Comparative Sensitivities of Zooplankton to Ocean Acidification Conditions in Experimental and Natural Settings

Abstract

Zooplankton can serve as indicators of ecosystem health, water quality, food web structure, and environmental change, including those associated with climate change and ocean acidification (OA). Laboratory studies demonstrate that low pH and high pCO2 associated with OA can significantly affect the physiology and survival of zooplankton, with differential responses among taxa. While laboratory studies can be indicative of zooplankton response to OA, in situ responses will ultimately determine the fate of populations and ecosystems. In this perspective, we compare expectations from experimental studies with observations made in Puget Sound (Washington, United States), a highly dynamic estuary with known vulnerabilities to low pH and high pCO2. We found little association between empirical measures of in situ pH and the abundance of sensitive taxa as revealed by meta-analysis, calling into question the coherence between experimental studies and field observations. The apparent mismatch between laboratory and field studies has important ramifications for the design of long-term monitoring programs and interpretation and use of the data produced. Important work remains to be done to connect traits that are sensitive to OA with those that are ecologically relevant and reliably observable in the field.

Pathogens and Passengers: Roles for Crustacean Zooplankton Viruses in the Global Ocean

“…These effects are made worse when pH stress is combined with low oxygen [89]. Ultimately, the complexity of conditions that plankton are exposed to in the wild makes it difficult to extrapolate laboratory-measured mortality and stress due to OA to natural communities [90]. Hypoxia is detrimental to zooplankton survival and reproduction as well [91][92][93], and is associated with changes in community structure [94].…”

Oxygen and irradiance constraints on visual habitat in a changing ocean: The luminoxyscape

“…The impacts of ocean deoxygenation in these species are, therefore, likely to be underestimated if only metabolic oxygen limits are considered. When matching species‐specific empirical physiological thresholds with abundance data, it is important to consider both sublethal effects and the role of behavior (Pörtner 2012; Keil et al 2021). The concept of the luminoxyscape places laboratory‐derived physiological and behavioral oxygen limits for vision in the context of past and current environmental conditions.…”

Evaluating Metabarcoding Markers for Identifying Zooplankton and Ichthyoplankton Communities to Species in the Salish Sea: Morphological Comparisons and Rare, Threatened or Invasive Species

“…These species frequently interact together, accentuating or dampening the effects of environmental stressors on one another. Notably, coastal zooplankton and ichthyoplankton communities are regarded as some of the most vulnerable to ocean acidification (OA), hypoxia (H), and warming [4][5][6] and are subject to other environmental, chemical, physical, and biological fluctuating conditions (e.g., [7,8]). Moreover, their larval stages often lack species-level diagnostic morphological characters, precluding their identifications using microscopy and DNA 2024, 4 2 other morphology techniques [9][10][11][12][13].…”

“…In many coastal areas around the world, including the Salish Sea in the temperate Northeastern (NE) Pacific region (Figure 1), zooplankton and ichthyoplankton diversity levels and the ranges of environmental conditions they encounter are high [6,15,16]. The Salish Sea (which includes the Strait of Georgia, the Strait of Juan de Fuca, and Puget Sound) is one of the most biologically rich and diverse inland seas, housing about 260 fish species and more than 3000 invertebrate species [15].…”

“…The Salish Sea (which includes the Strait of Georgia, the Strait of Juan de Fuca, and Puget Sound) is one of the most biologically rich and diverse inland seas, housing about 260 fish species and more than 3000 invertebrate species [15]. These species are adapted to a broad range of physical and chemical conditions, including salinity, temperature, pH, and dissolved oxygen levels that can fluctuate extensively with season, rainfall, tidal influences, land run-off, and other variables [6,15,16]. Because of its relatively low freshwater inputs and deep (>100 m) water column in many areas, the Salish Sea supports a diverse zooplankton and ichthyoplankton community assemblage that is more representative of coastal and oceanic regions than characteristic of most estuaries [6].…”