Impact of wind stress anomalies on the seasonal pattern of southern rock lobster (Jasus edwardsii) settlement in South Australia

2010 ◽  
Vol 19 (4) ◽  
pp. 290-300 ◽  
Author(s):  
ADRIAN LINNANE ◽  
CHARLES JAMES ◽  
JOHN MIDDLETON ◽  
PETER HAWTHORNE ◽  
MATTHEW HOARE
Keyword(s):  
Wind Stress ◽  
Seasonal Pattern ◽  
South Australia ◽  
Rock Lobster ◽  
Jasus Edwardsii

Residency and movement dynamics of southern rock lobster (Jasus edwardsii) after a translocation event

2015 ◽  
Vol 66 (7) ◽  
pp. 623 ◽  
Author(s):  
Adrian Linnane ◽  
Shane Penny ◽  
Peter Hawthorne ◽  
Matthew Hoare
Keyword(s):  
Large Scale ◽  
South Australia ◽  
Rock Lobster ◽  
Directed Movement ◽  
Translocation Event ◽  
South West ◽  
Movement Dynamics ◽  
Close Proximity ◽  
Jasus Edwardsii ◽  
Almost All

Previous movement studies on the southern rock lobster (Jasus edwardsii) have all involved releasing tagged animals at the point of capture. In 2007, 5298 lobsters, in total, were tagged and translocated from an offshore site (>100-m depth) to two inshore sites (<20-m depth) in South Australia. After a period of 735 days, 510 (9.6%) had been recaptured. The majority of translocated lobsters were located within close proximity to the release points, with 306 (60%) having moved <5km. Of the remainder, 133 (26%) were recaptured within 5–10km, with a further 71 (14%) individuals having moved >10km. Movement patterns were highly directional in nature, with individuals consistently travelling in a south-west bearing, regardless of distance moved. In almost all cases, movement was from inshore to offshore sites, with female lobsters travelling significantly further (mean 5.66km ±6.41s.d.) than males (mean 5.02km ±9.66s.d.). The results are consistent with previous large-scale tagging studies of J. edwardsii, which indicated high residency levels but with occasional directed movement by some individuals.

Contrasting fecundity, size at maturity and reproductive potential of southern rock lobster Jasus edwardsii in two South Australian fishing regions

2008 ◽  
Vol 88 (3) ◽  
pp. 583-589 ◽  
Author(s):  
A.J. Linnane ◽  
S.S. Penny ◽  
T.M. Ward
Keyword(s):  
Egg Production ◽  
Spatial Scales ◽  
Reproductive Potential ◽  
South Australia ◽  
Egg Mass ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Southern Zone ◽  
Significant Difference ◽  
Jasus Edwardsii

The annual commercial catch from the Southern Zone of the South Australian rock lobster (Jasus edwardsii) fishery is ~1900 tonnes, representing ~50% of total landings from south-east Australia. A single minimum legal size (MLS) of 98.5 mm carapace length (CL) exists across the entire zone. Fecundity (F), size at onset of maturity (SOM) and relative reproductive potential (RRP) of female rock lobsters were investigated in two major fishing regions, i.e. the North Southern Zone (NSZ) and South Southern Zone (SSZ) with a view to providing a basis for future fine-scale spatial management of the resource. F ranged from 45,292 to 466,800 eggs per female and increased proportionally with CL according to the relationship: F = 0.0584 × CL3.1642. F was significantly higher in the NSZ compared to the SSZ but was attributed to differences in lobster size between regions. There was no significant difference in the number of eggs · g−1 of egg mass between areas. SOM, estimated as the size at which 50% of females reached sexual maturity (L50) was higher in the NSZ (104.1 mm CL) compared to SSZ (92.3 mm CL). Approximately 20% of lobsters above the MLS in the commercial catch in the NSZ were under the L50 estimate. RRP, as a measure of egg production, was calculated for each size-class from the product of F, SOM and population length–frequency. The modal RRP size-classes in the NSZ were 117.5–122.5 mm CL, while in the SSZ it was 97.5–102.5 mm CL. Only 6% of RRP was contributed by female rock lobsters below the MLS in the NSZ, compared to 34% in the SSZ. Regional differences in SOM and RRP in the Southern Zone of South Australia suggest that different MLSs may be beneficial, particularly if the fishery is to be effectively managed at finer spatial scales.

Response of a southern rock lobster (Jasus edwardsii) population to three years of Marine Protected Area implementation within South Australia

2021 ◽  
pp. 1-9
Author(s):  
Lachlan McLeay ◽  
Adrian Linnane ◽  
Richard McGarvey ◽  
Simon Bryars ◽  
Peter Hawthorne
Keyword(s):  
Relative Abundance ◽  
Marine Protected Area ◽  
South Australia ◽  
Catch Per Unit Effort ◽  
Rock Lobster ◽  
Jasus Edwardsii ◽  
Data Survey ◽  
Mean Size ◽  
Survey Estimates ◽  
Representative System

Abstract The Western Kangaroo Island Marine Park (WKIMP) was declared as part of South Australia's representative system of Marine Protected Areas in 2009. Sanctuary Zone 3 (SZ-3) of the WKIMP is a no-take area protected from fishing since 1 October 2014 and is located within the Northern Zone Rock Lobster Fishery (NZRLF). In February 2017, a dedicated survey was undertaken to estimate the relative abundance (catch per unit effort (CPUE), kg/potlift) and size of southern rock lobster (Jasus edwardsii) inside and outside SZ-3. Survey results were then compared with historical estimates of abundance and size obtained from commercial fishery-dependent data. Survey estimates of relative abundance of legal-size lobsters were 4.4 times greater inside SZ-3 compared with outside in 2017. Since 2014, when fishing was last permitted inside SZ-3, the relative abundance of lobsters increased by 75%. The mean size of legal-size female and male lobsters also increased by 4.1% and 12.5%, respectively. The population responses recorded are consistent with the results recorded for southern rock lobster stocks in marine parks in other jurisdictions.

Growth rates of juvenile southern rock lobster (Jasus edwardsii) estimated through a diver-based tag - recapture program

2012 ◽  
Vol 63 (2) ◽  
pp. 110 ◽  
Author(s):  
Adrian Linnane ◽  
David Hobday ◽  
Stewart Frusher ◽  
Caleb Gardner
Keyword(s):  
Growth Rates ◽  
South Australia ◽  
Individual Growth ◽  
Rock Lobster ◽  
South Eastern ◽  
Growth Increments ◽  
Eastern Australia ◽  
Significant Difference ◽  
Jasus Edwardsii ◽  
South Eastern Australia

Despite being one of the most economically important fisheries in south-eastern Australia, growth rates of juvenile southern rock lobster (Jasus edwardsii) have not previously been quantified in the wild. This study utilised a diver-based tag–recapture program to estimate growth rates of individuals between 40–80 mm carapace length (CL) in temperate reef sites across south-eastern Australia. Of the 7064 lobsters tagged and released, 978 (14%) were recaptured with recapture rates of 23, 5 and 7% in the States of Tasmania, South Australia and Victoria respectively. Although individual growth increments were similar between the sexes, differences in annual growth rates were evident at 50 mm CL, with males growing ~1.4 times faster than females. Increased levels of growth in males resulted from a higher moult frequency, which was found to significantly reduce in females as they reached sexual maturity at ~70–80 mm CL. No significant difference was found in growth rates of males or females between the States when all sites within each State were combined. The growth estimates from this work contribute to the understanding of juvenile lobster population dynamics and will improve current fishery models by confirming relationships between early juvenile, pre-recruit abundance and entry to the fishable biomass.

Estimating the duration of the pelagic phyllosoma phase of the southern rock lobster, Jasus edwardsii (Hutton)

2015 ◽  
Vol 66 (3) ◽  
pp. 213 ◽  
Author(s):  
R. W. Bradford ◽  
D. Griffin ◽  
B. D. Bruce
Keyword(s):  
Regression Analysis ◽  
Larval Dispersal ◽  
Settlement Patterns ◽  
Rock Lobster ◽  
Planktonic Larva ◽  
New Model ◽  
Larval Stages ◽  
Biophysical Models ◽  
Jasus Edwardsii

The phyllosoma larva of the southern rock lobster, Jasus edwardsii, is thought to be among the longest larval phases of any planktonic larva, with estimates in the literature ranging from 12 to 24 months. In the present study, we have used an extensive archive of samples (over 2800 samples with 680 phyllosoma) to refine the estimate of the duration of the pelagic phase. The distribution through the year of larval stages suggested that larvae from two separate spawning events were present in any 12-month period. Using regression analysis, we have estimated the duration of the phyllosoma phase to be 547±47.5 days (~18.2±1.6 months). A new model of J. edwardsii phyllosoma development is presented and compared with data on known hatching and settlement patterns. The new model will improve the paramiterisation of stage-specific biophysical models of larval dispersal and regional connectivity, to better inform management of the southern rock lobster fisheries.

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