The Mapleleaf (Quadrula quadrula), Eastern Pondmussel (Ligumia nasuta), Rainbow (Villosa iris) and Fawnsfoot (Truncilla donaciformis) are freshwater mussels that have been assessed as Threatened (Ontario population of Mapleleaf) or Endangered (Manitoba population of Mapleleaf, Eastern Pondmussel, Rainbow and Fawnsfoot) by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). In support of a recovery potential assessment (RPA), we present population modelling of freshwater mussels and assess the sensitivity of population growth to changes in the model parameter values. Our analyses demonstrated that the population growth rate of freshwater unionid mussels is most sensitive to changes either in juvenile survival, adult survival, or reproduction related vital rates. Which of these rates is most sensitive can be predicted with knowledge of population specific vital rates; predictions are most accurate when fecundity and age at maturity are known. Harm to sensitive portions of the mussel’s life cycle should be minimized to avoid jeopardizing the survival and future recovery of Canadian populations.
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