Pattanaik Suchismita, Mohapatra Pradipta Kumar, Mohapatra Debasish, Swain Sanhita, Panda Chitta Ranjan, Dash Pradeep Kumar
Council of Scientific and Industrial Research (CSIR)-Institute of Minerals and Materials Technology, Bhubaneswar 751013, India.
Department of Botany, Ravenshaw University, Cuttack 753003, India.
Life (Basel). 2022 Oct 2;12(10):1536. doi: 10.3390/life12101536.
The exchange of CO between the air-water interfaces of estuaries is crucial from the perspective of the global carbon cycle and climate change feedback. In this regard, we evaluated the air-water CO exchanges in two major estuaries-the Mahanadi estuary (ME) and the Dhamra estuary (DE) in the northern part of the Bay of Bengal, India. Biogeochemical properties of these estuarine waters were quantified in three distinct seasons, namely, pre-monsoon (March to May), monsoon (June to October), and post-monsoon (November to February). The significant properties of water, such as the water temperature, pH, salinity, nutrients, dissolved oxygen, chlorophyll-a (chl ), and photosynthetic pigment fluorescence of phytoplankton, were estimated and correlated with CO fluxes. We found that the ME acted as a source of CO fluxes in the monsoon and post-monsoon, while DE acted as a sink during the monsoon. The stepwise regression model showed that the fluxes were primarily driven by water temperature, pH, and salinity, and they correlated well with the phytoplankton characteristics. The chl content, fluorescence yield, and phycobilisomes-to-photosystem II fluorescence ratios were major drivers of the fluxes. Therefore, for predicting air-water CO exchanges precisely in a large area over a seasonal and annual scale in the estuaries of the Bay of Bengal, India, critical key parameters such as water temperature, pH, salinity, chl , and fluorescence yield of phytoplankton should be taken into consideration. However, the responses of phytoplankton, both in terms of production and CO capture, are critical research areas for a better understanding of air-water CO exchanges in coastal ecology under climate change scenarios.
从全球碳循环和气候变化反馈的角度来看，河口空气 - 水界面之间的二氧化碳（CO）交换至关重要。在这方面，我们评估了印度孟加拉湾北部两个主要河口——默哈讷迪河河口（ME）和达姆拉河河口（DE）的空气 - 水CO交换情况。在三个不同季节对这些河口海水的生物地球化学性质进行了量化，即季风前（3月至5月）、季风期（6月至10月）和季风后（11月至2月）。估算了海水的重要性质，如水温、pH值、盐度、营养物质、溶解氧、叶绿素a（chl）以及浮游植物的光合色素荧光，并将其与CO通量进行关联。我们发现，默哈讷迪河河口在季风期和季风后充当CO通量的源，而达姆拉河河口在季风期充当汇。逐步回归模型表明，通量主要受水温、pH值和盐度驱动，并且它们与浮游植物特征具有良好的相关性。chl含量、荧光产量以及藻胆体与光系统II荧光比率是通量的主要驱动因素。因此，为了在印度孟加拉湾河口的季节性和年度尺度上大面积精确预测空气 - 水CO交换，应考虑水温、pH值、盐度、chl以及浮游植物荧光产量等关键参数。然而，浮游植物在生产和CO捕获方面的响应，是气候变化情景下更好理解沿海生态系统中空气 - 水CO交换的关键研究领域。
