The effects of subsampling and between haul variation on the size selectivity estimation of Chilean hake (Merluccius gayi gayi)

Using the data collected in a size selectivity experiment on Chilean hake (Merluccius gayi gayi) carried out in 2000, the selectivity parameters for four codend mesh sizes (100, 110, 130, and 140 mm of mesh size opening) were estimated and modelled by the SELECT model. These analyses included consid...

Full description

Saved in:
Bibliographic Details
Published in:Latin american journal of aquatic research 2012-07, Vol.40 (2), p.345-357
Main Authors: Queirolo, Dante, Ahumada, Mauricio, Hurtado, Carlos F., Soriguer, Milagrosa C., Erzini, Karim
Format: Article
Language:English
Subjects:
FISHERIES
MARINE & FRESHWATER BIOLOGY
OCEANOGRAPHY
Citations: Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Using the data collected in a size selectivity experiment on Chilean hake (Merluccius gayi gayi) carried out in 2000, the selectivity parameters for four codend mesh sizes (100, 110, 130, and 140 mm of mesh size opening) were estimated and modelled by the SELECT model. These analyses included considerations of the sampling proportions of the catch in the codend and cover. Furthermore, the analyses took into account between-haul variation. The [l.sub.50] values were 30.8, 29.9, 30.0, and 41.2 cm of total length, respectively, values lower than the estimates obtained from previous studies. The contribution of explanatory variables to the selectivity model was also tested in order to determine the role of mesh size, catch size (in number), and towing speed. Increases in catch size and in towing speed were accompanied by decreases in the [l.sub.50] estimates. These results demonstrate how incorporation of subsampling effect and explanatory variables to model between-haul variation can improve selectivity estimates and management of a valuable resource.
ISSN:0718-560X
0718-560X
DOI:10.3856/vol40-issue2-fulltext-9