Densities of planktonic Lepeophtheirus salmonis before and after an Atlantic salmon farm relocation

Penston, Michael J.; McBeath, Alastair; Millar, Colin P.

doi:10.3354/aei00022

Cited by 21 publications

(19 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This finding for nauplii is comparable to previous observations (Costelloe et al 1996, Gravil 1996. The dominance of nauplii at the fish farm is also similar to previous observations (Costelloe et al 1996, Morton et al 2011, Penston et al 2011, and in the present study the nauplii were highly abundant downstream of the farm, contrasting against the few nauplii found upstream (Fig. 3).…”

Section: Discussionsupporting

confidence: 63%

“…In the Loch Torridon system, sea lice abundance has been intensively studied at 5 open-water stations over several years, and the long time average density of copepodids at the stations was in the range of 0.01 to 0.6 copepodids (cop.) m −3 (Penston et al 2004(Penston et al , 2011. Nearshore and in river mouths, copepodids can be much more abundant, and densities >100 cop.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A method of estimating in situ salmon louse nauplii production at fish farms

Norði¹,

Simonsen²,

Patursson³

2016

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

Abundance and depth distribution of planktonic sea lice were investigated in relation to hydrodynamics and diurnal solar insolation at a salmon farm in Sundalagið, Faroe Islands. Plankton surveys were conducted by surface tows with a plankton net around the farm and by using a plankton pump at 1, 4 and 6 m depth in a fish cage. The entire sample content was investigated under a stereomicroscope and sea lice were identified. Sea lice of the species Lepeophtheirus salmonis and Caligus elongatus were present at the farm. Nauplii dominated the planktonic stages (> 95%) while copepodids were absent from most samples. The highest observed copepodid density was 0.3 ind. m −3 , which is within the range found in open water. No diurnal vertical distribution pattern was observed for salmon lice nauplii in the net cages, which were most abundant in the top meter of the water column, and density decreased with depth. At 1 m depth, nauplii density was inversely proportional to the current speed at the same depth. From this relation, and the abundance of adult female sea lice on the farmed fish, the in situ nauplii production was calculated to be within 26−68 nauplii female. The lower end of this range is similar to production rates suggested by laboratory studies at similar temperatures (7.8°C).

show abstract

Section: Discussionsupporting

confidence: 63%

Section: Discussionmentioning

confidence: 99%

A method of estimating in situ salmon louse nauplii production at fish farms

Norði¹,

Simonsen²,

Patursson³

2016

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

show abstract

“…diseases and parasites from the fish farms should not have negative effects on wild populations (www.fkd.dep.no). Removal or relocation of salmon farms may significantly reduce the production of salmon lice copepodites at the vacated site, but in a study by Penston et al (2011), the infection pressure at the farm site was still not reduced, probably because the infectious planktonic stages of salmon lice can be transported over large distances. Similarly, in modelling infections of salmon lice on Atlantic salmon in 44 farms in the Hardangerfjord, Gettingby et al (2011) obtained a better fit when the mobility of lice was included.…”

Section: Discussionmentioning

confidence: 99%

Evidence of salmon lice-induced mortality of anadromous brown trout (Salmo trutta) in the Hardangerfjord, Norway

Skaala

Kålås²,

Borgstrøm

2013

Marine Biology Research

View full text Add to dashboard Cite

The Hardangerfjord, western Norway, is an area with a high concentration of salmon farms, high levels of infection of salmon lice in anadromous brown trout, and declining trout populations. This study assessed the marine survival rate of anadromous trout from the River Guddalselva, in the central part of the fjord, and tested the hypothesis that trout populations in this area are depressed by salmon lice infection. From 2001 to 2011, all descending smolts and trout returning from the fjord were captured in the traps at the field station of the Institute of Marine Research. In 2004 and 2005, parts of the smolt cohorts were treated with the Substance EX to prevent sea lice infection. From 2007 to 2010, all smolts (n 03557) were also tagged with individual tags. The results show a survival rate in the sea of only 0.58Á3.41% for tagged smolts, which is extremely low. The highest survival rates appeared in the years with the lowest recordings of salmon lice in spring. The survival rate of Substance EX-treated smolts and controls was 3.41% and 1.76%, respectively. These findings suggest that salmon lice infection is an important contributor to the high mortality of anadromous trout populations in the Hardangerfjord.

show abstract

“…Jackson et al 2013, Krkošek et al 2013, as well as the role of salmon farms in contributing to the levels of sea lice in the environment (e.g. Penston et al 2011, Middlemas et al 2013.…”

Section: Discussionmentioning

confidence: 99%

“…These methods have proved useful in sampling plankton lice levels (e.g. Penston et al 2011) and attached lice in Torridon and Shieldaig, and the latter is similar to sentinel cage fish work in Norway (Bjørn et al 2011). A description of comparing observed sea lice data from tows and caged fish to simulated distributions is given by .…”

Section: Field Validationmentioning

confidence: 96%

Developing models for investigating the environmental transmission of disease-causing agents within open-cage salmon aquaculture

Salama¹,

Rabe²

2013

Aquacult. Environ. Interact.

View full text Add to dashboard Cite

Global aquaculture production continues to increase across a variety of sectors, including Atlantic salmon production in Scotland. One limitation to the expansion of open-cage aquaculture is disease-induced stock losses as well as the potential for disease agents from farms interacting with other farms and possibly with wild salmonids. Epidemiological studies of diseaseagent transmission often omit environmental transmission of organisms, although this process is an integral part of parasite spread and incidence. Within the aquatic environment, water movements enable pathogens and parasites to potentially be transmitted over long distances. As pathogens and parasites are transported, their status can change; they can degrade or, in the case of sea lice, develop into an infectious stage. A combination of biological and physical models is required to understand the transmission of disease-causing organisms. Here we propose a set of components that have been implemented in a range of modelling studies of sea lice dispersal, and describe how such attributes have been used in developing a study in one of Scotland's largest fjordic systems. By developing descriptive simulation model frameworks, which are validated using physical and biological observations, alternative methods of integrated pest management can be investigated and developed. The identification of dispersal routes of sea lice and establishment of potential farm−farm connections can inform sea lice management.

show abstract

Densities of planktonic Lepeophtheirus salmonis before and after an Atlantic salmon farm relocation

Cited by 21 publications

References 33 publications

A method of estimating in situ salmon louse nauplii production at fish farms

A method of estimating in situ salmon louse nauplii production at fish farms

Evidence of salmon lice-induced mortality of anadromous brown trout (Salmo trutta) in the Hardangerfjord, Norway

Developing models for investigating the environmental transmission of disease-causing agents within open-cage salmon aquaculture

Contact Info

Product

Resources

About