Division of Environment, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
Mar Pollut Bull. 2010 Jul;60(7):1005-9. doi: 10.1016/j.marpolbul.2010.02.001. Epub 2010 Mar 1.
Fecal pellet production rate and oxygen consumption rate of copepod fecal pellets egested by Paracalanus sp., Acartia spinicauda and Centropages orsinii feeding on a diatom Thalassiosira pseudonana were measured. Fecal pellet production rates varied between 3.6 and 80.6 pellets ind(-1)d(-1) among three species, with fecal pellet production of Paracalanus sp. significantly higher than the other two copepod species. Average pellet size varied between 2.82x10(5)microm(3) for Paracalanus sp. and 5.36x10(5)microm(3) for A. spinicauda. Average volumetric oxygen consumption rates were 27.32, 5.84 and 45 fmol O(2) microm(-3)d(-1) for fecal pellets produced by Paracalanus sp., A. spinicauda and C. orsinii, respectively. The potential oxygen consumption of fecal pellets egested from Paracalanus sp. was the highest due to its high fecal pellet production rate and high population abundance throughout the year. Overall, the approximate in situ oxygen consumption due to copepod fecal pellet degradation was significant in estuarine and coastal waters of Hong Kong. Results of this study give insight of the role of zooplankton in potential occurrence of hypoxia in coastal waters during summer.
测定了 Paracalanus sp.、Acartia spinicauda 和 Centropages orsinii 摄食硅藻 Thalassiosira pseudonana 时排出的桡足类粪便颗粒的生产速率和耗氧率。三种桡足类的粪便颗粒生产速率在 3.6 到 80.6 个颗粒 ind(-1)d(-1)之间变化，Paracalanus sp.的粪便颗粒生产速率明显高于其他两种桡足类。Paracalanus sp.的平均颗粒大小为 2.82x10(5)μm(3)，A. spinicauda 的平均颗粒大小为 5.36x10(5)μm(3)。Paracalanus sp.、A. spinicauda 和 C. orsinii 产生的粪便颗粒的平均体积耗氧率分别为 27.32、5.84 和 45 fmol O(2) μm(-3)d(-1)。由于 Paracalanus sp.的粪便颗粒生产速率高且全年种群丰度高，其排出的粪便颗粒的潜在耗氧量最高。总的来说，由于桡足类粪便颗粒降解，香港港湾和沿海水域的 Copepod fecal pellet degradation 导致的潜在耗氧量是显著的。本研究的结果为夏季沿海水域潜在缺氧的浮游动物作用提供了深入的了解。
