In:
Marine and Freshwater Research, CSIRO Publishing, Vol. 51, No. 3 ( 2000), p. 205-
Abstract:
The school shark
(Galeorhinus galeus) resource off southern Australia is assessed by use of an assessment approach that takes account of the spatial
structure of the population. The population dynamics model underlying the assessment considers the spatial as well as the age-specific characteristics
of school shark. It allows for a series of fisheries (each based on a different gear type), explicitly models the pupping/recruitment process,
and allows for multiple stocks. The values for the parameters of this model are determined by fitting it to catch-rate data and information from tagging
studies. The point estimates of the pup production at the start of 1997 range from 12% to 18% of the pre-exploitation equilibrium size,
depending on the specifications of the assessment. Allowing for spatial structure and incorporating tag release–recapture data lead to reduced
uncertainty compared with earlier assessments. The status of the resource, as reflected by the ratio of present to virgin pup production and total (1+)
biomass, is sensitive to the assumed level of movement between the stocks in New Zealand and those in Australia, with lower values corresponding to higher
levels of movement.
Type of Medium:
Online Resource
ISSN:
1323-1650
Language:
English
Publisher:
CSIRO Publishing
Publication Date:
2000
detail.hit.zdb_id:
1283028-8
SSG:
12
SSG:
21,3
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