Zooplankton in lakes and fiords along the northern coastline of Ellesmere Island (Ward Hunt Island observatory)

Zooplankton was sampled from Lake A on 8 June 1999 and Disraeli Fiord on 9 June 1999. At Lake A, a hole was cut through the ice and was kept open for 3 days before zooplankton sampling. A 1-m-long conical plankton net mesh size 100 μm; mouth diameter 20 cm) was used to sample the zooplankton. Duplicate net tows were made sequentially at the following depths: 2.5, 5, 7.5, 10, 12.5, 15, 17.5, 20, 25, and 30 m. The net was towed by hand vertically at approximately 1 m/s from a given depth to the surface. In Disraeli Fiord, logistical constraints allowed us only a single tow from the brackish-water layer, from 30 m to the surface. All samples were preserved with final concentrations of 0.2% glutaraldehyde and 0.02% formaldehyde, a preservative used for phytoplankton studies but which gave very good preservation of zooplankton. The specimens were identified and enumerated using a binocular microscope (X32 magnification). At Milne Fiord, two zooplankton vertical tows (14-0 m then 50-0 m, through the same hole) were made on 4 July 2009 with a 39-cm-long net with a 210-um mesh size and diameter of 13 cm. The zooplankton samples were preserved with formaldehyde (final concentration 10%), and all individuals were then counted and identified to species level using a binocular microscope.

本数据集的浮游动物（zooplankton）样本分别于1999年6月8日在A湖、1999年6月9日在迪斯雷利峡湾（Disraeli Fiord）采集。在A湖采样前，先于冰面凿开一处孔洞并维持开放状态3天，随后开展浮游动物采样。采用长1米的锥形浮游生物网（网孔孔径100 μm，网口直径20 cm）采集浮游动物样本，依次在2.5、5、7.5、10、12.5、15、17.5、20、25及30米深度进行两次平行拖网采样。拖网采用人工方式以约1 m/s的速度沿垂直方向从指定深度拖行至水面。
在迪斯雷利峡湾，受后勤条件限制，仅能从咸淡水层开展一次从30米至水面的垂直拖网采样。所有样本均采用终浓度为0.2%戊二醛与0.02%甲醛的混合固定液进行保存；该固定液虽常用于浮游植物（phytoplankton）研究，但对浮游动物的固定效果极佳。使用放大倍数为32倍的双目显微镜对样本进行物种鉴定与个体计数。
2009年7月4日，在米尔恩峡湾（Milne Fiord）通过同一冰孔开展两次浮游动物垂直拖网采样，分别为14米至水面、50米至水面；所用采样网长39 cm，网孔孔径210 μm，网口直径13 cm。该批次浮游动物样本采用终浓度为10%的甲醛溶液固定，随后通过双目显微镜完成全部个体的计数与物种水平鉴定。