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Catchability of the southern rock lobster Jasus edwardsii. I. Effects of sex, season and catch history

Citation

Ziegler, PE and Frusher, SD and Johnson, CR and Gardner, C, Catchability of the southern rock lobster Jasus edwardsii. I. Effects of sex, season and catch history, Marine and Freshwater Research, 53, (8) pp. 1143-1148. ISSN 1323-1650 (2002) [Refereed Article]

DOI: doi:10.1071/MF01243

Abstract

Seasonal variation in catchability of the southern rock lobster Jasus edwardsii, was estimated in a scientific reserve in south-east Tasmania by comparing estimates of lobster density based on direct visual observations underwater with concomitant estimates from trapping surveys. Underwater density estimates of undersized and legal-sized male and female lobsters >80 mm carapace length, did not change significantly over the 14-month study period, with the exception of undersized males (≤110 mm carapace length). Sex ratios remained constant at approximately 1:1. In marked contrast, catch rates of males and females and the sex ratio of trapped lobsters varied strongly with season, implying that catchability varies seasonally and with sex. Catchability of males and females was highest in early summer and lowest in winter. Impact of capture on subsequent catchability appeared to be weak, since the ratios of tagged animals in the population observed underwater generally reflected recapture rates of tagged animals in trap catches. Recapture rates increased with size and were higher for medium-sized and large males than for similar-sized females. However, for each particular sex-size group, recapture rates remained relatively constant throughout the study period.

Item Details

Item Type:Refereed Article
Research Division:Agricultural and Veterinary Sciences
Research Group:Fisheries Sciences
Research Field:Fisheries Sciences not elsewhere classified
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - Wild Caught
Objective Field:Fisheries - Wild Caught not elsewhere classified
Author:Ziegler, PE (Dr Philippe Ziegler)
Author:Frusher, SD (Professor Stewart Frusher)
Author:Johnson, CR (Professor Craig Johnson)
Author:Gardner, C (Professor Caleb Gardner)
ID Code:25173
Year Published:2002
Web of Science® Times Cited:19
Deposited By:TAFI - Marine Research Laboratory
Deposited On:2002-08-01
Last Modified:2009-08-06
Downloads:0

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