Production of nauplii of Lepeophtheirus salmonis (Krøyer) (Copepoda: Caligidae) from farmed and wild salmon and its relation to the infestation of wild sea trout (Salmo trutta L.) off the west coast of Ireland in 1991

Tully, Oliver; Whelan, Ken

doi:10.1016/0165-7836(93)90018-3

Cited by 96 publications

(83 citation statements)

References 7 publications

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“…It is not clear why these studies differ so much in the number of eggs produced per string. Field studies have suggested that water temperature during female development and egg production may explain some of this variation (Tully 1989, Ritchie et al 1993, Tully & Whelan 1993, since low temperatures give rise to larger adult female salmon lice (Tully & Whelan 1993, Nordhagen et al 2000 with a higher number of eggs per string (Tully & Whelan 1993). However, water temperature did not have a statistically significant effect on the number of eggs per string in the experiments by Heuch et al (2000).…”

Section: Discussionmentioning

confidence: 52%

“…However, water temperature did not have a statistically significant effect on the number of eggs per string in the experiments by Heuch et al (2000). Female salmon lice on farmed salmon have also been found to have a lower number of eggs per string than females on wild salmon (Jackson & Minchin 1992, Tully & Whelan 1993. Nordhagen et al (2000) suggested that a size and fecundity difference could be due to wild salmon feeding on oceanic feeding grounds with lower temperature, whereas farmed salmon are bred in warmer coastal waters.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Population dynamics of salmon lice Lepeophtheirus salmonis on Atlantic salmon and sea trout

Stien

Bjørn²,

Heuch³

et al. 2005

Mar. Ecol. Prog. Ser.

174

227

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Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Population dynamics of salmon lice Lepeophtheirus salmonis on Atlantic salmon and sea trout

Stien

Bjørn²,

Heuch³

et al. 2005

Mar. Ecol. Prog. Ser.

174

227

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“…Estimations of L. salmonis larval production from farms with infested salmon in Ireland, Norway, Scotland and Canada indicated that larvae from farmed sources can represent a high proportion (e.g. ca 95%; Tully & Whelan 1993, Butler 2002) of the L. salmonis larvae in coastal waters. This is largely because there are often many more farmed salmon than wild salmonids (Heuch & Mo 2001).…”

Section: Discussionmentioning

confidence: 99%

Reduced Lepeophtheirus salmonis larval abundance in a sea loch on the west coast of Scotland between 2002 and 2006

Penston¹,

Millar²,

Davies³

2008

Dis. Aquat. Org.

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A survey for planktonic sea louse larvae was carried out in Loch Shieldaig, Scotland, between 2002 and2006, and spanned 2 successive production cycles (Cycles 1 and 2) at a local Atlantic salmon Salmo salar L. farm. The vast majority of the caligid copepodids recovered were Lepeophtheirus salmonis; however, the methodology was unable to determine the species of the caligid nauplii. Greatest densities of nauplii were found at the sampling station adjacent to the salmon farm, and larval densities were low during the fallow period of both cycles. Peaks in nauplius densities occurred around the same time in the 2 cycles, but the peaks were significantly lower during Cycle 2 than Cycle 1. Lepeophtheirus salmonis copepodid densities varied temporally, but not spatially. During most of Cycle 2, copepodid densities were significantly lower than those recovered during Cycle 1. Numbers of gravid L. salmonis at the local salmon farm correlated significantly with densities of louse nauplii and L. salmonis copepodids in the water at time lags of 0 and 1 wk, and 1 and 2 wk, respectively. This survey demonstrated a reduction in densities of L. salmonis larvae in the plankton (an indication of L. salmonis infectious pressure) between the 2 cycles and indicated that the farm was an important source of L. salmonis larvae. The application of anti-louse treatments using emamectin benzoate reduced the numbers of gravid L. salmonis at the farm, and this was the main factor influencing the apparent reduction in L. salmonis infectious pressure in the loch between cycles. KEY WORDS: Lepeophtheirus salmonis · Sea lice · Larvae · Salmon farm · Scotland Resale or republication not permitted without written consent of the publisherDis Aquat Org 81: [109][110][111][112][113][114][115][116][117] 2008 duration of each stage of development is strongly dependent on temperature (Johnson & Albright 1991a). Under average sea surface temperatures in Loch Torridon (around 10°C), L. salmonis nauplii and copepodids would last approximately 3 and 8 d, respectively (Johnson & Albright 1991a), but may become less capable of finding a host after just a few days as finite energy reserves dwindle (Tucker et al. 2000).Few published accounts have described the behaviour of Lepeophtheirus salmonis larvae in the wild. Costelloe et al. (1998a,b) frequently recovered L. salmonis larvae near salmon farms in Ireland. They suggested that most of these larvae were probably of farm origin and that intermittent pulses of L. salmonis larvae that occurred near river mouths were probably of wild origin. A study in Loch Shieldaig, Scotland (Penston et al. 2008), suggested that the majority of louse larvae recovered near a salmon farm were the progeny of L. salmonis on farmed salmon. In contrast to Costelloe et al. (1998a,b), who concluded that farms only influence L. salmonis populations in their immediate environs, Penston et al. (2008) suggested that L. salmonis larvae can have a widespread effect in the surrounding waters.As with most salmon farms in Scotl...

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“…However, it is possible that heavily infested fishes die and are not observed, and evidence from wild fish species, including salmonids, suggests that pathogenicity may occur naturally (Costello 1993(Costello , 2006Hvidsten et al 2007). In 1989, sea lice epizootics were recorded on wild sea trout, Salmo trutta L., in Ireland for the first time, and it was proposed that salmon farms were the primary source (Tully & Whelan 1993). Similar epizootics were found on wild salmonid species in Scotland, Norway and British Columbia, including sea trout, char Salvelinus alpinus (L.) and pink salmon Oncorhynchus gorbuscha (Walbaum).…”

Section: Introductionmentioning

confidence: 99%

How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere

2009

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Fishes farmed in sea pens may become infested by parasites from wild fishes and in turn become point sources for parasites. Sea lice, copepods of the family Caligidae, are the best-studied example of this risk. Sea lice are the most significant parasitic pathogen in salmon farming in Europe and the Americas, are estimated to cost the world industry E300 million a year and may also be pathogenic to wild fishes under natural conditions. Epizootics, characteristically dominated by juvenile (copepodite and chalimus) stages, have repeatedly occurred on juvenile wild salmonids in areas where farms have sea lice infestations, but have not been recorded elsewhere. This paper synthesizes the literature, including modelling studies, to provide an understanding of how one species, the salmon louse, Lepeophtheirus salmonis, can infest wild salmonids from farm sources. Three-dimensional hydrographic models predicted the distribution of the planktonic salmon lice larvae best when they accounted for wind-driven surface currents and larval behaviour. Caligus species can also cause problems on farms and transfer from farms to wild fishes, and this genus is cosmopolitan. Sea lice thus threaten finfish farming worldwide, but with the possible exception of L. salmonis, their host relationships and transmission adaptations are unknown. The increasing evidence that lice from farms can be a significant cause of mortality on nearby wild fish populations provides an additional challenge to controlling lice on the farms and also raises conservation, economic and political issues about how to balance aquaculture and fisheries resource management.

show abstract

Production of nauplii of Lepeophtheirus salmonis (Krøyer) (Copepoda: Caligidae) from farmed and wild salmon and its relation to the infestation of wild sea trout (Salmo trutta L.) off the west coast of Ireland in 1991

Cited by 96 publications

References 7 publications

Population dynamics of salmon lice Lepeophtheirus salmonis on Atlantic salmon and sea trout

Population dynamics of salmon lice Lepeophtheirus salmonis on Atlantic salmon and sea trout

Reduced Lepeophtheirus salmonis larval abundance in a sea loch on the west coast of Scotland between 2002 and 2006

How sea lice from salmon farms may cause wild salmonid declines in Europe and North America and be a threat to fishes elsewhere

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