Highlights
- Ocean acidification reduces fitness and condition of a benthic ecosystem engineer.
- Degree of acidification determines the presence of effects.
- Ocean acidification decreased the energy intake of Abra alba.
- Physiological response resulted in higher metabolic losses through increased excretion rates.
- Physiological changes of benthic engineers likely induce cascading effects on the ecosystem.
Abstract
The presence and behaviour of bivalves can affect the functioning of seafloor sediments through the irrigation of deeper strata by feeding and respiring through siphonal channels. Here, we investigated the physiological response and consecutive impact on functioning and body condition of the white furrow shell Abra alba in three pH treatments (pH = 8.2, pH = 7.9 and pH = 7.7). Although no pH effect on survival was found, lowered respiration and calcification rates, decreased energy intake (lower absorption rate) and increased metabolic losses (increased excretion rates) occurred at pH ∼ 7.7. These physiological responses resulted in a negative Scope for Growth and a decreased condition index at this pH. This suggests that the physiological changes may not be sufficient to sustain survival in the long term, which would undoubtedly translate into consequences for ecosystem functioning.
Vlaminck E., Moens T., Vanaverbeke J. & Van Colen C., 2022. Physiological response to seawater pH of the bivalve Abra alba, a benthic ecosystem engineer, is modulated by low pH. Marine Environmental Research 179: 105704. doi: 10.1016/j.marenvres.2022.105704. Article (subscription required).
