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<br />MANAGEMENT IMPLICATIONS <br />Fluorescent pigment marking is an efficient, <br />economical means of mass-marking fish, and has definite <br />potential for short-term studies. Long-term (2-4 yr) <br />retention of fluorescent pigment by chinook salmon was <br />achieved in this study, but stock assessments using this <br />technique should consider the following qualifications: <br />l) Pigment retention and initial survival is highly <br />dependent upon spray pressure (Phinney et ale 1967; Hennick <br />and Tyler 1970; Bandow 1987). <br />2) Using pigment particles >250 ~ could increase <br />penetration and reduce mortalities resulting from clogged <br />gills (Phinney et ale 1967; Strange and Kennedy 1982; <br />Bandow 1987), but this also increases the cost of <br />materials. <br />3) Resistance to the treatment and retention of <br />pigment varies with fish age (both at the time of marking <br />and the time of monitoring) and species (Hennick and Tyler <br />1970; Moring and Fay 1984: Bandow 1987). <br />4) Disease and stress could contribute to mortality, <br />particularly if spray-marking is used in combination with <br />fin-clipping. Some researchers recommended treatment in <br />malachite green following marking (Phinney et al. 1967: <br />Pribble 1976), however that drug can no longer be used. <br />5) In this study, the chinook were dead when examined <br />for pigment granules. The tiny granules were not always <br />obvious, and use of this technique in the field to identify <br /> <br />II <br />