Transcript DISEASE & PEST MANAGEMENT

DISEASE & PEST MANAGEMENT
[objectives]
• Explain aquaculture diseases and pests and
how they cause problems
• Discuss how fish show signs of disease
• Explain diseases and how they are managed
• Explain parasites and how they are managed
• Explain predators and how they are managed
• Describe trash fish and the problems they
cause
• Explain what to do if fish appear unhealthy
• Discuss regulations in disease and pest
control
AQUACULTURE DISEASES AND
PESTS – chapter 6
• A disease is a condition that develops in
an organism and then damages it in some
way.
• A pest is a plant, animal, or other organism
that is detrimental to a species.
• Aquacrops need a healthy environment;
one that is free from diseases and pests.
• Diseases and pests cause losses.
EXAMPLES
KINDS OF LOSSES
• Direct losses occur when aquacrop is
attacked or injured.
• Water birds and predators (eat crop)
• Diseases (reduce growth or death)
• Parasites (reduce growth, produce stress)
• Poaching (theft by humans)
KINDS OF LOSSES
• Indirect losses result in less than ideal
environments.
• Weeds (make harvesting difficult)
• Trash fish (compete for food and oxygen)
• Rodents or other burrowing animals (may
cause water leaks)
SIGNS OF DISEASE IN FISH
(SYMPTOMS)
• Not eating (going off the feed)
• Skin abnormalities (ulcers, lesions,
abscesses)
• Lack of vigor (sluggish, drooping fins)
• Abnormal body shape (growths, swollen
belly, bulging eyes)
• Behavioral change (rubbing, gulping)
• Dead fish
KINDS OF DISEASES
• Infectious diseases – may be transferred
from one individual to another (examples –
bacterial infections, fungal and viral
diseases, parasite infestations)
• Noninfectious diseases – not transferred
from one individual to another (examples –
nutritional, environmental, chemical and
physiological disease)
INFECTIOUS DISEASES
Fungal
Bacterial
Viral
Parasitic fish lice
NONINFECTIOUS DISEASES
• Nutritional diseases – inadequate diet
• Environmental diseases – water gases,
improper temperatures and water quality
• Chemical diseases – contaminants such
as pesticides or heavy metals
• Physiological diseases – organ
malfunctions from sudden changes
DISEASE CONTROL
• Prevention – the practice of keeping
aquacrops healthy and disease free
• Sanitation – practice of keeping water and
facilities clean
• Quarantine – isolation of aquacrops not
known to be disease free from those that
are
DISEASE TREATMENT
• Dipping – immersing fish in concentrated
medication
• Feeding – using medicated feed
• Bathing – similar to dipping but less
concentrated for longer period of time
• Injecting – only for fish large enough to
hold
• Indefinite treatment – low dose of
medication added to tank or pond
PARASITES AND THEIR
CONTROL
• Ectoparasites (external) – found on skin,
gills, or fins
• Endoparasites (internal) – live in organs,
flesh, or digestive tract
• Examples – tapeworms, flukes, leeches,
roundworms, protozoans, crustaceans.
PARASITE CONTROL
• Quarantine - isolation
• Treatment of facilities – dry ponds and
sterilize
• Dipping – salt solution, formalin
• Bird elimination – birds often transfer
parasites
• Indefinite treatment
PREDATORS AND THEIR
CONTROL
• Birds – cormorants, kingfishers, herons,
grebes, and mergansers
• Fish – some prey on other fish, some prey
on eggs
• Snakes – do not eat large amount of fish
• Insects – can destroy eggs or fry
• Turtles and alligators – usually only eat
trash fish (gars, carp)
• Bullfrogs – eat fingerlings (crawfish, too!)
BIRDS
FISH, SNAKES,INSECTS,
BULLFROGS