Water Quality in Lotic Environments of Coastal Region

Water Quality in Lotic Environments of Coastal Region

Water Quality in Lotic Environments of Coastal Region

Suresh S., Ramachandra T. V.*, Raushan Kumar

Energy and Wetlands Research Group, Centre for Ecological Sciences,

Indian Institute of Science, Bangalore – 560012. Karnataka. India.

Phone: 080- 3600985 / 3092506

Fax: 91-80-3601428 / 3600085 /3600683{CES-TVR}

E-mail:

Lotic systems are fragile mobile aquatic ecosystems and their quality is entirely related to the geology, land use pattern as well as socio-economic, cultural and political factors of a region. The factors influencing lotic environments are soil characteristics, terrain of the region, landuse pattern, altitude etc. Changes in the characteristics of these factors influence the natural water quality bringing changes in the physico-chemical characteristics that in turn effect the biological characteristics of lotic system and water use for various applications. Also, non point source pollution due to agriculture and horticulture could impact the fragile ecosystem. In order to quantify the contamination from non-point sources a study was undertaken in selected streams [Locations – Panaji Kamapadi, Panaji Kondalkan, Kovvur Erakadapu, Belthangeri, Dhangundi, Bizale/Kochitota, Hallanthadka, Mallar, Pattanlattlu, Naduhalla, Bramasthana, Hemagunji, Kanyal, Lingamudre, Machiti, Kadanthalaje, Kadari] and monitored for two seasons [pre monsoon and post monsoon]. Results reveal pollutants from NPS through indiscriminate use of inorganic fertilizers and pesticides have contributed significantly in polluting the streams in Udupi and Mangalore districts, Karnataka state, necessitating suitable management strategies to conserve and manage the ecosystem.

INTRODUCTION

Water is the most vital renewable natural resource for the survival of plant and animal life including humans. It supports all the life sustaining processes on earth. It is available in the form of oceans, rivers, lakes, streams, ponds, reservoirs, ground water etc. Aquatic environment is broadly classified into surface and sub-surface waters. The surface water is further classified into lotic and lentic aquatic systems. Lotic systems are characterised by flowing water [streams and rivers] and the lentic systems by stagnant water [reservoirs, lakes, ponds]. The lotic bodies are connecting links between all aquatic and terrestrial habitats. Their quality, quantity and management are highly influenced by watershed characteristics like soil, vegetation, precipitation rates, land-use pattern [agriculture, industry etc.], human population and human usage of natural resources. These parameters are very important in the maintenance of water quality for human and animal consumption, irrigation, industry, power generation, recreation, transportation, etc. Water quality of lotic habitats is susceptible to various contaminants during their passage through the agricultural fields or urban areas. These contaminants determine the fate of lotic systems as they affect their functioning with respect to receiving and disposal of water.

Non-point sources [NPS] are diffuse source of pollution from the surrounding areas. Non-point contaminants are the substances introduced into the receiving waters as a consequence of urban and agricultural runoff that comprises of sewage, pesticides, fertilisers etc. NPS is a significant contributor to pollutant loads especially with reference to nutrients and pesticides.

NPS of pollution impacts aquatic habitats manifold and depends on the type and concentration of pollutants. Presence of suspended solids imparts turbidity to water and affects photosynthesis. Colour along with turbidity and other floating matter influence aesthetic quality. Excessive nitrogen and phosphorus leads to algal growth. Chlorides and sulphates impart a salty taste to water. Toxic substances cause fish kills and other imbalances in stream ecosystems. Non point sources especially agricultural contaminants such as pesticides and fertilisers, even at low concentrations impact the phytoplanktons, zooplanktons, periphyton, macrophytic rooted plants, benthic macro invertebrates and fish. Food web or food chain relationships and energy flow considerations indicate the dynamic aspects of the biological environment. An additional concern is the potential bioaccumulation of contaminants such as heavy metals or pesticides. The toxic effects of contaminants on aquatic habitats are based on the type, composition of the constituent and extent of contamination in aquatic habitats. To analyse the potential effects of contaminants it is necessary to assess the extent of contamination, which is done through physico-chemical and biological analysis of all parameters.

OBJECTIVE

The objective of the study was to assess the extent of contaminants in lotic environment, due to NPS pollution during pre and post monsoon. Water samples were collected in streams located at Panaje [Karnapadi], Panaje [Kondalkan], Koyyur, Belthangari, Bizzale, Hallanthadala, Mallar, Dhangundi, Pattanhittlu, Naduhalla, Bhramasthana, Hemagunji, Kanyal, Lingamudre, Machiti, Kadanthalaje, Khadari, Seshithulu [estuary] and Pavanje [estuary] in Udipi and Mangalore districts (erstwhile Dakshina Kannada district), Karnataka. Soil samples were collected in the catchment areas of the streams located in Panaje [Karnapadi] and Panaje [Kondalkan].

STUDY AREA

The study comprised of water sampling at 19 locations and sampling of soils at 2 locations. Water and soil samples were collected at Panaje [Karnapadi] and Panaje [Kondalkan] to assess the contamination from the near by areca gardens. 17 locations including two estuary points Seshithula and Pavanje were sampled for water. Table 1 depicts the stream locations with their respective GPS coordinates.

Table 1: Sample locations for water quality monitoring

No / Stream locations
Post monsoon / Latitude / Longitude / Habitat / Pre monsoon locations
1 / Panaje [Karnapadi]* / N120 39’353” / E75012’095” / Agriculture / Abdhegundi river
2 / Panaje [Kondalkan] / N12038 ’852” / E75009’493” / Agriculture
3 / Koyyur / N120 56’402” / E75016’835” / Forest / Koyyur
4 / Belthangari / N120 59’389” / E75017’217” / Forest
5 / Bizzale / N13013’305” / E75008’529” / Forest / Bizzale
6 / Hallanthadala / N130 13’839” / E75007’823” / Forest
7 / Mallar / N13013’888” / E75007’507” / Forest / Kanne gundi
8 / Dhangundi / N13014’504” / E75007’880” / Forest
9 / Pattanhittlu / N13014’267” / E75006’825” / Forest
10 / Naduhalla / N13016’071” / E75008’083” / Forest / Doddu gundi [I]
11 / Bhramasthana / N13014’961” / E75007’092” / Forest / Doddu gundi [II]
12 / Hemagunji / N13014’442” / E75005’770” / Forest / Hemagunje
13 / Kanyal / N13009’910” / E75008’347” / Forest / Vamanahalla
14 / Lingamudre / N13012’330” / E75005’874” / Forest
15 / Machiti / N130 12’625” / E75006’360” / Forest / Kodange mhachitt
16 / Kadanthalaje / N13011’650” / E75007’827” / Forest / Kadandalage river
17 / Khadari / N13013’251” / E75005’474” / Forest / Kadari
18 / Seshithulu [estuary] / N130 02’884” / E74046’940” / - / Nandani estuarine
19 / Pavanje [estuary] / N13001’918” / E74047’680” / - / Pavanje estuarine

* Soil sample collected.

METHODOLOGY

The water collected from these locations were analysed according to National Environmental Engineering Research Institute [NEERI] manual, American Public Health Association [APHA], Jal – Tara water testing Kit User’s manual, 2000. Dissolved oxygen [DO], ambient air and water temperatures were recorded at each location along with the description of physical features near the streams. The soil samples were analysed for pesticides according to Soil analysis (ed. Keith Smith, 1983).

RESULTS AND DISCUSSION

The results of the physico-chemical analyses carried out for inland and estuary samples during pre and post monsoon periods are listed in Tables 2 and 3. Colour varied from brownish green, blackish green to green due to the presence of algae and diatoms in these waters during the pre monsoon. During the post monsoon Hemagungi showed black colour due to the geological conditions existing there. During the post monsoon Panaje [Kondalkan] recorded DO 26 mg/l [26 OC], Koyyur 19.5 mg/l [29 OC] and Belthangari 18.6 mg/l [29 OC]. Continuous flow of water in these streams has resulted in oxygen saturation. pH varied from slightly acidic to neutral to slightly alkaline range in both the seasons. Turbidity level at Lingamudre has exceeded the stipulated limit with < 25 NTU in the post monsoon that is mainly due to the growth of phytoplanktons. All the streams possess soft waters. The nutrients like phosphates, nitrates, fluorides, sodium, and potassium were in low concentrations that are generally found in natural surface waters. During the post monsoon period, copper concentration at Vamanahalla 0.068 mg/l exceeded the standards. Also, during the pre monsoon manganese concentrations at all the locations exceeded the stipulated standards, which can be attributed to the geology of the region. Presence of coliform bacteria during the pre monsoon at Bizzale and Kadari and absence of coliform during the post monsoon is due to the lotic nature and less residence time of the contaminants.

Table 2: Seasonal variations of parameters

Parameters / Units / Obtained range
Post- monsoon / Obtained range
Pre- monsoon / IS 10500 -1983 / Agricultural stds
IS: 2291-1982 ISI / Methods
Physical appearance / Transparent, colorless / * / - / Visual
Odor / Odorless / Odorless / Unobjectionable / - / Sensory
Temperature / 0C / 22 – 29 / 24 – 36 / - / Thermometer
Turbidity / NTU / <10 - <25 / < 10 / 10 / - / Turbidity measuring tube
Dissolved Oxygen / Mg/L / 7.3 – 26.0 / 4.6 – 10 / - / Volumetric
TDS / ppm / 13.01 – 23.35 / 23 – 45 / 2100 / Electrochemical
TSS / Mg/L / Nil / Nil / - / Gravimetric
pH / Mg/L / 6.4 – 7.9 / 7.05 – 7.781 / 6.5 – 8.5 / 6.0 – 8.0 / Electrochemical
Conductivity / ms/cm / 0.025 – 0.04 / 0.034 – 0.064 / - / Electrochemical
Acidity / Mg/L / 1.8 – 3.6 / 10 – 25 / - / Volumetric
Alkalinity / Mg/L / 11 – 19.8 / 5 – 15 / - / Volumetric
Total Hardness / Mg/L / 10 – 16 / 21.8 – 76.3 / 300 / - / Volumetric
Calcium / Mg/L / 4 – 9 / 10.9 – 27.25 / 75 / - / Volumetric
Magnesium / Mg/L / 4 – 8 / 5.45 – 54.5 / 30 / - / Volumetric
Chlorides / Mg/L / 1.91 – 5.00 / 14.99 - 25.99 / 250 / 500 / Volumetric
Sulphates / Mg/L / 2.9 – 10.4 / 4.897 – 8.16 / 150 / 1000 / Spectrophotometric
Phosphates / Mg/L / 0.003 – 0.013 / 0.003 – 0.0074 / - / - / Spectrophotometric
Nitrates / mg/L / 0.137 – 0.308 / 0.061 – 0.201 / 45 / - / Spectrophotometric
Sodium / mg/L / 4.07 – 8.05 / 1.039 – 30.41 / 200 / - / Flame photometric
Potassium / mg/L / 0 – 0.86 / 1.249 – 4.271 / - / Flame photometric
Fluorides / mg/L / 0.6 / 0.6 / 0.6 – 1.2 / - / Tara water testing kit
Pesticides / mg/L / Nil / Nil / Absent / - / Gas chromatographic
Nickel / mg/L / 0.031 – 0.345 / 0.03 – 0.09 / - / - / Spectrophotometric
Iron [Fe3+] / mg/L / 0.0014 – 0.0153 / BDL / 0.3 / - / Spectrophotometric
Copper / mg/L / 0.003 – 0.068 / BDL / 0.05 / - / Spectrophotometric
Manganese / mg/L / - / 1.14 – 1.25 / 0.1 / - / Spectrophotometric
Chromium / mg/L / 0.00004 – 0.0004 / BDL / 0.05 / - / Spectrophotometric

Table 3: Estuary samples – Physico-chemical parameters

Season / Units / Pre monsoon range / Post monsoon range

Locations

/ - / Pavanje - Nandani / Seshithula - Pavanje
Parameter / - / - / -
Color / - / Bluish green - green / Colorless
Temperature / oc / 34 - 34 / 31 - 30
Turbidity / NTU / < 10 / < 10 - < 25
DO / mg/L / 8.7 – 9.1 / 7.3 – 7.3
Conductivity / ms/cm / 46.66 – 47.56 / 5.37 – 1.177
PH / - / 8.2 – 8.315 / 6.87 - 7.05
Acidity / mg/L / 100 - 115 / 3.6 – 3.6
Alkalinity / mg/L / 25 - 25 / 30.8 – 17.6
Total hardness / mg/L / 7030.5 - 7739 / 560 - 140
Calcium / mg/L / 1117.25 – 1253.5 / 90 – 20
Magnesium / mg/L / 5913.25 – 6485.5 / 470 - 120
Chlorides / mg/L / 20593.60 – 19593.90 / 1569.73 – 1722.87
Sulphates / mg/L / 2494.7 – 2534.6 / 18.36 – 4.2
Phosphates / mg/L / 0.0036 – 0.0025 / 0.012 – 0.009
Nitrates / mg/L / 0.059 – 0.06 / 0.167 – 0.149
Sodium / mg/L / 12414 - 11460 / 2179.25 – 770.5
Potassium / mg/L / 221 - 354 / 65.96 – 296.82
Fluorides / mg/L / (1.5 – 3) – (1.5 - 3) / 0.6 – 0.6
Coliform bacteria / - / Slightly present / Slightly present
Iron [Fe3+] / mg/L / 0.29 – 0.49 / 0.0095 – 0.008
Chromium / mg/L / BDL / 0.00015 – 0.00015
Nickel / mg/L / 0.25 –0.33 / 0.198 – 0.078
Copper / mg/L / 0.03 –0.04 / 0.169 – 0.052
Manganese / mg/L / 1.27 – 1.31 / -

The results indicated in the Table 3 show that during the pre monsoon the concentrations were high in comparison to the post monsoon. The lower concentrations recorded in the post monsoon may be due to the dilution effect by rains. pH exceeded the limit during the pre monsoon and was stabilized during the post monsoon. The presence of coliform bacteria is by faecal contaminations due to the human settlements surrounding the estuary points. The turbidity at Pavanje is due to the suspended matter that is due to obstruction of water for agricultural activity.

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CONCLUSIONS

The results obtained were compared with the Drinking water standards IS 10500 – 1983 and Agricultural standards IS: 2291-1982 Indian Standards Institute. Most of the physico-chemical parameters analysed were within the standards. Thus the water can be used for agricultural purposes and apart from some locations, the water can also be used for domestic purposes.

BIBLIOGRAPHY

American Public Health Association (APHA), American Water Works Association (AWWA) and Water Pollution Control Federation (WPCF), 1985. Standard Methods for the examination of water and wastewater. Sixteenth edition, Ed. by Arnold E.Greenberg, R. Rhodes Trussell and Lenore S. Clesceri, Washington DC.

Deborah Chapman, 1996. Water Quality Assessment. Second edition, United Nations Educational, Scientific and Cultural Organisation, World Health Organisation and UNEP, New York, pp 59-115.

Jal-Tara water testing kit User's manual, 2000. Environment Systems Branch Development Alternatives, New Delhi.

Ramteke, D.S and Moghi, C.A, 1988. Manual on Water and Wastewater Analysis. National Environmental Engineering Research Institute, Nehru Marg, Nagpur.

United Nation Environment Programme, 1994. The Pollution of Lakes and Reservoirs, Nairobi, UNEP PO Box 30552 Kenya. (Environment Library No.12).

Anthony S. Donigian, 1977. Nonpoint Source Pollution from Land Use Activities. Staff Paper No. 22, Chicago, Illinois.

http://www.epa.gov/safewater/dwh/c-ioc/nickel.html

http://wwwga.usgs.gov/publications/abstracts/ofr00-75.html ------estuarine water quality

---- surface water quality standards.

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