Research Document - 2011/020

Recovery Potential Modelling of Eastern Sand Darter (Ammocrypta pellucida) in Canada

By M. Finch, L.A. Vélez- Espino, S.E. Doka, M. Power, and M.A. Koops

Abstract

In 2002, the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assessed Eastern Sand Darter (Ammocrypta pellucida) as Threatened in Canada. In this study, we assess allowable harm, determine a population-based recovery target, conduct long-term projections of population recovery, and quantify habitat requirements in support of a recovery potential assessment (RPA). Our analyses showed that Eastern Sand Darter are sensitive to perturbations affecting 0+ survival and the fertility of 1+ spawners. Harm to these life stages should be minimized to avoid jeopardizing the survival and recovery of Canadian populations. Based on a demographic sustainability objective (i.e., the population is self-sustaining over the long term), we suggest abundance recovery targets of at least 4 244 to 52 500 adult fish with this range being a function of the risk of catastrophe events (5 to 15% per generation). These population abundances would require a minimum of 1.17 to 165.28 ha of suitable habitat. Given the high sensitivity of Eastern Sand Darter to catastrophic events and that small, short-lived species usually exhibit colonization-extinction dynamics, these abundance and area targets would represent all demes demographically linked and all fragments of suitable habitat, respectively. After anthropogenic threats are removed but without any additional recovery effort, it is estimated that Eastern Sand Darter populations could reach the recovery target within 34 to 67 years (22 to 44 generations). Implementing recovery strategies, such as habitat rehabilitation/enhancement, that allow for a 20% increase in juvenile survival could reduce recovery timeframes to less than 20 years (13 generations).

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