Exploring cosmopolitan jellyfish (Aurelia spp.) bloom dynamics and ecological implications in subtropical waters with mechanistic dynamic modeling

Abstract

Worldwide massive outbreaks of gelatinous zooplankton have drawn much attention to seeking relevant mechanisms and processes for better management and conservation of ocean ecosystems. In the present study, we developed an individual-based model (IBM) for cosmopolitan jellyfish Aurelia spp., which incorporates a fully coupled pelagic-benthic life cycle with fine-scaled (0.5° × 0.5°) dynamic ocean conditions to examine the spatio-temporal population dynamics of the species in the northern Gulf of Mexico (GoM) from 1995 to 2010. Model simulations highlighted the significant bottom-up effect of environmental conditions in triggering strobilation and subsequent jellyfish blooms. Dynamics of jellyfish populations exhibited large variability in time and space over the northern GoM continental shelf. Simulation results showed that the South Texas coast, the East Louisiana shelf, and the Mississippi Sound were potential bloom hotspots with distinctive driving processes. A case study of the Mississippi Sound region in 2008 revealed a mismatch of bloom timing whether defined as abundance or biomass, which spotlighted the need to further assess the consequence and ecological implication of jellyfish outbreaks to the biomass and energy flows in the ocean. Given that the GoM is vulnerable to jellyfish blooms, findings of this study contribute to the improved understanding of mechanisms and processes of jellyfish blooms with predictions of the status, trend, and hotspots of jellyfish population dynamics under variable environmental conditions and a changing climate. • Significant bottom-up effects that trigger strobilation and blooms of Aurelia spp. were identified. • Stage-structured dynamics of the species show space and time variability across the GoM continental shelf. • Jellyfish bloom hotspots on the GoM continental shelf coincide with particular oceanographic conditions. • Mismatched timing in jellyfish bloom abundance and biomass has implications for marine ecosystems.