Natural CO₂ seeps reveal adaptive potential to ocean acidification in fish

Abstract

Human-driven global change is challenging the scientific community to understand how marine species might adapt to predicted environmental conditions in the near future (e.g., hypoxia, ocean warming, and ocean acidification). The effects of the uptake of anthropogenic atmospheric CO 2 by oceans propagate across the biological hierarchy, from changes in the building blocks of life at nanoscales (Leung et al., 2020) to organismal physiology and behavior (Strader et al., 2020) through to ecosystem processes and their properties

Nest guarding behaviour of a temperate wrasse differs between sites off Mediterranean CO2 seeps

“…The present findings along with previous research assessing the mating behaviour, the reproductive success, and the abundance of the Mediterranean ocellated wrasse along a CO2 gradientsuggest this species may maintain fitness and population persistence under OA conditions (Milazzo et al, 2016;Cattano et al, 2016;Mirasole et al, 2020). Future research efforts should also consider the fundamental link between species behaviour and population responses under changing environmental conditions, for instance deepening the different processes and mechanisms underpinning tolerance to elevated CO2 in marine populations, including transgenerational effects (Schunter et al, 2016;Tsang et al, 2020;Petit-Mart et al, 2021).…”

Brain transcriptome of gobies inhabiting natural CO2 seeps reveal acclimation strategies to long-term acidification

“…2.3% of the brain transcriptome involved in key functions such as acid-base and ion homeostasis, neurological function, circadian rhythm, metabolism, cellular stress response, and immune response were differentially expressed (DE) between fish from the CO 2 seep and control sites. The majority of DE transcripts exhibited elevated expression in fish from the CO 2 seep similar to what has been observed in gonads of the common triplefin from the CO 2 seep in New Zealand, another species known to have increased population size in acidified environments (Petit-Marty et al, 2021). The gobies seem to be able to elicit acclimation responses to elevated CO 2 by differentially regulating transcripts associated with crucial functions which potentially enables them to maintain cellular homeostasis and thrive in the acidified waters of Vulcano Island.…”

“…The majority of DE transcripts exhibited elevated expression in fish from the CO2 seep similar to what has been observed in gonads of the common triplefin from the CO2 seep in New Zealand, another species known to have increased population size in acidified environments (Petit-Marty et al, 2021). The gobies seem to be able to elicit acclimation responses to elevated CO2 by differentially regulating transcripts associated with crucial functions which potentially enables them to maintain cellular homeostasis and thrive in the acidified waters of Vulcano Island.…”

“…At other CO2 seeps at White Island, New Zealand, a similar habitat shift with net resource enrichment can be found and the common triplefin F. lapillum also exhibit a higher abundance with a similar increase in metabolic capacity (Nagelkerken et al, 2015;Petit-Marty et al, 2021).…”

“…Prolonged exposure to elevated CO 2 at the seeps may enable fish to acclimate through physiological and behavioural compensation resulting in long-term survival and subsequent adaptation. Evidence from studies using transcriptomics to determine gene expression patterns in the brain and gonads of fish from natural CO 2 seeps revealed plasticity and adaptive selection to elevated CO 2 (Kang et al, 2022; Petit-Marty et al, 2021). These findings suggest that species that are continuously exposed to elevated CO 2 levels can develop mechanisms to mitigate negative effects of CO 2 exposure and have the potential to adapt to acidified environments.…”