國立臺南大學 1 「環境與生態學報」第 2 卷第 2 期（民國 98 年）：1~26 Cyanobacterial Bio-indicator Survey for Two Main Rivers in Taitung Taiwan Chia–Lien Lee Lu-Ye Township Public Health Center Yen Lee Life Science Institute, National Taitung University Abstract Monitoring and controlling river water quality have become key issues in industrialized countries. Application of cyanobacteria diversity could make up for the shortage of diatom bio-indicator in monitoring of river water quality. This study was to monitor cyanobacterial genus abundance and diversity in two major rivers (Beinan and Taiping river) in Taitung county, expect to find the relationship between levels of water pollution and cyanobacterial bio-indicators. Chroococcales was found to be the most numerous and species richest cyanobacteria in both rivers, which were either dominant in proportion or quantity from upstream (unpolluted) to downstream (polluted) area. The ecological distribution of cyanobacteria in Taitung county main rivers were different from research results of other countries (Nostocales dominated in polluted basin and Oscillatoriales dominated in unpolluted basin). Negative correlation was found between WQI (Water Quality Index) with relative abundance of Microcystis sp. and Stanieria sp.; On the other hand, positive correlation was found between WQI and relative abundance of Dermocarpella sp.. Results of regression analysis showed the combination of relative abundance of Microcystis sp., Stanieria sp. and Dermocarpella sp. might be an appropriate bio-indicator for river water quality monitoring. Key words: Cyanobacteria, Bio-indicator, Taitung county, Beinan river, Taiping river, 2 環境與生態學報 Introduction Monitoring and controlling river water quality have become key issues in industrialized countries since 1970s. USA adapted Federal Water Pollution Control Act(FWPCA) in 1972； EU(European Union) approved Surface Water Directive and Water Frame Directive in1975 as well as 2000 separately；Taiwan Legislative Yuan passed Water Pollution Prevention Act in 1974. At present, for monitoring river water quality, most countries still emphasize on physiochemical methods (temperature, pH, amount of dissolved oxygen, suspended solid, total phosphorus, total nitrogen, etc.). However, recent years biological findings pointed out the analysis of physical and chemical factors are unable to appraise the pollutant regarding ecosystem's cumulative effects （Watanabe, 1986, 1988, 1990, 1992; Whitton, 1991, 1995; Asai, 1995; Parikh, 2006）. Some bio-indicators were introduced as long-term indices supplement to short-term physiochemical indices in the task of river water quality monitoring after execution of Water Frame Directive in EU (phytoplanktons, river benthonic organisms, non-vertebrates, fish, etc.) (Liang et al., 2002). In monitoring long-term water quality changing condition, three major algae population of river system (phytoplanktons, cyanobacteria, and diatoms) were chosen for their dominant, fast growth, easily to collect and preserve, sensitive to environmental and ecological changes (such as small-scale, low polluted river water quality and nutrient changes)（Skulberg, 1995；Whitton and Kelly, 1995; Rosemond, 2000; Rott et al., 2003；Parikh, 2006）. In the past, mainly benthic algae, whether in the suitable situation, the floating algae (phytoplanktons) were applied in some large-scale river’s ecology monitor (Ziglio et al., 2006). Diatoms were the most widely applied benthic algae, and its merit already received the large affirmative (McCormick and Cairns, 1994; Reid et al., 1995; Stevenson and Pen, 2003). For water surveillance only needs to identify the collected diatoms to its genus names (Wu, 1999; Kelly, 1998; Hurlimann and Niederhauser, 2002). Many biological indicators were established upon the diversity of diatoms or species uniformity (eveness), and community composition. Such as; GDI (general diatom index), DAI (diatom assemblage index for organic pollution), GI (generic index of diatoms), IBD (indice biologique diatomique), TDI (trophic diatom index) etc.（Dokulil et al., 1997; Kwandrans et al., 1998; Montesanto et al., 1999; Eloranta and Soininen, 2002）. These systems demonstrated river benthic diatoms in water surveillance was already a mature biological indicator. As for the floating algae, they belong to main food web in rivers. They hold important status in ecology, the same with other algae, they have very high sensitivity to contaminating materials. However the rivers or brooks Cyanobacterial Bio-indicator Survey for Two Main Rivers in Taitung Taiwan 3 belong to lotic system, causes it difficult to collect floating algae. Meanwhile floating algae need massive samples in application, hence increases the cost of water surveillance (Kohler and Descy, 2003). Therefore their application in the water surveillance is rare (Friedrich et al., 1998; Ibelings et al., 1998). The related research literature is also scare (Mercado, 2003; Gao, 2005). Therefore researches limited mostly to either sampling chlorophyll a concentration or algal group density (cell number or colony number), and lacks the algal community identification (Kelly and Whitton, 1998; Ziglio et al., 2006). On the other hand, the distribution of floating algae was commonly used as the ecologyical and biological indicators for the lentic lakes or reservoirs, and relevance to the water quality, therefore have many research literatures (Voros and Padisak, 1991; Lo and Tsai, 1992; Wu, 1993; Michael and Paerl., 1994; Chang et al., 1995). The diatom, green alga, as well as cyanobacteria composed the three major groups of river algae. The water quality or the nutrient change will affect algae ecological distribution (Kelly and Whitton, 1998). However, cyanbobacteria didn’t popularly recognized as the biological indicator. In fact the cyanobacterial relative richness has high relationship to river water temperature and flow rate in small rivers compared to other algae (Kelly and Whitton, 1998). Scholars also discovered similar cyanobacterial IBD (indice biologique diatomique) in Spain (Aboal et al., 2002). They found, in non man made pollution or low pollution river, diatom biological indices were usually lower than the expected value (because of the cyanotoxic effect). This result showed that the diatom biological indicator really has its deficiency. Perhaps the diatom and the cyanobacteria can cooperating the insufficiency (Douterelo et al., 2004). Taiwan rivers are opposite to other country river systems, they are small rivers. In the past, the reservoir biological indicator researches were done primarily by using floating algae (Zhuang, et al., 1986, 1986, 1987, 1988; Lai, 1997; Wu, 1984, 1993). Recent years, very few river water biological indicator surveillance were done (Wu, 1986; 2002; Guo et al.,1990; Yu et al., 1995; Lai et al.,1997). Lee (1994) did the biological indicator investigation for Chipen river in Taitung. After that, no references could be found related to east Taiwan river water biological indicator. Our purpose of study was to: (1) Investigate ecological distribution and community composition of cyanobacteria within two major rivers (Beinan and Taiping river) in Taitung county. (2) Monitor river water quality and find the relationship between level of water pollution based on genus abundance and bio-diversity. 4 環境與生態學報 Materials and Methods Sampling sites： Beinan river has 84.35km, it is the longest river in Taitung county(fig. 1, and 2). Rice, corn, pineapple, cane, custard apple, and tea are major crops along the river side. Chulai Bridge (B1): an undeveloped area in Haiduan-a township with very low population density, located at upstream of Beinan river. Dien-Kwung Bridge (B2): located at mid-upstream of Beinan river in Guanshan-a township with approximately 10,000 residents and mainly agricultural area. Luming Bridge (B3): located at mid-downstream of Beinan river in Luye-a township with approximately 9,000 residents and mainly agricultural area. Taitung Bridge (B4): located at downstream of Beinan river, near the mouth to Pacific Ocean and Taitung city-metropolis of Taitung county with approximately 110,000 residents and mainly commercial and service business area. Taiping river has 20.05km, it is the only rather polluted river in Taitung county, flow through Taitung city. Rice, pineapple, and custard apple are major crops along the river side. Taiping Bridge (T1): located at mid-upstream of Taiping river in Beinan township, an agricultural area with very few residents. Malan Bridge (T2): located at the border between Beinan township and Taitung city, midstream of Taiping river and mainly agricultural area. Fon-Li Bridge (T3): downstream and at the mouth of Taiping river to Pacific Ocean, located at seashore of Taitung city. The longitudes, latitudes of sampling sites and site distance from the previous sampling site were listed in table1. Sampling time: From March 2005 to April 2006. Sampling method: When collecting water samples, we waded into the sampling site about 0.5-1meter from the river bank. Water samples were collected in 15 mL conical centrifuge tubes and wrapped with a piece of foil paper and kept in an ice bucket. Samples were processed within 4hrs of sampling. One hundred μl river water were spreaded on each C-10 plate. At last, the two plates were used for each sample. Plates wrapped with parafilm and were incubated in a photosynthesis incubator for 4 weeks Cyanobacterial Bio-indicator Survey for Two Main Rivers in Taitung Taiwan 5 at 25oC 1200 Lux. Colonies were picked