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Vol. 43 No. 2, 2004
A Review of the Impact of Parasitic Copepods on Marine Aquaculture
Stewart C. Johnson1,*, Jim W. Treasurer2, Sandra Bravo3, Kazuya Nagasawa4, and Zbigniew Kabata5
1Institute for Marine Biosciences, National Research Council, Canada, 1411 Oxford St., Halifax, Nova Scotia B3H 2Z1, Canada
2Sea
Fish Industry Authority, Marine Farming Unit, Ardtoe, Acharacle, Argyll
PH34 4LD, Scotland. E-mail: J_Treasurer@seafish.co.uk
3Instituto de Acuicultura, Universidad Austral de Chile, Puerto Mont Campus, Puerto Mont, Chile. E-mail: sbravo@uach.cl
4Nikko
Branch, National Research Institute of Aquaculture, Fisheries Research
Agency, Chugushi, Nikko, Tochigi, 321-1661, Japan. E-mail:
ornatus@fra.affrc.go.jp
5Biological Sciences Branch, Department of Fisheries and Oceans, Pacific Biological Station, Nanaimo V9R 5K6, B.C., Canada
Stewart C. Johnson, Jim W. Treasurer, Sandra Bravo, Kazuya Nagasawa, and Zbigniew Kabata (2004)
Parasitic copepods are common on cultured and wild marine finfish, and
there is a substantive literature describing their taxonomy, life
cycles, and host ranges. Although many species have long been
recognized to have the potential to affect the growth, fecundity, and
survival of their hosts, it has only been with the development of
semi-intensive and intensive aquaculture that their importance as
disease-causing agents has become evident. Members of the family
Caligidae are the most commonly reported species on fish reared in
brackish and marine waters. These species, often referred to as sea
lice, are responsible for most disease outbreaks. The impacts of sea
lice on marine salmonid aquaculture are well documented, with
catastrophic losses reported for disease outbreaks that have resulted
in high levels of mortality. With the development of a variety of
treatments and management strategies to reduce infection levels,
mortality caused by sea lice has been greatly reduced. At present,
economic losses due to sea lice are primarily from the costs of
treatments, the costs of the management strategies, the costs
associated with reduced growth rates that are a direct result of
infection and/or treatment, and the costs of carcass downgrading at
harvest. Indirect and direct losses due to sea lice in salmonid
aquaculture globally are estimated to be greater than US$100 million
annually. In other areas of marine aquaculture, the impact of parasitic
copepods is not well documented. This is especially true for species
such as Atlantic halibut, Atlantic cod, turbot, and haddock that have
only recently entered commercialscale production. This review discusses
the global importance of parasitic copepods as disease-causing agents
in marine aquaculture. We also provide a brief review of the
environmental and husbandry factors that may affect parasitic copepod
abundance and the potential roles that parasitic copepods play as
vectors for other disease agents.
Key words: Sea lice, Disease, Caligidae.
*Correspondence: Tel:902-426-2630. Fax: 902-426-9413. E-mail: Stewart.Johnson@nrc.ca
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