A Multi‐Factor Uncertain Model for Fishery Stock Assessment With Application to Pacific Halibut

ABSTRACT A mathematical framework for multi‐factor uncertain fishing is first articulated to model fish population dynamics. Assuming that both the additional mortality rate and natural growth rate fluctuate, we derive a multi‐factor uncertain fishing equation. Then we prove that the fish population size exists and is unique. The explicit expression of the inverse uncertainty distribution is given. Furthermore, we provide three applications of the solution, namely, the first hitting time, the supremum, and the infimum. Finally, the method of moments, a residual‐based approach, is utilized for parameter inference.