The physiological and behavioural responses of the shore crab Carcinus meanas (L) to near-future levels of ocean acidification.

• Main Author: Monaghan, Angus
• Other Authors: Hardege, Jorg, Bolland, Jonathan
• Format: Thesis
• Language: English
• Published: 2023
• Subjects: Biological sciences; Ocean acidification
• Online Access: https://hull-repository.worktribe.com/file/4564060/1/Thesis; https://hull-repository.worktribe.com/output/4564060

Ocean acidification as a result of increased anthropogenic Carbon Dioxide is a widely documented threat to marine life as a whole. According to current predictions, ocean pH is set to continue its hereto unprecedented level of decrease throughout the remainder of the 21st century. For this thesis, experiments were carried out on the shore crab Carcinus maenas (Linnaeus, 1758) to explore the effects of ocean acidification on their behaviour and physiology. Experiments on the species’ agonistic behaviour showed acute pH reduction induced significant differences in the influencing power of carapace width on fight outcomes in relation to perceived resource value. Further experiments on C. maenas’ dorsal-ventral righting reflex showed that, when conditioned at a highly plausible pH for the year 2100, the species exhibits significantly longer righting times when submerged and a consistently lower righting success rate when out of water. These results have concerning implications for the species’ survival, future ecosystem structure and biodiversity as a whole. Additionally, the concept, design and construction of an electromechanical device to measure C. maenas chelae force as a potential indicator for physiological stress from ocean acidification and other stressors is detailed. Due to time and funding constraints and unforeseen experimental difficulties, no data was collected with the device.