Fish Health Management

Introduction
• Health of fish is dependent on many factors
like environmental conditions
• Quality of diet
• Stocking density
• Quality of water
• Sources and types of pathogens
Species/strain of fish

Feed
• Use a species-appropriate high quality feed
• Different formulations for different life stages
Nutritional deficiencies lead to growth
defects, internal organ dysfunction, anemia,
etc.
• Poor diet can lead to immune dysfunction,
resulting in increased risk of infection

Stocking Density
• High density increases disease transmission
• Reduces water quality
• Increases stress

Water Quality
• Poor water quality can cause stress and hinder
immune responses
• support the growth of unwanted microbes
directly result in mortality.
• Maintaining a Biofilter
• Adequate surface area
• Limited use of chemicals in the system.

Infectious Agents
• Fish are susceptible to various infectious
agents
• Bacteria
• Viruses
• Fungi
• Parasites

Opportunistic Infectious Agents
• Cause disease when fish are stressed or
injured.
• Primary Infectious Agents
• Pathogens that infect healthy fish its tend to
cause more severe infections .

Susceptibility of Fish to Infection
• Young fish tend to be more susceptible
• Some pathogens are species or strainspecific,
while others infect many species
• Stress increases susceptibility – Temperature,
pH, water quality, etc
• Nutritional deficiencies increase
susceptibility.

What to Do Next
• Remove any dead fish immediately
• If possible quarantine sick fish
• Review water quality records; check feed
• Contact a veterinarian and/or submit fish to
a diagnostic lab.

• The best treatment is prevention :
• Quality fish
• Good water quality
• High quality feed
• Minimize stress
• Minimize cross-contamination between
systems.

Good and best management practices
• Aquaculture is an activity producing fish or
shellfish mainly for human consumption. It is
carried out in ponds, enclosures or in open
water bodies and thus involves continuous
interaction with the environment.
Aquaculture can be a sustainable activity, if it
is carried out in socially and environmentally
responsible manner, by adopting good
aquaculture practices.

Crop planning
• Introduction: Crop planning in advance of the
cropping season in consultation with all
farmers involves stocking density based on
pond carrying capacity, crop insurance and
bank finance and bulk input purchase like
good quality seed through contract hatchery
system,

Crop calendar
• Preparation of Crop calendar- two months
before stocking fix dates for pond preparation,
biosecurity, water pumping, contract hatchery,
seed stocking and harvest. for analysis of farm
inputs like seed, feed and any common
ingredient used and shrimp for presence of
banned antibiotic residues cluster
certification, renewals, inspections/audit
before the crop.

Adoption of Better Management Practices
• Pond preparation practices : To provide the
shrimp with a clean pond bottom and good,
stable water quality to reduce disease risks &
to reduce the excessive reliance on water
exchange, pond water holding capacity has to
be increased maintaining water depth at
minimum water level of 1.2 meter at the
middle of the pond.

Completely drain out the water from
the pond
• Complete draining of water helps in removing
the disease carrying fish and crustaceans from
previous crops in the pond. If it is not possible
to drain the water follow wet preparation
method.

Remove the organic waste from pond
bottom
• Organic matter releases toxic gases like
ammonia and hydrogen sulfide in the pond
leading to stress or death of shrimps. Organic
waste is in the form of layer on the soil with
black color found in feeding area, corners,
trenches and in the centre in ponds with
aerators and should be checked for the
presence of black layer when it is in wet
condition.

• Make sure that the displaced organic waste
does not enter the pond again through rain
water. If it is difficult to completely remove
the black soil, plough when it is wet and let it
dry.