Upwelling occurs on the coast of Java between June and October, forced by local alongshore winds associated with the southeasterly monsoon. This causes variations in phytoplankton community composition in the upwellin...Upwelling occurs on the coast of Java between June and October, forced by local alongshore winds associated with the southeasterly monsoon. This causes variations in phytoplankton community composition in the upwelling zone compared with the surrounding offshore area. Based on pigments analysis with subsequent calculations of group contributions to total chlorophyll a(Chl a) using CHEMTAX, we studied the distribution and composition of phytoplankton assemblages in the subsurface chlorophyll maximum along the south coast of Java and the influence of upwelling. Nineteen phytoplankton pigments were identified using high-performance liquid chromatography, and CHEMTAX analysis associated these to ten major phytoplankton groups. The phytoplankton community in the coastal area influenced by upwelling was characterized by high Chl a and fucoxanthin concentrations, indicating the dominance of diatoms. In contrast, in the offshore area, the Chl a and fucoxanthin concentrations declined to very low levels and the community was dominated by haptophytes represented by 19′-Hexanoyloxyfucoxanthin. Accordingly, microphytoplankton was found to be the major size class in the coastal area influenced by upwelling, while nanophytoplankton was most abundant in the offshore area. Low concentrations of other accessory pigments indicated less contribution from dinoflagellates,prasinophytes, chlorophytes and cryptophytes. Photo-pigment indices revealed that photosynthetic carotenoids(PSCs) were the largest component of the pigment pool, exceeding the proportion of Chl a, with the average PSCTP up to 0.62. These distribution trends can mainly be explained by phytoplankton adaption strategies to upwelling and subsurface conditions by changing species composition and adjusting the pigment pool.展开更多
根据1986年1月至1990年7月热带西太平洋海域(10°30′S～18°20′N、122°24′～165°00′E)中美海气联合调查(TOGA 调查)的第2、3、6、8航次资料,研究了热带西太平洋叶绿素 a 的时空分布.研究表明,4个航次叶绿素 a 总...根据1986年1月至1990年7月热带西太平洋海域(10°30′S～18°20′N、122°24′～165°00′E)中美海气联合调查(TOGA 调查)的第2、3、6、8航次资料,研究了热带西太平洋叶绿素 a 的时空分布.研究表明,4个航次叶绿素 a 总平均值为0.199 mg/m^3,实测资料变化范围为:未检出值～3.432 mg/m^3.水平分布不均匀,在海岛附近有叶绿素 a 高值区,而其它海域则较低.叶绿素 a 的垂直分布多数测站呈单峰曲线型,但也有个别测站呈双峰型,最大值多数测站出现在100m 水层,其次是75m 水层,最深可达到250m 水层.叶绿素 a 最大值出现在次表层,位于温跃层上界.4个航次叶绿素 a 的含量的大小顺序分别为第2航次(0.200)>第6航次(0.104)>第8航次(0.089)>第3航次(0.084),反映了不同调查时间叶绿素 a 的含量是有差异的.展开更多
基金The Global Change and Air-Sea Interaction Program under contract Nos GASI-02-IND-ST-Sspr and GASI-03-01-03-03the National Natural Science Foundation of China under contract No.41506185the Special Funds for Basic Ocean Science Research of the First Institute of Oceanography,State Oceanic Administration of China under contract Nos 2013T04 and 2012T08
文摘Upwelling occurs on the coast of Java between June and October, forced by local alongshore winds associated with the southeasterly monsoon. This causes variations in phytoplankton community composition in the upwelling zone compared with the surrounding offshore area. Based on pigments analysis with subsequent calculations of group contributions to total chlorophyll a(Chl a) using CHEMTAX, we studied the distribution and composition of phytoplankton assemblages in the subsurface chlorophyll maximum along the south coast of Java and the influence of upwelling. Nineteen phytoplankton pigments were identified using high-performance liquid chromatography, and CHEMTAX analysis associated these to ten major phytoplankton groups. The phytoplankton community in the coastal area influenced by upwelling was characterized by high Chl a and fucoxanthin concentrations, indicating the dominance of diatoms. In contrast, in the offshore area, the Chl a and fucoxanthin concentrations declined to very low levels and the community was dominated by haptophytes represented by 19′-Hexanoyloxyfucoxanthin. Accordingly, microphytoplankton was found to be the major size class in the coastal area influenced by upwelling, while nanophytoplankton was most abundant in the offshore area. Low concentrations of other accessory pigments indicated less contribution from dinoflagellates,prasinophytes, chlorophytes and cryptophytes. Photo-pigment indices revealed that photosynthetic carotenoids(PSCs) were the largest component of the pigment pool, exceeding the proportion of Chl a, with the average PSCTP up to 0.62. These distribution trends can mainly be explained by phytoplankton adaption strategies to upwelling and subsurface conditions by changing species composition and adjusting the pigment pool.
文摘根据1986年1月至1990年7月热带西太平洋海域(10°30′S～18°20′N、122°24′～165°00′E)中美海气联合调查(TOGA 调查)的第2、3、6、8航次资料,研究了热带西太平洋叶绿素 a 的时空分布.研究表明,4个航次叶绿素 a 总平均值为0.199 mg/m^3,实测资料变化范围为:未检出值～3.432 mg/m^3.水平分布不均匀,在海岛附近有叶绿素 a 高值区,而其它海域则较低.叶绿素 a 的垂直分布多数测站呈单峰曲线型,但也有个别测站呈双峰型,最大值多数测站出现在100m 水层,其次是75m 水层,最深可达到250m 水层.叶绿素 a 最大值出现在次表层,位于温跃层上界.4个航次叶绿素 a 的含量的大小顺序分别为第2航次(0.200)>第6航次(0.104)>第8航次(0.089)>第3航次(0.084),反映了不同调查时间叶绿素 a 的含量是有差异的.
