Synthesis of Thresholds of Ocean Acidification Impacts on Decapods

Abstract

Assessing decapod sensitivity to regional-scale ocean acidification (OA) conditions is limited because of a fragmented understanding of the thresholds at which they exhibit biological response. To address this need, we undertook a three-step data synthesis: first, we compiled a dataset composed of 27,000 datapoints from 55 studies of decapod responses to OA. Second, we used statistical threshold analyses to identify OA thresholds using pH as a proxy for 13 response pathways from physiology to behavior, growth, development and survival. Third, we worked with the panel of experts to review these thresholds, considering the contributing datasets based on quality of the study, and assign a final thresholds and associated confidence scores based on quality and consistency of findings among studies. The duration-dependent thresholds were within a pH range from 7.40 to 7.80, ranging from behavioral and physiological responses to mortality, with many of the thresholds being assigned medium-to-high confidence. Organism sensitivity increased with the duration of exposure but was not linked to a specific life-stage. The thresholds that emerge from our analyses provide the foundation for consistent interpretation of OA monitoring data or numerical ocean model simulations to support climate change marine vulnerability assessments and evaluation of ocean management strategies.

Attributing Controlling Factors of Acidification and Hypoxia in a Deep, Nutrient-Enriched Estuarine Embayment

“…To put these conditions in perspective, the review of Gazeau et al (2013) documented responses of adult and larval/juvenile shelled molluscs pH decreases of ≤0.4 units, and found that while adults showed few negative responses, larval stages were much more vulnerable to acidification stress. Recent review of acidification effects on crustacea (Bednaršek et al, 2021) found frequent negative effects on adults and larval/juvenile stages to pH reductions ≤ 0.4, and experiments on decapod larvae combining acidification and hypoxia (Tomasetti et al, 2021) have demonstrated potential for severe synergistic effects over short exposure time scales. For New Zealand taxa, Law et al (2018) found that acidification levels we show for the Firth approached deleterious levels for macroalgae (corallines), and early life stages of sea urchins, sand dollars, abalone and New Zealand Greenshell R mussels, which are grown in the large mussel farms in the Firth (Law et al, 2019).…”

Meta‐analysis suggests negative, but pCO2‐specific, effects of ocean acidification on the structural and functional properties of crustacean biomaterials

“…Recent meta-analyses on other physiological and life history traits (growth, fecundity, hatching success, and respiration) in decapod crustaceans confirm this difference between acute and chronic acclimation and strongly suggest that prolonged exposure to ocean acidification conditions further exacerbates negative physiological effects (Bednaršek et al, 2021). Definition of organismic responses at the acute versus chronic levels to climate change of any magnitude will require future studies to use physiologically and ecologically relevant timescales for their exposures.…”

“…Functional differences between crustacean exoskeletons could arise from divergent absolute levels of Ca 2+ , Mg 2+ , and their ratio. Other foci important in understanding the mechanisms of ocean acidification-mediated changes in exoskeletal properties include structural changes in the orientation of crystals within the mineralized layer (Chen et al, 2008;Rosen et al, 2020) and characterization of mineral deposition versus dissolution rates (Bednaršek et al, 2021), facets we did not assess in this study.…”

“…Previous multi‐taxa meta‐analyses on ocean acidification's biological effects usually focus on traits relevant to population dynamics and management, such as animal survival, developmental timing, growth rate, and fecundity (Kroeker et al, 2010 , 2013 ). Other meta‐analyses focusing on the biological impacts of ocean acidification center on specific taxa/clades (Bednaršek et al, 2019 ; Meyer & Riebesell, 2015 ), biogeographic regions (Hancock et al, 2020 ; Zunino et al, 2017 ), or physiological processes in specific taxa (Bednaršek et al, 2021 ; Chan & Connolly, 2013 ). To the best of our knowledge, no research synthesis and meta‐analysis has focused solely on crustacean mineralization and exoskeletal properties under ocean acidification, although Bednaršek et al ( 2021 ) strongly informs the need for such an assessment with their meta‐analysis of threshold limits for pH and exposure duration beyond which the physiology and development of decapod crustaceans are negatively affected.…”

Climate Change Will Fragment Florida Stone Crab Communities

“…Coastal areas are also more threatened by the increase in seawater temperature as they warm faster than open ocean (Hoegh-Guldberg et al, 2014;Fox-Kemper et al, 2021). The reductions in seawater pH and increases in seawater temperature can have deleterious effects on many coastal species, especially during earlier life-stages, which are often more sensitive than adult conspecifics (Kurihara, 2008;Ceballos-Osuna et al, 2013;Bednarsěk et al, 2021). Crustaceans are especially sensitive to those changes.…”