pyrethroid occurrence in environmental samples (i.e., water and sediment). For
seawater, passive sampling devices (PSDs) are proposed as a good alternative for
field monitoring. Finally, by means of ecotoxicological bioassays, the effects of
pyrethroids on native biota were assessed. The results show that the application of
pyrethroids may trigger some unintended risks to nontarget organisms, particularly
copepods, since modeled and observed concentrations in water (dissolved phase) are
in the range of fractions of ng L
À1
, but higher cypermethrin and deltamethrin
concentrations in sediment in the range of 1,323 and 1,020 ng g
À1 , respectively,
have been observed. These measured concentrations were in the range of concentrations toxic to native invertebrate species in Chile. We conclude that a stricter
process should be followed when pyrethroids, particularly cypermethrin, are
recommended for use in combating sea lice in the Chilean salmon farming industry.
Risk assessment procedures and the establishment of stricter regulations on matters
such as the maximum allowable concentrations around the cages when these pesticides are applied and recommended.
Keywords Aquaculture, Patagonia, Pyrethroids, Sea lice, Toxicity
1 Introduction
The salmon industry has become the driving force of aquaculture development in
Chile. The high volume of salmonids produced by Chilean aquaculture has positioned the industry as an important exporter in the international market. However,
salmon productivity in southern areas has been vulnerable to salmon lice infections
and other environmental issues [1]. The occurrence of ectoparasitic diseases caused
by sea lice called Caligus rogercresseyi [2] has forced to the industry to use
chemotherapeutic alternatives that contribute to the control and prevention of salmon
infections. In the 1990s, emamectin benzoate (Slice
® ) became the exclusive means
of treatment for salmonids; however, studies evidenced a loss of sensitivity in sea
lice [3–5]. Therefore, veterinary medicines have been required by the salmon
industry [6–8]. Currently, the synthetic pyrethroids cypermethrin (Betamax
® ) and
deltamethrin (AMX
® and Deltafav
® ) are alternatives for treating ectoparasites of
salmon. Nevertheless, it has been suggested that these pyrethroids have adverse
consequences for marine biota that ought to be of concern (e.g., [9–13]). This
chapter presents an overview of the occurrence, behavior, and potential environmental risks of pyrethroids currently used on salmon farms located in the northern
Chilean Patagonia.
178
F. Tucca and R. Barra
seawater, passive sampling devices (PSDs) are proposed as a good alternative for
field monitoring. Finally, by means of ecotoxicological bioassays, the effects of
pyrethroids on native biota were assessed. The results show that the application of
pyrethroids may trigger some unintended risks to nontarget organisms, particularly
copepods, since modeled and observed concentrations in water (dissolved phase) are
in the range of fractions of ng L
À1
, but higher cypermethrin and deltamethrin
concentrations in sediment in the range of 1,323 and 1,020 ng g
À1 , respectively,
have been observed. These measured concentrations were in the range of concentrations toxic to native invertebrate species in Chile. We conclude that a stricter
process should be followed when pyrethroids, particularly cypermethrin, are
recommended for use in combating sea lice in the Chilean salmon farming industry.
Risk assessment procedures and the establishment of stricter regulations on matters
such as the maximum allowable concentrations around the cages when these pesticides are applied and recommended.
Keywords Aquaculture, Patagonia, Pyrethroids, Sea lice, Toxicity
1 Introduction
The salmon industry has become the driving force of aquaculture development in
Chile. The high volume of salmonids produced by Chilean aquaculture has positioned the industry as an important exporter in the international market. However,
salmon productivity in southern areas has been vulnerable to salmon lice infections
and other environmental issues [1]. The occurrence of ectoparasitic diseases caused
by sea lice called Caligus rogercresseyi [2] has forced to the industry to use
chemotherapeutic alternatives that contribute to the control and prevention of salmon
infections. In the 1990s, emamectin benzoate (Slice
® ) became the exclusive means
of treatment for salmonids; however, studies evidenced a loss of sensitivity in sea
lice [3–5]. Therefore, veterinary medicines have been required by the salmon
industry [6–8]. Currently, the synthetic pyrethroids cypermethrin (Betamax
® ) and
deltamethrin (AMX
® and Deltafav
® ) are alternatives for treating ectoparasites of
salmon. Nevertheless, it has been suggested that these pyrethroids have adverse
consequences for marine biota that ought to be of concern (e.g., [9–13]). This
chapter presents an overview of the occurrence, behavior, and potential environmental risks of pyrethroids currently used on salmon farms located in the northern
Chilean Patagonia.
178
F. Tucca and R. Barra