Assessment of Genetic Variation and Species Distribution Modeling Used to Formulate a Conservation Plan for the Keystone Species Astacus astacus

    Anthropogenic impacts have decreased the genetic diversity of Astacus astacus, the noble crayfish. It is expected that only 13 percent of the crayfish will survive, excluding the most genetically diverse populations. 
    Mitochondrial and nuclear DNA variations among crayfish were assessed to determine genetic diversity across multiple populations. The mitochondrial DNA revealed that six genetic lineages exist. Using the nuclear DNA, 175 alleles were observed across the 15 microsatellite loci, with an average of 12 alleles per locus. 
    Species distribution modeling showed the current and future susceptibility of habitats to climate change. The information collected was then used to predict invasive species that cause disease in the indigenous populations' future migration patterns. The results also showed that many crayfish populations were isolated from gene flow.
     The conservation plan recommended assisted migration and repopulation to protect this keystone species. By creating a population with multiple genetic lineages and ensuring that the new locations are less susceptible to invasive species, assisted migration and repopulation have a higher chance of success.
    Genetic diversity is essential for increasing the adaptive capability of a population. A disease that affects one individual is likely to have the same effect on individuals that share similar genetic information. As such, crayfish should be prioritized for protection since the indigenous crayfish population is especially vulnerable due to its lack of genetic diversity. 
    There is still diversity across the different populations which allows for recovery; however, introducing species from one population to another should be done with caution. Previous studies have shown that genetic erosion can occur when introducing domesticated organisms to wild populations. Although, in this case, it would be the introduction of one wild population to another, the same principle still applies since genetic variation exists. It is vital to consider every outcome and test potential impacts before implementing conservation efforts since it is harder to reverse actions than to take them in the first place.

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