한국 송지천에서 저서성대형무척추동물의 종조성과 이를 이용한 수질 평가

Species Composition of Benthic Macroinvertebrates and Water Evaluation Using Their Species in the Songji River in Korea

Abstract

저서성대형무척추동물은 수질 평가를 위해 다년간 이용되었다. 본 연구는 한국 송지천에서 저서성대형무척추동물을 이용하여 이 하천의 수질을 평가하고자 수행되었다. 동정된 동물은 3문 5강 12목 18과 20종 447개체였다. 집모기류(Culicini sp.)가 가장 우점종이었고(203개체), 두번째 우점종은 집파리(Musca do­mestica)였다. 다양한 생태학적 척도로 수질의 상태를 평가하였다. 전체 생태 점수(total ecological score of benthic macroinvertebrate community, TESB)은 17(St. D)에서 41(St. A)으로 평균은 29였다. St. A에서 부수성 지수와 저서성 대형무척추동물생태 점수(ESB)는 II 등급으로 빈부수성, 수질은 약간 만족이며 보호가 요청되는 수질에 해당되었다. 저서성동물지수(benthic macroinvertebrate index, BMI)은 25.207(St. C)에서 39.348(St. A)까지 이며 평균은 31.810였다. St. C와 St. D의 하천 상태 평가는 강부수성이며 민감종이 결여되어 있었다. 다양도를 나타내는 Shannon-Weaver index (H')는 1.288(St. D)에서 2.250(St. A)였다. H'에 근거한 부수성 정도는 St. A에서는 ${\beta}$-중부수성이었으며 나머지 지점은 ${\alpha}$-중부수성이었다. 지리적 밀도는 1.229(St. A)에서 2.071(St. D)으로 평균은 1.582였다. 송지천에서 사용한 무척추동물을 이용한 여러 수질의 척도는 한국 내 다른 하천에서도 적용할 수 있을 것이다.

Benthic macroinvertebrates were analyzed in March, June, September, and December 2018 to evaluate water quality in the Songji River in Sacheon-ci, Korea. The identified benthic macroinvertebrates included 447 individuals belonging to 20 species, 18 families, 12 orders, 5 classes, and 3 phyla. Various ecological parameters were estimated for evaluation of the river status. The total ecological score of benthic macroinvertebrate community (TESB) varied from 17 (Station D) to 41 (Station A). The saprobic index and ecological score of benthic macroinvertebrate community (ESB) for the evaluation of river status revealed a water quality evaluation at Station A of II (oligosaprobic), indicating some satisfactory water protection. The benthic macroinvertebrate index (BMI) varied from 25.207 (Site C) to 39.348 (Station A). The evaluation of the river status at Stations C and D was polysaprobic, and sensitive taxa were absent. The mean Shannon-Weaver index (H') of diversity varied from 1.288 (Station D) to 2.250 (Station A). The classification of saprobity based on H' was ${\beta}$-mesosaprobic at Station A and ${\alpha}$-mesosaprobic at the other stations. The value of geometric density was varied from 1.229 (Station A) to 2.071 (Station D), with a mean of 1.582. An artificial load is being added to this river. One of load is the rectal river construction which flows straight through the river physics. Thus, the environment of living organisms deteriorates due to insufficient water. In order to secure the quality of the Songji River and a good environmental habitat, several low-height stepped-beam structures are required.

Fig. 1. Four sampling sites of the study area at Songji River.

Fig. 2. Variability of the dominance indices (DI) of macroinvertebrate species at Songji River.

Fig. 3. Variability of the Beck-Tsuda's Biotic Index (BI) of macroinvertebrate species at Songji River.

Fig. 4. The geometric mean of macroinvertebrate species at Songji River.

Table 1. Classification scheme of the environmental quality score of benthic macroinverterates according to the indicator table from NIER [20]

Table 2. The scheme of ESB accrding to the phase of environmental quality [19]

Table 3. Classification of benthic macroinvertebrates index (BMI) for the evaluation of river status [13]

Table 5. Species composition for invertebrates in the studied areas

Table 6. Total ecological score of benthic macroinvertebrate community (TESB), average ecological score of benthic macroinvertebrate community (AESB), and benthic macroinvertebrate index (BMI) for the evaluation of river status (Kong et al., 2018)

Table 7. Biological diversity index for invertebrates in the studied areas

Table 4. Classification of saprobity based on Shannon-Weaver's diversity, H' [28]