Natural mortality estimates throughout the life history of the sea cucumber (Holothuroidea: Aspidochirotida).

The Natural Mortality coefficient () is a key parameter for stock assessments. The need to establish age-specific natural mortality coefficients is widely recognized because decreases rapidly over the early stages of the life cycle until it reaches a stable value around the age-at-maturity. The aim of this study was to estimate during the life cycle of the sea cucumber , a species under heavy fishing exploitation in the Caribbean Sea and the Gulf of Mexico. Coefficients at age were estimated using two models: The Gnomonic Interval Model (GIM) and the Chen & Watanabe model. Two different scenarios were simulated considering early and late age-at-maturity. Estimated values using the GIM model for the early maturity scenario were 2.15 to 2.35 year (interquartile range) for the juvenile stage and 0.39 to 0.43 year for the adult stage; for the late maturity scenario were 0.65 to 0.71 year for the juvenile stage and 0.68 to 0.74 year for the adult stage. The Chen & Watanabe model estimates for juvenile stage were between 0.85 and 2.23 year and 0.39 and 2.23 year for the early and late maturity scenarios respectively; for adult stage were between 0.97 and 0.21 year and 0.62 and 0.43 year respectively. The GIM estimated high natural mortality rates during larval stages. These estimates provided a higher level of certainty for the population models to more effectively manage a fishery and improve stock assessments.