Growth and Mortality Rates of the Razor Clam (Siliqua patula) on Clatsop Beaches, Oregon

Identification Information

Citation

Originator: Hirschhorn, G.

Publish Date: June 1962

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: Clatsop Beaches, characterized by flat beach-face slope (1:70) and small sandsize (0.2 mm.), have supported commercial and recreational fisheries for the razor clam (Siliqua patula) for many years. Tracing the linear growth of two year classes through more than one year following set led to a validation of the ring method of age determination in the population studied. Annual ring lengths based on the means of samples from all subareas were fitted by von Bertalanffy equations. Increases in total length, wet weight, and relative width showed patterns of seasonal variation. Death rates of the Seaside Beach population were estimated from recoveries of 3,379 serially marked razor clams. Mortality coefficients obtained were: 2.52 for total mortality, based on the difference between estimated population sizes in 1952 and 1953 of year classes fully recruited at the beginning of the census; 1.78 for the estimated removals by actual harvesting; and 0.74 for other losses to which fishery-connected wastage was believed to have contributed, in addition to true natural mortality. The weight yield per 1,000 recruits, as function of age at first capture, was examined at three hypothetical levels of wastage indicating that potential increases in yield at each level could be realized by deferring the exploitation of a year class until its second year of age, regardless of whether the fisheries are continuous or seasonal.

Purpose:

Time Period of Content: 1952-1953

Geographic Extent: Clatsop Beaches

Status: Final

Use Constraints:

Format: PDF file

Data Quality Information

Lineage-Source:

Data Information

No data information was supplied.

Entity and Attribute Information

Attributes Description: Not yet described

Bibliography Information

Field Name	Value
Biblio ID	3005
Year	1962
Publisher
Request Type	Contributions
Location	Salem HQ
Date Created	1962 June
Date Cataloged	3/6/2007
Date Published	1962
Type	stp fold
Pages	1-55
Volume	27
Status	2
Descriptor	Razor Clams; Clatsop Beach
Date Entered	2007-03-06 00:00:00
Location In Clackamas Library	N wall, E end Contributions
Author	George Hirschhorn
Duplicates	1
Number Remaining After Requests	26
Presumed All Distributed
Back Room Duplicates	8
Author	Hirschhorn, G.
Risk
Species
Disposition Of Requests	State Archive: Request filled
Disposition Of Requests	StreamNet Library: Request filled
Disposition Of Requests	Tony D'Andrea: Request filled

Is a physical copy maintained for reference at Headquarters? Yes