Effects of ocean acidification relevant pH on foraging behaviour and response by the hermit crab, Pagurus bernhardus

• Main Author: Cook, Ellie-Mae Elizabeth
• Other Authors: Hardege, Jörg D.
• Format: Thesis
• Language: unknown
• Published: 2020
• Subjects: Biological sciences; Ocean acidification
• Online Access: https://hull-repository.worktribe.com/file/4223339/1/Thesis; https://hull-repository.worktribe.com/output/4223339

The current rise of atmospheric CO2 has led to an increased rate of ocean acidification (OA), a process that results in a decrease in oceanic pH. Forecasts predict the rate of OA to further increase, the largest to be seen in the past 300 million years. This process can consequently have significant implications upon marine life and their ecosystem functions. This study aims to expand on pre- existing knowledge, identifying effects of OA on olfaction by hermit crabs, Pagurus bernhardus. Investigations explored the variation in threshold concentrations of chemical foraging cues, required for successful detection by individuals at pH 8.15 and decreased pH levels 7.7 and 7.2. Response personality of individuals was examined through a series of biological assays. Statistical analysis and results suggest detection thresholds for chemical foraging cue, glutathione, are dependent upon and vary with trial individual and pH condition. As a population both reduced pH levels, 7.7 and 7.2, had great impact on abilities to successfully detect and respond to the presence of the chemical foraging cue glutathione. Additionally, response personality of individuals was exhibited across individuals. Some individuals displayed greater frequency in engaging foraging behaviours than conspecifics. This was also evident under subjection to reduced pH conditions. However, small sample size was a major limitation to the power of statistical significance here. Findings suggest, future rates of OA and further reduction in pH amongst coastal areas, will impact the olfactory process of P. bernhardus individuals. Future research should focus on long-term and multi- generational studies. These will best consider acclimation and genetic adaptation possibilities, in the event of rapidly accelerating OA related conditions.