Skip to main content

Atlantic Salmon in Maine (2004) / Chapter Skim
Currently Skimming:

Appendix C: Supportive Breeding, Effective Population Size, and Inbreeding
Pages 251-257

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 251...
... , is intended to increase the census population size without introducing exogenous genes into the managed population. Supportive breeding may increase the total population size through a higher reproductive output from the captive breeders than from those reproducing in the wild.
From page 252...
... Mating is random within each of the wild and captive groups, and the entire process of selecting breeders for captive propagation and releasing their progeny may be repeated in generation t + 1 and subsequent generations. The wild population is of constant size when mw = 2, it grows when mw > 2, and it is declining if mw < 2.
From page 253...
... Thus, the boost of census size is obtained at the cost of increased inbreeding, and the effect of this increase may persist for many subsequent generations. The reason for this extended effect is that the overall genetic success of a supportive breeding operation cannot be judged exclusively from the number of generations required for Ne to exceed the value it had before the program was launched.
From page 254...
... , and cumulative harmonic mean of effective size (Ne) during 10 generations of supportive breeding in a population of 50 individuals that would be of constant size if left on its own (initial N = 50)
From page 255...
... Nonbinomial distribution of family size: In natural populations of most organisms, including fishes, the variance of family size is frequently likely to be larger than binomial. The same is true for many captive populations unless active management measures are taken to reduce this variance.
From page 256...
... . Supportive breeding may drastically reduce the effective size of a population and thereby accelerate both the inbreeding and the loss of genetic diversity, also when the breeding program is successful in boosting the census population size.
From page 257...
... , declining wild populations (mw < 2) , variable number of captive breeders, preferentially selecting individuals of wild or captive origin for captive breeding, overlapping generations, and populations that crash when the support program is terminated.


This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.