Effect of diet changes in benthic ecosystems owing to climate change on the physiological responses of Turbo sazae in waters around Jeju Island, Korea

The benthic ecosystem in temperate regions is becoming barren owing to the replacement of macroalgae by calcareous algae as a result of climate change-induced increases in water temperature. The aim of this study was to observe how the top shell, Turbo sazae, an invertebrate that feeds on macroalgae, adapts to a benthic environment with a reduced macroalgae population owing to replacement by calcareous algae. Using tank experiments, the top shells were cultured for 18 weeks. Within this period, they were fed a diet comprising either Eclonia cava or Corallina officinalis. Thereafter, hemocyte response, reproductive development, and the levels of biochemical compounds in the individuals under investigation were analyzed. The results obtained showed no significant differences in immunological responses, gonad development, and general body weight between the two feeding groups. However, amino acid profiling showed a decreasing trend in amino acid contents in both feeding groups, but no significant differences were observed with respect to overall protein content. These findings indirectly suggested that even in a macroalgae-depleted environment, the top shells can survive by consuming crustose calcareous algae, but with the change in diet affecting the levels of some amino acids in their bodies. Therefore, this study provides valuable insights into the adaptability of the top shells inhabiting the waters around Jeju Island to changes in their feeding environment and may also serve as basis for enhancing resource management strategies in response to climate change-induced changes in the benthic ecosystem.