Ecological effect of seasonally changing temperature on the life cycle of Aurelia aurita

Jellyfish blooms, observed as seasonal phenomena and closely related to seasonal changes in temperature, have emerged as a significant challenge for global marine ecology and environmental protection. Investigating the interplay between jellyfish growth and seasonally changing temperature is essential to understand the triggering mechanism of jellyfish blooms. A non-autonomous two-stage (Medusa-Polyp) dynamical model, which incorporates the seasonally driven temperature, is formulated to elucidate this mechanism. Both theoretical analyses and numerical simulations are conducted to explore the ecological effect of seasonally changing temperatures on the life cycle of Aurelia aurita. Seasonal control strategies are proposed to regulate jellyfish abundance, and the comparison to year-round control strategies is discussed. It is demonstrated that the cyclic variation in the jellyfish population is indeed driven by seasonally changing temperatures and the global warming leads to an earlier onset and larger magnitude of jellyfish blooms. The temperature-dependent processes in the life cycle of jellyfish are crucial for determining the annual pattern of jellyfish dynamics, and sensitivity analyses indicate that the polyp strobilation and ephyra development are key processes in life cycle. Among the parameters that can be controlled in practice, controlling them in spring and autumn is cost-effective for regulating jellyfish abundance. The findings of this study offer valuable insights into the mechanisms driving jellyfish growth from an annual perspective, and propose control strategies from different viewpoints for managing jellyfish blooms in the context of global warming.