Evidence of Natural Reproduction of Aquaculture-Escaped Atlantic Salmon in a Coastal British Columbia River

Authors

  • John P. Volpe,

    Corresponding author
    1. Centre for Environmental Health, Department of Biology, University of Victoria, P.O. Box 3020, Stn. CSC, Victoria, British Columbia V8W N1G, Canada
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  • Eric B. Taylor,

    1. Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver,
      British Columbia V6T 1Z4, Canada
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  • David W. Rimmer,

    1. British Columbia Ministry of Environment, Lands and Parks, 2080-A Labieux Rd., Nanaimo,
      British Columbia V9T 6J9, Canada
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  • Barry W. Glickman

    1. Centre for Environmental Health, Department of Biology, University of Victoria, P.O. Box 3020, Stn. CSC, Victoria, British Columbia V8W N1G, Canada
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 email jvolpe@uvic.ca

Abstract

Abstract: We present evidence of the first successful natural spawning of Atlantic salmon (  Salmo salar) documented on the Pacific coast of North America. Twelve juvenile Atlantic salmon composed of two year classes were captured in the Tsitika River, British Columbia. We analyzed restriction-length polymorphisms of PCR-amplified 5S rDNA and mtDNA to confirm that these individuals were Atlantic salmon. Scale analysis strongly suggested they were the products of natural spawning by feral adults. The gut contents, size, and condition of these individuals suggest that Atlantic salmon are successfully maturing in the Tsitika River, British Columbia. This event has raised concerns that the presence and possible establishment of feral Atlantic salmon may further jeopardize the continued persistence of already fragile native Pacific salmonids through competition for resources and occupation of niches that are currently underutilized.

Abstract

Resumen: Presentamos evidencia del primer desove exitoso de salmón del Atlántico (  Salmo salar) documentado en la costa del Pacífico de Norte América. Doce salmones del Atlántico juveniles comprendiendo dos clases anuales de edad fueron capturados en el río Tsitika, British Columbia. Analizamos polimorfismos de longitud restringida de ADNmt amplificados con PCR para confirmar si estos individuos eran salmones del Atlántico. El análisis de escamas sugiere fuertemente que estos organismos son producto de un desove natural de adultos silvestres. El análisis de contenidos estomacales, tamaño y condición de estos individuos sugiere que el salmón del Atlántico esta desarrollándose de manera exitosa en el río Tsitika, British Columbia. Este evento ha elevado la preocupación de que la presencia y posible establecimiento de salmones del Atlántico silvestres podría poner en riesgo la persistencia continuada de los de por sí ya frágiles salmones del Pacífico mediante la competencia por recursos y la ocupación de nichos que actualmente son poco utilizados.

Ancillary