Estimated plankton abundance at station PS63/064-6

Arbitrary density units (++++ = very abundant; + = least abundant). Extremely dense sample; too dense to be counted, sample taken from sea water supply via large volume...采用任意密度单位（Arbitrary density units），其中符号++++代表丰度极高，+代表丰度最低。本次采集的样品密度极高，因过于浓密无法完成计数；该样品通过大体积采样方式取自海水补给系统……