Copepod abundance and fecal pellet production, sinking rate, and degradation in samples obtained during Leg 7 of Galathea 3 cruise 2006

The vertical distribution of copepods, fecal pellets and the fecal pellet production of copepods were measured at seven stations across the Southern Indian Ocean from productive areas off South Africa to oligotrophic waters off Northern Australia during October/November 2006. We quantified export of copepod fecal pellet from surface waters and how much was retained. Furthermore, the potential impact of Oncaea spp. and harpacticoid copepods on fecal pellets degradation was evaluated and found to be regional substantial. The highest copepod abundance and fecal pellet production was found in the western nutrient-rich stations close to South Africa and the lowest at the central oligotrophic stations. The in situ copepod fecal pellet production varied between 1 and 1,000 µg C/m**3/day. At all stations, the retention of fecal pellets in the upper 400 m of the water column was more than 99% and the vertical export of fecal pellets was low (<0.02 mg/m**2/day).

2006年10—11月，研究团队于南印度洋横跨7个站位开展野外调查，站位覆盖范围从南非近海的高生产力海域延伸至澳大利亚北部近海的寡营养海域，测定了桡足类（Copepods）、粪粒（fecal pellets）以及桡足类粪粒生产的垂直分布特征。本研究量化了桡足类粪粒从表层水体的输出通量及其留存比例；此外，评估了隆剑水蚤属（Oncaea spp.）与猛水蚤类桡足类（harpacticoid copepods）对粪粒降解的潜在影响，发现该影响存在显著的区域差异。桡足类丰度与粪粒生产速率的最高值出现在邻近南非的西部富营养站位，最低值则见于中部寡营养站位。原位桡足类粪粒生产速率介于1~1000 μg C/(m³·d)之间。所有站位的水柱上层400米内粪粒留存率均超过99%，粪粒垂直输出通量极低（<0.02 mg/(m²·d)）。