Ranching, cages, net pens... How low can you go? Lecture 14: FAS 1012.

Ranching, cages, net pens...Ranching, cages, net pens...

How low can you go?How low can you go?

Lecture 14: FAS 1012Lecture 14: FAS 1012

As traditional aquaculture and fishing practiceshave increases, so have the needs for alternatives.

Cage culture, ocean ranching and net pens have come under Cage culture, ocean ranching and net pens have come under intensive development recently.intensive development recently.

Cage CultureCage Culture

““is the cultivation of fish in existing is the cultivation of fish in existing

water resources such as farm ponds, water resources such as farm ponds, mining pits or barrow pits using smallmining pits or barrow pits using small

to large cages or net pens”to large cages or net pens”

““is the cultivation of fish in existing is the cultivation of fish in existing

water resources such as farm ponds, water resources such as farm ponds, mining pits or barrow pits using smallmining pits or barrow pits using small

to large cages or net pens”to large cages or net pens”

AdvantagesAdvantages

• One of the only ways to grow fish for sale One of the only ways to grow fish for sale in large, deep ponds, or lakes.in large, deep ponds, or lakes.

• If ponds are owned then relatively low If ponds are owned then relatively low start-up costs.start-up costs.

• Good way to learn aquaculture at a small Good way to learn aquaculture at a small scale.scale.

DisadvantagesDisadvantages

• Water quality may be harder to manageWater quality may be harder to manage

• Higher potential for disease outbreakHigher potential for disease outbreak

• Vandalism is easierVandalism is easier

Site SelectionSite Selection

• At least one surface acreAt least one surface acre

• Average depth of 4 ft.Average depth of 4 ft.

• No more than 10 acre watershed per No more than 10 acre watershed per

acre of water.acre of water.

• No direct access by livestockNo direct access by livestock

• No chronic problems with weeds.No chronic problems with weeds.

• No silt or pesticide runoff.No silt or pesticide runoff.

Cage ConsiderationsCage Considerations

• InvestmentInvestment• Management AidManagement Aid

– ObservationObservation– FeedingFeeding– TreatmentTreatment

• Design – MaterialsDesign – Materials• HarvestHarvest• OverwinteringOverwintering

Cage ConstructionCage Construction

• FloatationFloatation

• MeshMesh– 1/8 to 1/4 for Phase I (1-2”)1/8 to 1/4 for Phase I (1-2”)– 3/4 for Phase II (6-8”)3/4 for Phase II (6-8”)

• Feeding RingFeeding Ring

Water QualityWater Quality

• TemperatureTemperature– 7070ºF+ ºF+

• Dissolved OxygenDissolved Oxygen– 4 ppm+4 ppm+

• NitritesNitrites– <10ppm<10ppm

• pH 6.5-9.0pH 6.5-9.0

• TurbidityTurbidity– Around 24”Around 24”

• AlkalinityAlkalinity– 40 ppm+40 ppm+

• AmmoniaAmmonia– <1ppm<1ppm

Cage Placement in PondCage Placement in PondCage Placement in PondCage Placement in PondCages should be placed where water Cages should be placed where water can move freely between cages and can move freely between cages and circulate away from immediate area circulate away from immediate area

of cages.of cages.

Stocking PhaseStocking Phase

• Stock 1-3 in. fingerlings.Stock 1-3 in. fingerlings.

• Stock when water temperature is >55Stock when water temperature is >55ooF.F.

• Stock around 25-35 fingerlings per ftStock around 25-35 fingerlings per ft33..

Stocking Advanced FingerlingsStocking Advanced Fingerlings

• In the Midwest need to stock AT LEAST a In the Midwest need to stock AT LEAST a 6” fingerling with an 8 in. fingerling 6” fingerling with an 8 in. fingerling preferred.preferred.

• Stock when water temperature is >55Stock when water temperature is >55ooF.F.

• Stock 6-8 fingerlings per ftStock 6-8 fingerlings per ft33..

FeedsFeeds

• JuvenilesJuveniles– Non floatingNon floating– Crumble size particle Crumble size particle – 40% CP or greater40% CP or greater

• Advanced FingerlingsAdvanced Fingerlings– Floating pelletsFloating pellets– 36% CP acceptable36% CP acceptable

FeedingFeeding• JuvenilesJuveniles

– Feed often and plentyFeed often and plenty– Hand feeding or automatic feedersHand feeding or automatic feeders

• Advanced FingerlingsAdvanced Fingerlings– Morning and afternoon bestMorning and afternoon best– Hand feeding...Hand feeding...

advantageous, but slowadvantageous, but slow

ManagementManagement

• Grading of fingerlingsGrading of fingerlings

• Predator ControlPredator Control

• Weed Control in PondsWeed Control in Ponds

• Algae Control on CagesAlgae Control on Cages

DiseasesDiseases• ColumnarisColumnaris early in the season or from handling early in the season or from handling

stress.stress.• Gill Flukes Gill Flukes • Cannibalism among some small fish an issue.Cannibalism among some small fish an issue.

HarvestingHarvesting

• If fish are stocked in April, If fish are stocked in April,

then should be market size then should be market size

by late October (for HSB).by late October (for HSB).

• Forewarned is forearmed…Forewarned is forearmed…

Be prepared!!Be prepared!!

Overwintering

• Success depends on condition of fish afterSuccess depends on condition of fish after

harvesting and possible winter kills.harvesting and possible winter kills.• Blowers will keep ice from around the cages.Blowers will keep ice from around the cages.

EconomicsEconomics

• Break-even price for 5,000 lb production Break-even price for 5,000 lb production was $1.27/lb for HSB.was $1.27/lb for HSB.

• Based on:Based on:– five acre pondfive acre pond– 6 month production cycle6 month production cycle– $75/100 six inch fingerlings$75/100 six inch fingerlings– 1,000 lbs per acre yield1,000 lbs per acre yield

– 10% death loss10% death loss– $25/cwt feed$25/cwt feed– 2.0 FCR2.0 FCR