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

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 Mate limitation and sex ratio evolution

2018 ◽  
Vol 5 (2) ◽  
pp. 171135 ◽  
Author(s):  
Jussi Lehtonen ◽  
Lisa E. Schwanz
Keyword(s):  
Sex Ratio ◽  
Kin Selection ◽  
Sex Allocation ◽  
Evolutionarily Stable Strategy ◽  
Mathematical Relationship ◽  
Stable Strategy ◽  
Local Mate ◽  
Mate Limitation ◽  
Mating Function ◽  
Evolutionarily Stable

Sex ratio evolution has been one of the most successful areas of evolutionary theory. Pioneered by Düsing and Fisher under panmixia, and later extended by Hamilton to cover local mate competition (LMC), these models often assume, either implicitly or explicitly, that all females are fertilized. Here, we examine the effects of relaxing this assumption, under both panmictic and LMC models with diploid genetics. We revisit the question of the mathematical relationship between sex ratio and probability of fertilization, and use these results to model sex ratio evolution under risk of incomplete fertilization. We find that (i) under panmixia, mate limitation has no effect on the evolutionarily stable strategy (ESS) sex allocation; (ii) under LMC, mate limitation can make sex allocation less female-biased than under complete fertilization; (iii) contrary to what is occasionally stated, a significant fraction of daughters can remain unfertilized at the ESS in LMC with mate limitation; (iv) with a commonly used mating function, the fraction of unfertilized daughters can be quite large, and (v) with more realistic fertilization functions, the deviation becomes smaller. The models are presented in three equivalent forms: individual selection, kin selection and group selection. This serves as an example of the equivalence of the methods, while each approach has their own advantages. We discuss possible extensions of the model to haplodiploidy.

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.

scholarly journals Transmission dynamics of parasitic sea lice from farm to wild salmon

2005 ◽  
Vol 272 (1564) ◽  
pp. 689-696 ◽  
Author(s):  
Martin Krkošek ◽  
Mark A Lewis ◽  
John P Volpe
Keyword(s):  
Transmission Dynamics ◽  
Sea Lice ◽  
Wild Salmon

scholarly journals Sea Lice Are Sensitive to Low Frequency Sounds

2021 ◽  
Vol 9 (7) ◽  
pp. 765
Author(s):  
Marta Solé ◽  
Marc Lenoir ◽  
José-Manuel Fortuño ◽  
Steffen De Vreese ◽  
Mike van der Schaar ◽  
...  
Keyword(s):  
Low Frequency ◽  
Sea Lice ◽  
Lepeophtheirus Salmonis ◽  
Strong Impact ◽  
Associated Injuries ◽  
Pathological Changes ◽  
Salmon Louse ◽  
Wild Salmon ◽  
Sound Exposure ◽  
Major Disease

The salmon louse Lepeophtheirus salmonis is a major disease problem in salmonids farming and there are indications that it also plays a role in the decline of wild salmon stocks. This study shows the first ultrastructural images of pathological changes in the sensory setae of the first antenna and in inner tissues in different stages of L. salmonis development after sound exposure in laboratory and sea conditions. Given the current ineffectiveness of traditional methods to eradicate this plague, and the strong impact on the environment these treatments often provoke, the described response to sounds and the associated injuries in the lice sensory organs could represent an interesting basis for developing a bioacoustics method to prevent lice infection and to treat affected salmons.

scholarly journals Response to Comment on "Declining Wild Salmon Populations in Relation to Parasites from Farm Salmon"

Science ◽  
2008 ◽  
Vol 322 (5909) ◽  
pp. 1790.3-1790 ◽  
Author(s):  
Martin Krkošek ◽  
Jennifer S. Ford ◽  
Alexandra Morton ◽  
Subhash Lele ◽  
Mark A. Lewis
Keyword(s):  
British Columbia ◽  
Pink Salmon ◽  
Sea Lice ◽  
Oncorhynchus Gorbuscha ◽  
Lepeophtheirus Salmonis ◽  
Wild Salmon ◽  
Farm Salmon

We evaluated the effect of sea lice (Lepeophtheirus salmonis) infestations on wild pink salmon (Oncorhynchus gorbuscha) populations in the Broughton Archipelago, British Columbia. Riddell et al. suggest that we ignored factors and selectively used data. Here, we clarify misunderstandings and provide analysis to test the strength of our conclusions.

Comment on "Declining Wild Salmon Populations in Relation to Parasites from Farm Salmon"

Science ◽  
2008 ◽  
Vol 322 (5909) ◽  
pp. 1790.2-1790 ◽  
Author(s):  
Brian E. Riddell ◽  
Richard J. Beamish ◽  
Laura J. Richards ◽  
John R. Candy
Keyword(s):  
Pink Salmon ◽  
Local Extinction ◽  
Sea Lice ◽  
Wild Salmon ◽  
Salmon Farming ◽  
Farm Salmon

Krkošek et al. (Reports, 14 December 2007, p. 1772) claimed that sea lice spread from salmon farms placed wild pink salmon populations “on a trajectory toward rapid local extinction.” Their prediction is inconsistent with observed pink salmon returns and overstates the risks from sea lice and salmon farming.

scholarly journals Relationship of farm salmon, sea lice, and wild salmon populations

2010 ◽  
Vol 107 (52) ◽  
pp. 22599-22604 ◽  
Author(s):  
G. D. Marty ◽  
S. M. Saksida ◽  
T. J. Quinn
Keyword(s):  
Sea Lice ◽  
Wild Salmon ◽  
Farm Salmon ◽  
Relationship Of
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