Within‐ and transgenerational stress legacy effects of ocean acidification on red abalone (Haliotis rufescens) growth and survival

Abstract

Understanding the mechanisms by which individual organisms respond and populations adapt to global climate change is a critical challenge. The role of plasticity and acclimation, within and across generations, may be essential given the pace of change. We investigated plasticity across generations and life stages in response to ocean acidification (OA), which poses a growing threat to both wild populations and the sustainable aquaculture of shellfish. Most studies of OA on shellfish focus on acute effects, and less is known regarding the longer term carryover effects that may manifest within or across generations. We assessed these longer term effects in red abalone (Haliotis rufescens) using a multi‐generational split‐brood experiment. We spawned adults raised in ambient conditions to create offspring that we then exposed to high pCO2 (1180 μatm; simulating OA) or low pCO2 (450 μatm; control or ambient conditions) during the first 3 months of life. We then allowed these animals to reach maturity in ambient common garden conditions for 4 years before returning the adults into high or low pCO2 treatments for 11 months and measuring growth and reproductive potential. Early‐life exposure to OA in the F1 generation decreased adult growth rate even after 5 years especially when abalone were re‐exposed to OA as adults. Adult but not early‐life exposure to OA negatively impacted fecundity. We then exposed the F2 offspring to high or low pCO2 treatments for the first 3 months of life in a fully factorial, split‐brood design. We found negative transgenerational effects of parental OA exposure on survival and growth of F2 offspring, in addition to significant direct effects of OA on F2 survival. These results show that the negative impacts of OA can last within and across generations, but that buffering against OA conditions at critical life‐history windows can mitigate these effects.

Temperature-induced variations in dulse (Devaleraea mollis) nutrition provide indirect benefits on juvenile red abalone (Haliotis rufescens) Growth

“…Our results contribute to a comprehensive exploration of the effects of ocean warming on abalone physiology, including adult reproductive health, with consequences for hatchery management and juvenile abalone recruitment (Boles et al, 2022(Boles et al, , 2023. Concurrent efforts by Neylan et al (2023), revealed slower growth, delays in fecundity, and decreased gonad tissue thickness on adult abalone when exposed to elevated ocean acidification conditions at 14°C. Since consumption was not measured in Neylan et al (2023), it is conceivable that nutrition may have indirectly influenced measured endpoints, potentially through various mechanisms such as changes in feeding behavior or the impact of ocean acidification on digestive physiology.…”

“…Concurrent efforts by Neylan et al (2023), revealed slower growth, delays in fecundity, and decreased gonad tissue thickness on adult abalone when exposed to elevated ocean acidification conditions at 14°C. Since consumption was not measured in Neylan et al (2023), it is conceivable that nutrition may have indirectly influenced measured endpoints, potentially through various mechanisms such as changes in feeding behavior or the impact of ocean acidification on digestive physiology. In this study, our primary goal was to assess how temperature-induced variations in seaweed nutrition affects the growth of juvenile abalone under ambient conditions.…”

“…Our results may help inform abalone conservation management and farming practices by offering a strategy to increase the protein content of seaweed diets through temperature manipulation and consequently enhancing juvenile abalone growth. When coupled with the direct effects of climate stressors, including temperature (Vilchis et al, 2005;Rogers-Bennett et al, 2010), ocean acidification (Swezey et al, 2020;Neylan et al, 2023), and deoxygenation (Nam et al, 2020), further research is necessary to confirm the implications of these findings for abalone conservation management.…”