In:
Frontiers in Marine Science, Frontiers Media SA, Vol. 10 ( 2023-3-30)
Abstract:
Despite over 90% of China’s coastal bays have an area less than 500 km 2 , the geochemical effects of SGD on those ecosystems are ambiguous. Based on mapping and time-series observations of Ra isotopes and nutrients, a case study of small bays ( & lt;500 km 2 ), we revealed that submarine groundwater discharge (SGD) predominately regulated the distribution of nutrients and fueled algal growth in Dongshan Bay, China. On the bay-wide scale, the SGD rate was estimated to be 0.048 ± 0.022 m day −1 and contributed over 95% of the nutrients. At the time-series site where the bay-wide highest Ra activities in the bottom water marked an SGD hotspot with an average rate an order of magnitude greater, the maximum chlorophyll concentration co-occurred, suggesting that SGD may support the algal bloom. The ever-most significant positive correlations between 228 Ra and nutrients throughout the water column (P & lt; 0.01, R 2 & gt; 0.90 except for soluble reactive phosphorus in the surface) suggested the predominance of SGD in controlling nutrient distribution in the bay. Extrapolated to a national scale, the SGD-carried dissolved inorganic nitrogen flux in small bays was twice as much as those in large bays ( & gt;2,000 km 2 ). Thus, the SGD-carried nutrients in small bays merit immediate attention in environmental monitoring and management.
Type of Medium:
Online Resource
ISSN:
2296-7745
DOI:
10.3389/fmars.2023.1164589
DOI:
10.3389/fmars.2023.1164589.s001
Language:
Unknown
Publisher:
Frontiers Media SA
Publication Date:
2023
detail.hit.zdb_id:
2757748-X
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