Oyster Mortality Study, Summary Report 1966-72

Identification Information

Citation

Originator: Gibson, Gary G.

Publish Date: 1974

Online Link: None

BPA Project #:

Contact Information

Agency: Oregon Department of Fish and Wildlife

Name: Cedric Cooney

Job Position: Natural Resources Data and Systems Manager

Telephone: 503-947-6094

E-Mail Address: Cedric.X.Cooney@odfw.oregon.gov

Description

Abstract: We monitored oyster mortality in Yaquina, Coos, and Tillamook bays from July 1966-March 1972. Pacific oyster (Crassostrea gigas) mortality in Yaquina Bay appears to be lower than in any other reporting area on the Pacific Coast, generally less than 2% per year. Native oyster (Ostrea lurida) mortality ranged from 9.6-28.2%. Low salinity stress caused over one-half of this mortality each winter. In Tillamook Bay, Pacific oyster mortality generally averaged 4% per year; mortality in Coos Bay averaged 7% a year, excluding an unexplainable mortality of 19% during the summer of 1968. Bay mussel mortality totaled 49.9% in 1970-71 and 19.3% during 1971-72. Predation by small crabs probably caused these high mortalities. Shell growth of Pacific and native oysters in Yaquina Bay in 1968 and 1969 occurred almost entirely during April-September of each year. During 1966-72, we sent 1,950 Pacific oysters, 2,400 native oysters, 1,400 bay mussels (Mytilus edulis), 100 bent-nosed clams (Macoma nasuta), 5O irus macoma clams (Macoma irus), and 100 softshell clams (Mya arenaria) to the University of Washington and the NHFS Oxford laboratory for histological examination. We monitored changes in hydrographic conditions (salinity, temperature, dissolved oxygen, and turbidity) in Yaquina Bay. I also collected nutrient samples (phosphate, silicate, and nitrate-nitrite). We cooperated with the HMFS Oxford laboratory on a study to determine the nature and cause of a "neoplasm disease" of native oysters and bay mussels in Yaquina Bay. In a laboratory study, I found native oysters tolerant to reduced salinity during the winter. Significant winter mortality in a particular area in Yaquina Bay can be expected only when salinities fall below 10 ppt for more than 3 weeks. Bay mussels reflected high sensitivity to outboard motor effluent in a laboratory experiment. Native oysters showed a much higher tolerance to the contaminant.

Purpose:

Time Period of Content: 1966-1972

Geographic Extent: Yaquina, Coos and Tillamook bays

Status: Final

Use Constraints:

Format: PDF

Data Quality Information

Lineage-Source: U. S. Department of Commerce National Marine Fisheries Service Contract No. N 208-0133-72

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description: Field attribute information is available in the attached file(s).

Bibliography Information

Field Name	Value
Biblio ID	1042
Year	1974
Publisher
Request Type	Report (FCO Shellfish Pgm)
Location	Coast, OR
Date Created
Date Cataloged
Date Published	1974
Type
Pages	1-37
Volume
Status	0
Descriptor	Pacific oyster; Harvest; Coast, OR
Date Entered	1/1/1999
Location In Clackamas Library
Author
Duplicates
Number Remaining After Requests
Presumed All Distributed
Back Room Duplicates
Author	Gibson, G.G.
Risk	Harvest
Species
Disposition Of Requests	Tony D'Andrea: Requested, but no copies available

Is a physical copy maintained for reference at Headquarters? Unknown