Case Study Mass Mortalities BMPark

CASE STUDY ON THE OCCURRENCE OF MASS MORTALITIES IN
BALINGASAG MARICULTURE PARK
VIANNEY ANTHONY A. GAPUZ
MSc in Aquaculture Student
CLEVIN LIBAY
MSc in Aquaculture Student
LISA MATAQUIEL
MSc in Aquaculture Student
INTRODUCTION:
The Department of Agriculture – Bureau of Fisheries and Aquatic
Resources (DA-BFAR) through its Regional Field Office (RFO) 10
together with the support of the Local Government Unit (LGU) of
Balingasag established the Balingasag Mariculture Park in 2006. A
Mariculture Park concept is patterned after the Industrial Park
wherein the government provides the infrastructure while the different
investors put up their businesses (e.g. manufacturing plants, assembly
plants). In a mariculture park, the government provides the mooring
systems for marine cages considering that this is aquaculture in off
shore waters and consolidate and regulate support industries.
For over a decade, the production of milkfish in Region 10 has
tremendously increased. The bulk of the production is attributed to
the mariculture park in Balingasag. Although there were also produced
from brackishwater ponds in the provinces of Lanao del Norte and
Misamis Occidental, but the production ballooned after its
establishment. The presence of Balingasag MP not only yielded an
increase in production but also generates job.

The Epizootic
However, since the second half of 2017, incidence of mortalities
in fish cages has been observed. Based on interview of caretakers,
mortalities per cages upon harvest ranges from 10 to 20% and in some
instances would reach 40%. Much of the mortalities according to
caretakers, occurs during the conditioning of fingerlings in marine
cages. Bangus fingerlings are reared from fry to “5 inches”
fingerlings in brackishwater ponds. Mortalities are also observed
during the first month in grow-out cages. This case study takes a look
into possible reasons of the incidence of mass mortalities based from
conducted fish kill investigation, previous water quality monitorings
and fisherfolk interview; and recommended solutions for this
phenomenon. This case study focuses on the fish health management of
the mariculture park.
FISH KILL / MASS MORTALITIES
According to Meyer and Barclay as cited by Van and Cooke (2011)
fish kill is generally defined as localized mass die offs of fish that
can occur in marine, estuarine, or freshwaters. Fish kills are common
phenomenon.
In the Philippines, the major fish kill event that has affected
the aquaculture industry was the one that happened in 2002 at Bolinao,
Pangasinan. The site of the fish kill was in the waters of Bolinao,
an embayment on the western side of the Lingayen gulf and with an
average depth of 5 meters. The topography suits well for fishpen as
well as fish cage culture. This embayment is where intensive culture
of bangus is located. Fishpens in the area at the time of the fish
kill reach 1,000 plus units even if the limit was only 544 units based
on its carrying capacity. Each unit of fish pen measuring 1400m 2 to

2886m 2 has an average stocking density of 29,000 to 35,000 pcs of
bangus fingerlings. Each fishpen with stocked bangus need 12 bags of
feeds every day. The said fish kill also coincided with the sudden
bloom of dinoflagellate Prorocentrum minimum. Prior to the fish kill,
dissolved oxygen was <2.0mg/l in stratified waters. AT that time, the
Since the establishment of mariculrue parks in the region, the
first reported major fish kill that has occurred is during the
occurrence of Harmful Algal Bloom (HAB) Cochlodinium polykrokoides in
March 2016. During the occurrence of HAB from March to April 2016,
the reported number of mortalities from Balingasag Mariculture Park
is 45,594 pcs (BFAR 10 interdivision report). The estimated loss from
this fish kill phenomenon ranges from Php 500,000.00 to Php 1 million
pesos.
The present fish kill incidence in Balingasag Mariculture Park
is a first of its kind considering that the mortalities occurs in
random location throughout the area and the numbers are not that huge
immediately but at low in number but continuous mortalities. Fish kill
incidence started in the second half of 2017. It is not that massive
that it creates immediate impact but it is more of a low profile
mortality but after the culture period, fish cage operators realize
that the number of mortalities has significantly affected the
economics of the aquaculture investment. Due to its “low mortality
profile” operators sometimes does not report the mortalities as a
major fish kill. The occurrence of mortalities has led to almost all
operators to increase the stocking density in the belief that it will
offset the mortality losses starting in conditioning cages.

Estimated Number of Mortalities
The estimated total number of mortalities can be based from the
following statement from mariculture park caretakers and operators:
Mortalities starts in conditioning cages at 1% per day until
stocking in grow-out cages or until it reaches an ABW of 200
grams.
The prevailing FCR is 3.0 compared during the early years of the
mariculture park where FCR ranges from 2.0 to 2.2.
In a given time, not all cages are affected of the incidence of
mass mortalities. No specific area is affected. Fish kills just
happened at random.
In a given time, around 40% of the cages are affected.
In the mariculture park, it has been “standardized” that for
every 1,000 pcs fingerlings you need about 25 bags of feeds until
marketable size of 350 to 450 grams. In getting the estimated
mortalities, we based the computation on this feed consumption
standard.
In conditioning cages, the number of mortalities, based on the
1% assumption, after acclimatization of fingerlings to the marine
environment prior to grow-out cages is estimated at 3,000 pcs. For
grow-out cages, after 2-3 months of culture, the estimated mortality
is 4,500 pcs. In Norwegian cages, the estimated mortality is 18,000
pcs. Table 1 presents the estimated mortalities based on the 1%
mortality and the prevailing stocking density and the recommended
stocking density.

Table 1. Estimated Mortalities from the Fish Kill Phenomenon in
Balingasag Mariculture Park Based on the 1% Mortality Observation
No. of
Cages
Type of Cages
Stocking
Density
No. of Days
Culture Where
Mortalities
Are Observed
Estimated
Mortality
(1%)
TOTAL
1 Conditioning Cages 10,000 30 0.01 3000
Grow-out Cages 10m x
1 10m; 100sq m 15,000 30 0.01
4500
Grow-out Cages 15m dia;
1 176 sq m 60,000 30 0.01
18000
Using the prevailing Feed Conversion Ratio (FCR) at 3 during the
fish kill phenomenon, the expected mortalities from 10m x 10m bamboo
cages (100 sq m) and Norwegian Cages (176 sq m) is 5,530 pcs and
22,121 pcs respectively. These mortalities are based on the increase
stocking rate of 15,000 pcs per cage from the recommended rate of
10,000 pcs per cage for a 10m x 10m cage and 60,000 pcs per cage from
the recommended rate of 40,000 pcs per cage for the Norwegian Cage.
Table 2 presents the estimated production and estimated harvest based
on the recommended stocking rates and the prevailing stocking rates
for the grow-out cages.
Table 2. Estimated Production and Mortalities based on the Recommended
and Prevailing Stocking Rates
10m x 10x bamboo cage
FCR
TOTAL FEED Stocking
(bags) Density
PRODUCTION EST EST NO. OF PCS
2 250 10,000 3,125 9,470
2 375 15,000 4,688 14,205
3 375 15,000 3,125 9,470
Norwegian Cage 15m diameter 176 sq m
FCR
TOTAL FEED Stocking
(bags) Density
PRODUCTION EST EST NO. OF PCS
2 1000 40,000 12,500 37,879
2 1500 60,000 18,750 56,818
3 1500 60,000 12,500 37,879

Table 2 also shows the estimated production when the stocking
rate is increased to 15,000 pcs per cage for the 10m x 10m and 60,000
per cage for the Norwegian Cages and when FCR is at 2. The production
is very high. But when the incidence of mass mortalities occurred,
the FCR was less desirable and increased to 3 due to the mortalities.
The table also shows the increased bags of feeds used when stocking
density is increased.
WATER QUALITY and MONITORING
The DA – BFAR RFO 10 has been conducting regular water quality
monitoring in the mariculture park since its establishment. The
parameters that are monitored are as follows:
1. Dissolved Oxygen
2. Temperature
3. Salinity
4. pH range
5. Total Dissolved Solids
6. Ammonia - Nitrogen (NH3) Levels
7. Ammonia - Nitrates Level
8. Ammonia – Nitrites
The parameters that were not regularly monitored are as follows:
1. Alkalinity
2. Phosphorus
3. Heavy Metals
4. Pesticides
5. Coliform Bacteria
Through the years, the water quality parameters monitored by DA
– BFAR 10 were within optimum levels for aquaculture except during

the fish kill incidence caused by the dinoflagellate Cochlodinium
polykrokoides and the present fish kill phenomenon experienced by the
mariculture park today. Table 3 shows the optimum levels of some of
the water quality parameters for marine cage culture.
Table 3. Optimum levels for some of the water quality parameters
regularly monitored by DA – BFAR RFO 10
Water Quality Parameter
Optimum Level for
Aquaculture
Dissolved Oxygen
> 5mg/L
Temperature 26°C - 32°C
Source
pH 6.5 to 9.0
Salinity
28 - 35 ppt
Lawson 1995, Tarazona
and Munoz 1995
Ammonia - Nitrogen < 0.01 mg/l Zweig Morton and Stewart
Ammonia - Nitrite < 0.1 mg/l Pillay 1992
Ammonia - Nitrate < 100 mg /l Pillay 1992
Observed Water Quality Parameters During the Height of Fish Kill
Phenomenon (January 22 to 26, 2018)
At the onset of the fish kill phenomenon from October 2017 to
January 2018, the DA-BFAR RFO 10 through its Fish Health Laboratory
Section collected water samples in identified stations in order to
determine the condition of the waters in mariculture park.
The water quality parameters gathered were the following:
1. Dissolved Oxygen
2. Temperature

3. Salinity
4. Turbidity
5. pH
6. Total Dissolved Solids
7. Chlorophyll
8. Ammonia – Nitrogen Level
9. Ammonia – Nitrate Level
10. Water Current
The data gathered is shown in Table 4 for dissolved oxygen
readings and the water quality parameters readings is shown in Table
5. Figure 1 shows the average dissolved oxygen level in all sampled
stations in the mariculture park relative to depth of the water.
Figure 1. Mean DO levels in all samplings stations relative to depth.

1. Dissolved Oxygen
In any aquaculture activity, dissolved oxygen is one of the most
important parameters that is always considered first. In any fish kill
phenomenon, dissolved oxygen of the water is the first to be look
into.
A study by Roa et. al (2017) on the seasonal variation of water
quality in mariculture parks reveals that the average dissolved oxygen
in the cage area throughout the year is 6 mg/L or greater. Unlike in
some mariculture parks where DO levels goes down as low as 3 mg/L
depending on the season (NE monsoon, SW monsoon and Easterly Winds)
(Figure 6). The study was conducted when the mariculture park is
already fully operationalized and that year production reach 2,222
mt.

Table 4. Dissolved Oxygen Readings on January 22, 2018 – During the
Fish Kill Phenomenon
Dissolved Oxygen Monitoring
Station Depth
DO level (12NN DO level (4AM to
to 3PM
8AM)
1 1.2 2.03 2.38
1 2 1.03 1.91
2 0.8 2.03 2.56
2 6.9 2.24 2.27
2 13.4 1.69 2.7
3 0.3 3.93 2.94
3 7.5 2.38 2.85
3 14 2.29 2.74
4 7.8 5.52 3
4 8.3 1.94 2.94
4 12 1.5 2.77
5 0.2 3.4 3.28
5 1.2 2.97 3.06
5 2.4 1.82 1.82
6 3.42 1.73 3.98
6 6 1.99 2.23
6 12.7 1.89 2.36
7 1.3 2.4 3.32
7 5.9 2.81 2.81
7 10.7 2.4 2.8
8 1.4 2.98 3.71
8 6.8 2.13 3.15
8 13.7 2.18 3.03
9 0.2 2.55 3.17
9 7.4 2.42 2.56
9 13.5 2.23 2.44
10 0.8 2.6 2.91
10 2.8 2.26 2.2
10 6.2 2.45 2.18

Table 5. Water Quality Parameters Gathered by DA BFAR RFO 10 During
Date
Turbidity
Total
Temperature Salinity Range
Clorophyll
Range pH Range
Dissolved
Range ( °C ) (ppt)
( ug/L )
(NTU)
Solids
January 22, 2019 27.62 to 29.9 30.76 - 34.47 0.6 - 4.7 7 - 7.7 2.7 - 4 30 - 83
January 23, 2019 27.5 to 28.59 32.55 - 34.88 0.6 - 5.6 7.7 - 8.28 1.2 - 3.2 32.21 - 34.48
the Fish Kill Phenomenon
Figure 2. Average Dissolved Oxygen (DO) levels from 12nn to 3pm in
all sampled stations at varying depth
The dissolved oxygen levels taken during the on-going fish kill
is way below the optimum level for fish survival and growth. The depth
level critical to aquaculture activity in the area is 1m to 4m. DO
levels at these depth ranges only from 1.7 mg/L to 2.9 mg/L taken from
12nn to 3pm; and 2.7 mg/L to 3.98mg/L taken from 4am to 8am. This is
shown in Figure 2 and 3 respectively. A study by Roa et. al showed
that the mean DO levels in the sampling stations of the mariculture
parks is consistently at 6 mg/L or higher.

Figure 3. Average Dissolved Oxygen (DO) levels from 4am to 8am in
all sampled stations at varying depth
Figure 4. Mean Dissolved Oxygen Levels in Balinagsag MP from the study
by Roa et. al. (2017) on the Seasonal Variation of Water Quality of
the Selected Mariculture Parks in Northern Mindanao, Philippines

2. Temperature and Salinity
The observed temperature and salinity values during the on –
going fish kill is within the optimum level for aquaculture. The
observed temperature readings are comparable as observed by Roa et.
al. (2017) in the water quality monitoring studies. Figure 5 shows
the mean temperature levels based on a study by Roa et. al. (2017).
Figure 5. Observed temperature in Balingasag MP as presented by Roa
et. al. (2017) on their study on Seasonal Variation of Water Quality
of the Selected Mariculture Parks in Northern Mindanao, Philippines
3. Turbidity
Turbidity as stated by Loka (________) indicates the degree
optical clearness of sea water affected by the existence of dissolved
matters, suspended particles and also tides and water currents. The
suspended particles should be < 2 mg/L for cage farming of fish in
marine waters. The two major sources of turbidity in cage culture are
fish wastes and feed particulates.

The turbiduty readings in Balingasag Mariculture Park during the
fish kill phenomenon ranges from 0.6 to 4.7 and 0.6 to 5.6 NTU. This
is equivalent to 0.2 to 1.9 mg/L suspended particles.
According to Loka (__________) increase in turbidity of water
results in decrease in light penetration, which in turn affects the
phytoplankton production and may further affect photosynthesis of
benthic vegetation, and this leads to an increase in microbial loads
and in ammonia levels at the cage culture site.
4. Total Dissolved Solids
According to PILMINAQ (2008) total solids refer to any matter
either suspended or dissolved in water. Everything that retained by
a filter is considered a suspended solid, while those that passed
through are classified as dissolved solids, i.e. usually 0.45μ in size
(American Public Health Association, 1998). Concentrations in water
are both measured as Total Suspended Solids (TSS) and Total Dissolved
Solid (TDS), respectively.
Suspended solid (SS) can come from silt, decaying plant and
animals, industrial wastes, sewage, etc. They have particular
relevance for marine organisms that are dependent on solar radiation
and those whose life forms are sensitive to deposition. Dissolved
solid (DS), on the other hand includes those materials dissolved in
the water, such as, bicarbonate, sulphate, phosphate, nitrate,
calcium, magnesium, sodium, organic ions, and other ions. These ions
are important in sustaining aquatic life (PILMINAQ 2008)
The Total Dissolved Solids observed during the fish kill
phenomenon is 30 – 83 mg/L and 32.21 – 34.48 mg/L (Table 5). The study
by Roa et al (2017) revealed a Total Suspended Solid (TSS) within the
optimum level as it is below 0.8 mg/L (Figure 6)

TSS levels revealed to be also within the permissible limit of
0.08 g solids/L (DAO, 2008) for fish propagation and 400 mg or 4 g
solids/L for mussel grow-out (Prema 2013).
Figure 6. Total Suspended Solids in Balingasag MP as presented by Roa
et. al. (2017) on their study on Seasonal Variation of Water Quality
of the Selected Mariculture Parks in Northern Mindanao, Philippines
5. pH
According to Boyd (1998) as cited by PILMINAQ, the optimum pH of
marine fishes is between pH 7.5 to 8.5. pH can affect the health of
the fish in terms of the ability of the fish to maintain its salt
balance. The observed pH during the recent fish kill phenomenon ranges
from 7.0 to 8.28 and is shown in Table 5. pH can also be toxic at
certain levels. Extreme pH levels can damage gill surfaces of fishes
leading to death. Extreme pH can also toxicity of several common
pollutants like ammonia and heavy metals (Prema, 2013).

6. Chlorophyll a
A study by Bbalali et al (2013) stated that chlorophyll is the
major photosynthetic pigment in a lot of phytoplankton and a trophy
index in aquatic ecosystems. Chlorophyll a (Chl a) is often used as
an estimate of algal biomass, with blooms being estimated to happen
when Chl a concentrations go above 40 μg /L. So methods for the
estimation of the growth and development of the phytoplankton
community is to perform an analysis of photosynthetic pigments, even
though the content of chlorophyll in the cells changes with the
availability of light and thus with depth and trophic gradient.
The study by Bbalali et al (2013) illustrated that that there
was a significant correlation between chlorophyll a and logarithm
chlorophyll a with nitrate, nitrite (P<0.01) and ammonia (P<0.05) but
there was no significant correlation between chlorophyll a and
logarithm chlorophyll a with silica, total alkalinity, sulfate and
resolve phosphorus (P>0.05).
BFAR RFO 10 does not have past records of “chlorophyll a”
readings in mariculture park except during the recent fish kill
phenomenon. Chlorophyll readings at 2.7 – 4ug/L and 1.2 – 3.2ug/L
presented in Table 5 is below the chlorophyll a limits that would have
resulted in an algal bloom.
7. Ammonia – Nitrogen and Ammonia – Nitrates
According to Prema (2013) the level of ammonia-nitrogen in the
water should preferably be less than 0.1 mg/L. The total inorganic
nitrogen desirable for culture is < 0.1 mg l/L.
Lawson (1995) as cited by PILMINAQ (2008) stated that high
concentrations of ammonia causes an increase in pH and ammonia

concentration in the blood of the fish which can damage the gills,
the red blood cells, affect osmoregulation, reduce the oxygen-carrying
capacity of blood and increase the oxygen demand of tissues (Lawson,
1995).
The ammonia – nitrogen levels and ammonia – nitrate levels from
the Balimngasag Mariculture Park during the fish kill phenomenon was
way above the required limit for aquaculture. Ammonia – Nitrogen
ranges from 0.05 to .5 mg/L (Figure 7a) while ammonia – nitrate reach
10 mg/L (Figure 7b). The limits for ammonia – nitrogen and ammonia
nitrate is 0.05 mg/L and 0.25 mng/L respectively.
Figure 7a. Ammonia – Nitrogen

Figure 7b – Ammonia nitrates
8. Harmful Algal Blooms
Unfortunately, plankton analysis was not conducted during the
fish kill phenomenon. Increase population or presence of was not
verified during the fish kill phenomenon.
9. Other Findings by DA BFAR RFO 10
Fish Health experts from DA BFAR has the following observations
after collecting fish samples from the site:
a. After dissection lesions from the internal organs,
particularly liver and spleen, were seen. The lesions
include enlargement, deviation from the normal color of
the organ and hemorrhages from being petechial to
localized or diffused distribution

b. Secondary bacterial infection by Vibrio alginolticus,
Vibrio parahaemolyticus and Aeromonas hydrophilla /
caviae, Staphylococcus sciuri and Edwardsiella hoshinae
after bacterial isolation and identification from the
liver and spleen of the fish using Analytical Profile
Index.
c. Negative results from collected spleen samples using
molecular analysis particularly Insulated Isothermal
Polymerase Chain Reaction (IIPCR) detection for Red Sea
Bream Iridoviral Disease.
d. Histopathological lesions seen at the liver includes
nuclear pleomorphism, bile stagnation, vacuolation of
hepatocytes and sinusoid dilation and dearrangement of
gill lamellae.
DISCUSSION
Increased Stocking Rates
The production from the Balingasag MP has increased by 1,000 MT
since 2014. From a production of 2220.6 MT in 2014 it rises up to
3,010.23 MT in 2018 (Figure 8). Since 2016, its contribution to the
regional milkfish production has been above or within the 20%
contribution.
The increased in production comes from the increased in number
of Norwegian cages installed and also from the increased in stocking
rates of bangus per square meter. Table 6 shows the stocking rates in
2014, which was also the recommended rates. In 2014, the number of
cages in the mariculture park was only 148 units in which only 28 are

Norwegian cages. The stocking rate for a 10m x 10m bamboo cage is
15,000 pcs / cage while that of the Norwegian cage is 40,000 pcs. In
2017 the 10m x 10m cages increased by 125 units and the Norwegian
cages have increased by 80 units. The stocking density in Norwegian
cage also increased from 40,000 pcs to 80,000 pcs / cage. Based from
the following data the mariculture park stocking density increased
from 902 pcs / m 2 in 2014 to 1,080 / m 2 in 2017. The intensity of
culture in the mariculture park has increased.
Figure 8. Milkfish Production in Balingasag Mariculture Park from
2007 to 2018.
Figure 9. Percentage Contribution of Balingasag MP to the Regional
Milkfish Production.

Table 6. No. of cages in Balingasag and the recommended and the actual
stocking rates in Balingasag Mariculture Park in 2014.
The Balingasag Mariculture Park, is a 195.07 hectare municipal
waters which covers five coastal barangays. The proposed function of
the park is a center for fisheries and aquaculture activities, ranging
from finfish culture, shellfish culture, sea ranching and mangrove
rehabilitation area where mangrove aquaculture will be established.
However, only finfish culture activities specifically bangus culture
in cages has been successful and became highly commercialized.
The park was established in 2006, and ever since the aquaculture
wastes from the park has not been removed since the park depends on
the current movement to disperse its excess nutrients and wastes. With
the increased stocking rates, the amount of wastes within the park
has also been increased but the ability of the area to disperse the
wastes remain the same since its establishment.
Although the production of the park has increased in 2018
compared to that of 2014, its productivity rate has decreased from
0.37 MT/m 2 in 2014 to 0.20 MT/m 2 in 2018. The decrease productivity of
the park can be attributed to lot of factors and these needs to be
studied further.

On Water Quality in the Mariculture Park
Dissolved Oxygen (DO) levels were very low and it was below the
required optimum level for marine cage culture at 6mg/L. The DO levels
from 2 – 4 meters were very unstable. The DO levels in open waters is
usually = or > than 5mg/L so the DO readings is very unusual. The low
DO levels may be attributed to the increase in concentration of
microorganisms within the cage area because of increase in excess
nutrients (wastes) as shown in the turbidity readings, total suspended
solids (TSS) and ammonia levels. The increase in microorganisms means
increase utilization of DO within the cage area. The level of nitrogen
– ammonia and nitrogen – nitrate is above the acceptable level of
ammonia for any aquaculture operations. High levels of ammonia can be
attributed to high excess nutrients (feed wastes). The possible
reasons for the excess in nutrient (feed wastes) are inefficient
feeding system, low quality feeds and overfeeding.
Harmful Algal Blooms
As discussed earlier, presence of Prorocentrum minimum and
Cochlodinium polykroides were not validated since plankton analysis
was not conducted. But based on chlorophyll a readings, its states
that the level does not warrant algal blooms.
Nutritional and Other Factors
Observations on histopathological lesions seen at the liver
includes nuclear pleomorphism, bile stagnation, vacuolation of
hepatocytes and sinusoid dilation and dearrangement of gill lamellae

may indicate deficient in certain nutrients like lipids, vitamins and
minerals. The highly intensification of the aquaculture system puts
additional stress to the cultured organisms. If proper nutrition is
not supplied it leads to low metabolism and mortalities.
Vibrio parahaemolyticus and Aeromonas hydrophilla / caviae,
Staphylococcus sciuri and Edwardsiella hoshinae are all secondary
pathogens. However, Vibrio parahaemolyticus may become virulent when
intensity of culture operations is increased. V. parahaemolyticus
usually occurs in brackihwater ponds. This is the case of Penaeus
vannamei when, the bacteria became virulent and causes huge
mortalities to highly intensified shrimp ponds.
Bangus fingerlings are reared in brackishwater ponds in Lanao
del Norte and Misamis Oriental, with Lanao as the major fingerling
producing area. Lanao del Norte is also the major producers for our
prawn Penaeus monodon and in some case Penaeus vannamei. Since most
of the mortatlities occurs in conditioning cages when the fingerlings
from the brackishwater ponds are being acclimatize to seawater
conditions. There is a probability that because of the high intensity,
the bacteria present becomes virulent and causes mortalities.
RECOMMENDATIONS
1. Lower the stocking density in the mariculture park as a whole.
The LGU should open up a temporary area for culture while certain
areas are being rested. The culture area for the park may
subdivided into four areas and each area will have “closed
season” for six months to one year. The stocking rates should be
much lowered as practiced in 2014. Norwegian cages should only
be stocked with 30,000 pcs bangus and bamboo cages should be
stocked with only 10,000 pcs.

2. Check the actual nutritional value of the feeds. Check the
feeding system in the area. There should be a system wherein the
LGU can monitor the total amount of feeds (nutrients) poured
into the area. This can be regulated by the LGU.
3. Check the quality of fingerlings being stocked in the mariculture
park and it should be free from any potential diseases.
4. Its high time that the mariculture park establishes the
Integrated Multi-Trophic Aquaculture, so that their will
extractive culture organism both for excess organic and
inorganic compounds. This can be done by culturing oysters and
green mussel and seaweeds.
5. The distance between Norwegian cages should be look into.
6. A study to get the actual and the real situation of the carrying
capacity of the mariculture park should be immediately
conducted. This include bottom sediment analysis and excess
nutrient dispersion within Macajalar Bay.
REFERENCES:
Azanza R.V., David L.T., Borja R.T., Baula I.U., Y. Fukuyo 2006 An
Extensive Cochlodinium bloom Along the Western Coast of Palawan,
Philippines
Chinabut, S. (_____________) A Case Study of Isopod Infestation in
Tilapia Cage Culture in Thailand
Ferrer A.J.G., Francisco H.A., Predo C.D., Carmelita B.M.M., J.C.
Hopanda
2017 The First 15 years of Mariculture Parks in the Philippines:
Challenges and the Way Forward

Khan W., Vahab A., Mosood A., N. Hasan 2018 Water Quality and
Management
Strategies for Fish Farming (A Case Study of Ponds Around Gurgaon
Canal Nuh Palwal)
Loka, J. (_____________) Importance of Water Quality in Mariculture
Prema D. 2014 Site Selection and Water Quality in Mariculture
Price C., Black K.D., B.T. Hargrave, J.A. Morris Jr., 2015 Marine Cage
Culture and the Environment: Effects on Water Quality and Primary
Production
Roa E.C., Prado G.I., Quiao M.A.D., Pena G.D. de la, J.N.Gorospe, 2017
Seasonal Variation of Water Quality of the Selected Mariculture
Parks in Northern Mindanao
Van, LA. T., S.J. Cooke 2011 Advancing the Science and Practice of
Fish
Kill Investigations
****** PHILMINAQ, 2008 PHILMINAQ: Mitigating impact from aquaculture
in the Philippines. PHILMINIQ final activity, recommendations and
conclusions report. 6th Framewrok Programme. 8/2006 to 02/ 2008. Annex
2. Water quality criteria and standards for freshwater and marine
aquaculture.