Transcript Aquaculture (powerpoint)

Aquaculture
Aquaculture
• the controlled production of
animals that normally live in
water (fish farming)
• three thousand year old practice
started by the Egyptians and
Chinese
Aquaculture
• two types of water creatures
• freshwater
• saltwater
Aquaculture
• animals raised for production may
include
• crustaceans (shrimp and crayfish)
• mollusks (clams and oysters)
• amphibians (frogs)
• reptiles (alligators)
Aquaculture
• fish provide a high quality high
protein supply of meat
• as with other agriculture animals
humans soon discovered that by
producing their own aquatic
animals that the supply available to
the consumer would be more
dependable and easier to harvest
Aquaculture
• commercial growth growing of
fish
• five million tons a year
produced
• demands of the consumer has
increased
Aquaculture
• aquatic animals are produced
efficiently and economically
• fish account for 12% of the
meat consumed in the US
Fish Production
• many advantages over other
agricultural animals
• 9lbs. Feed for 1lbs. Of gain for
steer
• 2lbs. Feed for 1lbs. Of gain a
fish
Fish Production
• fish are ectothermic (coldblooded)
• this means less energy goes into
maintaining a constant body
temp
Fish Production
• fish have a higher percentage of
edible meat (up to 85%)
• up to 6000 pounds fish can be
raised on one acre
Fish Production
• Problems in fish production
• dissolved oxygen level must be
maintained
• shipping the meat (fish spoils
quickly)
• operations are labor intensive
• operations are high risk
Fish Respiration
• breathe oxygen
• use gills to take oxygen from
the water and put it to use in the
bloodstream
• gills act just as lungs do
Fish Respiration
• The oxygen is put into the water
through…
• photosynthesis
• process in which aquatic plants
which releases dissolved
oxygen into the water
Fish Respiration
• directly from the sun
penetrating the oxygen into the
waves
• aeration by crating waves
Fish Respiration
• if the dissolved oxygen level
falls below a certain point the
fish may suddenly die
(suffocate)
Commercially Grown
• grouped into two categories
• warm water
• thrive in temps above 60
degrees
• catfish and tilapia most popular
in US
Cold Water
• thrive in waters that are 70
degrees or less
• Trout and Salmon most popular
in the US
Catfish Production
• most widely grown production
fish in the US
• smooth skin with no scales
Catfish Production
• nearly 100,000 metric tons
produced each year at a value of
$380 million
• survive on lower levels of
dissolved oxygen than most
other production fish
Channel Catfish
• mose widely used
• Mississippi leads in channel cat
production
• raised in ponds less than 6 feet
deep
Egg production
• female catfish lay eggs in nests
that are provided by the
producer
• eggs are collected and placed in
tanks or jars in the hatchery
Egg production
• eggs are moved back and forth
by use of paddles in a wave-like
action
• fish eggs must be turned just as
bird eggs are in order to hatch
Egg production
• When small fish hatch (called
fry) they are placed in tanks
until they are about two inches
long (then called fingerlings)
• fingerlings are transferred into a
pond or huge tank until they
weigh two pounds
Egg production
• fish are fed twice a day
• fish are harvested using seines
(large nets)
• another method of raising
production fish is using large
submerged cages
Cages
• advantages
• fish may be inspected more
closely
• less feed is wasted
• predator problems are solved
• harvesting is easier
Tilapia Production
• native to Africa
• resemble our native sunfish
• reproduce prolifically
• grow rapidly
Tilapia Production
• can survive high temp, low
oxygen and overcrowded
conditions
• cannot survive in water below
50 degrees
Trout Production
• considered the best tasting fish
• high percentage of their body is
edible meat
• cold water fish
Trout Production
• most trout are raised in concrete
raceways where the water is
constantly moving
• moving water keeps the water
cooler and keeps the dissolved
oxygen level higher
Trout Production
• disease control is easier in this
environment
Salmon Production
• cold water fish
• raised in floating net cages that
are anchored in bays of oceans
• usually takes 18-24 months to
finish out the fish
• harvested at 9-11 pounds
Salmon Production
• very meaty fish with a favorable
taste
• most salmon that is consumed
is caught in the ocean rather
than raised in captivity
Sport fishing
• hatcheries stock lakes and
streams
• recreational fishing creates
other industry
• fishing tackle stores
• boats
Sport fishing
• guide services
• restaurant, hotel and other
stores near the water
Bullfrog Production
• frog legs are considered a
gourmet food
• most frogs are raised in the wild
• demand for frogs far exceed the
supply
Bullfrog Production
• attempts to raise bullfrogs in
captivity have been
unsuccessful for many reasons
• 1. Animals are territorial
• 2. Frogs only eat food that is
alive, no processed food
Bullfrog Production
• 3. Predators (raccoons and
snakes)
• research is still being done to
find a way to raise bullfrogs for
production purposes
Crayfish
• Craw Dads, Crawfish, or Mud
Bugs
• Louisiana leads in crawfish
production
• 1000 pounds per acre can be
produced
Crayfish
• raised in large earthen ponds
that are less than two feet deep
• can be grown along with crops
such as rice
• crawfish are omnivorous (they
eat both plants and animals)
Crayfish
• main diet is decaying plants,
worms and insect larvae
Alligator Production
• alligators were hunted to a point
near extinction
• hides are very valuable
• conservation efforts have
brought the population back
Alligator Production
• alligators are harvested at the
age of 26 months of age and
five to six feet long
• hides are sold to make bags,
boots, shoes and various other
leather type goods
Alligator Production
• skulls and teeth are also a hot
commodity
• meat is very tasty and is sold to
restaurants
Alligator Production
• process of raising alligators
• females build nests from
vegetation and mud and lay an
average of 40 eggs each time
Alligator Production
• producers remove the eggs from
the nest to limit the loss to
predators
• eggs are marked so that the
proper end will be in the right
position to ensure a good hatch
Alligator Production
• eggs are wrapped in hay and are
kept moist
• the hay contains a bacteria that
breaks down the shell allowing
the babies to break through the
shell
Alligator Production
• temperature is critical to
determining the sex of the
newborn alligator
• temps above 93 degrees
produce all males
Alligator Production
• temps below 86 degrees
produce all females
• temp of 88 degrees produces an
even mixture
• alligators are fed fish, products
from poultry industry
Alligator Production
• carcasses of animals that are
slaughtered for their fur only