长江口尖叶原甲藻赤潮消亡期叶绿素连续观测

Continuous observation of chlorophyll in Prorocentrum triestinum of the Changjiang (Yangtze River) Estuary in the red tide dying time.

通过对长江口赤潮发生水域水样叶绿素含量变化现场培养连续观测,发现2001年5月10日发生在长江口外羽状锋水域赤潮优势种为尖叶原甲藻(Prorocentrum triestinum Schiller),其爆发高峰时,细胞密度达到7.1×106~2.3×107个/m3.该赤潮种具有持续期短,消亡期更短的特点.其高浓度的叶绿素含量经历一个白昼后,在凌晨迅速减低,叶绿素的平均衰减率为Rt=9.76μg/(L·min),并由此证实赤潮藻体叶绿素已大量降解,失去了荧光活性.反映出在赤潮发生高峰时,由于水体营养盐和微营养盐被大量消耗,该赤潮种生长已面临巨大的环境压力,从而产生剧烈的生理反应,导致大量藻体快速消亡.

Through continuous observing the change of chlorophyll content in situ incubation of ride tide water sample occurred in the Changjiang (Yangtze River) Estuary, the results showed that on May 10, 2001 the superior species of this red tide was Prorocentrum triestinum, with the highest cell density of 7.1106~2.3107cells/m3 and the species possessed the characteristics of short occurring and very short dying time. Through a daytime, its high concentration of chlorophyll decreased quickly in the morning. An average attenuation rate of chlorophyll concentration was Rt=9.76mg/(Lmin), which proved that most of the algae chlorophyll were degraded and their chlorophylls lost fluorescent activity which reflected the red tide species had faced great environmental pressure at the peak of red tide due to consumption of large amount of water nutritious salt and micro-nutritious salt, thus producing severe physiological reaction causing rapid disappearance of large amount of algae.