Water characteristics for culturing fish.pptx

Water for culturing fish
Presented by : Fakeh Iqbal
Roll No:424 -M.phil-(M)Z-21

Water Sources
 Municipal water
 Tube well water
 Rain water/ Runoff water
 Surface water
 Ground water

Municipal water
Municipal water is tap water that's sent to various industries and homes
through pipes that have been placed underground. This water is fully
treated and processed before it's sent to these destinations, which means
that the majority of impurities are removed before you drink the water or
use it when taking a shower.
There are some advantages and dis advantages of municipal water in
culturing a fish.

Municipal water
Advantages
 Its easy to use
 Quality is good than other water
sources
Disadvantages
 It is expensive to achieve large
amount of water
 It may contain toxic chlorine or
chloramines
 To clean toxins cost is very high
 It may cause deficiency for humans

Rain water/ Runoff water
It is the water which comes from rain and then collected for different
purposes. It is called runoff because it enters into other sources after
falling down on earth. After raining this water enters into ocean lakes
streams etc.
It can be used in those areas where rain is high and annual evaporation is
low.
There are some advantages and disadvantages of this water for culturing
fish.

Rain water/ Runoff water
Advantages
 Inexpensive
 Does not have chemicals like
chlorine or chloramine
Disadvantages
 May contain contaminates(industrial
pollutants may cause acid rain)
 Susceptible to droughts or floods
 Its replacing is very difficult
 Only used in some areas where
conditions are feasible for rain

Surface water
Surface water is any body of water found on the Earth’s surface, including
both:
 saltwater in the ocean
 freshwater in rivers, streams, and lakes
Lakes and reservoirs can be good sources of water. The water from them can
be flowed into ponds or through raceways. Lakes and reservoirs can also be
used as sites for cage culture.

Marine water
70% of Earth's surface is covered in water, and 97% of that water is salt
water, marine ecosystems are the largest types of ecosystems on the planet.
Advantages
 Good source of water for marine
fishes
 Good source of sea food
Disadvantages
 Only cultured marine water fishes
e.g Salmon
 Salt content is more so PH values
are high
 Difficult to use in intensive culture

Freshwater
Freshwater is water that contains only minimal quantities of dissolved salts, thus distinguishing it
from sea water or brackish water. All freshwater ultimately comes from precipitation of atmospheric
water vapor, reaching inland lakes, rivers, and groundwater bodies directly, or after melting of snow or
ice.
Advantages
 Its easy to use for intensive and
extensive culture
 Easily available for culturing fresh
water fishes
Disadvantages
 Only suitable for fresh water
(trout) fishes not for marine fishes
e.g salmon

Ground water
• Groundwater is the water found underground in the cracks and spaces in
soil, sand and rock. It is stored in and moves slowly through geologic
formations of soil, sand and rocks called aquifers.

Advantages
 Groundwater is often the preferred source for aquaculture, particularly if
an abundant supply of good-quality water can be obtained without having
to drill a deep well.
 Natural filtration to remove organisms and suspended materials such as
silt and clay from the recharge water.

Disadvantages
 Bubbling of air (well water) can cause iron to precipitate to form ferric
hydroxide (FeOH3).It will stain pipes and other surfaces and if present at
high enough levels it can clog gills.
 Well water can come to the surface depleted in oxygen and may contain
relatively high levels of such things as hydrogen sulphide, iron or carbon
dioxide. Then aeration is needed to solve this problem.

Indication of gas bubble disease in fish downstream from spillways, with bubbles in integument (A), eyeball (B),
exophthalmos (A, B), along with the rays of the pectoral (C, D) and dorsal fins (E) and in the gill filament (F).

Water characteristics
To culture a fish water characteristics can be measured at following
parameters:
 Biological character
Physical character
Chemical character

Biological characters
• Microbes (Bacteria etc.)
• Phytoplankton
• Zooplankton(swimming , biological cover, living in mud (larvae of
Chironomus plumosus)
• Algae
• Aquatic weeds

Biological cycle
1. Nutritive substances in solution (inorganic stage)
2. Formation of higher plants, lower plant and phytoplankton (organic
stage)
3. Phytoplankton are consumed by smaller organisms (Microfauna)
4. Micro fauna and other plants are eaten by the fish
5. Reduction stage through mineralization mechanism by bacteria

Microbes
Microbes such as bacteria perform following functions:
 Organic matter decomposition
 Nitrification (conversion of ammonia into nitrates)
• Nitrosomonas , Nitrobacter
 Chemotrophic bacteria

Zooplankton
• Rotifers ( eaten by fry and small fish and other aquatic animals )
o Brachionus,Triarthra,polyarthra
• Worms ( Oligochetes e.g Naididae ,Tubifex)
• Crustaceans ( Cladocera)
• Molluscs ( Gastropods)
• Insects (Generally eaten as larvae and nymph e.g Ephemeroptera,
chironomids)

Aquatic weeds
• Partially aquatic weeds ( shore weeds e.g Filipendula ulmaria)
o Paludal weeds
o Semi emergent weeds
• Completely aquatic weeds (floating plants e.g Nymphaea alba)
Many aquatic plants are harmful when they become excessive. This
especially applies to emergent weeds and floating weeds.

Harmful effects of excessive weeds
 Accelerate siliting which make difficult the movement of fish and stops the water from
warming.
 It provide refuge to competitors seeking nourishment .
 It provide refuge to enemies of fish and create a bottom rich in cellulose.
 Aquatic weed growth provides quiet water areas ideal for mosquito breeding.
 Recreational activities such as swimming, fishing, and boating can be impaired and even
prevented.
 Weeds impede water flow in drainage ditches, irrigation canals, and culverts and cause water
to back up.
 Oxygen depletion due to consumption of more oxygen by weeds at night

Controlling Aquatic Weeds
• Aquatic weeds can be controlled by following method:
 Biological Methods
 Herbivorous Animals
 Fertilization
 Mechanical Methods
 Weed cutting
 Other method of weeding
 Chemical methods
 Use of herbicides

Physical character
• Colour
• Temperature
• Turbidity

Colour
Light green colour of water is good for healthy fish pond.
Dark green colour is not good for fish water. This is due to the many factors such
as:
 lack of proper filtration and beneficial bacteria to clean out water over time.
 using too much fish food
 ammonia and nitrites caused by fish waste
 Due to more algal blooms

Temperature
Temperature has a considerable influence on the vital activities of fish such
as breathing ,growth and reproduction.

Best ways of controlling the temperature of
ponds
Best way to control temperature is increasing or decreasing of water.
During the growing period it is good to increase the temperature ,but there
is a reason to reduce the temperature e.g when it is 30 to 33 ċ it will cause
reduction in the growth of carp.

Turbidity
Turbidity is the presence of suspended solids and excessive concentration of
phytoplankton that can reduce the penetration of light in water.
Suspended solids
suspended solids are pieces of particulate matter larger than 0.45 µm that occur in
the water column. If a particle is smaller than 0.45 µm it is considered to be
colloidal or dissolved. It consist of following
 Most common (silt, mud, sand)
 Organic particles(plants , animals)

Effects of turbidity
 phytoplankton bloom in ponds with turbid water can be very difficult because of greatly
reduced light penetration.
 Gills may become clogged, eggs being hatched in outdoor ponds can be buried and smothered,
and feeding may be impaired due to low visibility for sight-feeding species.
 Turbid water tends to warm more quickly than clear water, but it cools more slowly so it will
retain heat longer.
Control of turbidity
 Turbid water should be allowed to settle or be filtered before being put in culture chambers.
Large volume of water is difficult to filter so source of water should selected carefully.
 Add gypsum (CaSO4,H2O) and alum (Al2(SO4)3.14H2O) was found to be effective when
used at 15–25 mg/l.

Chemical character
• Dissolve oxygen
• PH value
• Ammonia load
• Nitrite
• Salinity
• Alkalinity
• Hardness
• Toxicant load

Dissolve oxygen
 Dissolved oxygen is linked with the temperature and vegetation.
 If the decomposing organic matter is in large amount then DO will be reduced.
 Danger of fluctuation in DO mostly occur during warm and thundery weather when ice
covered the surface of water.
 Over vegetation can also effect the DO because during day it can be increased above
saturation level .
 During night the same vegetation absorb the oxygen and can reduce the level of DO in
pond.
 DO for salmonids is 19mg/l and temperature is 20ċ.For Cyprinids DO is 6-7mg/l.

Effects due to insufficient DO
When there is a low oxygen fish come to the surface in an effort to breath
air.
Other fish group together near the fresh water inlet where they behave
normally.
Fish killed by asphyxia have raised gill covers and their gills are wide
apart.

PH
• Water can be neutral ( PH is 7) acidic (PH is lower than 7) and alkaline (PH is higher than
7) due to the change in PH.
• Best freshwater for fish cultivation is that which is neutral or slightly alkaline (6.5-8.5).
• Best saltwater for fish cultivation is that which is alkaline (above 7).This is maintained
with the presence of molluscs because their shell contain CaCo3.
• If PH drops from 7 than buffering compound is added in saltwater such as carbonates and bicarbonates
ions (lime stone, oyster shell).
CaCo3 → Ca+2 + Co3-2
Co3- + H+ → HCo3-

PH
Changes in PH
• Marshy and peaty water mostly have acidic PH.
• Due to low calcium PH will drop suddenly and cause fish death.
Determination of PH
 Colorimeteric method
 Electrometric method
 Litmus paper test strips

Ammonia load
Hochachka (1969) indicated that most of the nitrogenous waste fish produce is in
the form of ammonium ion (NH4+), which is excreted through the gills.
Ammonia is present in two forms
• Ionized form ( NH4+)
• Unionized form (NH3) this is toxic even in low level and effects on growth and
gills. Gills become deform.
Ammonia level for cold water species is 1mg/l and for warm water fish is
2.5mg/l.

Component effect Ammonia
• Dissolved oxygen
• Carbon dioxide
• Hardness
• Bicarbonates
• Carbonates
Determination of Ammonia
 Ammonia probe
 Colorimetric test of ammonia

Nitrite
Mostly nitrite are not present because they are converted into nitrate by
bacteria.
Nitrite are more due to the high concentration of fish biomass.
Measurement of nitrite
 Colorimeter
 spectrophotometer

Components effect nitrite
• Salinity
• Ammonia
• Temperature
• PH
• Nitrate
• Sulphate
• Phosphate
• Calcium

Effects due to more nitrite
 When nitrite is present in the water, it will combine with haemoglobin in the blood of finfish
to produce methaemoglobin.
 Methaemoglobin will not combine with oxygen, so the fish will be asphyxiated when it loses
its haemoglobin. A chocolate brown colour of the blood is a sign that the haemoglobin has
been converted to methaemoglobin.
Treatment
 Adding 25 mg/l of table salt (NaCl) for each milligram of nitrite that is present is an effective
treatment for the condition known as methaemoglobinaemia.
 Increasing the level of vitamin C (ascorbic acid) in the diet may also help protect fish against
nitrite toxicity. The vitamin apparently acts to reverse the process of conversion of
haemoglobin to methaemoglobin.

Salinity
salinity is basically the amount of elements and ions in the water after organic
matter and suspended particulate matter are removed.
The blood of a fish has a salt composition that is similar to that of ocean water,
but certainly not identical. Fish blood has a salinity that is typically around 10–12
ppt.
Freshwater fishes do not drink more water to maintain salt and produce very
dilute urine
Marine water fishes have low salt than its environment and move water from
body tissues to outside, so fish drink lot of water to avoid dehydration and
produce concentrated urine.

Methods of measurement
• Electrical conductivity of a water sample also relates to salinity.
• Titration
• The easiest method of determining salinity is by measuring the refractive
index of the water.

Alkalinity
 Alkalinity is the capacity of water to resist changes in pH by the buffer systems of
chemical reactions that occur in the water.
 Freshwater alkalinity levels of between 30 and 200 mg/l, though higher and lower levels
have been used in many instances. The minimum recommended level is 20 mg/l.
Measurement of alkalinity
Alkalinity is measured through a simple titration technique that involves determining how
much dilute sulphuric acid is required to change the colour of a water sample to which two
indicator chemicals, phenolphthalein and methyl orange, have been added. The methyl
orange endpoint provides the total alkalinity value, while the phenolphthalein endpoint
indicates the bicarbonate alkalinity.

Hardness
The concentration of divalent cations in a water sample is called hardness. The
dominant divalent cations are calcium and magnesium.
freshwater fish should be reared in water that has a hardness of 20 mg/l or higher.
 marine species live in water that has high levels of hardness at all times, so
measurement of hardness is not required in those environments.
Measurement of hardness
 Hardness is determined through a titration process and, like alkalinity, is reported
in mg/l or parts per million of calcium carbonate.

Water characteristics for culturing fish.pptx

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