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intra-agency organization, similar to that for the coded-wire program in the Pacific Northwest, will be necessary to aid effort and reduce cost of future PIT tagging projects. Branding Several types of brands have been used over the years to mark fish. Freeze-branding maybe the most popular technique (Everest and Edmundson 1967; Fujihara and Nakatani 1967; Mighell 1969; Smith 1973; Laird et al. 1975; Nahhas and Jones 1980; Gunnes and Refstie 1980; Fay and Pardue 1985; Burgeois et al. 1987), followed by thermal-branding (Groves and Jones 1969; Niggol 1969), or branding with electric current (Johnson and Fields 1959; Owens and Gebhardt 1968; Jenkins and Klain 1969). Less successful or less popular techniques include caustic (silver nitrate) brands (Thomas 1975; Harshbarger 1979) and laser branding (Brock and Farrel 1977). Freeze-branding tools, constructed of either silver or stainless steel, are dipped in a coolant, typically liquid nitrogen. Time of exposure to the brand is from 1 to 2 s (Park and Ebel 1974; Raymond 1974; Fay and Pardue 1985; Burgeois et al. 1987). Long-term mark retention (up to 2 yr) has been reported for anadromous salmonids (Park and Ebel 1974; Refstie and Aulstad 1975; Gunnes and Refstie 1980); however, two recent studies reported unsatisfactory results when cold brands were used as long-term markers for rainbow trout (Fay and Pardue 1985) and Atlantic salmon (Burgeois et al. 1987). Another freeze-branding technique that may hold promise involves the use of a cold jet of liquid nitrogen or other coolant. The marking instrument is commonly used by dermatologists to remove skin lesion or warts. It is readily portable (hand-held) and resembles a small blowtorch but has the ability to focus a jet of coolant directly on a small spot, making it ideal for use on small fish. We know of no experimental trial of this equipment but suggest it here as a method having potential. Thermal-branding requires heating the branding tool in boiling water, and electric branding involves a wire loop connected and heated with a microscope illuminator transformer or similar device. Biologists at the North American Salmon Research Center reported 90% readability of electrically applied brands on Atlantic salmon marked at a weight of 600 g (Moring and Fay 1984). Researchers at the Center have found "hot brands" on Atlantic salmon parr to be readable in fish at the stage at which they return from the sea, and consequently use the technique as a primary means of identifying fish (Gary Friars, Salmon Genetic Research Group, personal communication). Another thermal-branding method that remains (to our knowledge) untested, but that may prove suitable for marking small fish, involves the use of electronic epilators (instruments used to permanently remove human hair). These instruments use chair-thin needle tlhrough which an electrical current of known intensity and duration can be applied. In marking fish, the needle could be inserted subcutaneously and activated to dlisrupt melanophore development and consequently produce a brand. High intensity pulses could possibly produce a much higher temperature in a more confined area than more common heat branding devices. Again, investigative research would be required to determine tlhe potential of such a system. As mentioned by Moring and Fay (1984), Breeze-branding remains the most popular of the two branding techniques, even though electric branding is comparatively faster. They listed the following advantages and disadvantages. Advantages 1. Equipment and supplies are inexpensive; overall cost pier fish is low compared to tagging (Laird et al. 1975; Dumas 1977; Nahhas and Jones 1980; Fay and Pardue 1985). 2.. There is flexibility in marking permutations if dlifferent symbols are used. 3. Branding does not affect behavior (Groves and rdovotny 1965; Mighell 1969; Dumas 1977; Fay and Pardue 1984) or long-term survival and growth (Stolte 1973; Champion and Hill 1974; Dumas 1977; Fay and Pardue 1985). 4. Marking mortality is low. 5. Marking rate is fast (Piggins 1972; Refstie and Alstad 1975; Turner et al. 1974; Fay and Pardue 1984). 6. Field identification of brands can be made without specialized equipment on live or dead specimens (Moring and Fay 1984). 7. Excellent short-term retention and fair to good long-term retention (Moring and Fay 1984). Disadvantages 1. Symbol clarity maybe obscure with various letters. 2.. Effective recognition of the brand, particularly after 1 yr, depends on the experience of trained observers (Moring and Fay 1984). 3. Symbol recognition becomes difficult over long periods and rapid growth - perhaps a disadvantage in Atlantic salmon (Fujihara and Nakatini 1967; Raleigh et al. 1973; Raymond 1974). 4. Variation in methodology can greatly affect the mark (Moring and Fay 1984). 5. Smoltification tends to obscure brands (Dumas 1977). Tetracycline Tetracycline (TC), a broad spectrum antibiotic, was apparently first discussed as a marker for fish by Weber and Ridgeway (1962). It is bound in the growing fish at calcifying regions such as vertebrae, ribs, fin rays, 4