Seagrass-driven changes in carbonate chemistry enhance oyster shell growth

Aurora M Ricart, Brian Gaylord, Tessa M Hill, Julia D Sigwart, Priya Shukla, Melissa Ward, Aaron Ninokawa, Eric Sanford

Research output: Contribution to journalArticlepeer-review

Abstract

Quantifying the strength of non-trophic interactions exerted by foundation species is critical to understanding how natural communities respond to environmental stress. In the case of ocean acidification (OA), submerged marine macrophytes, such as seagrasses, may create local areas of elevated pH due to their capacity to sequester dissolved inorganic carbon through photosynthesis. However, although seagrasses may increase seawater pH during the day, they can also decrease pH at night due to respiration. Therefore, it remains unclear how consequences of such diel fluctuations may unfold for organisms vulnerable to OA. We established mesocosms containing different levels of seagrass biomass (Zostera marina) to create a gradient of carbonate chemistry conditions and explored consequences for growth of juvenile and adult oysters (Crassostrea gigas), a non-native species widely used in aquaculture that can co-occur, and is often grown, in proximity to seagrass beds. In particular, we investigated whether increased diel fluctuations in pH due to seagrass metabolism affected oyster growth. Seagrasses increased daytime pH up to 0.4 units but had little effect on nighttime pH (reductions less than 0.02 units). Thus, both the average pH and the amplitude of diel pH fluctuations increased with greater seagrass biomass. The highest seagrass biomass increased oyster shell growth rate (mm day ) up to 40%. Oyster somatic tissue weight and oyster condition index exhibited a different pattern, peaking at intermediate levels of seagrass biomass. This work demonstrates the ability of seagrasses to facilitate oyster calcification and illustrates how non-trophic metabolic interactions can modulate effects of environmental change.
Original languageEnglish
JournalOecologia
Early online date27 May 2021
DOIs
Publication statusEarly online date - 27 May 2021

Keywords

  • Climate refugia
  • Facilitative interaction
  • Marine macrophytes
  • Non-trophic interaction
  • Ocean acidification

Fingerprint

Dive into the research topics of 'Seagrass-driven changes in carbonate chemistry enhance oyster shell growth'. Together they form a unique fingerprint.

Cite this