INTERNATIONAL JOURNAL OF ENVIRONMENTAL SCIENCES Volume 4, No 3, 2013
© Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0
Research article
ISSN 0976 – 4402
Physicochemical characteristics of water and sediment in Thengapattanam
estuary, southwest coastal zone, Tamilnadu, India
Anitha .G1, Sugirtha P. Kumar2
1- Dept. of Chemistry, CSI Institute of Technology, Thovalai, K.K.Dist 629302
2- Dept of Chemistry, Women’s Christian College, Nagercoil-1, K.K.Dist 629001
[email protected]
doi: 10.6088/ijes.2013040300001
ABSTRACT
The present study was carried out to determine the physicochemical characteristics of water
and sediment in Thengapattanam estuary for the period of one year during October 2010 to
September 2012.Atmospheric temperature and surface water temperature varied from 28.3 o C
to 31.8oC and 26.2 to 29.4oC respectively. Salinity varied from 0.5 ‰ to 11‰. pH remained
alkaline throughout the study period in all the stations with maximum value during summer
and minimum during post monsoon. Higher dissolved oxygen concentration was observed
during monsoon season might be due to the cumulative effect of higher wind energy coupled
with heavy rainfall and river inflow. BOD was high during summer season and low during
post monsoon season. Concentration of nutrients showed significant spatial and temporal
variations and their levels in water increased during rainy season. Sediment characteristics
were also studied for one year. The organic carbon of the stations varied from0.061% to
0.522%.Nitrogen content varied from 0.012 %to 0.052 %. Total phosphorus ranged between
0.03% and 0.09%. Sediment texture ranges in terms of percentage of sand, silt and clay were
85.4% to96.8 % ,1.2% to11.9% and 1.1% to 8.8% respectively at all the stations.
Keyword: Physicochemical characteristics, water, sediments, nutrients
1. Introduction
Estuaries are fragile ecosystem with unique physical, chemical and biological features acting
as a transitional zone between land and sea. They are complex and dynamic aquatic
environment which receive substantial amount of nutrients as well as anthropogenic wastes
from land and transferred towards inshore sea (Shruthi et al 2011). When river water mixes
with sea water large number of physical and chemical process take place which may
influence water quality (Muduli Bipra Prasanna et al 2010).But this site is the breeding and
nursery ground for several species of commercially important fishes and crustaceans(Ahila
Angelin et al 2010). To establish the spatial and temporal variations in water quality, regular
monitoring programs are required
Many studies have been carried out so far on physicochemical parameters of various
estuaries of India, Kumar and Patterson (2007) from Manakudy estuary, Chanda et al (1996)
from Mandovi estuary, Bragadeeswaran et al (2007) from Arasalar estuary, Tukura et al
(2010) from Mada river, Robin et al (2012) from Cochin backwaters, Prabhahar et al (2011)
from
Vellar estuary , Kavitha et al (2006) from Rajakkamangalam estuary, Jeena Pearl from
Mankudy estuary, Rajani kumar et al from Krishna estuary, Anila kumari et al (1992) from
Received on September 2013 Published on November 2013
205
Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
Poonthura estuary ,Jayachandran et al from Kodungallur-Azhikode estuary ,Anila Kumary et
al from Adimalathura estuary etc. The present study was carried out for monitoring the
Thengapattanam estuary and future ecological assessment.
2. Study area
The study was carried out at Thengapattanam estuary which is located on
the south west coast of India (7o53’ N latitude and 77o07’ E longitude). It is formed by the
confluence of river Tampirabarani in between Thengapattanam and Eraiummanthurai about
56 km. west of Kanyakumari town. It is a tropical bar built estuary which remains land
locked on most of the occasions. During heavy inflow into the estuary the sand bar opens up
under the force of gravity. Nearby the estuary an AVM canal (Anandan Victoria
Marthandavarman Canal) runs along the west coast. It serves the fresh water needs of the
local people, but it is also used for coconut husk retting activities. The drainage channels
from the paddy fields and rubber plantation near the AVM canal are the main source of
pollution in this estuary. It is also one of the fishery resources in Tamil Nadu. There are no
major industries near the estuary, however small scale industries like coconut husk retting are
well established near the banks of the river.
But the perennial nature of Kuzhithuraiar within the farm land encourages inland valley
agricultural practice such as planting of vegetables, paddy fields, rubber plantation
throughout the year. The farmers apply agrochemicals such as fertilizers, herbicides and
germicides from time to time to improve crop yield without a follow up assessment of how
much of these agrochemicals affect the non- target component of the ecosystem. Hence this
study is very much used to monitor this estuary
Figure 1: Thengapattanam estuary-study area
In order to cover entire stretch of this estuary five sampling stations were selected from the
mouth of the estuary to the upstream side viz. station1.AVM canal joining the
Thengapattanam estuary, station 2 head of the estuary, station 3 &4 in between head and
Anitha .G, Sugirtha P. Kumar
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
mouth, station 5 mouth of the estuary. The study was carried out over a period of 12 months
from October 2011 to September2012. Through out the study period, sampling of water was
carried out on a monthly basis during the last week of every month between 7am to 9 am.
Kanyakumari coastal area receives rain in two monsoons namely, the Southwest monsoon
from June to September and the Northeast monsoon from October to December. Rainfall data
was obtained from Tamilnadu Agricultural University, Horticultural Research station,
Pechiparai, Kanyakumari Dist .The study area receives the bulk of rainfall during northeast
monsoon. For convenience and easy interpretation of result, three seasons have been
recognized in a calendar year viz post monsoon (October to January), pre monsoon (February
to May), monsoon (June- September).During the post monsoon season the northeast monsoon
commences. The seasonal variations of all the parameters are shown in figure 2 to 20.
2.1 Experimental methods
Water samples were collected every month with a clean plastic bucket in five different
stations. Preservation and transportation of the water samples to the laboratory were as per
standard methods Atmospheric temperature and water temperature were measured on the site
using mercury thermometer. The samples were analyzed for different parameters pH was
measured using digital Elico pH meter. Salinity was mesured by Erma hand refractometer.
Dissolved oxygen was fixed immediately after collection and then determined by Winkler’s
method, Flame photometer was used for the determination of metal ions, Ca, Mg
(APHA1998). Total hardness was calculated by complexometric titration using EDTA
(Vogel 1978).Nitrite, nitrate, phosphate, were measured according to the standard procedure
(APHA 1998). Turbidity was determined by using turbidity meter. Alkalinity of water sample
is determined by titration with standard acid.
The surface sediment samples were taken from five stations, for 12 months and quickly
packed in air tight polythene bags. After sampling, they were dried under shade and divided
into two fractions. One portion for the analysis of sediments texture parameters (sand, silt,
clay) and the other portion was powdered using mortar and pestle and sieved through 63µm
sieve and analyzed for organic carbon. Precautions were taken to avoid contamination during
drying, grinding, sieving and storage.
Sediment pH and EC were measured in a suspension of 1:2.5 sediment to water ratio using
calibrated pH meter (Elico) and conductivity meter (Systronics).Textural characteristics (sand,
silt, clay) were determined following pipette analysis (Kumbein and Pettijohn 1938). Organic
carbon content in sediment was determined by wet oxidation method (Walkley and Black
1934).
3. Result and discussion
3.1 Rainfall
Rainfall is the most important cyclic phenomenon in tropical countries as it brings important
changes in the hydrological characteristics of the coastal marine environment (Chandran et al
1984). Total rainfall of 1373mm was recorded from October 2011 to September 2012.
Maximum rainfall was recorded during post monsoon season (Nov 2011) and minimum
during pre monsoon season (Feb 2012).
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
Rainfall
200
150
mm 100
post monsoon
premonsoon
50
monsoon
0
s1
s2
s3
s4
s5
stations
Figure 2: Seasonal variations of rainfall at five stations
3.2 Air temperature and surface water temperature.
During the study period air temperature varied from 28.3 o C to 31.8 o C.The minimum was
recorded during post monsoon season (November 2011) and maximum during pre monsoon
season (Feb 2012). In general all the stations showed similar seasonal changes.The surface
water temperature varied from 28.3o C to 31.8o C. The minimum surface water temperature
was recorded during post monsoon season (Nov 2011) and maximum was recorded during
the pre monsoon season (Feb 2012). Like atmospheric temperature all the stations showed
similar seasonal changes. Surface water temperature is influenced by the intensity of solar
radiation, evaporation, fresh water influx and cooling and flow from adjoining neritic waters
(Govindasamy et al 2000). The observed low value during November was due to strong land
sea breeze and precipitation.
Atmospheric temperature showed a positive correlation with water temperature and the water
temperature showed a positive correlation with salinity, pH, and negatively correlated to
dissolved oxygen.
Atmospheric temperature
31.2
31
30.8
30.6
30.4
oC 30.2
30
29.8
29.6
29.4
29.2
Post monsoon
pre monsoon
monsoon
s1
s2
s3
s4
s5
stations
Figure 3: Seasonal variations of Atmospheric Temperature o C of water at five stations
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
Surface water temperature
28.8
28.6
28.4
oC
28.2
Post monsoon
28
premonsoon
27.8
monsoon
27.6
27.4
s1
s2
s3
s4
s5
stations
Figure 4: Seasonal variations of Surface water temperature
o
C in water at five stations
3.3 Salinity
The salinity values were ranged from 0.5 ppt to 11 ppt. Maximum salinity value was recorded
during pre monsoon (Feb) and minimum was recorded during post monsoon (Nov2011) at S 1,
and S2. High salinity value may be due to high rate of evaporation, low rainfall, absence of
river discharge, tidal mixing and dominance of neritic water from open sea (Saravana Kumar
et al 2008).Low value during monsoon season may be due to rainfall and fresh water inflow
from the land.
Generally changes in salinity of brackish water habitats such as estuaries, backwaters and
mangrove are due to the influx of freshwater from land run off caused by monsoon or by tidal
variations. Most species in the estuarine environment live under stress either due to low or
too high salinity depending on their origin from fresh or marine areas (Prasanna kumar et al
2010).Regarding station wise variation station 4 and 5 are in close proximity with the sea and
had salinity higher than that of other stations . During summer season sea water intrusion
along the estuarine region increase the salinity of drinking water resources provided along the
Kuzhithuraiar. Salinity showed a significant positive correlation with temperature but it is
negatively correlated with rainfall.
salinity
6
5
4
ppt 3
post monsoon
pre monsoon
2
monsoon
1
0
s1
s2
s3
s4
s5
stations
Figure 4: Seasonal variations of Salinity of water at five stations
3.4 pH
pH remained alkaline throughout the study period . It varied from 7.2 to 7.96. Fluctuations in
pH values during different season of the year were attributed to factors like removal of CO2
by photosynthesis through bicarbonate degradation, dilution of water with fresh water influx,
reduction in salinity and temperature and decomposition of organic matter (Rajasegar et al
2003).Maximum pH was observed during the summer season and the minimum was observed
during the monsoon season. It followed the trend similar to that of salinity. Statistical analysis
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
revealed that pH had highly significant negative correlation with rainfall and positive
correlation with water temperature and salinity, but DO had an inverse relationship with pH.
pH
7.8
7.75
7.7
7.65
7.6
7.55
7.5
7.45
7.4
7.35
7.3
post monsoon
premonsoon
monsoon
s1
s2
s3
s4
s5
STATIONS
Figure 5: Seasonal variations of pH in water at five stations
3.5 Turbidity
Turbidity is a measure of water clarity and the how much the material suspended in water
decreases the passage of light through water. Turbidity values varied from 2 to16 NTU.
Maximum turbidity was recorded during post monsoon season (Nov) and minimum during
pre monsoon season. High turbidity value during post monsoon may be due to fresh water
discharges, which carried lot of terregenous materials and low solar radiation (Kalaiarasi et al
2012). Regarding station wise variation, turbidity was maximum at station1which is near by
AVM canal, river mouth at station 2 and station 5 due to the movement of water in and out of
the estuary by tidal influence.
Turbidity serves as a main factor in governing light penetration in the study area. Least
amount of turbidity during the pre monsoon season at all the stations due to the bright
sunshine, clear water condition and removal of suspended materials from the water column
and cessation of fresh water flow, thereby reducing abiogenic turbidity.
Turbidity is affected by salinity as salt settles sediments .So the presence of salts in estuaries
has the effect of reducing turbidity. Turbidity values showed positive correlation with nitrate
–nitrogen and rainfall.
Turbidity
10
8
6
4
2
0
post monsoon
premonsoon
monsoon
s1 s2 s3 s4 s5
stations
Figure 6: Seasonal variations of Turbidity in water at five stations
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
3.6 Dissolved oxygen
Dissolved oxygen content varied from 4 to 7.6mg/L. Maximum value of dissolved oxygen
was observed at station 2 in the month of November during post monsoon season and
minimum value was observed at station 1 in the month of February during pre monsoon. In
general minimum and maximum values of value of dissolved oxygen were recorded during
pre monsoon and monsoon season at all the stations.
Higher dissolved oxygen observed during the monsoon season might be due to the
cumulative effect of higher wind energy coupled with heavy rainfall and the resultant fresh
water mixing Similar results were reported by Vijaya kumara et al (2011) Manikannan et al
(2011),and Damotharan et al (2010). Minimum value was observed at station 1 due to the
disposal of domestic sewage, agricultural run off and coconut husk retting wastes through
AVM canal.
Dissolved oxygen showed an inverse relationship with salinity and temperature with high
values at ebb tides and low values at flood tides (Chandran et al 1984, Govindasamy et al
2000, Chendur palpandi et al 2011,Kumar et al 2011,Ashok Prabu et al 2008, Shruthi et al
2011) etc. Thus it is clear that temperature and salinity affect dissolution of oxygen in sea
water.
DO
7
6
5
mg/L
4
post monsoon
3
premonsoon
2
monsoon
1
0
s1
s2
s3
s4
s5
STATIONS
Figure 7: Seasonal variations of DO in water at five stations
3.7 BOD
Bio-chemical oxygen demand reveals the content of micro organisms present in the water
under investigation and its organic matter load. BOD values were varied from 1.1mg/L to
2.8mg/L. Minimum value was recorded during post monsoon season and maximum during
pre monsoon season. BOD values were found to be high at station 1 due to the mixing of
water from AVM canal where retting activities occurs. The remaining stations are having low
values.
It is evident that the BOD showed positive correlation with salinity, pH, total hardness,
calcium and magnesium and negative correlation with rainfall, dissolved oxygen and
nutrients.
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
BOD
2.5
2
1.5
mg/L
post monsoon
1
pre monsoon
monsoon
0.5
0
s1
s2
s3
s4
s5
ststions
Figure 8: Seasonal variations of BOD in water at five stations
3.8 Total hardness and Alkalinity
Total hardness was registered to be maximum during pre monsoon season (May) at station 5
and minimum during post monsoon season (Nov) at station 2.Bicarbonates,
carbonates ,chlorides, nitrates, phosphates, and sulphates are present in the form of Na+, K+,.
Mg 2+.and Ca2+ and are mainly responsible for the alkalinity and hardness of water (Ravaniah
et al 2010).
Alkalinity of water is defined as the ionic concentration, which can neutralize the hydrogen
ions. Alkalinity is also imparted more by the presence of CO2 suggesting the decay of organic
matter and is the prominent activity elevating alkalinity in natural waters (Sujitha et al 2011).
Here bicarbonate alkalinity ranged from 28mg/L to 96mg/L.
Minimum value was observed at station 2 during post monsoon and maximum during pre
monsoon at station 5.
Total hardness
1800
1600
1400
1200
1000
mg/L
800
600
400
200
0
post monsoon
pre monsoon
monsoon
s1
s2
s3
s4
s5
stations
.
Figure 9: Seasonal variations of Total hardness in water at five stations
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
Alkalinity
80
70
60
50
mg/L 40
30
20
10
0
POST MONSOON
PREMONSOON
MONSOON
s1
s2
s3
s4
s5
stations
Figure 10: Seasonal variations of alkalinity in water at five stations
3.9 Calcium and Magnesium
The ranges of Ca2+ and Mg2+ concentrations were found to be 30mg/L to 163mg/L.and62
mg/L to 594 mg/L. The maximum calcium content was found in station 5 during the month
of February and minimum value found in station 1 in the month of November .Calcium
concentration is highest in estuaries due to the influx of riverine sources. Similar results were
reported by Vijaya kumara and Vijaya Kumar (2011).
Magnesium content varied among different sites. Maximum values of magnesium were
observed during the month of February at station 5 and the minimum values were observed
during the month of November at station 2.
Calcium
120
100
80
mg/L
60
post monsoon
40
premonsoon
monsoon
20
0
s1
s2
s3
s4
s5
stations
Figure 11: Seasonal variations of calcium in water at five stations
MAGNESIUM
500
400
300
mg/L
POST MONSOON
200
PREMONSOON
100
MONSOON
0
s1
s2
s3
s4
s5
STATIONS
Figure 12: Seasonal variations of magnesium in water at five stations
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
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For assessing sea water intrusion in to coastal aquifer the ratio of certain chemical parameters
such as Ca2+/Mg2+ and TA/TH can be used (Palanisamy Shanmugam et al 2006). Since Mg
present in sea water is much greater concentration than calcium Ca/Mg ratio is recommended
as a parameter for determining the salt water contamination. If the ratio is less than 1, then
the area is considered to be highly affected by salt water intrusion. Using this ratio it was
found that all the stations are affected with sea water intrusion.
3.10 Nitrite, Nitrate, Phosphate and sulphate
Nutrients are considered as one of the most important parameter in the estuarine environment.
It influences the growth, reproduction and metabolic activities of the living beings.
Distribution of nutrients is mainly based on the seasons, tidal condition and fresh water
inflow from land sources.
During the monsoon season the nutrients(both nitrogen and phosphorus) were added mainly
from the irrigation run off , river discharge rainfall and tidal conditions (Ashok Prabu et al
2010).But during the non- monsoon season nitrogen derivatives were coming more from the
retting zones through AVM canal. Higher value of nitrite concentration was recorded during
the monsoon season at stations 1&2 and low values are observed during the monsoon season.
Nitrite was recorded more or less similar in all the stations and seasons. Nitrite content
fluctuated between 0.04 and 0.67mg/L. Maximum nitrite was observed during post monsoon
and minimum was recorded during pre monsoon season. Low content of nitrite during
February was due to less fresh water input, higher salinity, higher pH and also uptake by
phytoplankton. The same report was given by Thirnavukarasu Karuppiah et al (2011) from
Kottakudi estuary.
Nitrate concentration was higher during the post monsoon and lower during summer season.
It varied from 2mg/L to 6mg/L. The higher nitrate content observed during post monsoon
period is mainly due to the river water discharge containing nitrogenous particles of various
origins, such as land run off contaminated with fertilizers from the surrounding paddy fields,
coconut and rubber plantations. Similar maximum value in rainy season and minimum in pre
monsoon were also recorded by Muthukumaravel et al (2012) from Arasalar estuary
Karaikal,Damotharan et al(2010)from Calimare coastal waters.Regarding station wise
variations station 1 is the polluted station with the direct discharges of coconut husk retting
wastes and dumping of fishery wastes. Most of the nitrate might have been derived from the
decomposition of organic wastes ( Ravaniah et al 2010).
High concentration of phosphate observed during post monsoon season might be due to the
intrusion of sea water as well as heavy rainfall, mixing of land run off from agricultural fields
contaminated with super phosphates and alkyl phosphates from soap and detergents used by
the public for bathing and washing clothes (Senthilkumar et al 2010) . Low phosphate value
recorded during pre monsoon could be attributed to the limited flow of fresh water, high
salinity and utilization of phosphate by phytoplankton. (Rajasegar 2003)
In general, higher nitrate and phosphate concentration in estuarine water was mainly due to
the intensive usage of urea and diammonium phosphate fertilizers in agricultural activities.
Nitrate and phosphate showed insignificant and inverse correlation with salinity and pH.
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
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Nitrite
0.4
0.35
0.3
0.25
mg/L 0.2
0.15
0.1
0.05
0
POST MONSOON
PREMONSOON
MONSOON
s1
s2
s3
s4
s5
stations
Figure 13: Seasonal variations of nitrite in water at five stations
Ntrate
4.5
4
3.5
3
2.5
mg/L
2
1.5
1
0.5
0
POST MONSOON
PRE MONSOON
MONSOON
s1
s2
s3
s4
s5
stations
Figure 14: Seasonal variations of nitrate in water at five stations
Phosphate
2
1.5
mg/L
1
POST MONSOON
PRE MONSOON
0.5
MONSOON
0
s1
s2
s3
s4
s5
stations
Figure 15: Seasonal variations of phosphorus in water at five stations
3.11 Sulphate
Sulphate values varied from 26mg/L to62mg/L.Minimum value was observed during post
monsoon and maximum during the pre monsoon season. High value during pre monsoon may
be due to decomposition of sulphide bearing minerals and sulphate rich effluents from husk
effluents from husk retting grounds and low value during monsoon could be due to dilution
effect.
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
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sulphate
60
50
40
mg/L 30
post monsoon
pre monsoon
20
monsoon
10
0
s1
s2
s3
s4
s5
stations
Figure 16: Seasonal variations of sulphate in water at five stations
4. Sediment
4.1 pH
pH in sediments ranged between 6.9 to 7.78. The sediment pH was higher in pre monsoon
and low during monsoon possibly due to redox changes in the sediments and water column
apart from the influence of fresh water (Saravanakumar et al 2008). Low value of pH
recorded during monsoon was due to the increased rate of inflow of fresh water,
decomposition of organic matter and conversion of released CO2 into carbonic acid
(Vasantha 2009). pH of all the stations indicated the alkaline nature of the stations, which lie
adjacent to the sea and influenced by influx of neritic waters during tidal cycle.
pH
7.7
7.6
7.5
7.4
7.3
VALUES 7.2
7.1
7
6.9
6.8
6.7
POST MONSOON
PRE MONSOON
MONSOON
s1
s2
s3
s4
s5
STATIONS
Figure 17: Seasonal variations of pH of sediment at five stations
4.2 Nitrogen and phosphorus
Nitrogen in sediments varied from0.014%to 0.052%. It was high during pre monsoon due to
the oxidation of dead plant organic matter which has settled on the top layer. Low value s of
nitrogen observed during post monsoon may be ascribed to the low level of organic matter
during rainy season along with high percentage of sand during rainy season.
The distribution of sediment nitrogen is in contrast to that of nitrate in the overlying water
which shows high values of nitrate during post monsoon and low values during pre monsoon.
The increasing values of nitrogen in sediments during pre monsoon was due to the oxidation
of dead planktonic matter which has settled from the top layer It is evidenced by obtaining
positive correlation between organic carbon and nitrogen. The subsequent decrease of nitrate
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
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in the overlying water is due to the utilization of nitrate by high planktonic production
(Chanda et al 1996). The significant correlation of sediment nitrogen with clay and silt
indicated that the adsorption is mainly affected by the finer fraction of the sediment.
Phosphorus in the sediment was high during pre monsoon season and low during post
monsoon season. High values were due to the dead organic matter settling from top and are
related to the permeability of the sediments and the lower values may be due to the removal
of top layer of sediments by heavy flood, deposition of sand and the leaching of phosphate
from sediments to the overlying water. Increased application of fertilizers, use of detergents
and domestic sewage play a great role in contributing to the heavy loading of phosphorus in
the sediment (Vasantha 2010).. Further it is evidenced by obtaining positive correlation
between organic carbon and phosphorus. However a similar pattern of variation of nitrogen
and phosphorous and the significant correlation between them revealed that the concentration
of one is dependent on the other and indicated a common source for both.
Nitrogen
0.04
0.035
0.03
0.025
% 0.02
0.015
0.01
0.005
0
POST MONSOON
PREMONSOON
MONSOON
S1
S2
S3
S4
S5
stations
Figure 18: Seasonal variations of nitrogen in sediment at five stations
phosphorus
0.07
0.06
0.05
%
0.04
post monsoon
0.03
pre monsoon
0.02
monsoon
0.01
0
S1
S2
S3
S4
S5
stations
Figure 19: Seasonal variations of phosphorus in sediment at five stations
4.3 organic carbon
Organic carbon content varied from 0.06% to 0.52% indicates peak value at station S1&S2
during pre monsoon months. The observed peak value of organic carbon in this month could
be attributed to the influx of land run off containing considerable amount of terrigenous
organic matter such as dead planktonic matter which settles at the bottom and get oxidized
and decomposed releasing high level of organic carbon in the sediment (Martin et al 2010).
Low value was observed during monsoon months associated with heavy flooding of river
water followed by opening of sand bar and flushing of sediments deposited at the bottom.
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
Organic carbon content was relatively high in the sediments at station 1 due to the discharge
of large amount of humus brought to this region through AVM canal.
Organic carbon
0.3
0.25
0.2
% 0.15
post monsoon
pre monsoon
0.1
monsoon
0.05
0
s1
s2
s3
s4
s5
stations
Figure 20: Seasonal variations of organic carbon in sediment at five stations
5. Conclusion
The various physico chemical constituents in the Thengapattanam estuarine water showed
wide seasonal fluctuations. In the rainy season, the estuary is dominated with fresh water
from Thamiraparani River and land run off through AVM Canal .While in the non monsoon
season the water showed predominantly saline characteristics. Salinity plays a dominant role
in controlling the water quality. In addition intense pollution from agricultural inputs and
retting activities deteriorate the water quality of this estuary.
Concentration of nutrients in the estuary shows spatial variation. It is regulated by the fresh
water flow and tidal mixing. Thus the increase of nutrients at station 1&2 are minimized by
the strong flushing characteristics of the estuary, by the removal of sand bar coupled with the
saturation of estuarine water with oxygen content, establishing this estuary to have a higher
capacity for self-purification. If proper measures are taken for the treatment of sewage before
discharge and restrictions are enforced on various anthropogenic activities the health of the
estuary can be maintained. Thus the present baseline information of the physicochemical
properties of water and sediment would form a useful tool for further ecological assessment
and monitoring of this estuary.
Table 1: Correlation matrix of water quality parameters:-post monsoon season
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Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
A.Temp- Atmospheric Temperature S.W.Temp- Surface water Temperature
T.H- Total Hardness, TA- Total Alkalinity
Table 2: Correlation matrix of water quality parameters:- premonsoon season
A.Temp- Atmospheric Temperature S.W.Temp- Surface water Temperature
T.H- Total Hardness, TA- Total Alkalinity
Table 3: Correlation matrix of water quality parameters:- monsoon season
A.Temp- Atmospheric Temperature S.W.Temp- Surface water Temperature
T.H- Total Hardness, TA- Total Alkalinity
6. References
1.
APHA (1995), Standard methods for the examination of water and waste water 19th
Edn., American public health association Washington D .C
2.
Ahila Angelin, Eyarin Jebamalar., (2010), Effect of salinity on the distribution of
aquatic insects of Manakudy estuary Journal of basic and applied biology, 4(3), pp 9197.
Anitha .G, Sugirtha P. Kumar
International Journal of Environmental Sciences Volume 4 No.3, 2013
219
Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
3.
Anila Kumari. K.S., Abdul Azis. P.K., Natarajan. P., (2007), Water quality of the
Adimalathura estuary, Southwest coast of India. Journal of the marine biological
association of India, 49(1), pp 1-6
4.
Anila kumari K.S., and Abdul Azis P.K., (1992), Water quality of Poonthura estuary
Thiruvanthapuram, MAHASAGAR, 25(1), pp 1-9.
5.
Ashok Prabu. V., RajKumar. M., and Perumal. P., (2008), Seasonal variations in
physic-chemical parameters in Uppanar estuary, Cuddalore (Southeast coast of India.
Journal of the marine biological association of India, 50(2), pp 161-165
6.
Bragadeeswaran.S., Rajasegar M., Srinivasan .M.,& Kanaga Rajan., (2007), Sediment
texture and nutrients of Arasalar estuary,Karaikkal South-east coast of India. Journal of
environmental biology, 28(2), pp 237-240
7.
Chandran R.,and Ramamoorthi K., (1984), Hydrobiological studies in the gradient
zone of the Vellar estuary Mahasagar 17(2), pp 69-77.
8.
Chendur Palpandi., (2011)., Hydrobiological parameters, population density and
distribution pattern in the gastropod Nerita (dostia) crepidularia Lamarck,1822,from
mangroves of Vellar estuary, Southeast India, International journal of biodiversity and
conservation, 3(4), pp 121-130
9.
Chanda M.,Nasnolkar P.V.,Shirodkar&Singbal Y.S., (1996), Studies on organic
carbon,nitrogen and phosphprius in the sediments of Mandovi estuary, Goa Indian
Journal of marine sciences, 25, pp 120-124.
10.
Damotharan N.,Vengadesh Perumal.,Arumugam M., Vijayalakshmi.S., and
Balasubramanian T., (2010), Seasonal variation of physico-chemical charactistics in
point Calimara coastal waters (South East Coast of India Middle-East Journal of
Scientific Research, 6(4), pp 333-339.
11.
Govindasamy.C., Kannan.L., Azariah.J., (2000), Seasonal variation in Physicochemical properties and primary production in the coastal water biotopes of
Coromandal coast, Indian Journal of Environmental Biology., 21, pp 1-7
12.
Jeena Pearl.A., (2010), Metal concentration in Manakudy estuarine sediments
South West coast of India. International journal of biological technology, 1(1), pp 47-51.
13.
Jayachandran. P.R., Bijoy Nandan.S., Sree Devi,O.K., (2011), Water quality variation
and nutrient characteristics of Kodungallur Azhikode estuary Kerala, India, Indian
Journal of geo-marine sciences, 41(2), pp 180-187
14.
Kalaiarasi M.,Paul P.,Lathasumathi.C., and Stella C., (2012), Seasonal variations in the
physico-chemical characteristics of the two coastal waters of Palk –Strait in Tamil Nadu.
India global journal of environmental research, 6(2), pp 66-74.
15.
Kavitha A., Regini Balasingh.G.S.,Palavesam A and Raj A.D.S., (2006), Microalgal
diversity of Rajakkamangalam estuary, South West coast of Tamilnadu Seaweed
Res.Utiln, 28(1), pp 33-41.
Anitha .G, Sugirtha P. Kumar
International Journal of Environmental Sciences Volume 4 No.3, 2013
220
Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
16.
Kumar. S.P,,&Patterson Edward .J.K., (2007), Hydrobiology of Manakudy estuary,
Southwest coast of India during closed period-a rapid study Indian Hydrobiology,
10(2), pp 219-230.
17.
Krumbein W C & Pettijohn F J. (1938), Manual of Sedimentary petrography (D.
Appleton Century Co Inc.,NewYork) pp 549-555.
18.
Manikandan.K.,Kannan P.,and Sankar.M., (2012), Evaluation and management of
ground water in coastal regions, Open access e-Journal, 5(1), pp 1-11.
19.
Martin G.D., Vijay J.G., Laluraj C.M., Madhu N,V., Joseph.T., Nair. M., Gupla G.V.,
Balachandran K.K., Fresh water influence on nutrient stoichiometry in a tropical
estuary,Southwest coast of India. Applied ecology and environmental research, 6(1), pp
57-64.
20.
Muthukumaravel K.,Vasanthi N.,Sivakami R.,Kandasami D.,Sukumaran N., (2012),
Physico-Chemical characteristics of Arasalar estuary Karaikal Southeast Coast of India.,
International journal of institutional pharmacy and life sciences, 2(3), pp 84-93.
21.
Muduli Bipra Prasanna., Panda Chitta Rajan., (2010), Physico chemical properties of
water collected from Dhamra estuary, International journal of environmental sciences,
1(3), pp 334-342.
22.
Palanisamy Shanmugam.S., Neelamani., Yu-Hwan Abn., Ligy Philip. Gi-Hoon
Hong,(2006)Assessment of the levels of coastal marine pollution of Chennai city,
Southern India water resour manage.
23.
Prasanna kumar.S., Ahila Angelin.J., Eyarin Jebamalar.E., Sam Manohar.S., (2010),
Effect of salinity on the distribution of aquatic insects of Manakudy estuary,
Kanyakumari District. Journal of basic and applied biology, 4(3), pp 91-97.
24.
Prasanna Kumar S SamManohar Das S., Ahila Angelin E.,and Eyarin Jehamalar.E.,
(2010), Effect of salinity on the distribution of aquatic insects of Mankudy estuary,
Journal of basic & applied biology, 4(3), pp 91-97.
25.
Prabhahar. C., Saleshrani. K., Dhana Sekaran.D., Tharmaraj. K., Seasonal Variations in
Physico-chemical parameters of Vellar river, Vellar estuary and Portonovo coastal
waters, Southeast coast of India, International journal of Pharmaceutical and biological
archives, 2(6), pp 1675-1679.
26.
Ravaniah.G., Georgeena Kumari. P., Narasimha morthy. C.V., (2010), Water quality
analysis of the Pennar estuary, Nellore. J. Curr.Sci., 15(2), pp 321-334.
27.
26.Rajasegar.M.,Sirnivasan M.., Ajmal Khan S., (2002), Distribution of sediment
nutrients of Vellar estuary in relation to shrimp farming. Indian journal of marine
sciences, 31(2), pp 153-156.
28.
Robin R.S., Pradipta R.Muduli.K., Vishnu Vardhan K., Abhilash K.R., Paneer Selvam
A., Caaran kumar B., and Balasubramanian T., Assessment of Hydrogeochemical
Characteristic in an Urbanized Estuary using Environmental Tcehniques. Geosciences,
2(4), pp 81-92.
Anitha .G, Sugirtha P. Kumar
International Journal of Environmental Sciences Volume 4 No.3, 2013
221
Physicochemical characteristics of water and sediment in Thengapattanam estuary, southwest coastal zone,
Tamilnadu, India
29.
Rajani Kumari V., and Mrutyunjaya Roa .I., (2010), Sespended sediment dynamics in
Krishna estuary, east coast of India. Indian journal of marine sciences, 39(2), pp 248256.
30.
Saravanakumar.A.,M. Rajkumar M.,Sesh Serebiah. J., Thivakaran.G.A., (2008),
Seasonal variations in physico-chemical characteristics of water, sediment and soil
texture in arid zone mangroves of Kachchh-Gujarat, Journal of environmental
biology, 29(5), pp 725-732.
31.
Senthil Kumar.S., Santhanam. P., and Perumal.P., (2002), diversity of Phytoplanton in
Vellar estuary ,Southeast coast of India. In;Proc.5th Indian Fisheries Forum, Published
by AFSIB, Mangalore and Aca, Bhubanewar, India , pp 245-248
32.
Sujitha P.C.,Mitra Dev D., Sowmya P.K.,, and Mini Priya R., (2011), Physico-Chemical
parameters of Karamana River Water in Trivandrum District, Kerala, India,
International journal of environmental sciences, 2(2), pp 472-490.
33.
Shruthi M.S., SushanthV.R., and Rajashekhar M., (2011), Diatoms as indicators of
water quality deterioration in the estuaries of Dakshina Kannada and Udupi districts of
Karnataka. International journal of environmental sciences, 2(2), pp 996-1006.
34.
Thirunavukkarasu Karuppiah., Gunalan Balakrishnan., Soundarapandian Peyail. Anand
Theivasigamani., Kotiya Anil S., Kumaran Ramachandran., Solanki Jitesh.B., and
Nithyamary Srinivasan., (2011), Studies on the physico-chemical characteristic and
nutrients in the Kottakudi Estuary of Thirupulani, Ramanathapuram-District, South East
Coast of India Aquaculture, Aqurium, Conservation & legislation international journal
of the bioflux society, 4(3), pp 313-319.
35.
Tukura.B.W., Gimba C.E.,Ndukwe I.G.,Kim B.C., (2012), Physicochemical
characteristics of water and sediments in Mada river, Nasarawa state, Nigeria,
International journal of environment and bioenergy, 1(3), pp 170-178.
36.
Vasantha.R., (2010), Studies on the distribution of sediment nutrients of Thengapatnam
estuary along the south west coast of India. Journal of basic &applied biology, 3(1&2),
pp 124-130.
37.
Vijaya Kumara., Vijaya Kumar K.M., (2011), Evaluation of water quality of mangrove
ecosyatems of Kundapura. Udupi District, Karnataka, Southwest coast of India journal
of eco biotechnology, 3(12).
Anitha .G, Sugirtha P. Kumar
International Journal of Environmental Sciences Volume 4 No.3, 2013
222