Effects of the copepod community structure on fecal pellet flux in Kagoshima bay, a deep, semi-enclosed embayment
- 133 Downloads
Seasonal changes in the shape and size composition of fecal pellets were investigated with sediment trap samples from 50 and 150 m in Kagoshima Bay to evaluate how the mesozooplankton community affects fecal pellet flux. Deep vertical mixing was evident in March, and thermal stratification was developed above 50 m in June, August and November. Chlorophyll a, suspended particulate organic carbon (POC) and copepod abundance were uniform throughout the water column during the seasonal mixing and concentrated above 50 m in the stratified seasons. Calanoids were the most predominant copepods in March and poecilostomatoids composed more than 45% of the copepod community in June, August and November. Fecal pellet fluxes at 50 and 150 m were the highest in March, nearly half of POC flux. The relative contribution declined considerably in the other months, especially for less than 4% of POC flux in August. The decline was corresponded to the predominance of cyclopoids and poecilostomatoids. Cylindrical pellets dominated the fecal matters at both depths throughout the study period, while larger cylindrical pellets nearly disappeared at 150 m in June, August and November. Copepod incubation revealed that cylindrical and oval pellets were egested by calanoids and the other copepods, respectively. We suggest that cylindrical fecal pellets produced by calanoid copepods contribute to feces flux but the predominance of poecilostomatoids and/or cyclopoids decreases feces flux via the increase of oval pellets and fragmentation of larger cylindrical pellets.
KeywordsParticulate organic carbon flux fecal pellet shape size copepods Kagoshima Bay
Unable to display preview. Download preview PDF.
- Chihara, M. and M. Murano (1997): An Illustrated Guide to Marine Plankton in Japan. Tokai Univ. Press, Tokyo, 1574 pp.Google Scholar
- Honjo, S. and M. R. Roman (1978): Marine copepod fecal pellets: production, preservation and sedimentation. J. Mar. Res., 36, 45–57.Google Scholar
- Ichikawa, T., N. Honda and K. Matsunaga (1999): Marine snow in Kagoshima Bay. Bull. Mar. Biomed. Inst., Sapporo Med. Univ., 4, 37–42.Google Scholar
- Kobari, T., A. Habano and T. Ichikawa (2002): Seasonal variations in phyto- and zooplankton biomass in Kagoshima Bay. Mem. Fac. Fish., Kagoshima Univ., 51, 19–25.Google Scholar
- Kobari, T., Y. Kobari, T. Ichikawa, Y. Kugita, T. Yoshida, T. Fujii, S. Furuhashi, T. Yamamoto, A. Habano and R. Fukuda (2009): Seasonal dynamics of microbial plankton community in Kagoshima Bay. Aquabiology, 31, 37–44 (in Japanese with English abstract).Google Scholar
- Martens, P. (1978): Faecal pellets. Fich. Ident. Zooplancton, 162, 1–4.Google Scholar
- Motoda, S. (1957): North Pacific standard plankton net. Inform. Bull. Plankt. Japan, 4, 13–15.Google Scholar
- Nozawa, K. and T. Saisyo (1980): Plankton in Kagoshima Bay. Kaiyo Monthly, 12, 654–672 (in Japanese).Google Scholar
- Paffenhöfer, G.-A. and S. A. Knowles (1979): Ecological implications of fecal pellet size, production and consumption by copepods. J. Mar. Res., 37, 35–49.Google Scholar
- Terazaki, M. and C. Tomatsu (1998): A vertical multiple opening and closing plankton sampler. J. Adv. Mar. Sci. Tech. Soc., 3, 127–132.Google Scholar