Premium
Benthic Diatoms as Indicators of Stream Sediment Concentrationin Hong Kong
Author(s) -
Dickman Michael David,
Peart Mervyn Richard,
WaiShu Yim Wyss
Publication year - 2005
Publication title -
international review of hydrobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.524
H-Index - 52
eISSN - 1522-2632
pISSN - 1434-2944
DOI - 10.1002/iroh.200410806
Subject(s) - benthic zone , suspended solids , silt , streams , diatom , algae , sediment , environmental chemistry , total suspended solids , nutrient , environmental science , volatile suspended solids , hydrology (agriculture) , chemistry , ecology , biology , geology , environmental engineering , chemical oxygen demand , computer network , geotechnical engineering , computer science , paleontology , wastewater
Diatoms are photosynthetic unicellular, eukaryotic, microorganisms (algae) that are distinguished by their silicified (SiO 2 ‐nH 2 O) cell walls. They have often been employed to assess salinity, pH, and nutrient conditions. Our data suggest that, they may also be used to assess suspended solid levels in streams. The ratio of motile to attached benthic diatoms from five different stream sites in Hong Kong was correlated with the level of suspended solids for each of these sites. Sites with high concentrations of suspended solids had a high percentage of motile diatoms on their rocks while sites with low concentrations of suspended solids had a high percentage of attached (non‐motile) diatoms on their rocks. When water carried by a stream has a high concentration of suspended solids, benthic diatoms in the stream are often covered in a layer of silt. Those diatoms that are motile are able to get on top of this silt layer while attached diatoms cannot. If the silt layer is not washed away, the attached diatoms perish and the percentage of motile diatoms increases. Thus, streams with high concentrations of suspended solids display a higher proportion of motile diatoms than do clear water streams with low concentrations of suspended solids. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)