- 學位論文
台灣北部近岸地區小型浮游動物群聚組成、時間變異及其對浮游植物攝食之影響
Mesozooplankton community structure、temporal variation as well as grazing impact on phytoplankton in the coastal sea of northern Taiwan
摘要
本研究在2001年11月到2004年5月期間，於台灣北部核能二廠入水口站進行週採樣。結果顯示，溫度（17.7-29.9℃）、葉綠素a （0.14-2.02 μgChl l-1）、初級生產力（<0.1-142 mgC m-3 d-1）與浮游動物豐度（63-34,881 ind. m-3），皆有相似的季節性趨勢：暖季（5-10月）較高、冷季（11-4月）較低。統計結果顯示，溫度、葉綠素a與初級生產力間皆有顯著正相關。浮游動物的季節變化和葉綠素a的時間分佈彼此間約有兩週的延滯現象，呈現典型的prey-predator關係。浮游動物的種類組成主要以橈足類為主，佔所有浮游動物的92 %；其中最優勢橈足類為哲水蚤，佔所有浮游動物的46%。浮游動物的總豐度在暖（902-34,881 ind. m-3）、冷季（63-3,366 ind. m-3）有顯著差異。暖季時，各浮游動物之豐度及浮游動物總豐度間皆沒有年間差異存在；而冷季時，除了猛水蚤外，其餘三種主要優勢橈足類群及浮游動物總豐度皆有顯著的年間變異。浮游動物個體攝食率（0.02-0.39 μgC ind.-1 d-1）與培養水樣中的葉綠素a濃度有顯著的正相關。而實驗室內的溫控實驗中發現，在相同葉綠素a濃度之狀況下，溫度提高5-10℃，個體攝食率可增加3-6倍。以個體攝食率與葉綠素a濃度間的迴歸公式（浮游動物個體攝食率＝-0.08+0.25×葉綠素a濃度）推算浮游動物群聚對浮游植物的攝食壓力，顯示暖季時最高每日可攝食63%（8.6 mgC m-3 d-1）的初級生產力。浮游動物群聚攝食初級生產力的百分比年平均值為5%（0.7 mgC m-3 d-1），較其他研究結果為低。原因推測與本研究區有高細菌生產力（細菌生產力為初級生產力的12倍）及顆粒態有機碳濃度（平均115 mgC m-3）有關，造成浮游動物對食物上有多方面的選擇性。
並列摘要
This study sampled at the water entrance of Taipower station weekly between 2001/11 to 2004/5. Variations in temperature（17.7-29.9℃）, chl-a（0.14-2.02 μgChl l-1）, primary production（0.01-141.7 mgC m-3 d-1）and zooplankton abundance（63-34881 ind. m-3）demonstrated a seasonal pattern with higher values recorded in warm season（May-Oct）and lower values in cold season（Nov-Apr）. Correlation analysis indicated that temperature, chl a and primary production was significantly correlated to each other. There are two weeks lag between total zooplankton abundance and chl-a concentration, and showed a prey-predator relationship. Throughout the study microzooplankton were dominated by copepods which comprised >92% of total zooplankton abundance；The most dominant species is calanoida which comprised 46% of total zooplankton abundance. There was a significantly difference on total zooplankton abundance between warm season（902-34881 ind. m-3）and cold season（63-3366 ind. m-3）. There was no annual variation on total zooplankton abundance in warm season. Except for Harpacticoida, there were annual variation on total zooplankton abundance and other three major copepod in cold season. Zooplankton specific grazing rate（0.02-0.39 μgC ind.-1 d-1）was significantly correlated to chl-a concentration. The temperature control experiments showed that in the same situation on chl-a, raise the temperature for 5-10℃ can enhance the specific grazing rate to 3-6 fold. Used the regression equation between zooplankton specific grazing rate and chl-a concentration（SGR＝-0.08+0.25×Chl-a）to estimate the zooplankton community grazing impact on phytoplankton showed the maximum grazing impact can consumed 63% of daily primary production（8.6 mgC m-3 d-1）in warm season. The mean value of zooplankton community grazing impact on primary production is 5%, lower than the value of other study area. Maybe the reason is: this study area has higher bacteria production（BP/PP=12）and POC concentration（mean=115 mg m-3）. Alternative carbon sources may be utilized.