iBet uBet web content aggregator. Adding the entire web to your favor.
iBet uBet web content aggregator. Adding the entire web to your favor.



Link to original content: http://pubmed.ncbi.nlm.nih.gov/38830941/
Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer - PubMed Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Jun 4;14(1):12757.
doi: 10.1038/s41598-024-63210-9.

Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer

Catarina P P Martins  1 , Maren Ziegler  2 , Patrick Schubert  2 , Thomas Wilke  2 , Marlene Wall  3
Affiliations

Effects of water flow and ocean acidification on oxygen and pH gradients in coral boundary layer

Catarina P P Martins et al. Sci Rep. .

Abstract

Reef-building corals live in highly hydrodynamic environments, where water flow largely controls the complex chemical microenvironments surrounding them-the concentration boundary layer (CBL). The CBL may be key to alleviate ocean acidification (OA) effects on coral colonies by partially isolating them. However, OA effects on coral CBL remain poorly understood, particularly under different flow velocities. Here, we investigated these effects on the reef-building corals Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. We preconditioned corals to a control (pH 8.0) and OA (pH 7.8) treatment for four months and tested how low flow (2 cm s-1) and moderate flow (6 cm s-1) affected O2 and H+ CBL traits (thickness, surface concentrations, and flux) inside a unidirectional-flow chamber. We found that CBL traits differed between species and flow velocities. Under OA, traits remained generally stable across flows, except surface pH. In all species, the H+ CBL was thin and led to lower surface pH. Still, low flow thickened H+ CBLs and increased light elevation of surface pH. In general, our findings reveal a weak to null OA modulation of the CBL. Moreover, the OA-buffering capacity by the H+ CBL may be limited in coral species, though low flow could enhance CBL sheltering.

PubMed Disclaimer

Conflict of interest statement

The authors declare no competing interests.

Figures

Figure 1
Figure 1
Effects of water flow and ocean acidification (OA) on the thickness of the concentration boundary layer (CBL) of Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. (A) O2 and (B) H+ CBL thickness after four months in a control and OA treatment and measured in light or darkness combined with low flow (LF, 2 cm s-1) and moderate flow (MF, 6 cm s-1). Values are presented pooled over light and dark conditions. Boxes represent the first and third quartiles with lines as medians and whiskers as the minimum and maximum values or up to the 1.5 * interquartile range (IQR), whichever is reached first. Stars indicate significant differences between the control and OA treatment within each flow condition (p < 0.01**, from linear mixed-effects models with ANOVA).
Figure 2
Figure 2
Effects of water flow and ocean acidification (OA) on traits of the concentration boundary layer (CBL) of Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. (A) O2 concentration change at the coral surface relative to bulk seawater (surface ∆O2), (B) pH change at the coral surface relative to bulk seawater (surface ∆pH), and (C) O2 flux, after four months in a control and OA treatment and measured in light or darkness combined with low flow (LF, 2 cm s-1) and moderate flow (MF, 6 cm s-1). Boxes represent the first and third quartiles with lines as medians and whiskers as the minimum and maximum values or up to the 1.5 * interquartile range (IQR), whichever is reached first. No significant interactive effects of flow and OA were observed.
Figure 3
Figure 3
Summary diagram of the effects of water flow and ocean acidification (OA) on traits of the concentration boundary layer (CBL) of Acropora cytherea, Pocillopora verrucosa, and Porites cylindrica. Effects on CBL thickness are presented pooled over light conditions, while change in surface O2 concentration (surface ∆O2) and pH (surface ∆pH) relative to bulk seawater, and O2 flux are presented in light and darkness. Asterisk indicates OA effects present exclusively under low flow. n/a, not available.
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Davis KA, Pawlak G, Monismith SG. Turbulence and coral reefs. Ann. Rev. Mar. Sci. 2021;13:343–373. - PubMed
    1. Roik A, et al. Year-long monitoring of physico-chemical and biological variables provide a comparative baseline of coral reef functioning in the central Red Sea. PLoS One. 2016;11:e0163939. - PMC - PubMed
    1. Green RH, Lowe RJ, Buckley ML. Hydrodynamics of a tidally forced coral reef atoll. J. Geophys. Res. Oceans. 2018;123:7084–7101.
    1. Noisette F, Pansch C, Wall M, Wahl M, Hurd CL. Role of hydrodynamics in shaping chemical habitats and modulating the responses of coastal benthic systems to ocean global change. Glob. Chang. Biol. 2022;28:3812–3829. - PubMed
    1. Lesser MP, Weis VM, Patterson MR, Jokiel PL. Effects of morphology and water motion on carbon delivery and productivity in the reef coral, Pocillopora damicornis (Linnaeus): Diffusion barriers, inorganic carbon limitation, and biochemical plasticity. J. Exp. Mar. Biol. Ecol. 1994;178:153–179.