An introduced pathogenic yeast may have caused the crash of the Strait of Georgia Neocalanus plumchrus and Cherry Point herring
Presentation Abstract
Gardner observed that the Strait of Georgia (SOG) Neocalanus plumchrus population went into steep decline in 1971. He predicted decline in fish populations due to the greater energy needed to acquire nutrition from smaller copepods. The cause for the crash of the SOG N. plumchrus may have contributed to the initial steep decline in Cherry Point herring. A literature search may have revealed a cause. Failed attempts from the 1870s to the 1950s by the U.S. and Canada to introduce lobster to the Pacific Coast inspired the release of lobsters in 1965 into confined conditions in Fatty Basin on Vancouver Island where they could be studied. Departure Bay at Nanaimo also received caged lobsters. Only 96 of 184 adult lobsters purchased in 1965 survived a week in quarantine. Survivors were then shipped to the Nanaimo Biological Station. 22 lobsters were placed in cages in Fatty Basin and 16 lobsters in Departure Bay. 58 lobsters were held in tanks at the Biological Station and used to replace dead lobsters in the Departure Bay cages. 17 lobsters died in Departure Bay. Only 3 died in Fatty Basin. No dead caged lobsters could be assessed for disease due to a lack of preservation. 32 of the 58 lobsters held in tanks died. Diseases were thought to be enhanced by tank crowding. Each lobster had its claws immobilized with wooden plugs also encouraging infection. Seki and Hardon in 1969 looking for diseases introduced by lobsters found Metschnikowia sp. (yeast pathogen of crustaceans) on a Fatty Basin rock crab. Even though the yeast infects intramuscular tissue, only lobster carapaces had been sampled. They stated experimental lobsters may have been infected with Metschnikowia. Seki and Fulton in 1968 found 5% of copepods below 200 meters at Station 1 in the SOG to be infected with Metschnikowia. The sea floor was littered with N. plumchrus exoskeletons.
Session Title
Session S-03D: Forage Fish Research and Protection in the Salish Sea
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 5:00 PM
End Date
1-5-2014 6:30 PM
Location
Room 6C
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Copepoda--Diseases and pests--Salish Sea (B.C. and Wash.); Pacific herring--Diseases and pests--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
An introduced pathogenic yeast may have caused the crash of the Strait of Georgia Neocalanus plumchrus and Cherry Point herring
Room 6C
Gardner observed that the Strait of Georgia (SOG) Neocalanus plumchrus population went into steep decline in 1971. He predicted decline in fish populations due to the greater energy needed to acquire nutrition from smaller copepods. The cause for the crash of the SOG N. plumchrus may have contributed to the initial steep decline in Cherry Point herring. A literature search may have revealed a cause. Failed attempts from the 1870s to the 1950s by the U.S. and Canada to introduce lobster to the Pacific Coast inspired the release of lobsters in 1965 into confined conditions in Fatty Basin on Vancouver Island where they could be studied. Departure Bay at Nanaimo also received caged lobsters. Only 96 of 184 adult lobsters purchased in 1965 survived a week in quarantine. Survivors were then shipped to the Nanaimo Biological Station. 22 lobsters were placed in cages in Fatty Basin and 16 lobsters in Departure Bay. 58 lobsters were held in tanks at the Biological Station and used to replace dead lobsters in the Departure Bay cages. 17 lobsters died in Departure Bay. Only 3 died in Fatty Basin. No dead caged lobsters could be assessed for disease due to a lack of preservation. 32 of the 58 lobsters held in tanks died. Diseases were thought to be enhanced by tank crowding. Each lobster had its claws immobilized with wooden plugs also encouraging infection. Seki and Hardon in 1969 looking for diseases introduced by lobsters found Metschnikowia sp. (yeast pathogen of crustaceans) on a Fatty Basin rock crab. Even though the yeast infects intramuscular tissue, only lobster carapaces had been sampled. They stated experimental lobsters may have been infected with Metschnikowia. Seki and Fulton in 1968 found 5% of copepods below 200 meters at Station 1 in the SOG to be infected with Metschnikowia. The sea floor was littered with N. plumchrus exoskeletons.
