Abundance of mesozooplankton in the western part of the Black Sea in summer 2001 during the National Monitoring Programme of the Bulgarian Institute of Oceanography

The dataset is based on samples collected in the summer of 2001 in the Western Black Sea in front of Bulgaria coast (transects at c. Kaliakra and c. Galata). The whole dataset is composed of 26 samples (from 10 stations of National Monitoring Grid) with data of mesozooplankton species composition abundance and biomass. Samples were collected in discrete layers 0-10, 10-20, 10-25, 25-50, 50-75, 75-90. Zooplankton samples were collected with vertical closing Juday net,diameter - 36cm, mesh size 150 µm. Tows were performed from surface down to bottom meters depths in discrete layers. Samples were preserved by a 4% formaldehyde sea water buffered solution. Sampling volume was estimated by multiplying the mouth area with the wire length. Mesozooplankton abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska and Kremena Stefanova using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972). Taxon-specific abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Copepods and Cladoceras were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska and Kremena Stefanova using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972).本数据集基于2001年夏季在保加利亚沿岸外的西黑海海域（约卡利亚克拉（Kaliakra）和加拉塔（Galata）断面）采集的样本构建。整个数据集包含来自国家监测网格10个站位的26份样本，涵盖中型浮游动物（mesozooplankton）的物种组成、丰度与生物量数据。样本采集于0-10、10-20、10-25、25-50、50-75、75-90米的离散水层。 浮游动物样本采用垂直闭锁式Juday网（Juday net）采集，该网直径36厘米，网孔尺寸150微米。拖网作业从表层至海底的离散水层分层开展。样本使用4%甲醛海水缓冲溶液进行固定保存。采样体积通过网口面积与拖网绳长的乘积估算得到。 中型浮游动物丰度分析：采集的样品采用Domov（1959）方法进行前处理与分析。根据浮游动物密度将样品定容至25-30毫升，并充分混匀直至所有生物在样液中随机均匀分布。随后取5毫升样品注入矩形计数室，用于分类鉴定与个体计数。体型大于1毫米且丰度较低的物种以全样进行计数。生物的计数与形态测量在实体显微镜下的Dimov计数室（Dimov chamber）内进行，尽可能鉴定至最低分类阶元。分类鉴定工作由海洋学研究所（Institute of Oceanology）的Lyudmila Kamburska与Kremena Stefanova完成，参考了相关分类学专著（Mordukhay-Boltovskoy, F.D.（主编）. 1968, 1969, 1972）。 类群特异性丰度分析：采集的样品同样采用Domov（1959）方法进行前处理与分析。根据浮游动物密度将样品定容至25-30毫升，并充分混匀直至所有生物在样液中随机均匀分布。随后取5毫升样品注入矩形计数室，用于分类鉴定与个体计数。其中桡足类（Copepods）与枝角类（Cladoceras）鉴定并计数至物种水平，其余中型浮游动物鉴定并计数至较高分类阶元（通常称为中型浮游动物类群）。体型大于1毫米且丰度较低的物种以全样进行计数。生物的计数与形态测量在实体显微镜下的Dimov计数室内进行，尽可能鉴定至最低分类阶元。分类鉴定工作由海洋学研究所（Institute of Oceanology）的Lyudmila Kamburska与Kremena Stefanova完成，参考了相关分类学专著（Mordukhay-Boltovskoy, F.D.（主编）. 1968, 1969, 1972）。