Variation in geographic stock area, catchability and natural mortality of ocean shrimp: some new evidence for a tropic interaction with pacific hake

Identification Information

Citation

Originator: Hannah, R. W.

Publish Date: 1995

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: Interannual variation in geographic stock area, catchability, and natural mortality of age 2 ocean shrimp (Panda/us jordani) was investigated for the years 1980-1990, using commercial catch and logbook data. Stock area changed gradually from 1980-1990, but showed wide variation, demonstrating that an assumption of constant catchability is not valid for ocean shrimp. Stock area was positively correlated with total catch, suggesting that stock area increases roughly in proportion to shrimp abundance. The time series of fishing effort and effort per unit stock area were quite different, showing that fishing effort probably gives incorrect information on time trends in ocean shrimp fishing mortality. Natural mortality rates varied widely over the study period also and were positively correlated with the abundance of age 2+ Pacific hake (Merluccius productus), a known shrimp predator. The best correlations were between natural mortality rates and the number of age 2-7 Pacific hake. Hake abundance indices that included only age 3+ fish were not significantly correlated with shrimp natural mortality rates, suggesting that if a trophic interaction exists between these two species, it may be influenced by hake recruitment events.

Purpose:

Time Period of Content:

Geographic Extent: Not Available

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	27179
Year	1995
Publisher
Request Type	Bibliography
Location	Salem HQ
Date Created
Date Cataloged	8/07
Date Published	1995
Type
Pages	pp 1018-1029
Volume	52
Status
Descriptor
Date Entered	2007-08-31 13:09:32
Location In Clackamas Library
Author	Robert W. Hannah
Duplicates	1
Number Remaining After Requests	1
Presumed All Distributed
Back Room Duplicates	0
Author
Risk
Species
Disposition Of Requests

Is a physical copy maintained for reference at Headquarters? Yes