Evolved differences in energy metabolism and growth dictate the impacts of ocean acidification on abalone aquaculture

Abstract

Ocean acidification (OA) poses a major threat to marine ecosystems and shellfish aquaculture. A promising mitigation strategy is the identification and breeding of shellfish varieties exhibiting resilience to acidification stress. We experimentally compared the effects of OA on two populations of red abalone (Haliotis rufescens), a marine mollusc important to fisheries and global aquaculture. Results from our experiments simulating captive aquaculture conditions demonstrated that abalone sourced from a strong upwelling region were tolerant of ongoing OA, whereas a captive-raised population sourced from a region of weaker upwelling exhibited significant mortality and vulnerability to OA. This difference was linked to population-specific variation in the maternal provisioning of lipids to offspring, with a positive correlation between lipid concentrations and survival under OA. This relationship also persisted in experiments on second-generation animals, and larval lipid consumption rates varied among paternal crosses, which is consistent with the presence of genetic variation for physiological traits relevant for OA survival. Across experimental trials, growth rates differed among family lineages, and the highest mortality under OA occurred in the fastest growing crosses. Identifying traits that convey resilience to OA is critical to the continued success of abalone and other shellfish production, and these mitigation efforts should be incorporated into breeding programs for commercial and restoration aquaculture.

Latent effects of winter warming on Olympia oyster reproduction and larval viability

“…Nevertheless, this and the related study (Spencer et al 2020) indicate that winter warming does not compromise O. lurida larval quality when reared in the hatchery, and larval size when released from the brood chamber is not predictive of survival through settlement. In the wild, where there is higher predation risk, conditions are more stressful, and phytoplankton abundance is less consistent, winter warming may benefit Puget Sound O. lurida populations by increasing larval recruitment due to increased size and/or growth rate (Swezey et al 2020).…”

Selection Experiments in the Sea: What Can Experimental Evolution Tell Us About How Marine Life Will Respond to Climate Change?

“…For example, an early selection experiment demonstrated genetic variation for the response to low pH in larvae of the purple sea urchin (Strongylocentrotus purpuratus) (Pespeni et al, 2013). Similar experiments have also demonstrated a capacity to evolve in response to pH in mussels and abalone (Thomsen et al, 2017;Swezey et al, 2020), temperature in corals (Quigley et al, 2020), and low salinity in oysters (JSG, MWK, and Kevin M. Johnson, California Polytechnic State University and California Sea Grant, unpubl. data).…”

“…Artificial selection may be a viable method to improve tolerance of climate change-related stressors. For example, genetic variation for low pH tolerance was found in a hatchery population of red abalone (Swezey et al, 2020), suggesting that this trait can be selectively bred in the hatchery to increase resiliency to ocean acidification. These techniques can also be applied to non-aquaculture species, such as corals.…”

“…Traits that are favored in captive breeding settings, such as fast growth and disease resistance, have been correlated with increased resistance to ecologically relevant stressors, such as ocean acidification resistance in oysters (Durland et al, 2019;Fitzer et al, 2019). However, in other systems, rapid growth has been negatively associated with fitness in acidified conditions, as in red abalone (Swezey et al, 2020), so that ecological resiliency runs antagonistic to traits that increase production yield.…”

Windows of vulnerability: Seasonal mismatches in exposure and resource identity determine ocean acidification’s effect on a primary consumer at high latitude

“…Pinto abalone are of high management concern due to the low population densities and recruitment failures in other areas of their range, as well as the existing recreational fishery in SE Alaska (Busch et al, 2014). Experiments suggest ocean acidification can limit growth and survival of pinto abalone (Crim et al, 2011) and other abalone species (Swezey et al, 2020). Seawater pH and carbonate saturation states are often lowest during winter months in the high latitude northern range edge of pinto abalone (Evans et al, 2015), when the standing biomass of primary producers is often lowest (Lobban, 1978; van Trussenbroek, 1989).…”