Potential ecological and economic impacts of sea lice from farmed salmon on wild salmon fisheries

2011 ◽  
Vol 70 (10) ◽  
pp. 1746-1755 ◽  
Author(s):  
Yajie Liu ◽  
Ussif Rashid Sumaila ◽  
John Paul Volpe
Keyword(s):  
Economic Impacts ◽  
Sea Lice ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Salmon Fisheries

Estimation of spatiotemporal transmission dynamics and analysis of management scenarios for sea lice of farmed and wild salmon

2020 ◽  
Vol 77 (1) ◽  
pp. 55-68 ◽  
Author(s):  
Stephanie J. Peacock ◽  
Martin Krkošek ◽  
Andrew W. Bateman ◽  
Mark A. Lewis
Keyword(s):  
Transmission Dynamics ◽  
Spatiotemporal Variability ◽  
Sea Lice ◽  
Spatial And Temporal Variation ◽  
Oncorhynchus Keta ◽  
Juvenile Salmon ◽  
Management Scenarios ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Parameterized Model

Parasite transmission between farmed and wild salmon affects the sustainability of salmon aquaculture in Pacific Canada. Understanding and managing parasites in aquaculture is challenged by spatial and temporal variation in transmission dynamics. We developed a mechanistic model that connects sea louse (Lepeoptheirus salmonis) outbreak and control on farmed salmon (Salmo salar) to spatiotemporal dynamics of sea lice on migrating wild juvenile salmon (Oncorhynchus keta and Oncorhynchus gorbuscha). We fitted the model to time series of sea lice on farmed salmon and spatial surveys of juvenile wild salmon in the Broughton Archipelago. We used the parameterized model to evaluate alternative management scenarios based on the resulting sea louse infestations and predicted mortality of wild salmon. Early and coordinated management of sea lice on salmon farms was most effective for controlling outbreaks in wild salmon, while uncoordinated treatments led to a resurgence of sea lice on salmon farms during the juvenile salmon migration. This study highlights the importance of incorporating spatiotemporal variability when considering infectious disease dynamics shared by farmed and wild hosts, particularly when migratory wildlife are involved.

Recent failure to control sea louse outbreaks on salmon in the Broughton Archipelago, British Columbia

2016 ◽  
Vol 73 (8) ◽  
pp. 1164-1172 ◽  
Author(s):  
Andrew W. Bateman ◽  
Stephanie J. Peacock ◽  
Brendan Connors ◽  
Zephyr Polk ◽  
Dana Berg ◽  
...  
Keyword(s):  
British Columbia ◽  
Environmental Conditions ◽  
Sea Lice ◽  
Oncorhynchus Gorbuscha ◽  
Effective Control ◽  
Juvenile Salmon ◽  
Data Set ◽  
Wild Salmon ◽  
Salmon Farming ◽  
Farmed Salmon

The advent and growth of salmon farming has changed the epidemiology of some salmon diseases. In 2015, in the salmon-farming region of the Broughton Archipelago, British Columbia, an outbreak of native ectoparasitic copepods (sea lice; Lepeophtheirus salmonis) recurred in wild juvenile salmon after a decade of effective control. We draw on a 15-year data set of sea lice on wild and farmed salmon in the area to assess the evidence for four factors that may explain the recent outbreak: (i) poorly timed parasiticide treatments of farmed salmon relative to wild salmon migration, (ii) evolution of resistance to parasiticide treatments in sea lice, (iii) anomalous environmental conditions promoting louse population growth, and (iv) a high influx of lice with an abundant pink salmon (Oncorhynchus gorbuscha) return in 2014. We propose that a combination of poorly timed treatments and warm environmental conditions likely explains the outbreak. Where wild salmon conservation is a concern, a more effective approach to managing sea lice on wild and farmed salmon could incorporate the out-migration timing of wild juvenile salmon and information on environmental conditions.

scholarly journals Sea-louse abundance on salmon farms in relation to parasite-control policy and climate change

2020 ◽  
Author(s):  
Sean C Godwin ◽  
Martin Krkosek ◽  
John D Reynolds ◽  
Andrew W Bateman
Keyword(s):  
Climate Change ◽  
High Temperature ◽  
Current System ◽  
Control Policy ◽  
Sea Lice ◽  
Future Climate Change ◽  
Parasite Control ◽  
Management Scenarios ◽  
Farmed Fish ◽  
Wild Salmon

Abstract The ectoparasitic copepods, sea lice (Lepeophtheirus salmonis and Caligus spp.), are major pests to salmon aquaculture and can also affect the health and survival of wild salmon. Policies exist to protect wild salmon by delousing farmed fish when louse abundance exceeds a threshold, but their effectiveness under future climate change is uncertain. We fitted a Bayesian model for sea-louse population dynamics and management to timeseries data of sea lice on farmed salmon in Pacific Canada and analysed the model under scenarios of warmer climates. We found that in high-temperature years, current parasite control policy becomes ineffective as sea-louse abundance is expected to increase. We simulated two alternative management scenarios and observed that both would decrease average louse counts on farms in high-temperature years relative to the current system but relied on more delousing treatments than are currently performed. We also found evidence that non-salmonids can play a role in louse transmission to farms, as increased farm colonization of Caligus clemensi occurs in April, coincident with wild herring (Clupea pallasii) spawner abundance. Our results highlight the need for careful management of sea lice on salmon farms in warmer years and the importance of policies designed to account for future environmental change.

scholarly journals Widespread genetic introgression of escaped farmed Atlantic salmon in wild salmon populations

2016 ◽  
Vol 73 (10) ◽  
pp. 2488-2498 ◽  
Author(s):  
Sten Karlsson ◽  
Ola H. Diserud ◽  
Peder Fiske ◽  
Kjetil Hindar ◽  
Keyword(s):  
Atlantic Salmon ◽  
Molecular Genetic ◽  
Genetic Introgression ◽  
Wild Salmon ◽  
Farmed Salmon ◽  
Geographical Regions ◽  
Average Proportion ◽  
Population Sizes ◽  
Farmed Atlantic Salmon ◽  
High Level

Abstract Farmed Atlantic salmon (Salmo salar) escape from net pens and enter rivers to spawn, potentially resulting in genetic introgression and reduced fitness of wild salmon. Here, we quantify genetic introgression of farmed to wild salmon, using molecular genetic markers, in populations from 147 salmon rivers, representing three-quarters of the total wild salmon spawning population in Norway. For 109 rivers with adult modern samples and sample sizes of 20 or more, the average level of farmed genetic introgression was 6.4% (median = 2.3%), with a range between 0.0% and 42.2%. Fifty-one of these rivers showed significant farmed genetic introgression when compared with historical reference samples. We observed a highly significant correlation between estimated farmed introgression and average proportion of escaped farmed salmon. We quantify levels of introgression as unweighted averages or weighted by population sizes, to compare geographical regions and to compare levels of introgression in rivers and fjords designated as locations deserving a high level of protection. We found a generally lower level of introgression in National Salmon Rivers and National Salmon Fjords subjected to formal protection by parliament. We conclude that farmed to wild genetic introgression is high in a large proportion of Norwegian salmon rivers, with the highest levels found in the most intensive areas of salmon farming. The extensive genetic introgression documented here poses a serious challenge to the management of farmed and wild Atlantic salmon in Norway and, in all likelihood, in other regions where farmed-salmon escape events occur with regularity

Monitoring and potential control of sea lice using an LED-based light trap

2009 ◽  
Vol 66 (8) ◽  
pp. 1371-1382 ◽  
Author(s):  
Iñigo Novales Flamarique ◽  
Christina Gulbransen ◽  
Moira Galbraith ◽  
Dario Stucchi
Keyword(s):  
Oncorhynchus Tshawytscha ◽  
Light Emitting Diode ◽  
Light Trap ◽  
Sea Lice ◽  
Light Traps ◽  
Light Emitting ◽  
Farmed Salmon ◽  
Potential Control ◽  
Larval Stages ◽  
Salmon Lice

Sea lice are ectoparasitic copepods that threaten salmon farming aquaculture and the viability of wild salmon populations. To control infestations on farmed salmon, several chemotherapeutants have been developed, but these are invasive (often causing fish stress and loss in production), costly, may induce parasite resistance over time, and their impact on the environment is a major social concern. Here, we show that a light-emitting diode (LED)-based light trap can be used to monitor sea lice presence on fish and in the water. The performance of the light trap was tested in experimental tanks and in the ocean. Plankton net tows were also performed to compare catches with those from light traps. The light trap caught ~70% of salmon lice larval stages loaded onto a tank and ~24% of the adults. It also acted as a delousing agent by removing ~8% of adult salmon lice infective on Chinook salmon ( Oncorhynchus tshawytscha ) smolts in tank experiments. In the ocean, the light trap caught 21 sea lice (10 Lepeophtheirus salmonis and 11 Caligus clemensi ), comprising free-swimming and attached stages, while plankton net tows failed to capture any. We conclude that light traps constitute an effective, noninvasive, environmentally friendly method to monitor sea lice.

scholarly journals Mate limitation in sea lice infesting wild salmon hosts: the influence of parasite sex ratio and aggregation

Ecosphere ◽  
2017 ◽  
Vol 8 (12) ◽  
pp. e02040 ◽  
Author(s):  
R. Cox ◽  
M. L. Groner ◽  
C. D. Todd ◽  
G. Gettinby ◽  
T. Patanasatienkul ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Sea Lice ◽  
Wild Salmon ◽  
Mate Limitation

Dispersion and toxicity to non-target crustaceans of azamethiphos and deltamethrin after sea lice treatments on farmed salmon, Salmo salar

Aquaculture ◽  
2014 ◽  
Vol 424-425 ◽  
pp. 104-112 ◽  
Author(s):  
W. Ernst ◽  
K. Doe ◽  
A. Cook ◽  
L. Burridge ◽  
B. Lalonde ◽  
...  
Keyword(s):  
Salmo Salar ◽  
Sea Lice ◽  
Farmed Salmon

scholarly journals Farmed Salmon Show No Pathological Alterations When Exposed to Acoustic Treatment for Sea Lice Infestation

2021 ◽  
Vol 9 (10) ◽  
pp. 1114
Author(s):  
Marta Solé ◽  
Maria Constenla ◽  
Francesc Padrós ◽  
Antoni Lombarte ◽  
José-Manuel Fortuño ◽  
...  
Keyword(s):  
Sound Pressure ◽  
Sea Lice ◽  
Histopathological Analysis ◽  
Microscopy Imaging ◽  
Farmed Salmon ◽  
Sound Exposure ◽  
Innovative Method ◽  
Exposure Levels ◽  
Exposure Sessions ◽  
Acoustic Treatment

The use of bioacoustic methods to address sea lice infestation in salmonid farming is a promising innovative method but implies an exposure to sound that could affect the fish. An assessment of the effects of these techniques related to the salmon’s welfare is presented here. The fish were repeatedly exposed to 350 Hz and 500 Hz tones in three- to four-hour exposure sessions, reaching received sound pressure levels of 140 to 150 dB re 1 µPa2, with the goal of reaching total sound exposure levels above 190 dB re 1 µPa2 s. Gross pathology and histopathological analysis performed on exposed salmons’ organs did not reveal any lesions that could be associated to sound exposure. The analysis of their otoliths through electron microscopy imaging confirmed that the sound dose that was used to impair the lice had no effects on the fish auditory organs.

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