Abundance of mesozooplankton during the long-tern mesozooplankton analysis in Sevastopol Bay from 1976 to 2003

The present dataset includes results of analysis of 227 zooplankton samples taken in and off the Sevastopol Bay in the Black Sea in 1976, 1979-1980, 1989-1990, 1995-1996 and 2002-2003. Exact coordinates for stations 1, 4, 5 and 6 are unknown and were calculated using Google-earth program. Data on Ctenophora Mnemiopsis leidyi and Beroe ovata are not included.
Juday net: Vertical tows of a Juday net, with mouth area 0.1 m**2, mesh size 150µm. Tows were performed at layers. Towing speed: about 0.5 m/s. Samples were preserved by a 4% formaldehyde sea water buffered solution. Sampling volume was estimated by multiplying the mouth area with the wire length.
The collected material was analysed using the method of portions (Yashnov, 1939). Samples were brought to volume of 50 - 100 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 1 ml of sample was taken by calibrated Stempel-pipette. This operation was produced twice. If divergence between two examined subsamples was more than 30% one more subsample was examined. Large (> 1 mm body length) and not abundant species were calculated in 1/2, 1/4, 1/8, 1/16 or 1/32 part of sample. Counting and measuring of organisms were made in the Bogorov chamber under the stereomicroscope to the lowest taxon possible. Number of organisms per sample was calculated as simple average of two subsamples meanings multiplied on subsample volume. Total abundance of mesozooplankton was calculated as sum of taxon-specific abundances and total abundance of Copepods was calculated as sum of copepods taxon-specific abundances.

本数据集包含1976年、1979-1980年、1989-1990年、1995-1996年及2002-2003年于黑海塞瓦斯托波尔湾内及周边海域采集的227份浮游动物样本的分析结果。其中1、4、5、6号站位的精确坐标未知，系通过谷歌地球（Google Earth）程序推算得到。本数据集未包含栉水母门（Ctenophora）的莱氏拟栉水母（Mnemiopsis leidyi）及卵形侧腕栉水母（Beroe ovata）的相关数据。

采样采用朱代网（Juday net）：垂直拖网作业，网口面积为0.1 m²，网目尺寸150μm。拖网于各水层开展，拖曳速度约0.5 m/s。样本采用4%甲醛缓冲海水溶液进行固定保存。采样体积通过网口面积与曳纲长度的乘积估算获得。

采集的浮游生物样本采用亚什诺夫（Yashnov）1939年提出的分样法进行分析。根据浮游动物密度将样本定容至50~100 ml，随后充分混匀以确保所有生物在样本中随机分布。使用校准后的施滕佩尔移液管（Stempel-pipette）移取1 ml子样本，该操作重复两次。若两次子样本的检测结果偏差超过30%，则需增加一次子样本检测。对于体长远大于1 mm且丰度较低的物种，需取样本的1/2、1/4、1/8、1/16或1/32进行计数。在体视显微镜下的博戈罗夫计数框（Bogorov chamber）中对生物进行计数与测量，尽可能鉴定至最低分类阶元。每份样本的生物数量计算方式为：两次子样本检测结果的算术平均值乘以子样本体积。中型浮游动物总丰度为各分类单元丰度之和，桡足类（Copepods）总丰度为各桡足类分类单元丰度之和。