Ocean Chemistry and Ecosystems Division, Atlantic Oceanographic and Meteorological Laboratory, National Oceanic and Atmospheric Administration, Miami, FL, 33149, USA.
Sci Rep. 2023 Mar 11;13(1):4071. doi: 10.1038/s41598-023-30905-4.
In recent decades, annual cyanobacteria blooms in Florida Bay displayed spatial and temporal patterns that are consistent with changes in alkalinity and dissolved silicon in water. In early summer, the blooms developed in the north-central bay and spread southward in fall. The blooms drew down dissolved inorganic carbon and increased water pH, causing in situ precipitation of calcium carbonate. Dissolved silicon concentrations in these waters were at minimum in spring (20-60 µM), increased during summer, and reached an annual maximum (100-200 µM) during late summer. The dissolution of silica as a result of high pH in bloom water was first observed in this study. During the peak of blooms, silica dissolution in Florida Bay varied from 0.9 × 10 to 6.9 × 10 mol per month over the study period, depending on the extent of cyanobacteria blooms in a given year. Concurrent calcium carbonate precipitations in the cyanobacteria bloom region are between 0.9 × 10 and 2.6 × 10 mol per month. It is estimated that 30-70% of atmospheric CO uptake in bloom waters was precipitated as calcium carbonate mineral and remainders of CO influx were used for the production of biomass.
在最近几十年中，佛罗里达湾的年度蓝藻水华呈现出与水中碱度和溶解硅变化一致的时空模式。在初夏，水华出现在湾的中北部，并在秋季向南扩散。水华消耗了溶解无机碳并增加了水的 pH 值，导致碳酸钙就地沉淀。这些水中的溶解硅浓度在春季（20-60 µM）最低，在夏季增加，并在夏末达到年度最大值（100-200 µM）。本研究首次观察到蓝藻水华高 pH 值导致的硅溶解。在水华高峰期，佛罗里达湾的硅溶解量在研究期间每月变化范围为 0.9×10 至 6.9×10 mol，具体取决于当年蓝藻水华的程度。在蓝藻水华区同时发生的碳酸钙沉淀量为每月 0.9×10 至 2.6×10 mol。据估计，水华水中 30-70%的大气 CO 吸收被沉淀为碳酸钙矿物，其余的 CO 流入被用于生物量的生产。
