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ANIMALS
FARM HYGIENE
GOVERNMENT
MONITORING
RECREATIONAL
ANIMALS
Background
- Disease has the potential to devastate the aquaculture
and fishing industries, slashing profits and, in some cases, closing
the industry. It is vital that we all act responsibly to prevent
the introduction of disease into Australian fisheries.
- History has shown repeatedly that the main way
to introduce disease into an aquaculture industry is through the
movement of live animals.
- The spread of first white spot disease and now
'Taura Syndrome' throughout the prawn farming industries of south-east
Asia clearly shows that the irresponsible movement of aquatic
animals will inevitably lead to the spread of disease.
- Daily observation of fish appearance, behaviour
and feeding activity allows early detection of problems when they
do occur so that a diagnosis can be made before the majority of
the population becomes sick.
- The most obvious sign of sick fish is the
presence of dead or dying animals. However, the careful observer
can usually tell that fish are sick before they start dying because
sick fish often stop feeding and may appear lethargic. Healthy
fish should eat aggressively if fed at regularly scheduled times.
Disease Awareness and Control
There are 3 basic areas that a farmer needs to
consider when seeking to prevent disease:
- Management
- Farm hygiene and
- Monitoring
Firstly, by ensuring management procedures on
the farm maintain high quality water and minimise any stress on
the animals, the farmer is lessening the environmental impact on
the 3 circles.
Secondly, by implementing appropriate farm hygiene, or biosecurity,
measures to the movements of stock, equipment, water, feed and people
on or off the facilities the farmer lessens the chance of the pathogen
entering or spreading through the farm. Thus decreasing the impact
of the pathogen circle.
Finally, the daily monitoring and recording on farm is essential
to check water quality parameters and to spot sick animals early,
allowing appropriate intervention. These records should be analysed
routinely to look for more subtle trends such as decreased growth
or changes in food consumption that may indicate a problem.
As the influence of each of the factors increases
or decreases it can be seen that the potential for disease changes.
If disease occurs, seek the advice of fish health
professional as early as possible.
Disease in aquatic animals is the end product of a complex interaction
between the animal, the environment and a disease agent, or pathogen.
It is extremely rare that a disease is produced just through the
presence of the pathogen, instead it is much more common that factors
in the environment make the animal more susceptible to disease.
When purchasing stock,
they should only be purchased from reliable suppliers that are known
to be disease free and preferably all new stock should come with
a health certificate attesting that they are free from important
diseases and pests.
When receiving delivery
of new stock, check them carefully and Reject batches displaying
obvious disease signs.
Quarantine procedures in the transport of all fish
should be rigorously enforced, whether they are arrivals from another
farm or simply transfers between ponds or tanks
New animals should be held separate in tanks or ponds
to allow for observation and detection of infections.
In some cases, preventative measures such as salt
treatment (5-10ppm) to kill ectoparasites and promote the healing
of wounds caused by capture methods can be undertaken.
If treatment is indicated, it will be most successful
if it is implemented early in the course of the disease while the
fish are still in good shape.
It is important to remember that disease does
not occur just because the pathogen is present in the environment
but it is a function of the animal itself, its environment and the
pathogen.
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FARM HYGIENE
Background
- Farm hygiene is important in all aquaculture operations
and should be part of normal farming procedures. Good farm hygiene
can prevent the accidental introduction of pathogens onto the
farm.
- Each Farm needs to have it's own specific farm
level health plan including contacts and what to do if there is
a disease outbreak.
- On farm' outbreaks should be handled by the separation
of equipment between production units. For example, don't use
nets or equipment from other ponds unless they have been thoroughly
cleaned and sun dried after previous use.
- Each Farm needs to have a step-by-step contingency
plan.
Disease Awareness and Control
Staff and visitors
constantly move around the farm and thus have the potential to introduce
and spread disease.
Visitors may pose a Biosecurity threat if they have
been exposed to potentially pathogenic material and it is important
to ensure that they declare any such exposure. It is also very important
that this declaration is followed up by appropriate actions to minimise
any risk.
Staff should avoid visiting other farms and other
places where disease might be picked up. Similarly, equipment should
not be shared between farms. Remember also that your farm hands
need to have a culture of farm level hygiene, that they respect
divisions in facilities, disinfect their equipment and understand
the importance of Biosecurity on your farm.
The provision of clean, dedicated, visitor protective clothing is
advisable as is some advice on visitor behaviour when on site regarding
handling fish, equipment etc. The restriction and adequate sanitation
of vehicles and equipment, including delivery vehicles, is vital
to the maintenance of Biosecurity.
Provision of handwashing facilities
and alcohol handsprays should also be considered to stop contamination
of facilities via dirty hands.
The use of footbaths at the entrance
to hatcheries and other buildings is not only good practice, but
it can help to instil a culture of health management and disease
control. To be effective, footbaths must be used and maintained
correctly. Useful points to note include:
They should be sited correctly to ensure usage
- Clean and undamaged.
- Covered against dilution from rain.
- Boots should be cleaned of organic material
before use of the footbath.
- The disinfectant should be. Changed regularly
and all organic material removed from the bath (no 'topping up')
- Signs directing personnel to use the bath.
A disinfectant spray
or impregnated pads may be a preferred alternative.
It must be borne in mind that organic matter reduces the effectiveness
of most disinfectants and the material to be disinfected, including
protective clothing, must be clean prior to disinfecting.
Some thought should also be given to the choice of sanitisers and
disinfectants to ensure that they are appropriate for the job. These
chemicals should also be stored and accounted for to prevent any
possible contamination.
Established cleaning routines
should be in place and monitored including those following depopulation
and deep terminal cleaning.
Appropriate storage
of equipment and protective clothing must also be provided.
Site specific protective clothing
for workers and visitors, wash equipment to remove organic debris
first (may need hot water and detergent), then use an appropriate
disinfectant ensuring adequate contact time, finally rinse thoroughly
before contact with fish. Keep records of disinfection especially
if moving equipment between sites
At the end of the day it's all about common sense.
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GOVERNMENT
Background
The Commonwealth government is acting on a range
of levels to protect Australia from introduction of disease.
Disease Awareness and Control
Biosecurity Australia conducts import risk assessments to determine
if it is safe to import fish and fish products into Australia. They
also set conditions on these imports so that importation is safe.
AQIS, the Australian Quarantine and Inspection Service
maintain our border inspection services to ensure that illegal imports
and dangerous materials do not get into the country.
Staff within the Commonwealth Department of
Agriculture, fisheries and Forestry are implementing a range of
projects to protect Australia's aquaculture and fisheries.
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MONITORING
Background
- One of the best ways of knowing when disease is
occurring is to have a solid understanding of what the normal
or usual situation is. In this way, a producer can readily identify
when something unusual is occurring.
- The combination of regular observation with detailed
and complete farm records provides a basis for disease investigation.
- If a historical record of water quality parameters,
temperature, animal growth, feed conversion ratios and other factors
are available, then a farmer can readily tell when things go wrong.
- Farmers should be looking at and assessing the
behaviour of their animals every day where possible. No one knows
the animals like the farmer, and when they notice that something
is wrong it is usually because there is something wrong.
- Generally speaking observations should include
the level of activity of the animals, their swimming behaviour,
colouration, feeding behaviour, an estimate of the extent of any
lesions or injuries on the animals, the number of any moribund
animals seen and a check on the mortality levels.
- There is always concern that damage could
be done to marine life before the source of any problem is discovered.
Disease Awareness and Control
Disease can cause a wide variety of clinical signs. The most important
thing is to know the 'normals', and thus be able to recognise any
abnormal signs that the animals are displaying and to get help at
that early stage.
Signs of disease problems can range from the dramatic
sudden increase in mortalities, the appearance of many lethargic
moribund animals, abnormal swimming behaviours and obvious lesions.
Other signs to look out for are sudden changes in
food intake, both increases and decreases.
Harvest, sample weighing or grading is also a good
time to look closely at your animals. The appearance of unusual
signs such as ulcers, organ damage, rashes and the like can be investigated
if noticed at this time before causing a major problem on the farm.
Those involved in the wild catch industry can perhaps
make the most impact on disease prevention by simply reporting to
State Authorities any 'observed changes in condition' of their catch….
or any catch that appear to be diseased or abnormal in any way.
This of course also applies to those involved in recreational fishing.
The responsibility of the prevention of disease does not rest solely
with aquaculture farmers.
Direct pollution can occur through deliberate or accidental
disposal of waste substances at sea…whilst indirect pollution
can result from land-based activities.
It has been estimated that at least 40% of marine
contaminants come from land-based sources.
The main thing is to act responsibly…and
quickly!
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RECREATIONAL
Background
Recreational Fishers need to be aware of the
potential to introduce or spread disease into or within Australia.
Disease Awareness and Control
Only local bait should be used. This way disease
cannot be introduced from overseas or from other areas within Australia.
Bait shops may have imported bait on sale but this
should be avoided in favour of Australian bait. Anglers should never
dump left over bait into the water or leave it on the shore.
The movement of fish from one location to another
is the surest way of spreading disease.
Anglers should only take enough fish for their own
personal needs and release the rest at the point of capture. Catching
fish at one location and releasing them in another spot is a great
way to spread disease.
All gear should be cleaned before packing away. Everything
from the boat through to the rods should be washed before the next
fishing trip.
There are several diseases that can be spread on fishing
gear.
Don't forget to remove mud and aquatic weeds
from the boat trailer too!
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