Effects of flood-associated stressors on growth and survival of early life stage oysters (Crassostrea virginica)

Spatiotemporal spatfall dynamics and prevailing estuarine conditions for optimal oyster (Crassostrea tulipa) spat availability in selected Gulf of Guinea brackish systems

“…This annual intervention is carried out to protect the integrity of the dam when it exceeds the threshold retention capacity, which occurs after periods of high and prolonged rains in the rainy season. Such major flooding events diminish the quality of estuarine water and further endanger populations of oysters by causing mass mortalities (Pruett et al, 2021). Stations 1 and 2 had a similar abundance of C. tulipa spat, whilst Station 3 was not secure for spat collection due to persistent interference with other fishing activities.…”

Life‐stage‐dependent effects of multiple flood‐associated stressors on a coastal foundational species

“…Embryos and trochophore larvae are highly vulnerable to stressful environmental conditions in the water column because they must balance the high energetic demands of early development with limited available energy (Hamdoun & Epel, 2007; Shumway, 1996). After larval shell formation (i.e., D stage), veliger larvae are better able to tolerate environmental stressors and demonstrate high levels of survivorship in suboptimal environments (Davis, 1958; Griffiths et al, 2021; Pruett et al, 2021). Our results also showed no effect of low pH due to elevated CO 2 on veliger shell growth, which is consistent with other studies, which have found that oyster larvae exposed after initial prodissoconch shell development (i.e., D stage) can grow and survive in high p CO 2 conditions and low calcium carbonate saturation states until the pediveliger stage (Ko et al, 2013; Lawlor & Arellano, 2020; Miller et al, 2020).…”

“…Test concentrations of stressors (DO, pH, and salinity) were chosen based on previous larval responses in individual flood‐associated stressor exposures and water quality conditions recorded in the MS Sound during a freshwater intrusion event in the summer of 2019 (Pruett et al, 2021). Control conditions (7 mg L −1 , 8.0, and 15; DO, pH, and salinity) were compared with seven stressor treatments within a full factorial design (Table 1): DO (1–2 mg L −1 , 8.0, and 15), pH (7 mg L −1 , 7.6, and 15), salinity (7 mg L −1 , 7.8, and 6), DO + pH (1–2 mg L −1 , 7.6, and 15), DO + salinity (1–2 mg L −1 , 7.8, and 6), pH + salinity (7 mg L −1 , 7.3, and 6), DO + pH + salinity (1–2 mg L −1 , 7.3, and 6).…”

“…Twenty‐five juveniles were added to buckets with freshly prepared stressor treatment seawater ( n = 5 per stressor treatment). Oysters were individually labeled with color‐coded and numbered bee tags (Betterbee, Greenwich, NY, USA; Pruett et al, 2021) prior to exposure. Initial wet mass and photographs were taken of each labeled individual to measure growth over the duration of the exposure.…”

“…Recently settled invertebrates are also highly susceptible to physiological stressors (Hunt & Scheibling, 1997) and acidification, hypoxia, or low salinity can independently increase mortality and decrease growth rates (Baker & Mann, 1992; Dove & O'Connor, 2007; Green et al, 2004). Slightly larger juvenile bivalves are better able to survive stressful conditions but still suffer reduced growth rates that can have latent effects on adult fitness (Donelan et al, 2021; Pruett et al, 2021; Stevens & Gobler, 2018). However, which water quality stressors cause the most severe outcome and whether these co‐occurring stressors interact to modify larval and juvenile responses is not well understood.…”