Pigment sampling in the coastal waters of south eastern Tasmania

Water samples for the analysis of pigments using High Performance Liquid Chromatography (HPLC) were collected only in the first 12 months of the sampling program. Pigment analysis is used to estimate algal community composition and concentration. Pigments which relate specifically to an algal class are termed marker or diagnostic pigments. Some of these diagnostic pigments are found exclusively in one algal class (e.g. prasinoxanthin in prasinophytes), while others are the principal pigments of one class, but are also found in other classes (e.g. fucoxanthin in diatoms and some haptophytes; 19′-butanoyloxyfucoxanthin in chrysophytes and some haptophytes). The presence or absence of these diagnostic pigments can provide a simple guide to the composition of a phytoplankton community, including identifying classes of small flagellates that cannot be determined by light microscopy techniques. There was general similarity in pigment composition between all sites, with a presence of diatoms (as indicated by fucoxanthin), haptophytes (hex-fucoxanthin), prasinophytes (prasinoxanthan), cryptophytes (alloxanthan), cyanophytes (zeaxanthan) and green algae (chl-b) in nearly all monthly samples at all sites. The green algae could be in the form of euglenophytes or prasinophytes; the absence of the pigment lutein in all samples indicates that chlorophytes are not present in Storm Bay, at least at the sites sampled.

本采样计划仅在开展的前12个月内，采集了用于高效液相色谱法（High Performance Liquid Chromatography，HPLC）分析的水样。色素分析可用于估算藻类群落的组成与生物量浓度。与特定藻类门类特异性相关的色素被称为标记色素或诊断色素（diagnostic pigments）。部分诊断色素仅存在于单一藻类门类中（如普拉西黄质（prasinoxanthin）仅见于青藻（prasinophytes））；另有部分诊断色素虽为某一门类的主要色素，但也可在其他门类中检出，例如岩藻黄质（fucoxanthin）可见于硅藻（diatoms）及部分定鞭金藻（haptophytes），19′-丁酰氧基岩藻黄质（19′-butanoyloxyfucoxanthin）可见于金藻（chrysophytes）及部分定鞭金藻。这类诊断色素的有无可为浮游植物群落组成提供简易判定依据，还可用于识别无法通过光学显微镜技术检测的小型鞭毛藻类门类。所有采样点的色素组成整体相似，几乎所有站点的月度样本中均检出硅藻（以岩藻黄质为指示标记）、定鞭金藻（以己酰基岩藻黄质（hex-fucoxanthin）为指示标记）、青藻（普拉西黄质）、隐藻（别藻黄质（alloxanthin））、蓝藻（玉米黄质（zeaxanthin））及绿藻（叶绿素b（chl-b））。此处检出的绿藻可涵盖裸藻（euglenophytes）或青藻门类；所有样本均未检出叶黄素（lutein），表明风暴湾（Storm Bay）内未存在绿藻门（chlorophytes），至少在所采样的站点中如此。