Aquaculture Chemicals
Authors: Schnick Rosalie A. 
Published: August 2004

Abstract

Intensive or extensive culture of aquatic animals requires chemicals that control disease, enhance the growth of cultured species, reduce handling trauma to organisms, improve water quality, disinfect water, and control aquatic vegetation, predaceous insects, or other nuisance organisms. The aquacultural chemical needs for various species have been described for rainbow trout,
Oncorhynchus mykiss
; Atlantic and Pacific salmon,
Salmo salar
and
Oncorhynchus
sp.; channel catfish,
Ictalurus punctatus
; striped bass,
Morone saxatilis
; milkfish,
Chanos chanos
; mollusks; penaeid (
Penaeus
sp.) shrimp; and a variety of other marine species. Laws and regulations on the use of chemicals in aquaculture vary by country. Regulations and therapeutants or other chemicals that are approved or allowed for use in the United States, Canada, Europe, and Japan are presented herein. In the United States, the application of chemicals to organisms or to their environments is regulated by the U.S. Food and Drug Administration (FDA) and the U.S. Environmental Protection Agency (EPA). FDA controls the use of drugs and anesthetics, and EPA controls the application of chemicals and pesticides to the environment. Each agency develops appropriate guidelines and policies to implement the laws for its field of responsibility. Few therapeutants are registered in the United States for use on any cultured aquatic species. In the most critical area of antibacterials, only two (Terramycin for Fish and Romet‐30) are fully registered and available. Formalin (Formalin‐F, Parasite‐S, Paracide‐F) is the only registered fungicide and is labeled for use on eggs of trout, salmon, and esocids at 1,000–2,000 mg/L for 15 min. Formalin (Formalin‐F, Parasite‐S, Paracide‐F) is the only parasiticide currently registered and available. It is only registered for use on trout, salmon, catfish, largemouth bass (
Micropterus salmoides
), and bluegill (
Lepomis macrohirus
). Povidone–iodine compounds can be used to disinfect the surface of fish eggs because FDA has classified them as low regulatory priority substances. Water treatment compounds (potassium permanganate, calcium chloride, potassium chloride, calcium carbonate, calcium hydroxide, sodium hydroxide, tris buffer, and sodium sulfite), anesthetics (tricaine, carbon dioxide gas, and sodium bicarbonate), herbicides (copper sulfate, chelated copper compounds, and diquat dibromide) and piscicides (antimycin and rotenone) are also approved and regulated. The control of aquacultural drugs varies according to country from no regulation to restrictive regulations. Generally, few requirements are needed for a therapeutant to be licensed or registered in South America, Africa, and most of Asia. Except for environmental studies, requirements for registration data in Canada are similar to requirements in the United States. However, Canada has significantly different regulations and approval processes. Canadian aquaculturalists use drugs that are either licensed for other food animals and prescribed by veterinarians or used in an emergency under the direction of the Canadian Bureau of Veterinary Drugs (BVD). Chemicals authorized for use in aquaculture in Canada include oxytetracycline, C
22
H
24
N
2
O
9
; sulfadimethoxine (Romet‐30), C
12
H
14
N
4
O
4
S, and ormetoprim (Romet‐B), C
14
H
18
N
4
O
2
erythromycin, C
37
H
67
NO
13
; and others. Chemicals authorized for use in aquaculture in certain European countries include ampicillin, C
16
H
19
N
3
O
4
S; chloramphenicol, C
11
H
12
Cl
2
N
2
O
5
; chlortetracycline, C
22
H
23
ClN
2
O
8
; dibutyltin oxide, C
8
H
18
SnO; dimetridozole, C
5
H
7
N
3
O
2
; and others. In Japan, registration of drugs for aquatic species requires the same data as those required for drugs on other animals. The Ministry of Agriculture, Forests, and Fisheries and the Ministry of Welfare control the use of chemicals and aquaculture in Japan. As of July 1990, more chemicals were registered for aquacultural use in Japan than in any other country. They include amoxicillin, C
16
H
19
N
3
O
5
S; ampicillin, C
16
H
19
N
3
O
4
S; florfenicol, C
12
H
14
Cl
2
FNO
4
S; tetracycline, C
22
H
24
N
2
O
8
; thiamphenicol, C
12
H
15
Cl
2
NO
5
S; eugenol, C
10
H
12
O
2
;

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; and hydrogen peroxide, H
2
O
2
. More therapeutants and vaccines may soon be added to the medicine chest of fish farmers. Research has been conducted on three important antibacterial compounds in the United States and the U.S. Fish and Wildlife Service (USFWS) is working on several fronts to improve the availability of fungicides and parasiticides.