| Title |
Evaluation of Organic Matter Sources of Phytoplankton in Paldang Reservoir using Stable Isotope Analysis |
| Authors |
김종민 ( Jong Min Kim ) ; 김보경 ( Bo Kyong Kim ) ; 김민섭 ( Min Seob Kim ) ; 신기식 ( Ki Sik Shin ) |
| DOI |
https://doi.org/10.15681/KSWE.2015.31.2.159 |
| Keywords |
CN ratio; δ15N; δ13C; organic matter sources; phytoplankton |
| Abstract |
The organic matter sources of phytoplankton and related environmental factors influencing algal bloom in Paldang reservoir were studied using nitrogen and carbon isotope ratio(δ15N, δ13C). Phytoplankton samples for stable isotope analysis were collected from four points in reservoir using a plankton net. Physicochemical water quality, algal taxa and hydrological data were collected from published monitoring material. Phytoplankton samples were analyzed by IRMS. CN ratio of each sample was very similar to that of phytoplankton from literature cited. δ15N of each sample was decreased during July. Mixing and dilution of nitrogen sources due to increment of influx by concentrated rainfall were considered as the main reason for the decline of δ15N. Based on analyzed δ15N value of each sample, nitrogen source of Bughan river sample was presumed to come from soil. The nitrogen sources of Namhan river and Kyeongan stream samples seemed to be sewage or animal waste. Low δ15N value in August (2012) seemed to be influenced by isotope fractionation due to the blooming of nitrogen-fixation blue-green algae (Anabaena spp.). Variation in δ15N values particularly by blue-green algal bloom was considered the important factor for estimating the organic matter sources of phytoplankton. |