Effects of Nutrient and Temperature on Macroalgal Biomass at Nanwan Bay (Kenting, Taiwan, Republic of China)

• Main Authors: Chuan-Chuan Tsai, 蔡娟娟
• Other Authors: Tse-Min Lee
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/21355536541295377788

碩士 === 國立中山大學 === 海洋生物研究所 === 89 === Temporary changes in macroalgal abundance, percentage cover and areal biomass were surveyed on Nanwan (GPS: 21o56'00'N; 120o50'10'E) and Tiaoshi (GPS: 21o55'30'N; 120o 50'40'E) reefs (Kenting, Taiwan, Republic of China), during 1999-2000. Community structure and areal biomass showed significant changes in time and the maximal biomass was observed during March-April due to Sargassum spp. at Nanwan and Codium spp. at Tiaoshi. The maximal total areal biomass is not different between two years for Nanwan but significantly different for Tiaoshi mainly due to a marked biomass of Codium edule during 2000. Eutrophication on Nanwan and Tiaoshi reefs is the main cause for macroalgal blooming. Tissue composition analysis, nutrient enrichment and starvation treatments, bioassay and in situ extracellular alkaline phosphatase activity determination showed that growth of Sargassum duplicatum, Codium edule and Ulva latuca were limited by phosphorus during the early growth period while nitrogen during the fast growth period. Growth of Enteromorpha linza, Gracilaria coronopifolia and Laurencia papillosa were limited by phosphorus. Water temperature is the factor affecting the time for the start of development of young shoots and also for the peak of areal biomass and subsequent die-off of thallus. This investigation suggests that the reduction of water nutrient levels is an effective way in the retardation of over-growth of macroalgae on Nanwan and Tiaoshi reefs.