Infestations of wild adult Atlantic salmon (Salmo salar L.) by the ectoparasitic copepod sea louse Lepeophtheirus salmonis Krøyer: prevalence, intensity and the spatial distribution of males and [2pt] females on the host fish

  title={Infestations of wild adult Atlantic salmon (Salmo salar L.) by the ectoparasitic copepod sea louse Lepeophtheirus salmonis Kr{\o}yer: prevalence, intensity and the spatial distribution of males and [2pt] females on the host fish},
  author={Christopher D. Todd and Alan M. Walker and Jane E. Hoyle and Sally J. Northcott and Andrew F. Walker and Michael G. Ritchie},
The copepod Lepeophtheirus salmonis Krøyer is a specific ectoparasite of North Atlantic and Pacific salmonids in their marine phases. We compared infestations of L. salmonis on wild Atlantic salmon (Salmo salarL.) captured in estuarine (Firth of Tay, east Scotland; 1995, 1996) and marine coastal waters (Strathy Point, north Scotland; 1998, 1999). Host fish from the Tay were caught by sweep netting, whilst those from Strathy Point were trapped in anchored bagnets. Fish capture method and… 
Ectoparasitic sea lice (Lepeophtheirus salmonis and Caligus elongatus) infestations of wild, adult, one sea-winter Atlantic salmon Salmo salar returning to Scotland
A positive association in abundance of the 2 species, for individual fish within any one year, indicates weak or absent competitive effects on abundances for individual hosts, although Taylor’s power regression showed clear differences in density-related patterns of overdispersion amongst hosts for the2 species.
The copepod parasite (Lepeophtheirus salmonis (Krøyer), Caligus elongatus Nordmann) interactions between wild and farmed Atlantic salmon (Salmo salar L.) and wild sea trout (Salmo trutta L.): a mini review
  • C. Todd
  • Biology, Environmental Science
  • 2007
Microsatellite analyses show that L. salmonis comprises a single panmictic population throughout the Atlantic; gene flow between parasites on wild and farmed hosts is sufficiently high to prevent population genetic differentiation by random drift.
Wild salmonids and sea louse infestations on the west coast of Scotland: sources of infection and implications for the management of marine salmon farms.
  • J. Butler
  • Environmental Science
    Pest management science
  • 2002
With the industry's continued expansion, and thus increased numbers of farm salmon, a target of zero ovigerous lice will be required on farms to minimise impacts on wild salmonids.
Temporal stability of sea louse Lepeophtheirus salmonis Krøyer populations on Atlantic salmon Salmo salar L. of wild, farm and hybrid parentage
Atlantic salmon satmo solar smolts of wild, hybrid and farmed parentage were individually tagged then reared in a sea cage for 8 months, suggesting that identification of individual Atlantic salmon that display reduced susceptibility to sea lice, may be problematic.
An assessment of salmon farms and wild salmonids as sources of Lepeophtheirus salmonis (Krøyer) copepodids in the water column in Loch Torridon, Scotland.
The study highlights the importance of control of L. salmonis on salmon farms for the co-existence of both wild salmonid populations and the aquaculture industry and suggests that louse management approaches, e.g. treatment trigger levels, need to take account of individual farm biomass, or numbers of fish.
Population genetic differentiation of sea lice (Lepeophtheirus salmonis) parasitic on Atlantic and Pacific salmonids: analyses of microsatellite DNA variation among wild and farmed hosts
There is no evidence of isolation of populations on farmed hosts from those on wild fish, consistent with long-distance oceanic migration of wild hosts and larval interchange between farmed and wild host stocks being sufficient to prevent genetic divergence of L. salmonis throughout the North Atlantic.
Anadromous Coastal Cutthroat Trout (Oncorhynchus clarkii clarkii) as a Host for Argulus pugettensis (Crustacea, Branchiura): Parasite Prevalence, Intensity and Distribution
Coastal cutthroat trout from the marine waters of Puget Sound, WA, was documented as a new host for the ectoparasite Argulus pugettensis, a first step in understanding the relationship between this wild, native trout and infestations by parasitic sea lice.
Changes in epidemiological patterns of sea lice infestation on farmed Atlantic salmon, Salmo salar L., in Scotland between 1996 and 2006.
Data indicate that both species of sea lice commonly found in Scotland, Lepeophtheirus salmonis and Caligus elongatus, have declined on farms over the past decade, with the overall pattern showing a particular reduction in the second and third quarters of the second year of production.
A survey of pathogens and metazoan parasites on wild sea trout (Salmo trutta) in Scottish waters
Sea trout from the east coast sites were larger than those from the west coast, and the abundance of Lepeophtheirus salmonis, Hysterothylacium aduncum, and Anisakis sp.
Distributions of planktonic sea lice larvae Lepeophtheirus salmonis in the inter-tidal zone in Loch Torridon, Western Scotland in relation to salmon farm production cycles
This study examines the relative density of sea lice, Lepeophtheirus salmonis (Kroyer), larvae in the inter-tidal areas of Loch Torridon, a fjordic sea loch in Western Scotland and the site of


Distribution and structure of the population of sea lice, Lepeophtheirus salmonis Krøyer, on Atlantic salmon, Salmo salar L., under typical rearing conditions
Frequency of mating has been found to increase with parasitic intensity in fish of different size and different lice categories have shown different susceptibility to delousing with dichlorvos.
Seasonal occurrence of Lepeophtheirus salmonis and Caligus elongatus (Copepoda: Caligidae) on sea trout (Salmo trutta), off southern Norway
The occurrence of the parasitic copepod Lepeophtheirus salmonis Kroyer and Caligus elongatus Nordmann on sea trout Salmo trutta L. salmonis and C. elongatus was investigated in the Arendal archipelago, southern Norway, an area without salmon farms.
Occurrence of Lepeophtheirus salmonis (Copepoda: Caligidae) on sea trout (Salmo trutta) in the inner Oslo Fjord, south-eastern Norway
The occurrence of the parasitic copepod Lepeophtheirus salmonis Kroyer on sea trout Salmo trutta L. was studied in the Askerelva river and in the adjacent Oslo Fjord, south-eastern Norway, where
Sea lice (Copepoda: Caligidae) on wild sea trout (Salmo trutta L.) in Scotland
The heaviest infection of sea trout with lice was recorded in the salmon farming areas of the west and north-west of Scotland, but no clear pattern emerged with levels of infection at single locations in relation to the proximity to the nearest salmon farm or with the pattern of infection (and larval production) within an adjacent salmon farm.
Prevalence and abundance of Lepeophtheirus salmonis (Copepoda: Caligidae) on high-seas salmon and trout in the North Pacific Ocean
The occurrence of the salmon louse Lepeophtheirus salmonis on Pacific salmon and steelhead trout caught in the central North Pacific Ocean was investigated and it was found that O. gorbuscha and O. keta were regarded as being the most important hosts in the ocean.
Aspects of the biology of the parasitic copepods Lepeophtheirus salmonis and Caligus elongatus on farmed salmonids, and their treatment
Prevention of infestation is difficult, a bath treatment for 1 h with 1 ppm of the organophosphorus compound Dichlorvos is effective against post-chalimus stages of L. salmonis on caged salmonids.