This document discusses the various chemicals used in aquaculture for disease control, increased production, and improved animal welfare. It outlines common disinfectants like hypochlorite, quaternary ammonium compounds, and EDTA. It also discusses feed additives and therapeutants like sulfonamides, terramycin, formalin, potassium permanganate, NaCl, and copper sulfate that are applied to water for disease treatment. Many of these chemicals are effective against bacteria and parasites but require proper dosing to avoid toxicity.

1. Chemicals used in
Aquaculture
Presented by- Jyoti Saroj
Department.- Fisheries Resource
Management
College of Fisheries, Veraval, Gujarat

2. Introduction
Chemicals are essential for-
 Control of pathogens and diseases.
 Increased and controlled production of seed in
hatcheries, increased feeding efficiency and
improvement of survival rates.
 Production efficiency increased and animal welfare
enhanced

3. Chemicals used in aquaculture
Disinfectants-
 Hypochlorite(Sodium or calciumhypochlorite)
• Used for disinfection of tanks and equipment.
• Chlorine decays with time by the action of sunlight
and consumption of chlorine through its oxidation
of organic matter.
 Quaternary Ammonium compounds
(Benzalkonium chloride)
• It have detergent and antibacterial activity
• Widely used in shrimp ponds
• Now only limited use in food fish

4. Chemicals used in aquaculture
Disinfectants(conti.)
-EDTA
• Added to larval rearing water in some shrimp
hatcheries
• Reduce the bioavailability of heavy metals .
-Lime
• Widely used to neutralise acidity, increase total
alkalinity
• Lime applied to the pond bottom during pond
preparation at 100-8,000 kg/ha

5. •Burnt lime also used (at 50-100 g/m2) in
conjunction with ammonium phosphate to kill pests
and predators.
Lime applied in pond

6. Chemicals used in aquaculture
Feed additives (Sulfonamides)
– Sulfamerazine and Romet-30
• Effective for bacterial infections
• 220 mg/kg fish for 14 days.
• Some treatments recommend 3 days, fewer
side-effects.
– Toxicity may occur -
• Kidney damage (drug crystal formation in
renal tubules)
• Clinical signs – bloating/dropsy (stomach full
of water)

7. Chemicals used in aquaculture
Continued-
– Romet-30
• Suggested dose (furunculosis) – 50mg/kg
fish/day for 5 to 7 days
• Also effective for ESC
• Still used in the catfish industry.

8. Chemicals used in aquaculture
Terramycin (oxytetracycline) – TM50
 Effective against gram neg. bacteria and gram
positive bacteria.
Recommended dose – 55-83mg/Kg fish/day for
10 days
Should not be fed on prophylactic basis!
• Resistance to oxytetracycline can occur in most
bacterial fish pathogens

9. Chemicals used in aquaculture
Therapeutants added to water
– Methods
• Static bath – most reliable for
raceways/tanks
• Constant flow – safe and can be used in most
situations when fish reared in running water
Chemicals
 Formalin
• Employed as an antifungal agent
• Used to control ectoparasites
• 15 to 250 ul/l used for fish and crustaceans

10. Chemicals used in aquaculture
Chemicals (cont.)
 Potassium Permanganate
• Great for fungus!!
• Strong oxidizing agent
 NaCl (salt) (uniodized!!)
• Most overlooked treatment
• Can be very effective
• 3% recommended if possible (10-30 min)

11. Chemicals used in aquaculture
Copper Sulfate (<6.4 mg copper/L water)
– Also called Cutrine
– Algaecide/bactericide/parasiticide
• Effective on scaled fish, but can cause
problems with scaleless fish (catfish).
• Can produce kidney necrosis, destruction
of hematopoietic tissue, increased liver fat
and inhibition of digestive enzymes.

12. Chemicals used in aquaculture
Malachite green
• Global use as an antifungal and antiprotozoal
• Its use is not permitted in the USA and some
Southeast Asian countries.
Methylene blue
• Effective against fungal and protozoan infections
• May also provide protection against nitrite
intoxication