Challenging childhood experiences can have lasting effects on an individual’s adult life and even impact subsequent generations. Researchers from the University of California, Davis, have identified a similar phenomenon in red abalone, where exposure to the stress of ocean acidification during both infancy and adulthood can leave enduring negative effects, as outlined in their study published in the journal Global Change Biology.
The study emphasizes that the adverse consequences of ocean acidification, a consequence of increased carbon dioxide emissions, persist over time and across multiple generations for red abalone. The research suggests that implementing measures to mitigate the impact of ocean acidification during crucial developmental stages can alleviate stress effects in captive and commercially bred red abalone. Moreover, the findings contribute valuable insights for conservation initiatives aimed at protecting wild abalone populations.
Isabelle Neylan, the lead author of the study and a Ph.D. student at UC Davis Bodega Marine Laboratory during the research, now a postdoctoral researcher at Louisiana State University, noted, “For red abalone, if your parents were exposed to ocean acidification, it does impact your ability to handle stress. It’s carrying over within that generation and on to the next generation.”
This research plays a vital role in the comprehensive efforts to safeguard the red abalone species, native to California and classified as critically endangered on the International Union for Conservation of Nature’s Red List. Despite being the most prevalent among the eight abalone species off the California coast, habitat deterioration and the consequences of climate change have significantly diminished their population.
Spawn, expose and repeat
To conduct the study, researchers initially bred adult red abalone, subjecting approximately half of the offspring to existing ocean conditions and the remaining half to anticipated near-future conditions characterized by high acidity during the initial three months of life.
After nurturing the surviving abalones for four years, they subjected them to high or low acidity conditions for 11 months during adulthood and gauged their reproductive potential and growth through ultrasound measurements. Subsequently, the researchers bred these animals, exposing the offspring of the second generation to either high or low acidity to examine the persistent effects of ocean acidification across generations.
The study uncovered that exposure to ocean acidification during early life resulted in a prolonged impact on the adult growth rate of abalones, even after a five-year period, particularly when re-exposed during adulthood. Furthermore, ocean acidification hindered the reproductive capacity of adult abalones, even if they hadn’t been exposed during their infancy. The negative consequences observed in the parent generation also influenced the survival and growth of the subsequent generation.
The experiment disclosed that abalone juveniles exhibited resilience to ocean acidification for a brief period of two to three weeks, but prolonged exposure over three months led to stress and mortality. This insight is valuable for abalone cultivators involved in commercial aquaculture or captive-breeding recovery programs, offering a clearer timeframe for when they should adjust water chemistry to safeguard abalone populations.
Sometimes, the future is not so far away
Isabelle Neylan conveyed the research’s primary focus, explaining that the study aimed to investigate whether being born to parents exposed to ocean acidification could act as a protective buffer against its impacts. However, the findings did not support this expectation. Neylan emphasized that the severity of the effects increased with greater exposure to ocean acidification, highlighting a challenging scenario. Despite this, she also mentioned that within the challenges, there are glimpses of hope.
Neylan pointed out that certain red abalone families exhibit better resilience than others. In general, adult abalones demonstrated a degree of resilience to ocean acidification, albeit with a smaller size. Nevertheless, they were able to successfully spawn without significant mortality. However, consistent with the vulnerability of many species, the younger individuals proved to be the most susceptible. In their natural habitat, red abalone often experience strong coastal upwelling events during their spawning period, bringing acidic water from the ocean depths to the surface.
Typically, upwelling events are sporadic and influenced by coastal surface winds. However, the highly acidic conditions, referred to as “high pCO2,” observed in the experiment already occur in brief pulses during upwelling events off the coast of California. Climate models project that elevated upwelling levels, driven by ongoing carbon dioxide emissions and intensified coastal winds, will become more frequent and endure for longer durations, posing additional challenges for red abalone and other marine life.
A California icon
Red abalone, a species with a potential lifespan of 50 years or more, holds significant ecological importance as a key member of kelp forest ecosystems. They have been integral to the diet and cultural heritage of coastal Native communities in the region for millennia.
Describing red abalone as a California icon, co-author Daniel Swezey, a research scientist at the UC Davis Coastal and Marine Sciences Institute and Bodega Marine Laboratory, highlighted their beauty, size, longevity, and profound cultural significance. The species has a rich history and holds considerable meaning for many people in the region.
However, red abalone faces a multitude of threats, including rising ocean temperatures, diseases, the decline of kelp forests, voracious purple sea urchins, and habitat degradation. These combined challenges led to the closure of the red abalone fishery in 2018, a closure expected to last until at least 2026.
Swezey emphasized the dire state of the fishery, with slow kelp recovery and unprecedentedly high populations of sea urchins. In light of these challenges, the critical question becomes: How can interventions be implemented to create positive impacts that allow red abalone populations to recover? While acknowledging the complexity of the task, Swezey affirmed the commitment to addressing these issues and finding solutions for the recovery of red abalone.
Resources
- ONLINE NEWS Kerlin, K. & UC Davis. (2023, December 6). Ocean acidification creates legacy of stress for red abalone, study finds. Phys.org. [Phys.org]
- JOURNAL Neylan, I. P., Swezey, D. S., Boles, S. E., Gross, J. A., Sih, A., & Stachowicz, J. J. (2023). Within‐ and transgenerational stress legacy effects of ocean acidification on red abalone (Haliotis rufescens) growth and survival. Global Change Biology. [Global Change Biology]
Cite this page:
APA 7: TWs Editor. (2023, December 7). The Stress Legacy of Ocean Acidification on Red Abalone. PerEXP Teamworks. [News Link]
