Salinity, pH, dissolved oxygen (DO), dissolved inorganic nitrate (DIN), dissolved inorganic phosphate (DIP), and reactive silicate (DSi) concentrations were measured in three tidal creeks in the Sagar Island (situated within the Sundarban Biosphere Reserve, India) during 2016–17, once in a month throughout an annual cycle. The present observations were compared with a study carried out three-decade ago in the same locations during 1988–89. There was no significant difference in salinity between the years 1988-89 and 2016-17. Compared to the 1988–89 scenario, pH reduced considerably during 2016–17, indicating the dominance of heterotrophic activities over autotrophic processes. The comparative analysis shows that DO varied between 3.8 mg l^− 1 and 5.4 mg l^− 1 during 1988–89, which went to hypoxic levels (< 2 mg l^− 1) during 2016–17. Such hypoxic conditions can lead to direct mortality of several marine biotas that thrives in these creeks. DIN and DSi concentrations reduced significantly. Compared to the 1988–89 scenario, DIN and DSi concentrations reduced by three times and ten times, respectively, in the year 2016-17. DIP concentration showed an increase in annual mean concentration, which was statistically not significant. Despite that DIN:DIP ratio reduced significantly during 2016–17 compared to that of 1988–89, which can lead to changes in the primary productivity potential of the phytoplankton community. Such changes in concentrations of the physicochemical and nutrient parameters can adversely affect the sustenance of several aquatic life forms and lead to changes in species composition or total abandonment.

在印度桑格班生物圈保护区的萨加尔岛的三个潮汐小溪中测量了盐度，pH，溶解氧（DO），溶解无机硝酸盐（DIN），溶解无机磷酸盐（DIP）和反应性硅酸盐（DSi）的浓度。 ）在2016-17年度期间，在整个年度周期中每月一次。将当前的观察结果与十年前在1988-89年期间在相同地点进行的一项研究进行了比较。在1988-89年和2016-17年之间，盐度没有显着差异。与1988-89年的情景相比，2016-17年的pH值显着降低，表明异养活动比自养过程占主导地位。对比分析表明，溶解氧在3.8 mg l ^{− 1}至5.4 mg l ^{− 1之间变化}在1988–89年间达到低氧水平（<2 mg l ^{− 1}）在2016-17年期间。这种低氧条件可能导致在这些小溪中繁茂的几种海洋生物直接死亡。DIN和DSi浓度显着降低。与1988-89年的情景相比，2016-17年DIN和DSi的浓度分别降低了三倍和十倍。DIP浓度显示年平均浓度增加，这在统计学上不显着。尽管DIN：DIP比率在2016-17年度比1988-89期间显着降低，这可能导致浮游植物群落初级生产力潜力的变化。物理化学和营养参数浓度的这种变化可能对几种水生生物的维持产生不利影响，并导致物种组成或总废弃率的变化。