Ocean acidification induces carry-over effects on the larval settlement of the New Zealand abalone,Haliotis iris

Abstract

Larval settlement is a key process in the lifecycle of benthic marine organisms; however, little is known on how it could change in reduced seawater pH and carbonate saturation states under future ocean acidification (OA). This is important, as settlement ensures species occur in optimal environments and, for commercially important species such as abalone, reduced settlement could decrease future population success. We investigated how OA could affect settlement success in the New Zealand abalone Haliotis iris by examining: (1) direct effects of seawater at ambient (pHT 8.05) and reduced pHT (7.65) at the time of settlement, (2) indirect effects of settlement substrates (crustose coralline algae, CCA) preconditioned at ambient and reduced pHT for 171 days, and (3) carry-over effects, by examining settlement in larvae reared to competency at ambient and reduced pHT (7.80). We found no effects of seawater pH or CCA incubation on larval settlement success. OA-induced carry-over effects were evident, with lower settlement in larvae reared at reduced pH. Understanding the mechanisms behind these responses is key to fully comprehend the extent to which OA will affect marine organisms and the industries that rely on them.

Responses of early life stages of European abalone (Haliotis tuberculata) to ocean acidification after parental conditioning: Insights from a transgenerational experiment

“…Our results also showed that pH decrease did not have any impact on post-larval settlement 9 days after fertilisation. These results are consistent with previous findings in H. tuberculata (Kavousi et al, 2021) and H. kamtschatkana (Crim et al, 2011) Velasco et al, 2021;Tahil and Dy, 2016). These contrasting effects among Haliotis species may be due either to differences in larval sensitivity or to other indirect effects of decreased pH on the settlement substrate, as previously shown in abalone larvae (O'Leary et al, 2017).…”

Acclimatory gene expression of primed clams enhances robustness to elevated pCO2

“…Thus, the timing and magnitude of environmental change is likely to have a joint effect on plasticity (Donelson et al, 2018). Carryover effects of environmental history have physiological (Espinel‐Velasco et al, 2021; Parker et al, 2012), ecological (Costantini, 2014; Hettinger et al, 2013) and evolutionary implications (Thomsen et al, 2017). In light of this, it is essential to understand how intermittent or repeated environmental signals, such as the challenges posed from climate change, are transduced to elicit acclimatory mechanisms.…”

The future is now: marine aquaculture in the anthropocene

“…On an industrial scale, the most striking illustration of possible OA effects is the correlation between the pH of seawater and the survival of oyster larvae, clearly linking the pH T / pCO 2 of seawater to hatchery failures (Barton et al, 2012). Espinel-Velasco et al (2021) investigated how OA influenced settlement success in the New Zealand abalone, Haliotis iris. They examined direct effects of seawater pH T at the time of settlement, indirect effects of pH on settlement substrates made of crustose coralline algae (a calcifying organism susceptible to OA) and carryover effects by examining settlement in larvae reared to competency at ambient and reduced pH.…”

“…Indeed, these approaches are essential for understanding the effects of climate change and providing guidelines to policymakers (Riebesell and Gattuso, 2015). The research articles that we received were generally multi-factorial (Endo et al, 2021;Espinel-Velasco et al, 2021;Godwin et al, 2021;Nordio et al, 2021;Shephard and Gargan, 2021) and several address adaptation issues (Clements et al, 2021;Espinel-Velasco et al, 2021;Nordio et al, 2021). However, they focus on the species of interest and pay relatively little attention to other ecosystem components.…”