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considered even if only a single introduction is to be made. Precautions that will be <br />taken during propagation and stocking are summarized in Box 8. <br />Box 8. Precautions to be taken during propagation and when stocking <br />endangered and candidate fish. (Listed in priority order) <br />1. Precautions must be taken to prevent escapement of fish from <br />refugia or captive propagation facilities. <br />2. Stocking of captive-reared fish will be conducted only in locations <br />where it can be demonstrated that such stocking will not adversely <br />and significantly affect any indigenous fish population or stock <br />of the same or different species <br />3. Supplemental stocking (i.e., experimental, augmentation, and <br />restoration stocking) will be restricted to locations with suitable <br />habitat that will support a viable population or stock, or to <br />historic habitats. <br />4. All captive-reared fish will be marked before initial release <br />and stocked as equal family lots from pedigreed mat.ings so that <br />an adequate evaluation of stocking can be made. <br />5. Large-scale augmentation or restoration stocking will be done only <br />when knowledge of life history and ecological requirements of the <br />target species is known sufficiently well to predict the likelihood <br />of stocking success. <br />6. Any proposed stocking will be described in a reintroduction, <br />augmentation plan that is approved by the Recovery Team and <br />Regional Director, and covered by a Federal Fish and Wildlife <br />Permit or a supplemental permit. <br />H. Effective Population Size in Captive Propagation The effective population size <br />(Ne) is a key parameter in conservation of genetic diversity. The rate of <br />inbreeding and the loss of genetic heterozygosity is proportional to the inverse <br />of the effective population size (Ryman and Laikre 1991). The effective <br />population size can be calculated using the following formula Mande and <br />Barrowclough 1987): <br />4XNMxNF <br />Ne = (NM + NF) <br />20