Mesozooplankton and phytoplankton time series of the Baltic Monitoring Program (BMP)

Within the monitoring programme of the Helsinki Commission (HELCOM) the mesozooplankton of the Bornholm Basin (ICES subdivision 25, station BMP-K2) was sampled by the WP-2 net (lOOfJm) 5-8 times a year in 1988-1992. Abundance, biomass, secondary production and productivity (P/B) were given for mesozooplankton groups and copepod species. Environmental factors recorded were temperature, chlorophyll a and primary production.
Within copepods, the dominant species were Temora longicornis and Pseudocalanus minutus with yearly peak values of 40-50% of the monthly copepod numbers and biomasses. The annual production of Temora longicornis was highest (6.5g C/m**2/y). The biomass of all copepods was at its maximum in June (mean = 2.25g C/m**2), especially in 1992 (3.65g C/m**2). The differences between results from two methods used to calculate the production of copepods were greatest in June and July. The cladocerans were only important in summer and the appendicularians only in spring. The productivity (P/B) of the appendicularians was highest of all mesozooplankton groups. Numbers and the biomass of the meroplankton were one or two orders of magnitude below the holoplanktic groups.

在赫尔辛基委员会（HELCOM）的监测计划框架内，研究人员于1988-1992年间，每年采用WP-2浮游生物网（孔径100μm）对博恩霍尔姆湾（ICES区划25，站位BMP-K2）的中型浮游动物（mesozooplankton）开展采样，年均采样5至8次。本数据集记录了中型浮游动物类群及桡足类（copepod）物种的丰度、生物量、次级生产力与生产力比值（P/B）。同步监测的环境因子包括水温、叶绿素a浓度与初级生产力。
桡足类的优势物种为长角捷氏水蚤（Temora longicornis）和微小纺锤水蚤（Pseudocalanus minutus），二者在桡足类月种群数量和生物量中的占比年度峰值可达40%~50%。长角捷氏水蚤的年次级生产力最高，达6.5g C/m²·y。所有桡足类的生物量峰值均出现在6月（均值为2.25g C/m²），其中1992年的峰值最高（3.65g C/m²）。两种用于计算桡足类生产力的方法所得结果的差异在6月和7月最为显著。枝角类浮游动物（cladocerans）仅在夏季具有生态重要性，而尾海鞘类（appendicularians）仅在春季较为关键。尾海鞘类的生产力比值（P/B）在所有中型浮游动物类群中位居首位。阶段性浮游生物（meroplankton）的数量与生物量较终生浮游类群低1至2个数量级。