water quality report of - Laguna Lake Development Authority

Transcription

Water Quality Report
WATER QUALITY REPORT
OF
of
the
THE SEVEN CRATER LAKES
Seven Crater lakes
2006-2008
Prepared by:
Imelda R. Zapanta – Chemist II
Michael Salandanan – Biologist I
Marilou G. Directo – Senior Environmental Management Specialist
Usman Datu Mamadra Jr. – Laboratory Technologist II
Jonathan U. Nicolas – Aquaculturist II
Archilles R. de la Cruz – Data Encoder
Reviewed by :
Jocelyn G. Sta. Ana – OIC, Environmental Quality and Research Div.
Adelina C. Santos-Borja – OIC, Environmental Regulations Department
Jacqueline N. Davo – Licensing officer III
For more information, please contact
Environmental Quality Management Division (EQMD)
Laguna Lake Development Authority
Km. 24 Manila East Road
Club Manila East Compound
Taytay, Rizal
LAGUNA LAKE DEVELOPMENT AUTHORITY
Environmental Quality and Research Division
WATER QUALITY REPORT OF
THE SEVEN CRATER LAKES
2006-2008
Prepared by:
Imelda R. Zapanta – Chemist II
Michael Salandanan – Biologist I
Marilou G. Directo – Senior Environmental Management Specialist
Usman Datu Mamadra Jr. – Laboratory Technologist II
Jonathan U. Nicolas – Aquaculturist II
Archilles R. de la Cruz – Data Encoder
Reviewed by :
Jocelyn G. Sta. Ana – OIC, Environmental Quality and Research Div.
Adelina C. Santos-Borja – OIC, Environmental Regulations Department
Jacqueline N. Davo – Licensing officer III
For more information, please contact
Environmental Quality Management Division (EQMD)
Km. 24 Manila East Road
Club Manila East Compound
Taytay, Rizal
Tel. No. 286-61-43
Fax No. 286-61-43
Email Address: [email protected]
TABLE OF CONTENTS
Page
INTRODUCTION ………………………………………………………………………….
1
METHODOLOGY ……………………………….…………………………………………
3
WATER QUALITY EVALUATION…….………………………………………………….
4
pH………………………………………………………………………………………….
4
Dissolved Oxygen (DO)….……………………………………………………………..
4
Biochemical Oxygen Demand (BOD)………………………………………………….
10
Ammonia (NH3-N)…………. ……………………………………………………………
11
Nitrate (NO3-N)…………………………………………………………………………..
12
Phosphate (PO4-P)………………………………………………………………………
13
Chloride……………………………………………………………………………………
14
Turbidity…………………………… …………………………………………………….
15
Total Dissolved Solids (TDS) ….……………………………………………………...
16
Total Suspended Solids (TSS)………………………………………………………….
17
Total Coliform/Fecal Coliform ………………………………………………………….
18
Chlorophyll-a…………………..………………………………………………………….
20
Phytoplanktons….………………………………………………………………………
21
Zooplanktons……………………………………………………………………………
23
RECOMMENDATIONS………………………..…………………………………………
25
LIST OF FIGURES
Page
FIGURE 1. Seven Crater Lakes…………. …………………..………………………...
2
FIGURE 2. pH Level in the Seven Crater Lakes………………..……………………..
4
FIGURE 3. Dissolved Oxygen Level in the Seven Crater Lakes…..………….………
5
FIGURE 4. Dissolved Oxygen Profile in Bunot Lake….…………….………………...
6
FIGURE 5. Dissolved Oxygen Profile in Calibato Lake……….……………………….
6
FIGURE 6. Dissolved Oxygen Profile in Mohicap Lake ..……………………………..
7
FIGURE 7. Dissolved Oxygen Profile in Palakpakin Lake………..……………………
7
FIGURE 8. Dissolved Oxygen Profile in Sampaloc Lake……..……………………….
8
FIGURE 9. Dissolved Oxygen Profile in Pandin Lake………….……………………..
8
FIGURE 10. Dissolved Oxygen Profile in Yambo Lake………..………………………
9
FIGURE 11. Biochemical Oxygen Demand Level in the Seven Crater Lakes ....…..
10
FIGURE 12.Ammonia Level in the Seven Crater Lakes .……………………………..
11
FIGURE 13.Nitrate Level in the Seven Crater Lakes …………………………………
12
FIGURE 14. Phosphate Level in the Seven Crater Lakes………….…………………
13
FIGURE 15. Chloride Level in the Seven Crater Lakes….………….…………………
14
FIGURE 16. Turbidity Level in the Seven Crater Lakes’’’’.………….…………………
15
FIGURE 17. Total Dissolved Solids Level in the Seven Crater Lakes.………………
16
FIGURE 18. Total Suspended Solids Level in the Seven Crater Lakes.……………
17
FIGURE 19. Total Coliform Counts in the Seven Crater Lakes…….…………………
18
FIGURE 20. Fecal Coliform Counts in the Seven Crater Lakes….…………………
19
FIGURE 21. Chlorophyll-a Level in the Seven Crater Lakes..…….…………………
20
FIGURE 22. Total Phytoplankton Counts in the Seven Crater Lakes.……………
21
FIGURE 23. Total Zooplankton Counts in the Seven Crater Lakes.…………………
24
LIST OF TABLES
Page
TABLE 1.
Characteristics of the Seven Crater Lakes …………………………..
1
TABLE 2.
Phytoplankton Counts by Group………………………………….……
21-22
TABLE 3.
Zooplankton Counts by Group …………………………………..…….
23
Water Quality Report of the Seven Crater Lakes 2006-2008
WATER QUALITY REPORT OF THE SEVEN CRATER LAKES
I.Introduction
San Pablo City is a chartered city in the Province of Laguna. It is approximately
70 kilometers away from Metropolitan Manila. It is famous for its Seven Crater
Lakes, also known as Maar Lakes namely: Bunot Lake, Calibato Lake, Mohicap
Lake, Palakpakin Lake, Pandin Lake, Sampaloc Lake and Yambo Lake. Its
catchment area is Mt. San Cristobal with an area of 27.5 square kilometers.
Lake
Elevation
(m,asl )
Water
Depth
Area
(hectares)
(m)
Bunot
110±
23.0
30.5
170±
156.0
43.0
80±
30.40
22.89
100±
7.7
47.98
160±
61.75
24
106
27.60
104.0
160±
38
30.5
( Brgy Concepcion SPC)
Calibato
(Brgy Sto. Angel SPC,Brgy Tala &
Brgy Antipolo Rizal Laguna )
Mohicap
( Brgy. San Buenaventura SPC )
Palakpakin
(Brgy.Dolorez,San Lorenzo,San
Buenaventura SPC )
Pandin
(Brgy Sto. Angel SPC )
Sampaloc
( Brgy Concepcion, IV-A,V-A, San
Lucas I SPC)
Yambo
(Brgy San Lorenzo SPC,Brgy
Sulsugin Nagcarlan Laguna )
Table 1: Characteristics of the Seven Crater Lakes
The Seven Freshwater Lakes of San Pablo City were formed by a unique
process called phreatic eruption where shallow lava from Mt. San Cristobal
intersected groundwater which blew out (steam-heated eruption) the overlying
rocks to form a circular and crater-like depression that eventually filled up with
1
rainwater. The varying depths of these lakes which are from 7 meters to 156
meters suggest a volcanic origin. (Ramon B. San Andres – FSLF, Inc.)
Sampaloc Lake is the largest among San Pablo’s Seven Crater Lakes. It is
considered one of the prime tourist spots in the city. It abounds with tilapia, big
head carp and several species of freshwater fish like ayungin, dalag and hito
including shrimps.
Calibato Lake is the deepest of all the seven lakes with an average depth of 156
meters. It has the greatest volume of water in storage which is approximately
29,600 cubic meters. Calibato Lake supplies the city and nearby towns with
abundant fish.
Pandin Lake and Yambo Lake are known as “ The Twin Lakes “.Both lakes are
considered oligotropic because of their deep clear lakes with low nutrient
supplies, high dissolved oxygen level and containing little organic matter. Pandin
Lake is San Pablo’s best kept lake.
Mohicap Lake is also a major source of tilapia for Metro Manila and suburbs.
Palakpakin Lake, the shallowest among the seven lakes, is utilized as
communal fishing ground. An increasing construction of fishcages resulted to
limited open fishing ground for the fisherfolks.
Bunot Lake is used primarily for floating cages operation where most of the
resident derived their source of income.
Fig. 1 – Seven Crater Lakes
2
II. METHODOLOGY
The monitoring and sampling of the Seven Crater Lakes is conducted every
month in the 1st and 4th quarters of the year and every 3rd month of the 2nd and
3rd quarters of the year.
Parameters monitored include:
Physico-Chemical parameters:
pH
Dissolved Oxygen at different depth
Biochemical Oxygen Demand
Ammonia
Nitrate,
Phosphate
Total Dissolved Solids
Total Suspended Solids
Chloride
Turbidity
Biological parameters:
Phytoplankton
Zooplankton
Chlorophyll-a
Bacteriological parameters:
Total Coliforms
Fecal Coliforms
3
III. WATER QUALITY EVALUATION
Monitoring data are evaluated based on the Class C Water Quality Criteria under
the Department of Environment and NaturaL Resources (DENR) Administrative
Order #34 Series of 1990.
1. pH
The term “pH” was originally derived from the French term “pouvoir hydrogene”;
in English, this means “hydrogen power.” pH is a measure of the acidity or
alkalinity of water. It is usually measured by a colorimetric test - litmus paper
which changes color with increased acidity or alkalinity or by electrometric
method - pH meter. The pH scale ranges from 0 to 14. If the water is acidic, the
pH is 0 to 6.9; neutral is 7.0; alkaline is 7.1 to 14. A pH range of 6.5 to 8 is
optimal for freshwater.
All the Maar lake stations conformed to the pH criterion of 6.5 to 8.5 units for the
period 2006 to 2008.
2006
pH
2007
2008
C las s C C riterion
YA
M
BO
M
PA
LO
C
SA
PA
ND
IN
M
OH
IC
AP
PA
LA
KP
AK
IN
C las s C C riterion
CA
LIB
AT
O
BU
NO
T
u
n
i
t
s
9
8
7
6
5
4
3
2
1
0
Figure 2. ph Level in the Seven Crater Lakes
4
2. DISSOLVED OXYGEN ( DO )
Dissolved Oxygen is a very important indicator of a water body’s ability to support
aquatic life. It is found in microscopic bubbles of oxygen that are mixed in the
water and occurs between water molecules. Oxygen enters the water by
absorption directly from the atmosphere or by aquatic plant and algae
photosynthesis. Oxygen is removed from the water by respiration and
decomposition of organic matter. The colder the water, the more oxygen can be
dissolved in water. In general, as water temperature increases, dissolved oxygen
decreases. Freshwater lakes, streams, and tap water generally contain much
less salt, so dissolved oxygen are higher.
The annual mean DO concentration ranges from 4.1 mg/L (Lake Mohicap, 2006)
to 7.3 mg/L (Lake Pandin, 2006). Lake Palakpakin, Pandin,and Yambo,
consistently passed the DO criterion for Class “C” water set at 5 mg/L from 2006
to 2008 while Lake Calibato consistently failed the DO criterion. Both Bunot
and Mohicap Lakes passed the criterion in 2006 but failed in 2007 and 2008.,
whereas Lake Sampaloc failed only in 2006 .
Dis s olved Oxyg en
2006
2007
2008
8
7
m 6
g 5
/ 4
L 3
2
1
0
YA
M
BO
IN
M
PA
LO
C
SA
PA
ND
CA
LIB
AT
O
M
OH
IC
AP
PA
LA
KP
AK
IN
BU
NO
T
C las s C
C riterion
Figure 3. Dissolved Oxygen Level in the Seven Crater Lakes
Annual mean DO at different depths
Dissolved oxygen was measured at various depths in the Crater lakes: surface,
2, 4, 6, 10, 15, 20, 25, 30, and 35 meters.
5
For Bunot, Mohicap and Calibato lakes, the DO compliance to the set criterion of
5 mg/L was up to 2 meters only.
DO , B unot ( mg /L )
12
10
2006
m 8
g
/ 6
L
4
2007
2008
C las s C
C riterion
2
0
S
2
4
6
10
15
20
25
De pth , m
Figure 4. Dissolved Oxygen Profile in Bunot Lake
DO , C alibato ( mg /L )
12
10
m
g
/
L
2006
8
2007
6
4
2008
2
0
S
2
4
6
10 15
20
25 30
35
C las s C
C riterion
De pth , m .
Figure 5. Dissolved Oxygen Profile in Calibato Lake
6
DO , Mohic ap ( mg /L )
12
10
2006
8
2007
m
g
/
L
6
2008
4
C las s C
C riterion
2
0
S
2
4
6
10
15
20
25
De pth , m .
Figure 6. Dissolved Oxygen Profile in Mohicap Lake
Palakpakin and Samplaloc Lakes showed slight improvement in the water quality
in terms of dissolved oxygen. In Palakpakin, the desirable DO was attained up to
2 meters in 2006 and 2007 and increased up to 4 meters in 2008. In the same
manner, Sampaloc Lake attained a DO >5 mg/L up to 4 meters in 2006 and
increased to 6 meters in 2007 and 2008.
DO , P alakpakin , ( mg /L )
m
g
/
L
10
9
8
7
6
5
4
3
2
1
0
2006
2007
2008
C las s C
C riterion
S
2
4
6
De pth , m .
Figure 7. Dissolved Oxygen Profile in Palakpakin Lake
7
DO, S ampaloc (mg /L )
m
g
/
L
9
8
7
6
5
4
3
2
1
0
2006
2007
2008
C las s C
C riterion
S
2
4
6
10
15
20
25
Figure 8. Dissolved Oxygen Profile in Sampaloc Lake
Pandin and Yambo Lakes consistently complied with the DO criterion up to 25
meters.
DO , P andin ( mg /L )
9
8
7
m 6
g 5
/
4
L
3
2
1
0
2006
2007
2008
C las s C
C riterion
S
2
4
6
10
15
20
25
De pth , m .
Figure 9. Dissolved Oxygen Profile in Pandin Lake
8
DO , Y ambo ( mg /L )
m
g
/
L
9
8
7
6
5
4
3
2
1
0
2006
2007
2008
C las s C
C riterion
S
2
4
6
10
15
20
25
De pth , m .
Figure 10. Dissolved Oxygen Profile in Yambo Lake
9
3. BIOCHEMICAL OXYGEN DEMAND ( BOD )
BOD is a measure of how much oxygen is used by microorganism in the aerobic
oxidation, or breakdown of organic matter in the streams. Usually, the higher the
amount of organic matter found in the stream, the more oxygen is used for
aerobic oxidation. The higher the BOD, the more polluted the water.
B OD 5 ,mg / L
2006
2007
12
2008
10
m
8
g
/ 6
L 4
C lass C
C riterion
2
BO
YA
M
PA
ND
IN
SA
M
PA
LO
C
OH
IC
AP
PA
LA
KP
AK
IN
M
CA
LIB
AT
O
BU
NO
T
0
Figure 11. Biochemical Oxygen Demand Levels in the Seven Crater Lakes
Bunot Lake consistently failed in the Class “C” water criterion of 7 mg/L for BOD
while Palakpakin, Pandin, and Yambo Lakes showed consistent compliance in
the BOD criterion. Sampaloc, Calibato and Mohicap
Lakes showed
improvement as evidenced by the decrease in BOD concentrations.
10
4. NUTRIENTS
4.1 AMMONIA (NH3-N)
Pure ammonia is strong smelling, colorless gas. In nature, ammonia is formed
by the action of bacteria on protein and urea. Ammonia is toxic to fish and
aquatic organisms, even in very low concentration
There is no Philippine criterion for ammonia at the moment. Instead, the
monitored data was compared with the criterion set by the Environmental Study
Board, 1973.
Pandin, Palakpakin, and Yambo Lakes consistently conformed with the criterion
of 0.2 mg/L (Environmental Study Board, 1973). On the other hand, Bunot,
Calibato, Mohicap, and Sampaloc Lakes consistently failed the criteria for
ammonia (2006-2008). The ammonia concentration ranges from 0.0163 mg/L
(Yambo, 2008) to 4.9406 mg/L (Bunot, 2007).
A mmonia , mg /L
2006
2007
ESB
C riterion
SA
M
YA
M
BO
IN
PA
LO
C
2008
PA
ND
BU
NO
T
CA
LIB
AT
O
M
OH
IC
PA
AP
LA
KP
AK
IN
m
g
/
L
6
5
4
3
2
1
0
Figure 12. Ammonia Levels in the Seven Crater Lakes
11
4.2 NITRATE (NO3-N)
Nitrogen in water is naturally derived from the atmosphere in gaseous form. In
water, it is converted to fixed forms by biological or chemical processes. Nitrate is
found in sewage discharge, fertilizer run-off, and leakage from septic system.
For 2006-2008, all the Crater Lakes conformed with the Class “C” criterion of 10
mg/L for nitrate. The nitrate concentration ranges from 0.0103 mg/L (Pandin,
2006) to 0.1709 mg/L (Sampaloc, 2008).
Nitrate , mg /L
2006
2007
YA
M
BO
PA
LO
C
IN
SA
M
PA
ND
CA
LIB
AT
O
M
OH
IC
AP
PA
LA
KP
AK
IN
2008
BU
NO
T
m
g
/
L
0.18
0.16
0.14
0.12
0.1
0.08
0.06
0.04
0.02
0
Figure 13. Nitrate Levels in the Seven Crater Lakes
12
4.3 PHOSPHATE (PO4)
Phosphate is found in fertilizer and some detergents. Phosphorus is necessary
for plant and animal growth. Too much production of these nutrients leads to
eutrophication.
For Class”C” waters, the allowable phosphate concentration is set at 0.4 mg/L.
When applied to lakes and reservoir, the phosphate concentration should not
exceed an average of 0.05 mg/L nor a maximum of 0.1 mg/L.
The annual mean phosphate concentration ranges from 0.0162 mg/L (Yambo,
2006) to 1.8585 mg/L (Bunot, 2006). Only Pandin and Yambo Lakes consistently
conformed with the Class “C” water criterion of 0.05 mg/L for phosphate while the
rest failed. Lake Bunot registers the highest concentration of phosphate.
P hos phate , mg /L
2006
2007
2008
YA
M
BO
C las s C
C riterion
BU
NO
CA
T
LIB
AT
O
M
OH
PA
IC
A
LA
KP P
AK
IN
PA
ND
SA
IN
M
PA
LO
C
m
g
/
L
2
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0
Figure 14. Phosphate Levels in the Seven Crater Lakes
13
5. CHLORIDE
Chloride anions are usually present in natural waters. A high concentration of
chloride is evident in water that is in contact with rock formation. It can also be an
indication of sewage and industrial pollution or by an intrusion of salt water into a
fresh water body. A high chloride content has a corrosive effect on metal pipes
and structure and is harmful to most trees and plants.
All the Crater Lakes conformed with the Class”C” water criterion of 350 mg/L for
chloride. The annual mean chloride concentration range from 10 mg/L (Yambo,
2006) to 29 mg/L (Pandin, 2007).
C hloride , mg /L
2006
400
350
m
300
g250
200
/
150
L100
50
0
2007
2008
YA
M
BO
PA
LO
C
SA
M
PA
ND
IN
CA
LIB
AT
O
M
OH
IC
AP
PA
LA
KP
AK
IN
BU
NO
T
C las s C
C riterion
Figure 15. Chloride Levels in the Seven Crater Lakes
14
6. TURBIDITY
Turbidity is a measure of the amount of particulate matter that is suspended in
water. Water that has high turbidity appears cloudy or opaque. The most frequent
causes of turbidity in lakes and rivers are plankton and soil erosion from logging,
mining, and dredging operation. Fish cannot see very well in turbid water and
may have difficulty finding food. On the other hand, turbid water may make it
easier for fish to hide from predators. Turbidity is measured in NTU
(Nephelometric Turbidity Unit).
The annual mean turbidity range from 1 NTU (Palakpakin, 2006 and 2008) to 28
mg/L (Bunot, 2006). Lake Bunot exhibits the highest turbidity reading (20062008). At present there is no established criterion for turbidity.
T urbidity , NT U
30
25
N 20
T 15
U
10
2006
2007
2008
5
BO
YA
M
PA
LO
C
IN
SA
M
PA
ND
OH
IC
AP
PA
LA
KP
AK
IN
M
AT
O
CA
LIB
BU
NO
T
0
Figure 16. Turbidity Levels in the Seven Crater Lakes
15
7. TOTAL DISSOLVED SOLIDS (TDS)
Total Dissolved Solids are solids in water that can pass through a filter. These
maybe anions and cations, such as carbonate, bicarbonate, calcium,
magnesium, which are necessary for aquatic life. High TDS concentrations can
produce laxative effect and can give unpleasant mineral taste to water.
Total Dissolved Solids
300
mg/L
250
200
2006
150
2007
100
2008
50
M
BO
YA
M
PA
LO
C
N
DI
N
PA
SA
PA
LA
KP
AK
IN
IC
AP
M
O
H
AT
O
C
AL
IB
BU
N
O
T
0
Figure 17. Total Dissolved Solids Levels in the Seven Crater Lakes
The annual mean Total Dissolved Solids ranges from 89 mg/L (Yambo, 2008) to
243 mg/L (Mohicap, 2007). No criterion was set for TDS. The results of annual
mean TDS are relatively close to each other.
16
8. TOTAL SUSPENDED SOLIDS (TSS)
Total Suspended Solids are solids in water that can be trapped by a filter. TSS
can include silt, decaying plants, animal matter, industrial waste and sewage.
High concentration of suspended solids can cause many problems for stream
health and aquatic life.
The annual mean TSS ranges from 1 mg/L (Pandin,2007-2008) to 41 mg/L
(Bunot,2006) Lake Bunot showed decreasing trend from 2006 to 2008. There is
no mark difference in the annual mean TSS for the other lakes..
45
40
35
30
25
20
15
10
5
0
2006
2007
M
BO
YA
SA
M
PA
LO
C
N
DI
N
PA
AK
IN
LA
KP
PA
M
O
H
AT
O
C
AL
IB
O
BU
N
IC
AP
2008
T
mg/L
Total Suspended Solids
Figure 18. Total Suspended Solids Levels in the Seven Crater Lakes
17
9. TOTAL COLIFORM/ FECAL COLIFORM
The coliform group is used as an indicator of the sanitary quality of the water
because its presence in the water body would suggest fecal contamination or
would indicate the disease-producing potential of the water. Ideally, water should
not contain any microorganisms known to be pathogenic or any bacteria
indicative of fecal pollution. In order to estimate the probability of the pathogens
being contributed from human feces as well as from animal droppings, the total
coliform and fecal coliform must be quantified. High counts of coliform bacteria
will render the water unsuitable for domestic water supply, fishery, agricultural,
recreational and some industrial uses.
The annual geomean of total coliform of 6361 MPN/100 ml at Bunot Lake in
2006 exceeded the Water Quality Criterion for Class C of 5000 MPN/100 ml.
However, the annual total coliform geomean of 812 MPN/100 ml in 2007 and 963
MPN/100 ml in 2008 both met the Water Quality Criterion for total coliform of
5000 MPN/100 ml. The other Crater Lakes like Yambo, Calibato, Palakpakin,
Sampaloc and Mohicap met the Water Quality Criterion for Class C of 5000
MPN/100 ml for 2006, 2007 and 2008.
Total Coliform
6000
Class C Criterion
MPN
5000
5000 MPN/100
2006
Year
4000
3000
2000
2007
1000
0
Bunot
Calibat o
Mohicap
Palakpakin
Pandin
Sampaloc
Yambo
2008
Crater Lakes
Figure 19. Total Coliform Counts in the Seven Crater Lakes
During the study period the annual geomean of fecal coliform was highest at
Bunot Lake recorded at 1603 MPN/100 ml, 399 MPN/100 ml and 660 MPN/100
ml in 2006, 2007 and 2008, respectively. This was followed by Yambo with a total
annual geomean for 3 years (2006-2008) of 1404 MPN/100 ml. Palakpakin was
third with a fecal coliform annual geomean measured at 1062 MPN/100 ml,
followed by Calibato with 976 MPN/100 ml, Mohicap with 893 MPN/100 ml and
Sampaloc with 543 MPN/100 ml. The least in terms of fecal coliform
concentration was measured at Pandin with 498 MPN/100 ml.
Bunot Lake gave the highest annual geomean of total and fecal coliform during
the three (3) year study period as compared with the Other Crater Lakes which in
18
effect indicated the increasing aquaculture and human activities. Urban
development is often reported as a factor that could affect bacterial count in lakes
because human and domestic animal wastes, are potential sources of
contamination and can increase with present urban development.
Fecal Coliform
1600
1400
2006
Year
MPN
1200
1000
800
2007
600
400
2008
200
0
Bunot
Calibato
M ohicap
Palakpakin
Pandin
Sampaloc
Yambo
Crater Lakes
Figure 20. Fecal Coliform Counts in the Seven Crater Lakes
19
10. CHLOROPHYLL –a
Chlorophyll-a is an indicator of phytoplankton standing biomass in the water
body.
The cholorophyll –a annual averages for Calibato, Palakpakin Pandin and
Mohicap Lakes were increasing in trend, while Sampaloc Lake, Bunot Lake and
Yambo Lake showed fluctuations in the concentrations. The highest annual
chlorophyll-a reading was measured at 150.63 ug/L in Bunot Lake in 2008 and
the lowest annual average reading was 12.3 ug/L recorded at Lake Pandin in
2006. Bunot Lake registered the highest concentration in three (3) years with an
average of 124.26 ug/L, while Pandin Lake got the lowest average during the
three-year period measured at 24.96 ug/L.
The high transparency measurements could have affected the high Chlorophyll-a
concentration particularly in Calibato, Palakpakin, Pandin and Mohicap Lakes.
160
140
120
100
80
60
40
20
0
2006
2007
am
bo
Y
oc
an
di
n
P
am
pa
l
S
P
al
ak
pa
ki
n
oh
ic
ap
M
C
B
al
ib
at
o
2008
un
ot
ug/L
Chlorophyll-a
Figure 21. Chlorophyll-a Levels in the Seven Crater Lakes
20
11. PHYTOPLANKTONS
Phytoplankton, also known as algae, is a microscopic aquatic plant commonly
found in lakes and other bodies of water. It plays a vital role in aquatic
productivity because it occupies the first link in the food chain for being the
primary producer. Phytoplankton serves as food for the zooplankton, fish, benthic
fauna and other aquatic organisms. Its abundance is mainly dependent upon the
light intensity, turbidity, and nutrients availability among other factors.
Calibato was the most diversified among the crater lakes with a total of 36
genera identified. It is followed by Bunot with 32 genera and Palakpakin with 30
genera. Sampaloc and Yambo are the least diversified with 26 genera.
The algal composition in the seven crater lakes belong to four (4) divisions,
namely, Cyanophyta (bluegreen), Chlorophyta (green), Bacillariophyta (diatom)
and Pyrrophyta (dinoflagellates).
The phytoplankton counts by group for the crater lakes are presented in the next
table.
Bluegreen
Green
Diatoms
Dinoflagellates
Total
154322
47113
58922
28901
18168
83525
9385
9084
29647
1807
269
2227
194415
74634
174321
5985
3991
218791
13127
13265
27504
14076
5746
78369
155
134
3827
33343
23136
328491
5893
78850
304230
15567
17867
14524
9265
11218
37617
186
282
4593
30911
108217
360964
99690
4610
41671
5194
3442
23327
164933
12892
146737
1563
1294
5400
271380
22238
217135
2494
8617
60540
16380
498
3558
3523
831
20265
76
159
1276
22473
10105
85639
15567
53815
281583
7946
1532
42233
10734
9358
101836
27
10
380
34274
64715
426032
Bunot
2006
2007
2008
Calibato
2006
2007
2008
Mohicap
2006
2007
2008
Palkpakin
2006
2007
2008
Pandin
2006
2007
2008
Sampaloc
2006
2007
2008
21
Yambo
2006
2007
2008
316
29388
89643
4712
4065
27653
1991
38465
56022
33
3666
1220
7052
75584
174538
Table 2. Phytoplankton Counts by Group
Microcystis sp., a blue green algae, was the dominant species in almost all of the
lakes for the period 2006 to 2008.
Green algae became dominant in Bunot in 2008, in Calibato in 2007, in Mohicap,
Yambo and Pandin in 2006.
Diatoms such as Melosira sp. and Stephanodiscus sp., consistently dominated
the algal population in Palakpakin Lake for three years. Diatoms also was the
dominant groupin Calibato in 2006 and in Yambo in 2007.
Dinoflagellates remained low in number.
The annual total phytoplankton counts for the seven lakes are presented in
Figure 22. 2008 registered the highest total counts for Calibato, Sampaloc,
Pandin, Mohicap and Yambo. For Bunot and Palakpakin, the highest counts
were registered in 2006.
450000
400000
350000
300000
250000
200000
150000
100000
50000
0
2006
2007
bo
Ya
m
pa
lo
c
Sa
m
Pa
nd
in
Pa
la
kp
ak
in
M
oh
ic
ap
C
al
ib
at
o
2008
Bu
no
t
Counts/mL
Total Phytoplankton Counts
Figure 22. Total Phytoplankton Counts in the Seven Crater Lakes
22
12. ZOOPLANKTONS
Zooplankton occupies the consumer level in the food chain. These consumers
utilized the phytoplankton as food. The zooplankton identified belonged to three
(3) major groups namely: Rotifera, Cladocera, and Copepoda.
Copepoda was the dominant species in Bunot, Palakpakin, Pandin and Yambo
throughout the three year period. It was also dominant in Calibato and
Samplaloc in 2006 and 2008, and in Mohicap in 2006 and 2007.
Rotifera dominated the zooplankton counts in Calibato and Samplaoc in 2007, in
Mohicap in 2008.Cladocera remained consistently low in number.
Rotifer
Cladoceran
Copepod
Total
14
13
89
8
4
12
94
29
136
116
46
237
6
14
99
4
2
23
20
13
168
30
29
290
5
3
233
5
3
10
38
22
130
48
28
373
4
6
29
3
3
13
29
30
58
36
39
100
5
7
38
2
11
21
87
41
97
94
59
156
3
53
73
5
2
28
64
18
187
72
73
288
0
3
7
0
4
7
6
24
42
6
31
56
Bunot
2006
2007
2008
Calibato
2006
2007
2008
Mohicap
2006
2007
2008
Palakpakin
2006
2007
2008
Pandin
2006
2007
2008
Sampaloc
2006
2007
2008
Yambo
2006
2007
2008
Table 3. Zooplankton Counts by Group
23
The total zooplankton counts for the seven crater lakes are shown in the Figure
23. There was a significant increase in the zooplankton population in all the
lakes in 2008.
Total Zooplankton Counts
Counts/mL
400
350
300
250
2006
200
150
2007
2008
100
50
bo
Ya
m
pa
lo
c
Sa
m
Pa
nd
in
Pa
la
kp
ak
in
M
oh
ic
ap
al
ib
at
o
C
Bu
no
t
0
Figure 23. Total Zooplankton Counts in the Seven Crater Lakes
24
IV. RECOMMENDATIONS
The Seven Crater Lakes are extremely threatened by the resulting pollution from
the surrounding areas (domestic wastes pollution and solid wastes), by illegal
fishpens, crowded fishpens and overfeeding using artificial feeds.
The case of Samplaoc lake is a good example of rehabilitation measures being
done in San Pablo. A number of settlers in the area had been relocated, hence
the discharge of untreated domestic wastes had been reduced. As a result, the
Biochemical Oxygen Demand (BOD) and the Dissolved Oxygen has improved.
In order to arrest further degradation of the lakes, it is recommended that the
following be implemented and sustained:





Zoning and Management / Development Plan
Compliance to 10 % aquaculture area as provided by RA 8550 ( Fishery
Code )
Appropriate feeding practices in the aquaculture structures
Adequate treatment of wastes before discharge into the lake
No introduction of invasive species such as jaguar guapote and red pacu.
.
25

water quality report of - Laguna Lake Development Authority

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