wetland water quality and biological assessment

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 systemStanding 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)

Coastal Water Quality Standards

Coastal Water Quality Standards (p. 2/7)

Groundwater Quality Standards

Groundwater Quality Standards (p. 2/5)

Chemical index*Saubain et al. index

I = 1/n Σn qiI = 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 = Σn qiI = 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.

BioindicatorThe use of individual plant and/or animal species or, more rarely, groups of closely interdependent species to indicate thequality 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 periphytoncommunities in Germany by Kolkwitz and Masson (1902).

*Macroinvertebrate indicators started in USA by Richardson in 1928.

Both groups have evolved from qualitative to quantitativesystems.

Biological Assessment SystemsBIOINDICATORS

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

PlanktonPlankton=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

BenthosBenthos = 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 indexA 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 indexExample: 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 indexMacroinvertebrate 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 index3) 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.

Belgian Biotic indexDe Pauw and Vanhooren, 1983

*The biological assessment of surface-water quality is based on a qualitative sampling of the aquatic macroinvertebratefauna and use of the biotic index to express the biological results.

Belgian Biotic indexSampling equipment*Handnet consisting of a metal frame holding a conical net;the fraame width of 30 cm, height of 20 cm and length of 50cm; a two meter long steel shaft; net being made of synthetic textile with a mesh size of minimum 300 micron and maximum 500 micron.

Belgian Biotic indexSampling procedure*To allow a comparison of qualitative data, the sampling technique and effort were standardized.

*The objective: collecting the most representative diversity of macroinvertebrates at the station examined.

-All accessible aquatic habitats or microbiotopes must be explored including bottom substrata (stones, sand, mud),macrovegetation (floating, submerging, emerging) and all other substrata, natual and artificial, floating or submerged in the water.

Belgian Biotic indexSampling procedure*To obtain comparable results, a sampling effort should cover:

-an effective river streatch of 10 to 20 m in a limited period of time: from 3 min for water courses less than 2 m wide up to 5 min for larger rivers;

-the sampling time may be divided in ‘intervals’ to explore all the characteristic habitats of the location

-a collection of animals taken by hand

Belgian Biotic indexSampling procedureSampling in shallow fast running waters

The handnet is held in a vertical position on the river bottom in downstream direction. The bottom material located immeddiately upstream is turned over by hand or by foot.The dislodged animals are carried into the net by the current.

Attached or creeping specimens are removed by hand or with a soft brush and added to the sample.

Repeated in several places of the river in longitudinal as well as transversal direction, within the riffles as well as within the slower flowing parts.

Belgian Biotic indexSampling procedureSampling in deep watercourses

The sampling can be done along the river bank in a stretch covering up to 1 m in depth.

Benthic animals are caught by moving and jerking the handnet in the upstream direction over the substratum or by disturbing and rooting up bottom material with one’s feet.Water plants, stones and other natural or artificial substrates are lifted and washed off in a bucket with water.

Larger animals may be also be handpicked and added directly to the sample.

Belgian Biotic indexSampling procedureSampling in slow running or stagnant watercourses

The handnet is swept with jerky movements through the upper layer of sediment (3 to 5 cm) and through the macrovegetation if present.

Care should be taken not to use the handnet as a shovel.

Additional hand sampling of the vegetation, stones and other substrates is required to collect the attached species.

Belgian Biotic indexSampling procedureSome recommendations

*It is strongly recommended not to sample after a period of heavy rainfall in order to avoid collection of too many drift organisms.

*For large river it is highly recommended to sample both the left and the right banks.

*Not to sample in the immediate proximity of the confluence of two rivers or of a waste discharge. Sampling must be done beyond the mixing zone to avoid misleading results.

Belgian Biotic indexCalculation of the biotic index*The determination is based on the standard table having a double horizontal and vertical entrance, one for the faunistic groups and one for the number of systematic units.

Faunistic groups rank from 1 to 7 with regard to decreasing environmental requirements or increasing tolerance to pollution (Column I).

Systematic units: the number of systematic units found in the sample (also see Table 3.1).

The crossing of a row and a column determines the biotic index for a station.

Belgian Biotic indexInterpretation of the biotic indexGenerally, the highest biotic index of 10 is indicative of good water quality or absence of pollution. As the value of the index decreases, the water quality deteriorates.

In order to synthesize the results, the 10 indices can be ranged in five quality classes which may be visualised by different colors (Table 3.3).

Belgian Biotic indexInterpretation of the biotic indexGenerally, the highest biotic index of 10 is indicative of good water quality or absence of pollution. As the value of the index decreases, the water quality deteriorates.

In order to synthesize the results, the 10 indices can be ranged in five quality classes which may be visualised by different colors.

EphemeropteraMayfly

Minnow Mayfly larva

Adult

PlecopteraStonefly

Perlodidae

TrichopteraCaddisfly

Brachycentrusmontanus

Glossosomatidae

Limnephilus lunatus

Polycentropus sp.

Leptoceridae

Odonata: Family Lestidae

Odonata: Family Gomphidae

Odonata: Family Cordulegasteridae

Odonata: Family Aeshnidae

Odonata: Family Corduliidae

Odonata: Family Libellulidae

Mollusca: Family Viviparidae

Mollusca: Family Ancylidae

Mollusca: Family Unionidae

DipteraTruefly

Family :Chironomidae

Diptera: Family Tipulidae - The Crane Flies

Diptera:Family Simuliidae - The Black Flies

Crustacean: Family Gammaridae

wetland water quality and biological assessment

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