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Marine Baitfish Aquaculture:
An Overview of Many Species
Cortney Ohs, Ph.D.
University of Florida
Indian River Research and Education Center
School of Forest Resources and Conservation
Program in Fisheries and Aquatic Sciences
Why Culture Marine Baitfish?
• Recreational fishing‐related expenditures contribute an estimated $9.7 billion annually to Florida’s economy (about 2/3 is saltwater fishing)
• Florida accounts for approximately 42% of recreational fishing‐related expenditures nationwide
• In 2006, only 2 baitfish farms in Florida of 257 farms nationally. About 10 bait farms in Florida in 2010.
• Daily freshwater bait is trucked to FL from AR
• Marine baitfish ‐ demand is high
– Supply is almost all wild caught
– Seasonal and Regional
– Size demanded are not available
Species Selection
• Established markets
– Demand high
– Seasonal supply
• Culture methods
– What is known?
– Hardiness
– Salinity tolerance
– Time to market size
Species of Cultured Marine Baitfish
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Mud minnow Bull minnow
Pinfish
Pigfish
Croaker
Spot
Goggle eye
Bullminnow Fundulus grandis
Chris Green, Ph.D.
LSU Renewable Natural Resources
LSU Aquaculture Research Station Louisiana Sea Grant
LSU AgCenter
Fundulus grandis
• The bull minnow belongs to the family Cyprinodontidae , is an egg layer, and is known regionally as Gulf Killifish, Mud Minnow or Cocahoe Minnow. Introduction • Bull minnow Fundulus grandis show great potential and has received the most study.
• The bull minnow is an excellent live bait for flounder, speckled trout and red drum.
• Currently bait dealers rely on trapped wild stocks. • Large local winter markets for flounder fishing
Wild Caught Minnows: Negatives
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Seasonal availability (erratic supply) Running traps is labor intensive and takes time
Fish captured are variable in size Survival is poor due to injury during trapping and parasites and diseases that are common in wild fish. SStreptococcus infection
Wild Caught Minnows: Positives
• Low cost – Boat
– Traps
– Holding tank or Net pen
– Salt water supply
Cultured Minnows: Positives
• Unlimited supply of high quality product for distribution. • Uniform size (makes it easy to sell by weight)
• High survivability (in transport, in the bait shop, and on the hook)
• High health fish (diseases are eradicated or controlled in the hatchery and grow out) Cultured Minnows: Negatives
• Production costs
– Outdoor Pond Culture • Land and Pond Construction
• Feed
– Indoor Tank Culture
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Tanks
Pumps
Filters
Electricity
Feed
Biology
• Natural Range: St. John‘s River to Veracruz, Mexico along bay shores and tidal marshes.
• Salinity Range: 0‐40 ppt • Temperature Range: 32°F (0°C) – 94°F (35°C)
• Maximum size: Approximately 7 inches Female
Male
Spawning and Egg Production • Occurs over and extended period from early March to mid‐September with two peaks, spring (March‐April) and fall (August‐
September). The spring spawning is much more intense.
• Egg production is generally low when compared to fresh water baitfish such as the golden shiner, goldfish and fathead minnows. Egg Production
• A 3 inch bull minnow will carry approximately 650 mature and developing ova in a single ovary.
• In aquarium studies 10‐12 gram females deposit around 20 eggs/day/female (3 day cycles). • Egg hatching occurs in 3 weeks at 68°F (20°C) and in two weeks at temperatures of 77°F (25°C). Pool Spawning
• Exclude predators
• Little water exchange
• Observe population
Pool Spawning
• 500-gallon pools
• 25 lbs salt per pool
• mats harvested 3d
• 2:1 sex ratio F:M
• shade cloth (varying %)
Egg output over time
3000
Mean eggs collected
2500
2000
1500
1000
500
0
31-Mar
15-Apr
30-Apr
15-May 30-May
14-Jun
Date
29-Jun
14-Jul
29-Jul
13-Aug
Broodstock Growth
Mean female weight (g)
35
30
25
• Females - small
20
15
10
5
0
Feb
Mar
Apr
May
Jun
Jul
Aug
Mean male weight (g)
35
30
• Males - early
maturity
25
20
15
10
5
0
Feb
Mar
Apr
May
Jun
Jul
Air Incubation
• estuarine adaptation
• synchronous hatch
• hatchery technique
• practical use
Pond Spawning – Auburn Univ.
• Stocking Rate 10,000 fish /acre (ponds 0.2‐0.5 acre). • Stock before water temps reach 59°F (15°C )
• Mats are placed around the shallow edge of the edge of the pond (@100 per acre) about 6 inches deep. • Mats should be in place when water temperatures reach 64°F (18°C) and are left in the pond for 7‐12 days depending on rate of egg deposition. • As mats are removed they are replaced with new mats. Pond Spawning – Auburn Results
• Achieved ~ 8 eggs/day/female over a 30 day period = 240 eggs/female on cured spanish
moss mats. Ponds 10‐12 ppt salinity.
• Explanation for low numbers: •
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brood fish consume a portion of eggs
Competition for spawning sites
Eggs not being deposited on the mats Eggs are adhesive when first deposited but as they mature they lose adhesiveness and can fall through or off the mat. Hatching Ponds
• As mats are removed from spawning ponds they are placed in 0.2 to 0.5 acre Phase 2 hatching ponds • Hatching ponds are stocked with 500,000 to 1 million eggs/acre collected over a 10‐12 day period to ensure all fry are similar in age. • Hatching ponds are prepared in advance by filling pond and fertilizing with organic and inorganic fertilizers 2 wks prior to stocking to promote plankton blooms.
• This provides a first food for newly hatched fish. Hatching Ponds • Fry/fingerlings are cultured in Phase 2 hatching ponds for 5‐7 weeks. • A commercial minnow meal (32% protein) is fed at 13 lbs/acre/day until fingerlings reach 2200/lb (0.2 g). • Fingerlings are then fed minnow meal at 27 lbs/acre/day until harvest. • Survival at CPMC averaged 74% in hatching ponds and fish were about 900 per pound (0.5 g) at harvest. Production Ponds
• Production ponds (Phase 3) are stocked at 100,000/acre for fast growth or 200,000/acre for reduced growth. • Ponds are harvested when the average weight of minnows is in the range of 4 grams (113/lb)
• Production in crop 1 (June – July) Crop 2 (June ‐ September) crop 3 (overwinter). • Culture ponds may need to be covered with netting to prevent bird predation. Pond Maintenance •
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Salinity 5‐15 ppt
Use saline ground water where possible
Predator Control
Monitor Water Quality
– Ammonia – Dissolved Oxygen
Market Value • Minnows are sold wholesale at $0.10 each or $100 per 1000 ($11 per pound) or retail at $0.25 to $0.30 each or $300 per 1000 fish ($34 per pound).
• A distribution system should be established from the farm to the bait shops. References
• Production of bull minnows for the live bait market in coastal Alabama. Alabama Marine Resources Bulletin #13. Claude Peteet
Mariculture Center Gulf Shores, AL.
• Raising Mudminnows (TAMUSG‐86‐506R). Sea Grant College Program. Texas A&M University.
• Growing Bull Minnows (Circular ANR‐1103), Auburn University, Sea Grant, Marine Extension. Outreach materials
www.lsuagcenter.com/en/crops_livestock/aquaculture
Fundulus seminolis
• Seminole killifish, Mud minnow, Bull minnow
• Native to peninsular Florida
• Most commonly located inland from fresh to brackish waters
• Larger than F. grandis
• Euryhaline
Justification
• A few producers in Florida – high pond production observed
• Marketed as both freshwater and marine bait
• Can be cultured inland in freshwater then acclimated to saltwater and used as a marine bait
• My graduate student (DiMaggio) defined procedures for successful salinity acclimation
• F. seminolis works well as a marine baitfish for snook, tarpon, flounder, snapper
F. Seminolis Salinity Tolerance
• Seawater is the preferred salinity acclimation source versus rock salt
– Tolerates acute transfer from 0 to 24 g/L
– Survives for 13 h after acute transfer to 32 g/L
– 100% Survival using gradual acclimation
• Maximum salinity of 78 g/L
– LC‐50 of 60 g/L Substrate Orientations Tested
Results – Fecundity
• Females spawned between 7 and 82 eggs/female/week
• Females were 20 g each
• Females produced from 0.4 to 4.1 eggs/g/week
Egg Production at Various Salinities
Percent Fertilization at Various Salinities
Egg Hatching Percent at Various Salinities
F. seminolis Summary
• Good seasonal markets both fresh and marine
• Will reproduce in tanks but fecundity is low
• The higher density fish have lower egg output
– Possibly due to not spawning or egg consumption by other fish
• F. seminolis eggs can be air incubated with at least 80% hatchability after 8 days
• Pond production can be very high but has not been tested by UF
• Establishment of F. seminolis in water above 30 g/L is not very likely
Atlantic Croaker
• Micropogonias undulatus
• Common bait species
• Also has large markets as food fish
• A lot of research has been conducted on this species over the past 20 years
Research and Extension
• Reseach results summarized in EDIS publication
• Southern Regional Aquaculture Center (SRAC) publication will be published this year by Todd Sink at UAPB
General Life History
• Less than 14 inches in length
• Sexually mature by second year
• Spawn over near shore reefs during late fall and winter
• Post‐larvae and juveniles occupy estuaries
• Euryhaline and can tolerate salinities from 0‐
35 g/L
• Temperature tolerance 9‐32˚C
Spawning
• Successful spawning using HCG (125 IU/g) but must be administered three times over three weeks
• 6‐7 day period of latency after first dose for successful ovulation
• Ovaplant also used to induce spawning, implant then 7 days later inject ovaprim
Spawning
• Fecundity 180,000 eggs from a 15 inch female
• Use egg collectors
• Pelagic floating eggs
• 800‐1000 microns Spawning Issues
• Ovaprim requires resolving dosages, at least one for egg maturation, one for spawning
• Ovaplant implants did not successfully induce spawning in all females
• Some mortality of egg bound females
• Attempts to off‐cycle spawning have not been successful using 90 and 120 day short cycles
Larval Culture
• Green water
• Start feeding 3 dph
• Feed enriched rotifers 3‐12 dph at 5/mL
• Artemia fed 10‐25 dph at 0.5‐1.0/mL
• Microparticulate diet can be introduced 6‐13 dph with increasing particle size
Juvenile Culture
• Cultured in recirculating aquaculture systems, floating cages, ponds
• Salinity 0‐35 g/L
• Acclimation rates not known
• Feed pelleted feed 45% protein 8‐12% lipid
• Market size 5‐10 inches
• Growout from 1 to 5 inches takes about 8 months
• Wholesale prices (Adams) $0.19 per fish • Retail price $8.90/dozen
Atlantic Spot
• Leiostomus xanthurus
• Found from Cape Cod through the Gulf of Mexico • Caught as food fish even though < 10 inches
• Common bait along Atlantic east coast
• Used for striped bass fishing
Research and Extension
• Virginia Institute of Marine Science (VIMS) has conducted research
• Company in VA is commercially producing spot and distributing to several states
• Mid‐Atlantic Aquatic Technlogy
34247 Bradfords Neck Rd.
Quinby, VA 23423
http://www.maatfarms.com/Home.html
General Life History
• Temperature tolerance 4‐35˚C
• Spawn offshore and use inshore estuaries as nursery grounds
• Spawn offshore during fall and winter months
• Fecundity is 30,000‐60,000 eggs per female, will spawn multiple times per year
• Pelagic floating egg which will hatch in 48h at 20˚C • Grow to 3.5 ‐ 8 inches in one year
• Sexually mature during the second year
Culture Methods
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Cultured in recirculating aqauculture systems
Brood tanks VIMS used were 1200 gallons
Egg collectors
Biofilters, UV sterilizer, foam fractionator, aeration, heater or heat pump
Spawning ‐ VIMS Research • Individual females will produce 4000 eggs per day for 7 days
• Standard spawning methods
• HCG at 0.5 IU per gram
• Only inject females if males are running
• Spawn at night
Larval Culture
Eggs 800 micron diameter
Larvae < 2 mm
Yolk used for 5 days
Stocking density 20 eggs/L
12 h of diffuse lighting
Green water
Feed enriched rotifers at >7/mL for 24 days
• Feed Artemia at 1‐2/mL starting 18 dph
• Start weaning with inert diet at 22 dph
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Juvenile Culture
• Completely weaned onto inert diet by 45 dph
• At 45 dph they are about 1 inch in length and ready for growout
• Growout in tanks stocking density 0.5‐
1.5/L
• 130 dph 70% were > 3 inches (market size)
Production
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Based on VIMS research results:
Survival from egg to market assume 3%
To produce 10,000 market sized fish
333,333 eggs must be produced
This would require 12 brood females
• However, VIMS research had 10% survival
Markets
• Retail price $6.00‐
9.00/dozen
• Wholesale price based on local supply from wild and size
• 3 inches $0.25/fish
• 4 inches and > $0.50/fish
• 3 inches and > in Florida wholesale value $1/fish Other Species
• Ballyhoo Hemiramphus spp.
• Substrate spawners
• Large egg and newly hatched larvae consume Artemia
• Further research needed on growout
Contact Information
Cortney L. Ohs, Ph.D.
University of Florida
Indian River Research and Education Center
2199 S. Rock Road
Fort Pierce FL 34945
(772) 468‐3922 ext. 130
[email protected]
http://irrec.ifas.ufl.edu/aquaculture/