Rapid physiological and transcriptomic changes associated with oxygen delivery in larval anemonefish suggest a role in adaptation to life on hypoxic coral reefs.

Connectivity of coral reef fish populations relies on successful dispersal of a pelagic larval phase. Pelagic larvae must exhibit high swimming abilities to overcome ocean and reef currents, but once settling onto the reef, larvae transition to endure habitats that become hypoxic at night. Therefore, coral reef fish larvae must rapidly and dramatically shift their physiology over a short period of time.

Diel pCO fluctuations alter the molecular response of coral reef fishes to ocean acidification conditions.

Environmental partial pressure of CO (pCO ) variation can modify the responses of marine organisms to ocean acidification, yet the underlying mechanisms for this effect remain unclear. On coral reefs, environmental pCO  fluctuates on a regular day-night cycle. Effects of future ocean acidification on coral reef fishes might therefore depend on their response to this diel cycle of pCO .

Beneficial effects of diel CO cycles on reef fish metabolic performance are diminished under elevated temperature.

Elevated CO levels have been shown to affect metabolic performance in some coral reef fishes. However, all studies to date have employed stable elevated CO levels, whereas reef habitats can experience substantial diel fluctuations in pCO ranging from ±50 to 600 μatm around the mean, fluctuations that are predicted to increase in magnitude by the end of the century. Additionally, past studies have often investigated the effect of elevated CO in isolation, despite the fact that ocean temperatures will increase in tandem with CO levels.

Elevated CO affects anxiety but not a range of other behaviours in juvenile yellowtail kingfish.

Elevated seawater CO can cause a range of behavioural impairments in marine fishes. However, most studies to date have been conducted on small benthic species and very little is known about how higher oceanic CO levels could affect the behaviour of large pelagic species. Here, we tested the effects of elevated CO, and where possible the interacting effects of high temperature, on a range of ecologically important behaviours (anxiety, routine activity, behavioural lateralization and visual acuity) in juvenile yellowtail kingfish, Seriola lalandi.

Life-history trade-offs and limitations associated with phenotypic adaptation under future ocean warming and elevated salinity.

Little is known about the life-history trade-offs and limitations, and the physiological mechanisms that are associated with phenotypic adaptation to future ocean conditions. To address this knowledge gap, we investigated the within- and trans-generation life-history responses and aerobic capacity of a marine polychaete, Ophryotrocha labronica, to elevated temperature and elevated temperature combined with elevated salinity for its entire lifespan. In addition, transplants between treatments were carried out at both the egg mass and juvenile stage to identify the potential influence of developmental effects.

Diel CO cycles and parental effects have similar benefits to growth of a coral reef fish under ocean acidification.

Parental effects have been shown to buffer the negative effects of within-generation exposure to ocean acidification (OA) conditions on the offspring of shallow water marine organisms. However, it remains unknown if parental effects will be impacted by the presence of diel CO cycles that are prevalent in many shallow water marine habitats. Here, we examined the effects that parental exposure to stable elevated (1000 µatm) and diel-cycling elevated (1000 ± 300 µatm) CO had on the survival and growth of juvenile coral reef anemonefish, Amphiprion melanopus.

The evolution of phenotypic plasticity under global change.

Marine ecosystems are currently in a state of flux, with ocean warming and acidification occurring at unprecedented rates. Phenotypic plasticity underpins acclimatory responses by shifting the mean phenotype in a population, which may buffer the negative effects of global change. However, little is known about how phenotypic plasticity evolves across multiple generations.

Diel CO cycles reduce severity of behavioural abnormalities in coral reef fish under ocean acidification.

Elevated CO levels associated with ocean acidification (OA) have been shown to alter behavioural responses in coral reef fishes. However, all studies to date have used stable pCO treatments, not considering the substantial diel pCO variation that occurs in shallow reef habitats. Here, we reared juvenile damselfish, Acanthochromis polyacanthus, and clownfish, Amphiprion percula, at stable and diel cycling pCO treatments in two experiments.

Can multi-generational exposure to ocean warming and acidification lead to the adaptation of life history and physiology in a marine metazoan?

Ocean warming and acidification are concomitant global drivers that are currently threatening the survival of marine organisms. How species will respond to these changes depends on their capacity for plastic and adaptive responses. Little is known about the mechanisms that govern plasticity and adaptability or how global changes will influence these relationships across multiple generations.

Can trans-generational experiments be used to enhance species resilience to ocean warming and acidification?

Human-assisted, trans-generational exposure to ocean warming and acidification has been proposed as a conservation and/or restoration tool to produce resilient offspring. To improve our understanding of the need for and the efficacy of this approach, we characterized life-history and physiological responses in offspring of the marine polychaete exposed to predicted ocean warming (OW: + 3°C), ocean acidification (OA: pH -0.5) and their combination (OWA: + 3°C, pH -0.

Multi-generational responses of a marine polychaete to a rapid change in seawater CO.

Little is known of the capacity that marine metazoans have to evolve under rapid CO changes. Consequently, we reared a marine polychaete, , previously cultured for approximately 33 generations under a low/variable pH regime, under elevated and low CO for six generations. The strain used was found to be tolerant to elevated CO conditions.