According to Alaska Fishermen's Union records, nearly 60 men drowned from 1905-1909. Improvements to vessels, gear, techniques, safety and the organizing of more unions helped alleviate some of these risks.

The oldest and most popular apparatus in the Pacific coast salmon fishery has been the gill net – the "drift net" and "set net" being the two kinds used in purse seining. Many types of floating traps, from the one invented by Mr. J. R. Heckman, of Ketchikan, Alaska, were used in southeastern Alaska, the first having been installed in 1907. Native fishing methods in Alaska have included the use of wickerwork traps, the bow and arrow, spears and gaffs, and fish wheels, whose first operation in coastal waters was in Taku River, Southeast Alaska, in 1908.

  • Cobb, J. N. 1921. Apparatus and Methods of the Fisheries, p. 75-91. In J. N. Cobb, Pacific Salmon Fisheries, Appendix I to the Report of the U.S. Commissioner of Fisheries for 1921 (doc. 902). Wash. G.P.O. 268 p. + figs.  (.pdf, 2.04 MB).
  • Collins, J. W. 1892. The Fishing Vessels and Boats of the Pacific-Coast, p. 13-48 + plates. In Bulletin of the United States Fish Commission, Vol. X, for 1890. Wash. G.P.O. 450 p.  (.pdf, 20.7 MB)
  • West, C. W. 1985. Harvesting Technology in the Pacific Whiting, Merluccius productus, Fishery. Mar. Fish. Rev. 47(2):47-54.  (.pdf, 4.81 MB).
  • Taylor, H. F. 1921. Preservation of Fish Nets (doc. 898), 35 p. In Report of the United States Commissioner of Fisheries for the Fiscal Year 1920. Wash. G.P.O. 306 p.  (.pdf, 1.88 MB).
  fish scale ridges
Magnified fish scale ridges taken in 1919.
Auke Bay Laboratories photo.

Ageing:  An important aspect of developing appropriate fisheries management polices was the study of age and growth of fish. In 1910, Charles Gilbert adapted an existing European method of ageing Pacific salmon that entailed counting ridges on the scales.

An important breakthrough in the fur seal research occurred around 1948, when a biologist extracted 36 teeth from a freshly killed animal to photograph dentition. During the process he noticed faint ridges circling the root of each tooth and hypothesized that each ridge might indicate 1 year of life. His theory proved to be correct and, as a result, a routine part of the field operations on the Pribilof Islands after that time was the collection of teeth for age determination.

Fish otoliths (ear bones) have been used in age determination. Under a microscope, the thickness of individual rings on an otolith are measured in order to estimate fish growth. "Determining fish ages from reading otoliths underwent a revolution during the early 1980s when it was determined that older specimens of many species aged from otolith surfaces were being underaged. At the AFSC, the Age and Growth Program began applying a new technique of ageing otoliths, the break and burn method, in 1981. The break and burn method entails taking a transverse cross section by breaking (usually sawing) an otolith in half and then exposing the transverse surface to an alcohol flame. This process makes finer marks associated with later annual marks more visible than viewing from the otolith surface"
From:  Kimura, D. 2007. A Bit of AFSC Ageing History. In AFSC Quarterly Report, July-Sept. 2007.

Bomb-derived radiocarbon (C-14) has been a method more recently used in age validation studies. "During the Cold War era in the 1950s to 1960s, above-ground testing of atomic bombs led to a substantial increase in marine C-14. Any marine organism alive at that time incorporated bomb-produced C-14 in their calcified hard parts, providing a time stamp for age estimation. The bomb radiocarbon age validation method relies on fish of known age that were alive during the era of increasing C-14 and on measurements of C-14 in their otolith cores to create a reference."
From:  Kastelle, C. 2009. Fish Age Validation with Radiocarbon from Atomic Bombs. In AFSC Quarterly Report, Apr-June 2009.


  • Kimura, D. K. 2008 (rev.) A Brief History of Age Determination of Walleye Pollock (Theragra chalcogramma) at the Alaska Fisheries Science Center. (AFSC Age and Growth Program page)
  • Kimura, D. K., and D. M. Anderl. 2005. Quality Control of Age Data at the Alaska Fisheries Science Center. Mar. Freshwater Res. 56:783-789.
  • Kastelle, C., and T. Helser. 2010. Regional Environmental Factors Affecting Bomb-Derived Radiocarbon Age Validation Studies. In AFSC Quarterly Report Feature, April-June 2010, 5 p. (.pdf, 692 KB).

Event items:

  • Fish tagging/marking experiments, 1920s-1950s

    In the early 1920s, Charles Henry Gilbert and Willlis H. Rich began extensive tagging salmon in the Alaska Peninsula. In 1923, roughly 10,000 numbered aluminum tags were attached to red salmon with reliably reported recaptures during the commercial fishing season. Tongs were used to attach the 3-inch long bent tags to the upper lobe of the tail at its base (see photo).  From:  Gilbert, C. H., and W. H. Rich. 1925. Second Experiment in Tagging Salmon in the Alaska Peninsula Fisheries Reservation, Summer of 1923 (doc. 991), p. 27-75 + figs. In Bulletin of the U.S. Bureau of Fisheries, Vol. XLII, 1926. Wash. G.P.O. 385 p.  (.pdf, 4.3 MB).

    In the spring of 1930, the first known attempt to mark pink salmon fry as they migrate from the streams was done at the Duckabush River hatchery – 36,000 fry were marked. The process involved using finger nail clippers to remove the dorsal and adipose fins, widely separated on the body. Both fins were removed because mature salmon often lose one of them from natural causes. Despite the loss of fins, the mortality of the fry was apparently unaffected.

    A sizable herring tagging program began in 1932 conducted by Dr. George A. Rounsefell, Edwin Dahlgren, and Samuel Hutchinson in southeastern Alaska using the Bureau's motor launch Heron. Some 5,000 herring were tagged and released using new metal "belly" tags, made of pure nickel, that could be recovered by a magnetic detection system on the conveyer belts at processing plants. Three years later, Dahlgren refined the tags and developed electronic and magnetic systems for recovering the tags as the fish pass through the reduction plant.

    By the mid-1950s, the common type of tag had evolved to to the "Petersen-disk", consisting of two plastic disks, about one-half inches in diameter, attached on each side of the salmon by a 2-inch pin inserted through the fleshy part of the back below the dorsal fin. A "tagging box", built to waist-height and used on the water, had a padded cradle to hold each fish while being tagged and a foot-lever-operated door that opened to release the fish into the water.

  • NMFS laboratory tags Tanner crabs

    A team of National Marine Fisheries Service Auke Bay Biological Laboratory scientists, headed by John Karinen, project supervisor, has developed a method for tagging Tanner crab with identification that is retained through molting. Up to now, there had been no known method for accomplishing this task. After small-scale tagging studies, laboratory scientists report that of nine male crabs fitted with Floy anchor tags in the area of the third walking leg, 30 percent molted successfully and retained the tag. It is believed that molting success of tagged crab can be improved by modifying the tag and method of insertion. The tagging problem also has shown that Tanner crabs return to a "home" area to molt and mate each year. Scuba divers recently recovered a tagged male Tanner crab in 30 feet of water at the Auke Bay Biological Laboratory dock that was one of ten tagged in March 1970 and released at the same location. Further tagging of Tanner crabs is underway to learn more about their migration and behavior.

    From:  NOAA Week newsletter.4 June 1971, 2(22):4.

  • Fishery acoustic surveys

    Fishery surveys are used to estimate the total population of a fish stock–information that is critical to making fishery management decisions. Since 1970, NOAA’s Alaska Fisheries Science Center has pioneered the development of acoustics, or sound waves, to conduct these surveys. Innovative technologies, such as digital data collection systems or multi-beam sonar, as well as techniques for collecting acoustic data developed by the Center have improved the quality of data collected, allowing better overall management of our nation’s fisheries.

    From:  "Breakthroughs: Honorable Mentions"  ("NOAA Celebrates 200 Years of Science, Service, and Stewardship" website)

  • New way to ship live crabs to market is perfected by NMFS, 1973-74
    see "Canning, Curing and other Preservation Techniques"

Additional reading:

  • Rounsefell, G. A., and J. L. Kask. 1945. How to Mark Fish. Trans. Amer. Fish. Soc. 73(1):320-363.
  • "Regional Fisheries Data Sets"  ("NOAA Celebrates 200 Years of Science, Service, and Stewardship" website).

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