The challenge of securing future food production for aquaculture species under environmental change: enhancing physiological performance under environmental stress

• Main Author: Abbas, Ahmed Salama Ali
• Other Authors: Truebano, Manuela, Faculty of Science and Engineering
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Plymouth 2024
• Subjects: Environmental multi-stressors; Ocean acidification and ocean warming; Heat hardening; Thermal performance; Heart rates; Reproductive mode; Parental effects; Thermal acclimation; Physiological plasticity; Scope for growth; Chronic warming; larval performance; Abalone; Intertidal gastropods; PhD; Ocean acidification
• Online Access: https://pearl.plymouth.ac.uk/handle/10026.1/22265; https://doi.org/10.24382/5169

Rising sea surface temperatures and ocean acidification present profound challenges for many marine species, leading to cascading effects on ecosystem functionality and food security. Phenotypic plasticity is anticipated to play a key role in helping marine ectotherms maintain performance and acclimate to changes in these global environmental drivers. However, our understanding of phenotypic plasticity in the context of climate change is largely based on short-term studies, with limited ecological relevance, which often overlook some important response modifiers such as environmental context, exposure nature, reproductive modes, and potential trade-offs between fitness components. As a result, the full potential for marine ectotherms to exhibit physiological acclimation within and across generations remains not well understood. This thesis addresses this knowledge gap by investigating the extent of physiological plasticity in key intertidal species, which are crucial for both ecological and commercial purposes, considering such response modifiers. Different species are exposed to ocean warming (OW) and/or ocean acidification (OA) across various life-cycle stages. I first characterize metabolic plasticity in adult intertidal gastropods after exposure to OW and OA, exploring the effects of exposure length (over 12 months) and seasonal dynamics on metabolic responses (Chapter 2). I then assess the cost of thermal acclimation in adults of two gastropods with different reproductive modes, examining the potential trade-off between scope for growth (SfG), reproduction, and survival in relation to reproductive mode and the magnitude of temperature change (Chapter 3). I also compare the effects of two thermal regimes different in their nature (repeated heat shocks vs chronic warming) on thermal tolerance and performance in adults of a commercial gastropod, characterizing differences in condition index and thermal performance and tolerance traits (Chapter 4). Lastly, I evaluate the effects of exposing parents of a ...