scholarly journals Maintenance of old-growth size structure and fecundity of the red rock lobster Jasus edwardsii among marine protected areas in Fiordland, New Zealand

2010 ◽  
Vol 404 ◽  
pp. 161-172 ◽  
Author(s):  
L Jack ◽  
SR Wing
Keyword(s):  
New Zealand ◽  
Protected Areas ◽  
Marine Protected Areas ◽  
Size Structure ◽  
Rock Lobster ◽  
Old Growth ◽  
Jasus Edwardsii

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 Fewer eggs from larger size limits: counterintuitive outcomes in a spatially heterogeneous fishery

2014 ◽  
Vol 72 (suppl_1) ◽  
pp. i252-i259 ◽  
Author(s):  
Caleb Gardner ◽  
Klaas Hartmann ◽  
André E. Punt ◽  
Eriko Hoshino
Keyword(s):  
Marine Protected Areas ◽  
Egg Production ◽  
Slow Growth ◽  
Minimum Length ◽  
Bioeconomic Model ◽  
Rock Lobster ◽  
Total Allowable Catch ◽  
Jasus Edwardsii ◽  
Negative Impacts ◽  
Size Limits

Abstract The legal minimum length (LML) of female Southern Rock Lobster (Jasus edwardsii) was reduced in the Tasmanian fishery in 1966 for higher sustainable catches. Originally, the LML was to be reduced in slow growth southern areas only; however, the change was implemented across the entire fishery due to lobbying by commercial fishers. The lower LML has been controversial ever since, including during recent years when low recruitment resulted in a lower total allowable catch (TAC). Fishers argued that this could have been prevented with a higher female LML across the jurisdiction. A length- and sex-based bioeconomic model was used to examine probable outcomes of the larger statewide LML. This model showed that management of egg production would be poorly served by raising the statewide LML because of spatial patterns in the stock and fishery. Catch would be displaced from areas where egg production was already high and into the most depleted areas thus reducing production in areas of greatest concern. Spatial variation in biological parameters can have a profound effect on outcomes of management perceived to be conservative, possibly leading to negative impacts. This risk exists wherever catch is displaced, such as with Marine Protected Areas, spatial TACs and gear restrictions.

scholarly journals Impact of lobster size on selectivity of traps for southern rock lobster (Jasus edwardsii)

2001 ◽  
Vol 58 (12) ◽  
pp. 2482-2489 ◽  
Author(s):  
S D Frusher ◽  
J M Hoenig
Keyword(s):  
Size Range ◽  
Size Structure ◽  
Rock Lobster ◽  
Size Change ◽  
Temporal Differences ◽  
Structure Changes ◽  
Jasus Edwardsii ◽  
Spatial Differences ◽  
Over Time

Most lobster fisheries are characterized by high exploitation rates. This has led to substantial declines in the size structures of the populations over time as larger lobsters have been removed. Although both scientists and fishers have suggested that size related hierarchies could impact on lobsters entering traps, the effect of the size change on the selectivity of lobster traps as a population's size structure changes has not been investigated. This paper demonstrates that larger lobsters affect the entrapment of smaller lobsters and that this behaviour affects the selectivity of lobster traps. Both spatial and temporal (within season) factors were found to affect the selectivity plots. Spatial differences in selectivity were attributed to the broader size range of larger lobsters found in regions of faster growth. Temporal differences were attributed to the decline in larger lobsters over the course of a season caused by exploitation. There are also differences in trap selectivity between the sexes.

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

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
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