Dynamics of a ratio-dependent population model for Green Sea Turtle with age structure

The reproduction of the green sea turtles is characterized by the temperature dependent sex determination (TSD). Green sea turtle eggs are laid asexually. Temperature during hatching determines the sex of baby green sea turtles. In order to study the population dynamics of the green sea turtles and understand the dynamics of the sex ratio, in this paper we establish a stage-structured model by incorporating TSD and the ratio dependent Holling III functional response in the reproduction process of the green sea turtle population. The effects of incubation temperature and sex ratio deviation on persistence of the population are captured by the sole basic reproduction number. The persistent mode can be either a stable equilibrium or periodic oscillations. Numerical simulations and sensitive analysis help us to identify vital parameters in our model. Our research in the paper is in favor of elevating sexual encounter rates, reducing the searching time for males and increasing survival odds from baby state into adult in order to maintain sustainability of the green sea turtles. (C) 2021 Elsevier Ltd. All rights reserved.