A bioeconomic analysis of management strategies for rebuilding and maintenance of the NSS rock lobster (Jasus edwardsii) stock in southern New Zealand

2005 ◽  
Vol 62 (7) ◽  
pp. 1553-1569 ◽  
Author(s):  
Daniel S Holland ◽  
Nokome Bentley ◽  
Philippe Lallemand
Keyword(s):  
New Zealand ◽  
Economic Performance ◽  
Performance Indicators ◽  
Management Strategies ◽  
Rock Lobster ◽  
Rule Based ◽  
Alternative Management ◽  
Management Objectives ◽  
Jasus Edwardsii ◽  
Quota Management

We evaluated alternative management strategies for the Otago and Southland rock lobster (Jasus edwardsii) fisheries in New Zealand. We compare a number of decision-rule-based management strategies and assess amalgamation of the two separate quota management areas that currently comprise the fishery. The analysis combines a spatial sex- and length-structured simulation model of the fishery with an economic module that converts catches and effort into revenues and costs. We compare performance of alternative management strategies using a variety of biological and economic performance indicators relevant to a range of management objectives identified by stakeholders. The results demonstrate the importance of modelling economic performance, since the relative performance of different management strategies differ when considering catch versus net revenues. The analysis also reveals important distributional issues, since some strategies that increase the overall value of the fishery create both winners and losers.

scholarly journals Population Genetics of the Red Rock Lobster,  Jasus edwardsii

2021 ◽  
Author(s):  
◽  
Luke Thomas
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
New Zealand ◽  
Genetic Differentiation ◽  
Microsatellite Markers ◽  
Rocky Reef ◽  
Rock Lobster ◽  
Wide Range ◽  
Jasus Edwardsii ◽  
Polymorphic Microsatellite

<p>Understanding patterns of gene flow across a species range is a vital component of an effective fisheries management strategy. The advent of highly polymorphic microsatellite markers has facilitated the detection of fine-scale patterns of genetic differentiation at levels below the resolving power of earlier techniques. This has triggered the wide-spread re-examination of population structure for a number of commercially targeted species. The aims of thesis were to re-investigate patterns of gene flow of the red rock lobster Jasus edwardsii throughout New Zealand and across the Tasman Sea using novel microsatellite markers. Jasus edwardsii is a keystone species of subtidal rocky reef system and supports lucrative export markets in both Australia and New Zealand. Eight highly polymorphic microsatellite markers were developed from 454 sequence data and screened across a Wellington south coast population to obtain basic diversity indices. All loci were polymorphic with the number of alleles per locus ranging from 6-39. Observed and expected heterozygosity ranged from 0.563-0.937 and 0.583-0.961, respectively. There were no significant deviations from Hardy-Weinberg equilibrium following standard Bonferroni corrections. The loci were used in a population analysis of J. edwardsii that spanned 10 degrees of latitude and stretched 3,500 km across the South Pacific. The analysis rejected the null-hypothesis of panmixia based on earlier mDNA analysis and revealed significant population structure (FST=0.011, RST=0.028) at a wide range of scales. Stewart Island was determined to have the highest levels of genetic differentiation of all populations sampled suggesting a high degree of reproductive isolation and self-recruitment. This study also identified high levels of asymmetric gene flow from Australia to New Zealand indicating a historical source-sink relationship between the two countries. Results from the genetic analysis were consistent with results from oceanographic dispersal models and it is likely that the genetic results reflect historical and contemporary patterns of Jasus edwardsii dispersal and recruitment throughout its range.</p>

scholarly journals Daily settlement of the puerulus stage of the red rock lobster Jasus edwardsii at Castlepoint, New Zealand.

1990 ◽  
Vol 56 (11) ◽  
pp. 1703-1716 ◽  
Author(s):  
Yasuhiro Hayakawa ◽  
John D. Booth ◽  
Shuhei Nishida ◽  
Hideo Sekiguchi ◽  
Toshio Saisho ◽  
...  
Keyword(s):  
New Zealand ◽  
Rock Lobster ◽  
Jasus Edwardsii

Bayesian hierarchical modelling of maturity-at-length for rock lobsters, Jasus edwardsii, off Victoria, Australia

2006 ◽  
Vol 57 (5) ◽  
pp. 503 ◽  
Author(s):  
André E. Punt ◽  
David K. Hobday ◽  
Rhonda Flint
Keyword(s):  
Mixed Effects ◽  
Population Projections ◽  
Reference Level ◽  
Rock Lobster ◽  
Bayesian Hierarchical ◽  
Management Objectives ◽  
Level Data ◽  
Stock Assessments ◽  
Jasus Edwardsii ◽  
Is Value

Maturity-at-length is a key input to stock assessments when the management objectives are expressed in terms of the size of the spawning output relative to some reference level. Data for rock lobsters, Jasus edwardsii (Hutton, 1875), off Victoria, Australia, are used to estimate logistic relationships between carapace length and the probability of being mature. The analyses are based primarily on mixed-effects models in which the parameters governing maturity-at-length depend on year and region, fitted using a Bayesian hierarchical approach. Maturity-at-length differs among years and regions, and the length-at-50%-maturity increases from west to east and then remains relatively constant. However, the estimates for all years and regions are not equally precise, so there is value in using a mixed-effects approach to allow the years for which the dataset is large to ‘provide support’ for the years for which the data are sparse. The results provide the input needed to conduct assessments of rock lobster populations off Victoria and to form the basis for conducting population projections.

Stakeholder management of the New Zealand red rock lobster ( Jasus edwardsii ) fishery

2016 ◽  
Vol 183 ◽  
pp. 530-538 ◽  
Author(s):  
Paul A. Breen ◽  
Andrew R. Branson ◽  
Nokome Bentley ◽  
Vivian Haist ◽  
Malcolm Lawson ◽  
...  
Keyword(s):  
New Zealand ◽  
Stakeholder Management ◽  
Rock Lobster ◽  
Jasus Edwardsii

scholarly journals Status of New Zealand fresh-water eel stocks and management initiatives

2007 ◽  
Vol 64 (7) ◽  
pp. 1379-1386 ◽  
Author(s):  
Don J. Jellyman
Keyword(s):  
New Zealand ◽  
Fresh Water ◽  
Management Strategies ◽  
Wetland Loss ◽  
Commercial Catch ◽  
Anguilla Australis ◽  
Generation Times ◽  
The Status ◽  
Quota Management ◽  
Average Size

Abstract Jellyman, D. J. 2007. Status of New Zealand fresh-water eel stocks and management initiatives. – ICES Journal of Marine Science, 64: 1379–1386. New Zealand has two main species of fresh-water eel, shortfin (Anguilla australis), which is shared with Southeast Australia, and the endemic longfin eel (A. dieffenbachii). Both species are subject to extensive commercial and customary fishing. The shortfin is the smaller and shorter lived, with typical generation times for females ranging from 15 to 30 years; generation times for longfin females are double this. The distribution and the abundance of both species have been compromised by habitat modifications, shortfins, the more lowland species, being affected by wetland loss, and longfins by weirs and dams. Although there are few concerns about the status of shortfins, there is increasing evidence of overexploitation of longfins, including reduced recruitment, reduction in catch rates, reduction in abundance and average size, and a regional reduction in the proportion of females. Eels are managed under the quota management system, although individual and regional quotas are set from catch histories because biological parameters are inadequate. Maori, New Zealand's indigenous people, have been allocated 20% of commercial quota, with additional quota set for customary take. The annual commercial catch of eels has halved over the past decade, and is now ∼700–800 t, shortfins comprising 66% of catches. Recent management developments have included enhancement of upstream waters with juvenile eels, consolidation of processing into fewer but larger units, setting aside of additional reserve areas to increase escapement of silver eels, increased management involvement of Maori, and development of regional management strategies.

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