Short-Term Spatial and Temporal Carbonate Chemistry Variability in Two Contrasting Seagrass Meadows: Implications for pH Buffering Capacities

Authors

Tyler Cyronak, University of California - San DiegoFollow
Andreas J. Andersson, University of California - San Diego
Sydney D'Angelo, University of California - San Diego
Philip Bresnahan, University of California - San Diego
Charles Davidson, University of California - San Diego
Alyssa Griffin, University of California - San Diego
Theodor Kindeberg, University of California - San Diego
Jimmy Pennise, Ocean Discovery Institute
Yuichiro Takeshita, Monterey Bay Aquarium Research Institute
Margot White, University of California - San Diego

ORCID

0000-0003-3556-7616

Document Type

Article

Publication Title

Estuaries and Coasts

ISSN

1559-2723

Publication Date

7-2018

Keywords

Ocean acidification, Coastal ecosystems, Buffering, Seagrass, Carbonate chemistry, SeapHOx

Abstract

It has been hypothesized that highly productive coastal ecosystems, such as seagrass meadows, could lead to the establishment of ocean acidification (OA) refugia, or areas of elevated pH and aragonite saturation state (Ω_a) compared to source seawater. However, seagrass ecosystems experience extreme variability in carbonate chemistry across short temporal and small spatial scales, which could impact the pH buffering capacity of these potential refugia. Herein, short-term (hourly to diel) and small-scale (across 0.01–0.14 km²) spatiotemporal carbonate chemistry variability was assessed within two seagrass meadows in order to determine their short-term potential to elevate seawater pH relative to source seawater. Two locations at similar latitudes were chosen in order to compare systems dominated by coarse calcium carbonate (Bailey’s Bay, Bermuda) and muddy silicate (Mission Bay, CA, USA) sediments. In both systems, spatial variability of pH across the seagrass meadow at any given time was often greater than diel variability (e.g., the average range over 24 h) at any one site, with greater spatial variability occurring at low tide in Mission Bay. Mission Bay (spatial ΔpH = 0.08 ± 0.08; diel ΔpH = 0.12 ± 0.01; mean ± SD) had a greater average range in both temporal and spatial seawater chemistry than Bailey’s Bay (spatial ΔpH = 0.02 ± 0.01; diel ΔpH = 0.03 ± 0.00; mean ± SD). These differences were most likely due to a combination of slower currents, a larger tidal range, and more favorable weather conditions for photosynthesis (e.g., sunny with no rain) in Mission Bay. In both systems, there was a substantial amount of time (usually at night) when seawater pH within the seagrass beds was lower relative to the source seawater. Future studies aimed at assessing the potential of seagrass ecosystems to act as OA refugia for marine organisms need to account for the small-scale, high-frequency carbonate chemistry variability in both space and time, as this variability will impact where and when OA will be buffered or intensified.

DOI

10.1007/s12237-017-0356-5

Volume

41

Issue

5

First Page

1282

Last Page

1296

Comments

©Coastal and Estuarine Research Federation 2018

Additional Comments

NSF grant #: OCE 12-55042

NSUWorks Citation

Tyler Cyronak, Andreas J. Andersson, Sydney D'Angelo, Philip Bresnahan, Charles Davidson, Alyssa Griffin, Theodor Kindeberg, Jimmy Pennise, Yuichiro Takeshita, and Margot White. 2018. Short-Term Spatial and Temporal Carbonate Chemistry Variability in Two Contrasting Seagrass Meadows: Implications for pH Buffering Capacities .Estuaries and Coasts , (5) : 1282 -1296. https://nsuworks.nova.edu/occ_facarticles/1044.