Management of Disease in Management of Disease in Warmwater Aquaculture Warmwater Aquaculture

John P. Hawke Ph.D. John P. Hawke Ph.D. Louisiana Aquatic Diagnostic LaboratoryLouisiana Aquatic Diagnostic LaboratoryDepartment of Pathobiological SciencesDepartment of Pathobiological Sciences

School of Veterinary MedicineSchool of Veterinary MedicineLouisiana State UniversityLouisiana State University

AASV BIVI Pre-conference Symposium, New Orleans, LA 2/26/16

Start Healthy, End Strong!Start Healthy, End Strong!

Healthy Pigs?Healthy Pigs?

OutlineOutline

►Why do we need domestic aquaculture ?Why do we need domestic aquaculture ?►Introduction to aquaculture and aquaculture Introduction to aquaculture and aquaculture

systems.systems.►Common diseases in catfish pond cultureCommon diseases in catfish pond culture►Common diseases of tilapia in fresh water closed Common diseases of tilapia in fresh water closed

recirculating systems. recirculating systems. ►Prevention and control of disease in aquaculture Prevention and control of disease in aquaculture

““Start Healthy, End StrongStart Healthy, End Strong””

http://www.nmfs.aquaculture.noaa.gov

World Seafood Demand World Seafood Demand • Global wild harvest is 95 million tons, has Global wild harvest is 95 million tons, has

leveled and likely cannot be sustained leveled and likely cannot be sustained • Present global aquaculture production is nearly Present global aquaculture production is nearly

60 million tons, valued at $70 billion 60 million tons, valued at $70 billion • To meet increased demand for seafood, the To meet increased demand for seafood, the

world will need an additional 40 million tons world will need an additional 40 million tons from aquaculture by 2030. from aquaculture by 2030.

World Aquaculture ProductionWorld Aquaculture Production

• 70% is produced in China 70% is produced in China • 22% is from the rest of Asia 22% is from the rest of Asia • 6.7% is from Latin America and the Caribbean 6.7% is from Latin America and the Caribbean • 1.3% is from North America1.3% is from North America

http://www.nmfs.aquaculture.noaa.gov

The FutureThe Future

• 86% of the seafood consumed in the U.S. is imported 86% of the seafood consumed in the U.S. is imported and 40% of those imports are from aquaculture and 40% of those imports are from aquaculture

• The U.S. annual seafood trade deficit is over $9 billion.The U.S. annual seafood trade deficit is over $9 billion.• Based on demand and population growth projections in Based on demand and population growth projections in

the United States, the projected domestic seafood gap in the United States, the projected domestic seafood gap in 2025 is 2-4 million tons. 2025 is 2-4 million tons.

• Domestic aquaculture could help offset this deficit.Domestic aquaculture could help offset this deficit.

http://www.nmfs.aquaculture.noaa.gov

Aquaculture and Mariculture Aquaculture and Mariculture fueled by over-fishing and regulationfueled by over-fishing and regulation

Alabama Marine Resources Division

U.S. Aquaculture IndustryU.S. Aquaculture Industry594 million lbs, value $1.23 billion594 million lbs, value $1.23 billion

►Catfish 340 million lbsCatfish 340 million lbs►Crawfish 96 million lbsCrawfish 96 million lbs►Trout 36 million lbsTrout 36 million lbs►Salmon 43 million lbs Salmon 43 million lbs ►Oysters 37 million lbsOysters 37 million lbs►Tilapia 23 million lbsTilapia 23 million lbs

http://www.nmfs.aquaculture.noaa.gov

Louisiana AquacultureLouisiana Aquaculture$476 million industry$476 million industry

►Crawfish: Crawfish: $ 172 million$ 172 million►Oysters: Oysters: $ 41 $ 41 ““►Alligators: Alligators: $ 77 $ 77 ““►Catfish: Catfish: $ 1.5 $ 1.5 ““►Pet turtles:Pet turtles: $ 3.8 $ 3.8 ““ ►Other:Other: $ 2.0$ 2.0 ““►Processing:Processing: $ 177$ 177 ““

LSU AgCenter

U.S. Warmwater U.S. Warmwater AquacultureAquaculture

Intensive Open PondIntensive Open PondFreshwater Aquaculture Freshwater Aquaculture

channel catfish

Extensive Open Pond Extensive Open Pond Fresh Water Aquaculture Fresh Water Aquaculture

Crawfish

Intensive Closed Recirculating Intensive Closed Recirculating Systems Systems

0.5 lbs /gallon in 150,000 liter systems

Proposed Offshore Mariculture Proposed Offshore Mariculture in the Gulf of Mexicoin the Gulf of Mexico

•On 1/11/16 final ruling by NOAA allows aquaculture permits to be issued for culture of species like red drum and cobia in federal waters of the Gulf of Mexico.

Fish Health Status

Host

Age

FacilitiesPhysiological Status “stress”

Pathogen

Nutrition

Environment

Species Strain

Acquired immunity

Natural resistance

Type

Species

Strain

Schedule Quantity Quality

Water quality

Organic load

Temperature

Density

Design

Handling

Plumb, 1999

Intensive Open Pond Intensive Open Pond Aquaculture:Aquaculture:

Channel catfish Channel catfish Ictalurus punctatusIctalurus punctatus 10 to 20 acre earthen ponds10 to 20 acre earthen ponds

Stocking: 4,000 to 10,000 per acre Stocking: 4,000 to 10,000 per acre Feeding: 100-200 lbs/acre/dayFeeding: 100-200 lbs/acre/day

Feed Conversion: 1.5 to 1Feed Conversion: 1.5 to 1 Production: 4000 to 6000 lbs/acreProduction: 4000 to 6000 lbs/acre

The U.S. Catfish IndustryThe U.S. Catfish Industry

►95% of Production in Mississippi, Alabama, 95% of Production in Mississippi, Alabama, Arkansas, Texas and Louisiana.Arkansas, Texas and Louisiana.

►660 million lbs produced in 2003 valued at $425 660 million lbs produced in 2003 valued at $425 million.million.

►Problems:Problems: Water quality Water quality Rising feed costs ($306/ton)Rising feed costs ($306/ton) 214 million lbs of imported 214 million lbs of imported ““BasaBasa”” (2014) (2014) Infectious diseases Infectious diseases

Production: Spawning ponds (Jan-June)Hatchery Phase (May – June)Nursery Phase (June – October)Grow-out Phase (year round)

Multiple Batch CroppingMultiple Batch Cropping::

Ponds are seined 2-3 times per year and market size fish harvested. Fish must be “on flavor”.

Higher production levels have led to low Higher production levels have led to low dissolved oxygen levels, high ammonia, high dissolved oxygen levels, high ammonia, high

nitrites and stress on fish populations.nitrites and stress on fish populations.

Disease in Warmwater AquacultureDisease in Warmwater Aquaculture

►45% of losses in aquaculture due to disease45% of losses in aquaculture due to disease►60% of this total due to bacterial diseases60% of this total due to bacterial diseases►A single bacterial disease, enteric septicemia of A single bacterial disease, enteric septicemia of

catfish (ESC) caused by catfish (ESC) caused by Edwardsiella ictaluriEdwardsiella ictaluri, , costs the U.S. catfish industry $20 million costs the U.S. catfish industry $20 million annually.annually.

Delta farmers put Delta farmers put ““sick catfishsick catfish”” at at the top of their list of problemsthe top of their list of problems

Major Catfish Diseases Major Catfish Diseases

►Columnaris Disease – 44.1%Columnaris Disease – 44.1%►Enteric Septicemia of Catfish, ESC – 37.2%Enteric Septicemia of Catfish, ESC – 37.2%►Proliferative Gill Disease, PGD – 21.7%Proliferative Gill Disease, PGD – 21.7%►Saprolegnia Saprolegnia ““Winter FungusWinter Fungus”” – 8.6% – 8.6%►Channel Catfish Virus – 4.6%Channel Catfish Virus – 4.6%►Ichthyophthirius Ichthyophthirius ““ICHICH”” – 1.3% – 1.3%

NWAC/MSU 2006

Other Catfish DiseasesOther Catfish Diseases

►Bolbophorus damnificusBolbophorus damnificus – trematode – trematode ““white grubwhite grub””►Protozoan parasites and ectocommensalsProtozoan parasites and ectocommensals►Visceral Toxicosis (botulinum toxin) Visceral Toxicosis (botulinum toxin) ►Algal toxinsAlgal toxins►Severe Idiopathic Anemia (iron deficiency)Severe Idiopathic Anemia (iron deficiency)►Brown Blood – methemoglobinemia (nitrite toxicity) Brown Blood – methemoglobinemia (nitrite toxicity) ►Aeromonas hydrophilaAeromonas hydrophila

NWAC/MSU 2006

Catfish Disease SeasonalityCatfish Disease Seasonality

020406080

100120140160180200

J F M A M J J A S O N D

ESCCOLPGDSAP

NWAC/MSU 2000

Enteric Septicemia of Catfish Enteric Septicemia of Catfish Edwardsiella ictaluriEdwardsiella ictaluri

Acute Acute

Sub Acute Chronic

Acute ESCAcute ESC Edwardsiella ictaluri Edwardsiella ictaluri is an enteric bacterium and is an enteric bacterium and

is transmitted horizontally by the fecal-oral route. is transmitted horizontally by the fecal-oral route. The acute form of the disease begins as an The acute form of the disease begins as an

enteritis. The bacterium crosses the gut enteritis. The bacterium crosses the gut epithelium, enters the circulation and via epithelium, enters the circulation and via intracellular replication proliferates in the blood intracellular replication proliferates in the blood and organs (primarily in macrophages). and organs (primarily in macrophages).

Primary target organs are the liver, spleen, and Primary target organs are the liver, spleen, and kidneys. kidneys.

Chronic ESCChronic ESC Edwardsiella enters the nares from the waterEdwardsiella enters the nares from the water Travels the olfactory tract to the brain where a Travels the olfactory tract to the brain where a

meningitis and/or menigoencephalitis resultsmeningitis and/or menigoencephalitis results Inflammatory exudate forms in the cranium Inflammatory exudate forms in the cranium

and oozes out through the fontanelle in the top and oozes out through the fontanelle in the top of the skull forming the typical chronic ulcer of the skull forming the typical chronic ulcer

Disease Management in Aquaculture Disease Management in Aquaculture

Herd Health Management ?Herd Health Management ?► Individual fish not very valuable – $2.00 each.Individual fish not very valuable – $2.00 each.► Population size: 10 acre pond may contain 40,000 Population size: 10 acre pond may contain 40,000

individual harvestable food size fish. Value = $80,000 individual harvestable food size fish. Value = $80,000 for 2.0 lb fish @ $1.00 / lb.for 2.0 lb fish @ $1.00 / lb.

► Individual fish may be periodically sacrificed to obtain Individual fish may be periodically sacrificed to obtain information about the population.information about the population.

► The population is underwater and not visibleThe population is underwater and not visible► Entire pond or population is treated rather than Entire pond or population is treated rather than

individuals. individuals.

Management of ESCManagement of ESCmedicated feeds-restrictive feeding medicated feeds-restrictive feeding

► Anticipate disease during temperature window (22 – Anticipate disease during temperature window (22 – 28°C) 28°C)

► Monitor feeding response (early detection)Monitor feeding response (early detection)► Submit specimens for necropsySubmit specimens for necropsy► Isolation and antibiotic susceptibility Isolation and antibiotic susceptibility ► Feed medicated feeds as labeled - Terramycin 14 days, Feed medicated feeds as labeled - Terramycin 14 days,

Romet 5 days, Aquaflor 10 days (available only through Romet 5 days, Aquaflor 10 days (available only through VFD). VFD).

► Restrictive feeding - at first sign of disease outbreakRestrictive feeding - at first sign of disease outbreak

Management of ESC – Management of ESC – preventionprevention““Start Healthy / End StrongStart Healthy / End Strong””

►Screen for disease free stocks and stock SPF Screen for disease free stocks and stock SPF fingerlingsfingerlings

►Biosecurity in the hatcheryBiosecurity in the hatchery►Vaccinate new fingerlings by immersion with Vaccinate new fingerlings by immersion with

live attenuated vaccine. live attenuated vaccine. ►Improved genetics – breeding for enhanced Improved genetics – breeding for enhanced

growth and disease resistancegrowth and disease resistance

Tilapia Culture Tilapia Culture

►In the US, all in indoor closed recirculating In the US, all in indoor closed recirculating systems (bead filters, blown air)systems (bead filters, blown air)

►Greenhouses in the SouthGreenhouses in the South►Closed well insulated buildings in the North and Closed well insulated buildings in the North and

MidwestMidwest►Stocking is high density (all male)Stocking is high density (all male)►Production - 0.5 lb/gallonProduction - 0.5 lb/gallon►Feeding - 1.0 lbs/200 gallons Feeding - 1.0 lbs/200 gallons

Intensive Closed Recirculating Intensive Closed Recirculating System CultureSystem Culture - Tilapia - Tilapia

Tilapia Tilapia ((Oreochromis niloticusOreochromis niloticus ) )

Diseases of TilapiaDiseases of Tilapia Streptococcus iniae Streptococcus iniae

►Causative agent of beta-hemolytic Causative agent of beta-hemolytic streptococcosis.streptococcosis.

►Synonyms: beta-hemolytic streptococcal Synonyms: beta-hemolytic streptococcal disease, bacterial meningoencephalitis, disease, bacterial meningoencephalitis, ““mad mad fish diseasefish disease””

►Acute and chronic Acute and chronic

Clinical Signs Clinical Signs (S. iniae)(S. iniae)

Management of Streptococcal Disease Management of Streptococcal Disease in Closed Systemsin Closed Systems

►Exclusion is paramount (biofilms)Exclusion is paramount (biofilms)►Screening of new introductions (quarantine)Screening of new introductions (quarantine)►Reduce feeding ratesReduce feeding rates►Improve water quality (suspended solids)Improve water quality (suspended solids)►Ozone and UV treatment (water sterilization)Ozone and UV treatment (water sterilization)►Reduce fish density, grading and handlingReduce fish density, grading and handling►Maintain constant temperature 28Maintain constant temperature 28 ˚̊CC►Antibiotic feeds: Aquaflor now approvedAntibiotic feeds: Aquaflor now approved

Rickettsia-like Organism of TilapiaRickettsia-like Organism of Tilapia

►Identified as a new species of Identified as a new species of Francisella. F. Francisella. F. noatunensis subsp. orientalisnoatunensis subsp. orientalis

►Causes chronic disease in tilapiaCauses chronic disease in tilapia►Intracellular bacteriumIntracellular bacterium►Cultured on specialized media or in cell linesCultured on specialized media or in cell lines►Parasites may play a role as vectorsParasites may play a role as vectors

Francisella noatunensis Francisella noatunensis subspsubsp. . orientalisorientalis

FrancisellaFrancisella management management

►Detection by necropsy, culture and real time Detection by necropsy, culture and real time PCR PCR

►Limit movement of infected fishLimit movement of infected fish►Antibiotics effective in vitro but only marginally Antibiotics effective in vitro but only marginally

effective following oral administration.effective following oral administration.►Maintain constant temperature >27°CMaintain constant temperature >27°C►Experimental vaccines. Live attenuated vaccine Experimental vaccines. Live attenuated vaccine

with mutation inwith mutation in iglC iglC genegene

Prevention of Disease in Aquaculture Prevention of Disease in Aquaculture ““Start Healthy, End StrongStart Healthy, End Strong””

► An ounce of prevention is worth a pound of cureAn ounce of prevention is worth a pound of cure BiosecurityBiosecurity Quarantine (asymptomatic carriers) Quarantine (asymptomatic carriers) VaccinationVaccination

► Anticipate problems - understand the host specificity Anticipate problems - understand the host specificity and seasonality of diseasesand seasonality of diseases

► Early detection – be observant!Early detection – be observant! Daily monitoring and record keepingDaily monitoring and record keeping

► Judicious use of antibioticsJudicious use of antibiotics

Sources of InformationSources of Information

American Fisheries Society, Fish Health Section

AVMA

Louisiana Aquatic Diagnostic Laboratory

LSU AgCenter

National Marine Fisheries Service

Alabama Marine Resources Division

Southern Regional Aquaculture Center SRAC

LADL