Development of an acute sediment toxicity test using an endemic benthic macroinvertebrate, Chironomus species to assess the toxicity of Philippines' Pasig River sediments

4th International Conference on Water Resource and Environment

地球科学;生态环境科学

Mababa, S.J.^1 ; Apodaca, D.C.^1 ; David, C.P.C.^2

School of Chemical, Biological and Materials Engineering and Sciences, MAPUA University, Manila Philippines

1002, Philippines^1

National Institute of Geological Sciences, University of the Philippines, Diliman

1100, Philippines^2

关键词: Acute toxicity test;    Aquatic environments;    Benthic macro invertebrates;    Point and nonpoint sources;    Sediment quality guidelines;    Sediment toxicity tests;    Strategic locations;    Tropical climates;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/191/1/012140/pdf
DOI  :  10.1088/1755-1315/191/1/012140

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

In the absence of a sediment quality guideline, mere characterization regarding the identity and levels of the constituents present in sediments, will not contribute much to an effort of establishing the impact of sediment quality to the aquatic environment. Available standard methods for sediment toxicity tests require the use of species that may not be accustomed to a tropical climate such as in the Philippines. In this regard, area of this study was to assess toxicity of the sediment from Pasig River through the use of an endemic midge (order Diptera, family Chironomidae) collected from Los Baos, Laguna, Philippines as test species. Pasig River is one of the most important waterways in the Philippines, traversing six major cities of Metro Manila. Such strategic location of the River, also explains why it is heavily impacted by both point and nonpoint sources of toxicants. Sediment samples were collected in April 2007, month of dry season and November 2007, month of wet season at five sampling stations along the Pasig River - Delpan, Nagtahan, Pandacan, Guadalupe, and Bambang. A modified 96-hour acute toxicity test was adopted in this study in which sediment samples were mixed with "control" sediment, also obtained locally and subsequently and exposed to the test species. Results suggested that the most polluted and most toxic was the Delpan station which yielded the lowest LC50. The LC50 was experimentally determined via probit analysis. Moreover, it was determined that sediment samples collected during the dry season exhibited lower toxicity towards these organisms than those samples collected during the wet season possibly due the effect of runoff. In view of the results obtained, the locally developed ecotoxicological assay performed on sediments of Pasig River can be used to assess and to distinguish sites along Pasig River that could be potentially toxic based upon its response to the locally grown Chironomids species.