Mandal Subir Kumar, Patel Vipul R, Temkar Ganesh, George Basil M, Raman Mini
Marine Biotechnology and Ecology, Marine Algal Research Station, Central Salt and Marine Chemicals Research Institute, Council of Scientific and Industrial Research (CSIR), Mandapam Camp, Mandapam, Dist-Ramnathapuram, 623519, Tamil Nadu, India,
Environ Monit Assess. 2015 Sep;187(9):597. doi: 10.1007/s10661-015-4798-6. Epub 2015 Aug 28.
Discosphaera tubifer, a coccolithophore has been first time reported as a bloom-forming organism from an over-crowded fishing harbour at Veraval, west coast of India. Physiochemical and optical parameters were measured following standard protocols. Average concentration of inorganic nutrients, such as NO2-N (17.26 ± 2.92 μM), NO3-N (643.80 ± 215.99 μM), PO4-P (74.10 ± 26.52 μM) and SiO3-Si (137.66 ± 25.83 μM) were recorded as very high at Veraval port as compared to other coastal stations i.e., 1.48 ± 0.66, 49.16 ± 13.73, 10.03 ± 5.31 and 96.23 ± 22.74 μM, respectively. The pH and salinity (‰) were observed to be low (7.80 ± 0.15 and 28.00 ± 4.54 ‰) as compared to coastal seawaters (8.34 ± 0.06 and 33.24 ± 2.32 ‰). Scanning electron microscopy (SEM) and spectral signature (absorbance and reflectance) study revealed that the bloom-forming organism was D. tubifer. High-performance liquid chromatography (HPLC) study detected that chlorophyllide-a represent nearly 47.53 % of total pigment composition followed by chlorophyll c2 (27.40 %) and chlorophyll c3 (14.25 %). Four prominent absorption peaks were observed within 350 to 700 nm. The first peak was very wide and ranged from 350 to 530 nm and the rest of the three peaks ranged from 550 to 590, 590 to 650 and 650 to 690 nm, respectively. In case of reflection, three peaks appeared between 550 and 590, 590 and 630 and 630 and 670 nm. Nearly 100 % reflection was observed after 720 nm. The eutrophic condition of the port water along with low salinity and low pH might be the reason for D. tubifer bloom formation. This species-specific spectral signature of the D. tubifer bloom may be helpful for developing algorithm of remote sensing data analysis.
球石藻属的管形盘球藻（Discosphaera tubifer）首次被报道为一种在印度西海岸韦拉瓦尔一个过度拥挤的渔港形成水华的生物。按照标准方案测量了理化和光学参数。与其他沿海站点相比，韦拉瓦尔港无机营养物的平均浓度，如亚硝酸盐氮（17.26±2.92 μM）、硝酸盐氮（643.80±215.99 μM）、磷酸盐磷（74.10±26.52 μM）和硅酸盐硅（137.66±25.83 μM）记录为非常高，其他沿海站点的相应浓度分别为1.48±0.66、49.16±13.73、10.03±5.31和96.23±22.74 μM。与沿海海水（8.34±0.06和33.24±2.32‰）相比，观察到pH值和盐度（‰）较低（7.80±0.15和28.00±4.54‰）。扫描电子显微镜（SEM）和光谱特征（吸光度和反射率）研究表明，形成水华的生物是管形盘球藻。高效液相色谱（HPLC）研究检测到叶绿素酸a占总色素组成的近47.53%，其次是叶绿素c2（27.40%）和叶绿素c3（14.25%）。在350至700纳米范围内观察到四个明显的吸收峰。第一个峰非常宽，范围从350到530纳米，其余三个峰分别范围从550到590、590到650和650到690纳米。在反射情况下，在550到590、590到630和630到670纳米之间出现三个峰。在720纳米之后观察到近100%的反射。港口水体的富营养化状况以及低盐度和低pH值可能是管形盘球藻形成水华的原因。管形盘球藻水华这种物种特异性的光谱特征可能有助于开发遥感数据分析算法。
