Response to Dr. Neil Frazer's comment on “Sea lice on adult Pacific salmon in the coastal waters of British Columbia, Canada” by R.J. Beamish et al. (2005)

Fraser River Pacific salmon have declined in recent decades, possibly from parasitism by sea lice (Caligus clemensi and Lepeophtheirus salmonis). We describe the abundance of both louse species infesting co-migrating juvenile pink (Oncorhynchus gorbuscha), chum (Oncorhynchus keta), and sockeye (Oncorhynchus nerka) salmon over 5 years in the Discovery Islands and Johnstone Strait, British Columbia. The generalist louse, C. clemensi, was 5, 7, and 39 times more abundant than the salmonid specialist, L. salmonis, on pink, chum, and sockeye salmon, respectively. Caligus clemensi abundance was higher on pink salmon (0.45, 95% CI: 0.38–0.55) and sockeye (0.39, 95% CI: 0.33–0.47) than on chum salmon. Lepeophtheirus salmonis abundance was highest on pink salmon (0.09, 95% CI = 0.06–0.15). Caligus clemensi had higher abundances in Johnstone Strait than in the Discovery Islands. These results suggest differences in host specialization and transmission dynamics between louse species. Because both lice infest farmed salmon, but only C. clemensi infests Pacific herring (Clupea pallasii), conservation science and management regarding lice and Fraser River salmon should further consider C. clemensi and transmission from farmed salmon and wild herring.

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Sea lice on wild juvenile Pacific salmon and farmed Atlantic salmon in the northernmost salmon farming region of British Columbia

Aquaculture ◽

10.1016/j.aquaculture.2011.07.018 ◽

2011 ◽

Vol 320 (3-4) ◽

pp. 193-198 ◽

Cited By ~ 8

Author(s):

Sonja M. Saksida ◽

Larry Greba ◽

Diane Morrison ◽

Crawford W. Revie

Keyword(s):

British Columbia ◽

Atlantic Salmon ◽

Pacific Salmon ◽

Sea Lice ◽

Salmon Farming ◽

Juvenile Pacific Salmon ◽

Farmed Atlantic Salmon

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A large, natural infection of sea lice on juvenile Pacific salmon in the Gulf Islands area of British Columbia, Canada

Aquaculture ◽

10.1016/j.aquaculture.2009.09.001 ◽

2009 ◽

Vol 297 (1-4) ◽

pp. 31-37 ◽

Cited By ~ 22

Author(s):

R. Beamish ◽

J. Wade ◽

W. Pennell ◽

E. Gordon ◽

S. Jones ◽

...

Keyword(s):

British Columbia ◽

Pacific Salmon ◽

Natural Infection ◽

Sea Lice ◽

Juvenile Pacific Salmon ◽

Gulf Islands

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Physiological resilience of pink salmon to naturally occurring ocean acidification

Conservation Physiology ◽

10.1093/conphys/coaa059 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Andrea Y Frommel ◽

Justin Carless ◽

Brian P V Hunt ◽

Colin J Brauner

Keyword(s):

British Columbia ◽

Elevated Co2 ◽

Condition Factor ◽

Pacific Salmon ◽

Pink Salmon ◽

Hypoxia Tolerance ◽

High Co2 ◽

The North ◽

Naturally Occurring ◽

Co2 Levels

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.

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Caligids-potential pathogens for marine finfish aquaculture in Mexico?

Latin American Journal of Aquatic Research ◽

10.3856/vol44-issue3-fulltext-1 ◽

2017 ◽

Vol 44 (3) ◽

pp. 433-441

Author(s):

Francisco Neptalí Morales-Serna ◽

Juan Manuel Martínez-Brown ◽

Rosa Maria Medina-Guerrero ◽

Emma Josefina Fajer-Ávila

Keyword(s):

Coastal Waters ◽

Host Location ◽

Current Knowledge ◽

Control Strategies ◽

Sea Lice ◽

Ecological Studies ◽

Parasitic Copepods ◽

The Family ◽

And Control ◽

Finfish Aquaculture

Parasitic copepods of the family Caligidae, the so-called sea lice, may be deleterious to marine or brackish finfish aquaculture. To date, biological and ecological studies of sea lice have been mostly restricted to species from cold or temperate regions. In Mexico there are some records of sea lice species on marine fishes; however, the research regarding their biology and ecology has been scarce. It is possible that a high biodiversity of sea lice is distributed in coastal waters of Mexico; therefore, their significance as pathogenic parasites should increase. The purpose of this review is to outline the current knowledge of the life cycle, host location, ecology, effect on fish health, and control strategies of sea lice in order to establish supportive basis for natural resource management and control of parasites and diseases of marine fish cultured in Mexico.

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Evidence for Freshwater Residualism in Coho Salmon, Oncorhynchus kisutch, From a Watershed on the North Coast of British Columbia

The Canadian Field-Naturalist ◽

10.22621/cfn.v130i4.1928 ◽

2017 ◽

Vol 130 (4) ◽

pp. 336 ◽

Cited By ~ 3

Author(s):

Eric A Parkinson ◽

Chris J Perrin ◽

Daniel Ramos-Espinoza ◽

Eric B Taylor

Keyword(s):

British Columbia ◽

Fresh Water ◽

Coho Salmon ◽

Pacific Salmon ◽

Oncorhynchus Kisutch ◽

Water Levels ◽

North Coast ◽

The North ◽

Seaward Migration ◽

Mature Fish

The Coho Salmon, Oncorhynchus kisutch, is one of seven species of Pacific salmon and trout native to northeastern Pacific Ocean watersheds. The species is typically anadromous; adults reproduce in fresh water where juveniles reside for 1–2 years before seaward migration after which the majority of growth occurs in the ocean before maturation at 2–4 years old when adults return to fresh water to spawn. Here, we report maturation of Coho Salmon in two freshwater lakes on the north coast of British Columbia apparently without their being to sea. A total of 15 mature fish (11 males and four females) were collected in two lakes across two years. The mature fish were all at least 29 cm in total length and ranged in age from three to five years old. The occurrence of Coho Salmon that have matured in fresh water without first going to sea is exceedingly rare in their natural range, especially for females. Such mature Coho Salmon may represent residual and distinct breeding populations from those in adjacent streams. Alternatively, they may result from the ephemeral restriction in the opportunity to migrate seaward owing to low water levels in the spring when Coho Salmon typically migrate to sea after 1–2 years in fresh water. Regardless of their origin, the ability to mature in fresh water without seaward migration may represent important adaptive life history plasticity in response to variable environments.

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Sea Lice Management on Salmon Farms in British Columbia, Canada

Salmon Lice ◽

10.1002/9780470961568.ch8 ◽

2011 ◽

pp. 235-278 ◽

Cited By ~ 8

Author(s):

Sonja M. Saksida ◽

Diane Morrison ◽

Mark Sheppard ◽

Ian Keith

Keyword(s):

British Columbia ◽

Sea Lice

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The Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons

The Ecology of Juvenile Salmon in the Northeast Pacific Ocean: Regional Comparisons ◽

10.47886/9781888569957.ch6 ◽

2007 ◽

Keyword(s):

Coastal Waters ◽

Pacific Salmon ◽

Size Class ◽

Small Fish ◽

Lepeophtheirus Salmonis ◽

Northeast Pacific ◽

Salmon Lice ◽

Regional Comparisons ◽

Northeast Pacific Ocean ◽

Over Time

Abstract.—We report patterns of infestation with motile salmon lice, <em>Lepeophtheirus salmonis</em>, on Pacific salmon collected with a surface trawl in coastal waters of Oregon, Washington, British Columbia, and Alaska during 2002 and 2003. Salmon lice were observed on all salmon species examined and in all areas surveyed. The prevalence and abundance of lice infestation varied significantly among species, size-classes, seasons, regions, and years, with larger salmon being consistently more heavily infested than small salmon. The number of lice infesting the small size-class (100–400 mm) of salmon rarely exceeded 5 lice per fish with a mean abundance generally below 0.2 lice per fish. Lice prevalence and, to a lesser extent, lice abundance increased over time in small fish, with lower values during spring and higher values in the following winter, and continued to increase in larger and older fish. There were no apparent effects of water temperature on lice infestation in Pacific salmon. This study suggested that salmon infested with lice remained in coastal waters throughout the year. We suggest that lice on salmon that overwinter in coastal waters will contribute to a pool of infective copepodids in these habitats.

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