Patterns of carbonate chemistry in mangroves of the Northern Persian Gulf

Highlights

• Pattern of carbonate chemistry in mangroves of the northern Persian Gulf was examined for the first time.
• The Nayband surface waters were undersaturated with respect to aragonite.
• Anthropogenic CO2 emission from PSEEZ has affected the Nayband mangrove ecosystem.
• Higher TA in the Nayband site compared to the other two sites, might be due to the presence of denser mangrove forest in this site.

Abstract

The mangroves located in the Northern Persian Gulf are reeling from anthropogenic pressures including from intense industrial activities (Pars Special Economic Energy Zone-PSEEZ). Given the unique geographical location of these mangroves, understanding the initial basis of seawater carbonate chemistry is key to link with global patterns of coastal ocean carbonate dynamics. In this study, water samples were collected from pre-designated stations representing the mangrove forest and nearshore water namely Nayband, Mel-e-Gonzeh and Bardestan of the Persian Gulf in September of 2016. Based on extensive carbonate chemistry measurements, the results show that the pCO₂ at the Nayband site (13217.9±5841.5 µatm) was significantly higher than the other two sites (Mel-e-Gonzeh: 416.4±49.3 µatm and Bardestan: 294.3±95.0 µatm) while pH (6.92±0.18) was significantly lower than the two other sites (Mel-e-Gonzeh: 8.18±0.02, Bardestan: 8.26±0.04). The observed increase of pCO₂ and decrease of surface water pH at the Nayband site compared to other two sites may have due to the emission of CO₂ originating from oil and gas refining facilities located PSEEZ. Moreover, surface water in Nayband was undersaturated with respect to aragonite (Ω_arg<1) and supersaturated (Ω_arg>1) in case of the Mel-e-Gonzeh and Bardestan sites. This study although preliminary provides much-needed baseline information to address issues of changing carbonate chemistry and can help towards understanding the basis of coastal ocean acidification.

Ghaemi M., Bhadury P. & Gholmipour S., 2024. Patterns of carbonate chemistry in mangroves of the Northern Persian Gulf. Regional Studies in Marine Science: 103652. doi: 10.1016/j.rsma.2024.103652. Article (subscription required).

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