Use of Diatoms in River Health Assessment
Xing Wang
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Enviro nmental Sciences, Beijing 100012, P.R. China and State Environmental Protection Key Laboratory of Drink Water Resource Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, P.R. China.
Binghui Zheng
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Enviro nmental Sciences, Beijing 100012, P.R. China and State Environmental Protection Key Laboratory of Drink Water Resource Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, P.R. China.
Lusan Liu *
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Enviro nmental Sciences, Beijing 100012, P.R. China and State Environmental Protection Key Laboratory of Drink Water Resource Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, P.R. China.
Li Li
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Enviro nmental Sciences, Beijing 100012, P.R. China and State Environmental Protection Key Laboratory of Drink Water Resource Protection, Chinese Research Academy of Environmental Sciences, Beijing 100012, P.R. China.
*Author to whom correspondence should be addressed.
Abstract
We review the use of diatoms in monitoring and assessment of river health in the world. First, we summarize the use of diatoms as indicators of nutritional status, acidification, and organic and metal pollution. We then examine some problems that have been associated with diatoms and indices that were used in different regions around the world: 1) incomplete taxonomy; 2) effects of natural geographic differences on diatom distributions (e.g., climate, lithology); 3) effects of natural site differences on diatom distribution and abundance (e.g., substrate, depth, chemistry); 4) differences in sampling, sample processing, and analytical methods; and 5) difficulties in finding minimally disturbed reference sites. Based on these problems, we present the different selections and the research progress of diatoms and indices used in monitoring and assessing river health around the world including the Americas, Europe, Africa, Asia, and Australia. We recommend that future studies and uses of diatoms focus on the following aspects: 1) improve the classification and identification of diatoms; 2) increase the use of diatom predictive indices to monitor and assess water quality; 3) develop global standard methods for sampling diatoms in streams, rivers, and lakes; and 4) apply hind-casting predictive models.
Keywords: Diatoms, diatom indices, river health, bioassessment, monitoring