Wetland Water Quality and Biological Assessment Raywadee Roachanakanan, Ph.D. Faculty of Environment and Resource Studies Mahidol University November 9, 2007
Standing water system VS Running water system Standing water system (Still water, Lentic habitat) *Wide open space and only narrow connection partway with other sources *Material gain from running water system *Lake, pond and bog etc. Running water system (Flowing water, Lotic system) *Narrow open space and distinct moving direction of water *Material loss through mechanical and chemical erosions *Brook, stream and river etc.
Tools *Selected physico-chemical parameters: Standard *Chemical index *Biological indicators/ index
Surface Water Quality Standards
Surface Water Quality Standards (p. 2/4)
Surface Water Quality Standards (p. 3/4)
Surface Water Quality Standards (p. 4/4)
Coastal Water Quality Standards
Coastal Water Quality Standards
Coastal Water Quality Standards (p. 2/7)
Coastal Water Quality Standards (p. 3/7)
Coastal Water Quality Standards (p. 4/7)
Coastal Water Quality Standards (p. 5/7)
Coastal Water Quality Standards (p. 6/7)
Coastal Water Quality Standards (p. 7/7)
Groundwater Quality Standards
Groundwater Quality Standards (p. 2/5)
Groundwater Quality Standards (p. 3/5)
Groundwater Quality Standards (p. 4/5)
Groundwater Quality Standards (p. 5/5)
Chemical index *Saubain et al. index I = 1/n Σ n qi I = Chemical index n = Number of parameter (can be calculated even on a number of parameters less than 7) qi = Index value of parameter Seven parameters are Dissolved oxygen, Nitrate-N, Nitrite-N, Ammonia-N, Total- N, Phosphate, Chemical oxygen demand. Interpretation: Classes 1-5= Very low water quality-Very good water quality
Chemical index *Dutch score I = Σ n qi I = Chemical index n = Number of parameter qi = Score for each parameter Three parameters are Dissolved oxygen, Biochemical oxygen demand, Ammonia-N. Interpretation: Classes 1-5= Very good water quality-Very low water quality
Chemical index *Only in some European countries are interested and developed these indices: France, Dutch and Belgium. *Not popular and not in use. In Thailand, it is used to be a research on this index (almost 20 years ago). *Problem: it is difficult to identify the relationship amongst the parameters (the summation??).
Physico-chemical indicators VS Biological indicators *biological effects often occur at the concentrations that are lower than the analytical techniques can demonstrate; *toxicants result in effects which are different in complex variable mixtures than each separately; *characteristics of the receiving environment strongly influence the (toxic) effects which can be both antagonistic and synergistic; *organisms integrate environmental conditions over long periods of time, whereas chemical data are instantaneous in nature and therefore require large numbers of measurements for an accurate assessment.
Bioindicator The use of individual plant and/or animal species or, more rarely, groups of closely interdependent species to indicate the quality of an environment. Evaluation of ecosystems usually involves the identification of indicator species which have critical environmental requirements. Example: Ecdyonuridae (belonging to Ephemeroptera: May fly) is the most sensitive group for very good water quality (high dissolved oxygen).
Biological Assessment Systems *The Saprobic system mainly based on the presence of microorganisms belonging to the plankton and periphyton communities in Germany by Kolkwitz and Masson (1902). *Macroinvertebrate indicators started in USA by Richardson in 1928. Both groups have evolved from qualitative to quantitative systems.
Biological Assessment Systems BIOINDICATORS Micro-organisms Macro-organisms -bacteria -macrophytes -protozoans -molluscs -microalgae -crustaceans -insects -fish (Macroinvertebrates approximately >0.5 mm in size)
Biological Assessment Systems Biological water quality assessment is incapable of representing the entire ecosystem, one usually analyzes only one community: -plankton (floating microorganism) -periphyton (attached organisms) -macrobenthon (macroinvertebrates living an and on the bottom) -necton (fish, amphibians)
Bacteria and fungi *Agents of decay for breaking down of dead organic matter. *Contaminations of faecal coliform bacteria (pathogen): domestic waste, effects on human health *A sewage fungus community is found below severe organic pollution. *Link to the parameters of BOD (Biochemical oxygen demand) *Natural bacterial fauna: Self-purification process (Figure of self-purification process)
Food web
Plankton Plankton =microscopic aquatic forms having little or on resistance to currents/ living free-floating and suspended in open or pelagic waters/ ranging in size from single-celled picoplankton, which are < 5 um in diameter, to colonial form Algae =simple plants that lack true stems, roots and leaves but perform photosynthesis/diverse life forms-simple unicellular forms to complex colonial and filamentous forms
Plankton -Phytoplankton (plant) and Zooplankton (animal) Generally zooplankton are larger than phytoplankton -Holoplankton (whole life) and Meroplankton (a certain stage in life cycle e.g. larva stage of shrimp and dragon fly)
Phytoplankton
Zooplankton
Plankton *Short life cycles: planktons respond quickly to environmental changes. *Standing crop and species composition indicate the quality of the water mass. *Plankton are predominant in lentic habitats (ponds, lakes and oceans) and large rivers with slow moving waters. *Eutrophication *Drawback: small size and difficulty of specific identification.
Fish *Species composition and abundance of fish are important in assessing the health of water body. *In the aquatic food webs, normally fish occupy the highest trophic level therefore they can represent the summation of conditions for lower biological forms and the overall water quality. *Certain fish species or group of species are more sensitive to pollutants including siltation. * Catfish generally are considered pollution-tolerant but many species such as “madtoms” are sensitive to some environmental alterations. *Drawback: being more mobile therefore they can avoid pollution to some extent.
Macrophyte *Higher plants are affected by oxygen conditions and turbidity. *High nutrients contents can lead to high biomass. Good?? *Drawback: difficulty to interpret according to water quality; being not very diverse; being not good as indicators
Benthos Benthos = Greek “bottom” = the plant or animal communities associate with the bottom or any solid-liquid interface in the aquatic systems *Now: Animals associate with substrata -Epifauna (on: attatched, motile forms) -Infauna (in: tubes/burrows) Macroinvertebrate = a heterogenous assemblage of animal phyla: Mollusc/Insect larvae/Worm/Star fish etc.
Importance • the diversity of invertebrates, particularly insects, makes up about 54% of all described species of organisms • invertebrates are almost ubiquitous in aquatic systems • invertebrates have limited mobility; the history of the site, enabling intermittent contaminants to be detected • their life cycles are usually on the order of months to years long, which limits their ability to recolonize sites rapidly
Biotic index A rating used in assessing the quality of the environment in ecological terms. Rivers can be classified according to the type of invertebrate community present in the water using a biotic index which is largely an indication of the amount of dissolved oxygen present = a measure of the level of organic pollution.
Biotic index Example: very clean water, holding a wide variety of species including pollution-sensitive animals (e.g. stonefly and mayfly nymphs) has a high biotic score. As pollution increases, oxygen levels decrease and the more sensitive species disappear. Badly polluted water, in which only a few tolerant species (e.g. red midge larvae and annelid worms) can survive, together with a few animals which breathe air at the surface, has a very low biotic source.
Biotic index Macroinvertebrate community assessments are being used as a planning tool for managing water uses, for ambient monitoring and for evaluating the effectiveness of pollution control measures owing to the following reasons: 1) macroinvertebrates are differentially sensitive to pollutants of various types and react to them quickly (wide range of tolerances). 2) macroinvertebrates are ubiquitous, abundant and relatively easy to collect, their identification and enumeration is not as tedious and difficult (especially for most family level).
Biotic index 3) benthic macroinvertebrates are relatively sedentary and are therefore representative of local conditions. 4) macroinvertebrates have life spans long enough to provide a record of environmental quality. 5) macroinvertebrate community is very heterogeneous consisting of representatives of several phyla (high diversity). 6) the ease of sampling in most rivers.
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