Aquaculture in the Classroom Notes – July 18, 2002
Aquaculture at Virginia Tech is now divided among three academic divisions:
–Agriculture (including Food Science and Technology Department, and Fisheries and Wildlife Sciences)
–Veterinary Medicine (Bio-Medical Sciences and Pathobiology)
–Civil and Environmental Engineering
George Flick: Fish-Tech course was oriented to Home Ec teachers many years ago.
Laura Douglas
–CEU Credits:
Eric F.: Graduate Credit: ALS 5984 (Aquaculture in the Classroom) – Lesson on Integration in the Classroom – and 1 page classroom. $435 for 3 credits (Summer 2) – October 8 (at Ag Ed Society meeting)
CFAST =
Ewin McLean
By 2030, fisheries must increase by 50% (but probably over 100%), but most fisheries are at or above maximum capacity.
Fastest Growing food sector in the world until overtaken by organic farming this year.
Production vs. Value leads to a gold rush mentality in aquaculture, which leads to environmental degradation (shrimp is still the biggest culprit)
Non-Food Aquaculture:
Ornamental plants, fish
Bait
Crustaceans
Sport/gamefish
Corals
Amphibians
Reptiles – second most valuable (crocadilians)
Holuthuria – Sea cucumber
Nudibranchs
Molluscs
Seaweed is the most important aquaculture species in both production and importance to
Production, by species (most not familiar to US):
Kelp
Silver carp
Grass carp
Common carp
Bighead carp
Yesso scallop
Pacific oyster
Tilapia
Salmonids
Photos on CD ROM
Algal products are single-most important food additives (George Flick specialty)
Used from cooling power tools to biotech substrates, toothpastes, etc. Many sell for over $2000 per pound
Squid in Galveston, TX is now important for biotech
Risk is proportional to inputs:
Financial
Water requirements and availability
Environmental damage
Theft
Animal damage
Natural disaster
Fishmeal availability/competition
Elevated management needs
Power failures
Disease
Water quality
Mechanical and engineering failure
Trout farmers in Denmark didn’t meet effluent guidelines.
PBS.org has a pearl production video
See CD-ROM
Greg Boardman – Civil and Environmental Engineering
Michael Schwartz
See CD-ROM or handouts
Recirculating = 90% of water stays in system per day.
Biosolids can consume more O2 than the fish!
Biosolids cause gill irritation in slamonids and perch
Sand filters by Jaccuzzi
B-cell and KMT are state-of-the art (replacing bio-balls)
O3 is very effective in freshwater research systems without the byproducts that occur in saltwater.
Avoid ozone in a school – use a protein skimmer and UV system instead
Anaesthesia – Dr. Steve Smith
MS-222 is the only aneathetic allowed by FDA (tricaine Methanesulfonate). It is a carcinogen and a terratogen. Only two sources: Agent Chemical and Western Chemical. 10g will cost $120.
Use a standard dose 150mg per Liter of water rather than a dose effect. Sedation happens at 5 minutes, anesthesia in 7 minutes.
MS-222 will euthenize. Freezing is inhumane. Other humane methods are CO2 or cervical separation.
You must isolate them for 21 days in a revival tank if they are a food fish.
You must buffer MS-222 with sodium Bicarboanate Na CO3 – otherwise it will drop the pH (MS-222 has a pH of 4)
Clove oil (available in pharmacies) will sedate but not anesthetize. CO is too dangerous.
Striped bass react5 quickly, tilapia are resistant.
Catfish don’t roll over.
Tags: Pit tag (abdominal scannable), operculum tag, or fillet tag.
Steve Smith and Kathleen Hughes
Get a spectrophotometer to be more accurate than test kits.
Consider gill clip technique for parasites.
Prophylactic treatment is not legal by FDA, even with salt
1-2 PPT of salt is sufficient for treating fish but it will be detrimental to plants.
Formalin will be detrimental to your bio-filter, so do it externally or bypass the filter.
Top-dress feed (chemoth
Most only approved for catfish, salmonids, and lobster. You must have a vet prescribe for tilapia, bass, and all others.
Use quarantine!
Necrospy Technique
Cervical separation – sever the spinal chord with a scissor (no flopping, either)
- Examine external surface
- Remove operculum
- Remove gill arch (not just filaments) – put in 10% neutral buffered formula
- Cut across chest in front of pelvic fins
- Cut toward vent, but steer away from opening
Trout – carnivore – very short digestive tract
Goldfish – herbivore – long, coiled, no stomach
Tilapia – often fed carnivore diet, but even more herbivorous than goldfish
- Remove viscera to expose gonads, swim bladder, and even deeper, the kidney
- Bacterial culture from posterior kidney with culturette or sterile pipette
- From original cut, remove frontal cranial cap, break through cartilage. Take sample with culturette.
Nutrition – Steve Craig
See handouts or CD-Rom
Protein - Kjeldahl method for crude protein- sulfuric acid extraction to measure nitrogen content
Fish meal supply has been flat for the last ten years and could be a limiting factor. Salmonids cannot use plant protein effectively.
Protein is a major source of nitrogen in effluents.
10 essential amino acids
We aim for minimum protein requirement that allows for maximum growth (also reduces impact of effluent).
Lipids – most efficient energy source - protein should not be used for energy.
Marine source are major source of N3 fatty acids (omega)
Fish oil supplies are also decreasing.
Carbohydates – not much work done to date – hard for some fish to use, but red drum can use up to 35% carbos
Energy – growth , maintenance and reproduction
Fish have several energy advantages:
Secrete ammonia
Do not regulate body temp.
Do not have to fight gravity
Energy:Protein ratio is the hot topic – too high energy, fish will stop feeding before sated.
Ask Steve () - Can tilapia survive on alfalfa pellets?
You should not keep a 50 lb bag over 90 days, and if kept that long you should keep it cool and dry and rodent-protected.
Hydroponics – Charlie Schultz
William James quote: “In teaching you must simply work…”
Permit required.
VTU is a source for fingerlings. Dr. Hollerman? (Genetics)
Lynn ____
Bert ____
Nile Tilapia – grown to 2 pounds for tourist (filets)
Hybrid Red Tilia – grown to 1 pound (fits on a plate)
Biomass Density Estimate
Tilapia mozambiqua – best for salt water
Tilapia aurais – colder water
Mouth brooders – held up to 2 weeks from fertilized eggs
Commercial system – best is ¼ acre or larger
Ideas for classroom:
Multiple tanks of different size fish
Water leaves tank to a clarifier to remove larger solids (fine solids benefit plants)
Tilapia sludge is a valuable fertilizer
Fine solids “mineralize”
Anaerobic zones in the
In hydroponic system you want 4-5 mg/L D.O.
Tetras (blackfin) are used under the plants and feed on zooplankton.
Snails feed on good bacteria, use a red-ear sunfish (pumpkinseed?) to eat the snails.
One pump for the whole system – ½ HP 105 GPM
To control worms, use B.t. products.
White flies, aphids use Buvera buvins (a fungus)
Do not use Neem(sp?) (toxic to fish)
See handout for educational components
1.5 pounds of food produces 1 pound of Tilapia (cows are over 13!)
Float system with “net cups” placed in insulation board.
Floating lettuce, collards, beans and melons, mint and chives (gravel might be better to allow spreading).
Nutrient film technique (NFT) – rain gutters
Flood and drain system (ebb and flow) – use pea gravel – flowers too
S&S (SNS?) system
Sand Culture
Gravel culture
Sodium thiosulfate to treat chlorine
7.0 in an aquaponic system
Add iron, calcium and potassium (by adding potassium hydroxide and calcium hydroxide)
PH pen is necessary
27oC should be max.
Feed ratios – 80g food per M2 of growing area
Grow 1 fish per ½ gallon of water but 1 fish per 2 gallons is safer
Rps.uvi.edu/AES/Aquaculture/UVIShortcourse.html
Aquaponics listserve – others too
Aquaponics journal
Hydrogardens.com
Aquaponics.com
Vermiculture – Lori Marsh
Some aquaculture facilities have to pay a surcharge because of the O2 demand on their systems.
Vermicomposting in the classroom paper is in our
Worms:
Turn and aerate
Grind
Greatly accelerate
Don’t have a backbone (therefore few humane concerns)
Are hermaphrodites
But:
Don’t like salts
Ammonia above 500ppm
Can’t freeze
Eisenia fetida (or foetida) – red wiggler, manure worm, tiger worm
In classroom:
Scientific method - Food preferences, bin designs
Cafeteria waste
Pre-consumer wastes: prior to being served – best for many reasons
Post-consumer wastes – may cause problems in a school
Vermicomposters:
Bin – Rubbermaid tub with aeration and drain
Stacking trays
Continuous flow reactor
“Worms eat my Garbage” – Mary
Stacking tray system
“Can-O-Worms” – version of stacking system
Continuous flow system:
Worm wigwam system – crank drives a scraper bar
Google:vermitech
Youth Aquaculture Program
Use virtual farm to connect to aquaculture links
State Fair Aquaculture competition (scholarship points awarded)
Targeting youth at risk
Bert Reid
Contact Ron Southwick for a permit.
State Fair contest
Jim McVey
National SeaGrant Program office in DC
Book on Marine Education – Texas SeaGrant
See handouts for Dept. Commerce objectives
-$5,000,000 competition every year.
Ornamentals in the classroom (higher $$ returns)
-Zebrafish
-Nori sushi – pigments (several hundred dollars per pound)
-Ginat clams
-Aquarium fish (live-bearers)
Aquacultre Education in Kentucky
-Gordon J. Mengel
Pat Beachy and Tom Hawthorne - Linganore HS
FFA Engineering!
Bill Shumate and Dennis Blalok – Tunstall HS (Pittsylvania Co.)
DuPont $8,000 grant (did not get Toyota grant)
Tissue cultures with Fralin folks
Partnership with Blue Ridge Aquaculture
½ of greenhouses in the county are dormant because of tobacco settlements
Biological Applications in Agriculture or Technical Biology/Chemistry II
-Must have completed Biology or Algebra I
-No ag pre-requisite
Second year had a 1:1 feed conversion ratio
See CD-ROM for pictures
Exotic Fish Permit through Blue Ridge
Hold and Sell permit was harder because of open lagoon
Strawberries and tomatoes
Put barley straw in a sack and sink it – produces an algae that kills the algae.
$11,700 grant from federal money.
$20,000 start-up total