FAILURE OF A STOCKING POLICY, OF HATCHERY REARED BROWN TROUT, SALMO-TRUTTA L, IN ASTURIAS, SPAIN, DETECTED USING LDH-5-STAR AS A GENETIC-MARKER

A useful genetic marker exists through the apparent fixation of the LDH‐5*100 allele in wild populations of brown trout in rivers from Asturias, Spain, contrasted with the near fixation of the LDH‐5*90 allele in hatchery populations used to stock these rivers. In sampling locations where natural reproduction occurred, the *100 allele was found exclusively in all areas having no record of hatchery stocking. The *100 allele also predominated in three stocked areas having natural reproduction; in two of these areas a few individuals of the 0 + age class were homozygous for the *90 allele. These data indicated that all catchable and reproductive fish originated from indigenous populations and thus the policy of hatchery supplementation was a failure in these areas. Copyright © 1991, Wiley Blackwell. All rights reserved