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 (cold-blooded)

• 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