Palmisano A C, Wharton R A, Cronin S E, Des Marais D J
National Aeronautics and Space Administration, Ames Research Center, Moffett Field, California 94035, USA.
Hydrobiologia. 1989;178:73-80. doi: 10.1007/BF00006114.
The benthos of a perennially ice-covered Antarctic lake, Lake Hoare, contained three distinct 'signatures' of lipophilic pigments. Cyanobacterial mats found in the moat at the periphery of the lake were dominated by the carotenoid myxoxanthophyll; carotenoids: chlorophyll a ratios in this high light environment ranged from 3 to 6.8. Chlorophyll c and fucoxanthin, pigments typical of golden-brown algae, were found at 10 to 20 m depths where the benthos is aerobic. Anaerobic benthic sediments at 20 to 30 m depths were characterized by a third pigment signature dominated by a carotenoid, tentatively identified as alloxanthin from planktonic cryptomonads, and by phaeophytin b from senescent green algae. Pigments were not found associated with alternating organic and sediment layers. As microzooplankton grazers are absent from this closed system and transformation rates are reduced at low temperatures, the benthos beneath the lake ice appears to contain a record of past phytoplankton blooms undergoing decay.
常年被冰覆盖的南极湖泊——霍尔湖的底栖生物含有三种不同的亲脂性色素“特征”。在湖周边护城河区域发现的蓝藻席以类胡萝卜素粘球藻黄素为主；在这种高光环境下，类胡萝卜素与叶绿素a的比例在3至6.8之间。叶绿素c和岩藻黄素是金褐色藻类的典型色素，在底栖生物为需氧环境的10至20米深处被发现。在20至30米深处的厌氧底栖沉积物的特征是第三种色素特征，主要由一种类胡萝卜素主导，初步鉴定为来自浮游隐藻的别藻黄素，以及来自衰老绿藻的脱镁叶绿素b。未发现色素与交替的有机层和沉积层相关。由于这个封闭系统中没有微型浮游动物食草动物，且在低温下转化率降低，湖冰下的底栖生物似乎包含了过去正在腐烂的浮游植物大量繁殖的记录。
