Jasus edwardsii

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Andrew G Jeffs - One of the best experts on this subject based on the ideXlab platform.

  • SWIMMING BEHAVIOUR OF THE PUERULUS OF THE SPINY LOBSTER, Jasus edwardsii (HUTTON, 1875) (DECAPODA, PALINURIDAE)
    Crustaceana, 2020
    Co-Authors: Andrew G Jeffs, Rebecca C. Holland
    Abstract:

    [The swimming behaviour of the puerulus of the spiny lobster Jasus edwardsii is poorly described despite its ecological significance. Therefore, the swimming behaviour of pueruli of this species was recorded for captive animals caught from the east coast of northern New Zealand. Forward swimming velocities were variable among individual puerulus and ranged from 13.0 to 30.7 cm s ­-1 . Backward swimming velocities of 28.6-52.2 cm s ­-1 were recorded. Individuals were capable of sustained forward swimming, whereas backward swimming was primarily used as a rapid reverse escape reaction. The forward swimming posture of the puerulus is described, including swimming with the tips of the antennae protruding from the surface of the water. Attempts to measure the duration of sustained forward swimming of pueruli in a small flume tank failed because the lobsters were not rheotactic, as has been commonly found in fish., The swimming behaviour of the puerulus of the spiny lobster Jasus edwardsii is poorly described despite its ecological significance. Therefore, the swimming behaviour of pueruli of this species was recorded for captive animals caught from the east coast of northern New Zealand. Forward swimming velocities were variable among individual puerulus and ranged from 13.0 to 30.7 cm s ­-1 . Backward swimming velocities of 28.6-52.2 cm s ­-1 were recorded. Individuals were capable of sustained forward swimming, whereas backward swimming was primarily used as a rapid reverse escape reaction. The forward swimming posture of the puerulus is described, including swimming with the tips of the antennae protruding from the surface of the water. Attempts to measure the duration of sustained forward swimming of pueruli in a small flume tank failed because the lobsters were not rheotactic, as has been commonly found in fish.]

  • pathology of tail fan necrosis in the spiny lobster Jasus edwardsii
    Journal of Invertebrate Pathology, 2018
    Co-Authors: Brian Jones, Gillian Lewis, Yimin Dong, Andrew G Jeffs
    Abstract:

    Tail fan necrosis (TFN) is the bacterial infection of the tail fan of spiny lobsters which leads to melanosis and erosion of the tail fan tissues. The condition is commonly found among spiny lobsters in aquaculture and commercial fisheries, and greatly reduces their commercial value. This study describes the pathology of TFN by examining the tail fans (telson, uropods) and internal organs (mid-gut, hepatopancreas, heart and gill) of 29 affected wild spiny lobsters (Jasus edwardsii) and 14 unaffected in New Zealand. Initial signs of TFN were observed around the margins of lacerations to the tail fan, with more extensive signs extending from these presumptive sites of initiation. The establishment of the condition at points of injury is consistent with the penetration of TFN through the cuticle and tissue layers of the affected tail fans, which is rarely seen in other forms of shell disease. Entry into these tissues was characterised initially by caseous necrosis and haemocyte accumulation, followed by the spread of these responses together with melanisation. Additional pathological changes to the tail fans included pseudomembrane formation, detachment of epidermis or cuticle, clotted haemolymph and fibrosis. Among internal organs, pathological changes were found in a total of two mid-gut, four heart and two gill samples from eight lobsters with TFN, while no suspected changes were found in the organs of lobsters without TFN. The causes of internal organ pathology associated with TFN in spiny lobsters warrants more detailed research.

  • coastal chemical cues for settlement of the southern rock lobster Jasus edwardsii
    11th International Conference and Workshop on Lobster Biology & Management, 2018
    Co-Authors: Ivan A Hinojosa, Bridget S Green, C Gardner, Andrew G Jeffs
    Abstract:

    Larval behavior plays an important role in dispersal and settlement of marine organisms with cues from the environment often providing crucial guidance for facilitating these processes. The post-larvae, or pueruli, of the southern rock lobster, Jasus edwardsii (Hutton, 1875), are known to migrate over long distances from oceanic water and settle on coastal reefs using a combination of onshore transport and active nocturnal swimming. In laboratory experiments, we examined environmental cues used for this migration, specifically whether chemical cues in coastal vs oceanic seawater influenced their swimming orientation and their rate of development to juveniles. In total, 66% of pueruli actively swam toward coastal water rather than oceanic water (n = 41), indicating that they may use chemical cues in their settlement processes. Holding pueruli in coastal water vs artificial seawater did not expedite the development of pueruli to benthic juvenile stage, indicating that other cues could be important to the final settlement process. The present study suggests that chemical cues are being used in settlement processes during the onshore migration to settlement sites in this ecologically and economically important species.

  • immune status of the spiny lobster Jasus edwardsii with tail fan necrosis
    Diseases of Aquatic Organisms, 2017
    Co-Authors: Gillian Lewis, Yimin Dong, Andrea C Alfaro, Shuqi Wang, Roffi Grandiosa, Andrew G Jeffs
    Abstract:

    : Tail fan necrosis (TFN), a disorder commonly found in some populations of commercially fished and cultured lobsters, is thought to be initiated by injuries caused by handling and containment. The unsightly appearance of affected lobster tails significantly lowers their commercial value. Knowledge about TFN is limited. In this study we describe the morphological features of TFN and apply 6 common methods for evaluating the immune status of wild-caught Australasian red spiny lobsters Jasus edwardsii with and without TFN. The disease was more frequent in uropods than in telsons of the tail fan, and more extensive on the ventral versus the dorsal surfaces of the tail fan. Missing appendages (i.e. antenna, pereiopod or pleopod) were significantly more common and greater in number for individual lobsters affected with TFN versus those without, possibly as a result of handling in the fishery or as an indirect effect of the disease. Two immune parameters, total haemocyte count and phenoloxidase activity in the haemocyte lysate supernatant (HLS), were significantly compromised in lobsters with TFN. No differences were found in the other immune parameters, i.e. haemocyte viability, haemolymph bacterial count and the protein content of haemolymph plasma and HLS. The results are consistent with injury sustained during prior capture and handling that initiates TFN in these natural caught lobsters. These results raise some potential concerns about the fitness of lobsters in natural populations that are affected by TFN, and some potential solutions are proposed.

  • dna identification of the phyllosoma diet of Jasus edwardsii and scyllarus sp z
    New Zealand Journal of Marine and Freshwater Research, 2014
    Co-Authors: S C Connell, Andrew G Jeffs, Richard Ororke, Shane Lavery
    Abstract:

    The development of an effective artificial larval diet has been a major stumbling block for advancing the aquaculture of spiny lobsters internationally. Attempts to determine the natural diet of spiny lobster larvae have been impeded by their small size and sparse distribution in the open ocean, making these larvae difficult to study using conventional methods. Recent advances in molecular genetic techniques have provided a novel route for identifying the natural prey of spiny lobster larvae (phyllosoma). In this study, sequences from zooplankton found associated with phyllosomas, along with sequences from GenBank, were used to design a suite of group-specific primers. These primers were able to amplify via the polymerase chain reaction (PCR) a short (100–200 base pair) DNA fragment from the 16S or COI locus of potential prey but not from lobster. These methods were applied to four wild-caught phyllosomas of Jasus edwardsii and two phyllosomas of Scyllarus sp. Z. Gadiforme, Cnidaria, Gastropoda and Decapo...

Andre E Punt - One of the best experts on this subject based on the ideXlab platform.

  • environmental influences on daily commercial catch rates of south australia s southern rock lobster Jasus edwardsii
    Fisheries Oceanography, 2014
    Co-Authors: Adrian Linnane, Andre E Punt, John E Feenstra, Richard Mcgarvey, Nigel G Bean
    Abstract:

    The extent to which catchability of southern rock lobster (Jasus edwardsii) due to short-term environmental factors, rather than abundance, may be affecting legal-size catch rates from the South Australian Southern Zone rock lobster fishery was examined. Multivariate weighted linear regression was applied to daily aggregated commercial catch rates using several environmental covariates in addition to year and month. Model pruning via backward selection identified the following variables as being significantly related to catch rate: wave height and period, lagged wave height, bottom temperature, moon phase, and a spatial block index. These variables explained 7% of the total variance in log-transformed daily catch rates and another 84% was explained by month and year. A negative relationship was found between catch rate and each of bottom temperature and same-day wave height, while the relationships between catch rate and days prior to full moon, and average wave height over the past 3 days were positive.

  • management strategy evaluation for rock lobster Jasus edwardsii off victoria australia accounting for uncertainty in stock structure
    New Zealand Journal of Marine and Freshwater Research, 2009
    Co-Authors: Andre E Punt, David Hobday
    Abstract:

    Abstract The management strategy evaluation (MSE) approach was used to evaluate management strategies based on the current method of stock assessment for rock lobster (Jasus edwardsii) off Victoria, Australia, and decision rules inferred from the management plan for Victorian rock lobster and past practice when selecting total allowable catches, TACs. The results are expressed in terms of whether it is possible to keep stocks above limit reference points with high probability and recover over‐exploited stocks to the target level. Three categories of management strategy were examined using the MSE, which differed in whether assessments were conducted, and TACs set, by management zone or by region within management zone. A management strategy based on conducting assessments and setting TACs by management zone is most similar to the way assessments are currently conducted and management regulations implemented for rock lobster off Victoria. However, this management strategy performed poorest in recovering st...

  • modelling growth of rock lobsters Jasus edwardsii off victoria australia using models that allow for individual variation in growth parameters
    Fisheries Research, 2006
    Co-Authors: Andre E Punt, David Hobday, Joy Gerhard, Vladimir S Troynikov
    Abstract:

    A method for modelling the growth of crustaceans, including rock lobsters, that assumes that all animals in a population grow differently, but that the individual variation in the parameters of the growth curve can be captured using a probability distribution, is developed. The method allows for the impact of selectivity on the probability of recapturing a tagged animal. The method is applied to rock lobsters, Jasus edwardsii, off Victoria, Australia. The results suggest that growth differs between males and females, as well as spatially. Ignoring the impact of selectivity on the probability of recapturing a tagged animal is shown to lead to over-estimation of growth rates, which could potentially lead to over-optimistic management advice.

  • bayesian hierarchical modelling of maturity at length for rock lobsters Jasus edwardsii off victoria australia
    Marine and Freshwater Research, 2006
    Co-Authors: Andre E Punt, David Hobday, Rhonda Flint
    Abstract:

    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.

  • modelling the effects of marine protected areas mpas on the southern rock lobster Jasus edwardsii fishery of victoria australia
    New Zealand Journal of Marine and Freshwater Research, 2005
    Co-Authors: David Hobday, Andre E Punt, David C Smith
    Abstract:

    Abstract Since 2002, 5.3% of the Victorian coastal waters have been declared as Marine Protected Areas (MPAs). These are aimed at safeguarding important marine habitats and species, significant natural features, and areas of cultural heritage and aesthetic value. However, MPAs impact the fishery for southern rock lobster (Jasus edwardsii), as total allowable catches (TACs) were previously set to allow the biomass to recover to pre‐specified target levels. The model on which assessments and risk analyses are based is extended to include the impact of MPAs. The MPAs and the area open to fishing are modelled as subpopulations with different levels of mortality and consequently different density and population size‐structure. A range for the probability of a lobster moving from a MPA to the fished area from 0 to 15% is considered, based on the results of tagging studies. The reduction of biomass available to the commercial fishery because of the introduction of MPAs is estimated to be 8% and 16% (Western and ...

Bridget S Green - One of the best experts on this subject based on the ideXlab platform.

  • coastal chemical cues for settlement of the southern rock lobster Jasus edwardsii
    11th International Conference and Workshop on Lobster Biology & Management, 2018
    Co-Authors: Ivan A Hinojosa, Bridget S Green, C Gardner, Andrew G Jeffs
    Abstract:

    Larval behavior plays an important role in dispersal and settlement of marine organisms with cues from the environment often providing crucial guidance for facilitating these processes. The post-larvae, or pueruli, of the southern rock lobster, Jasus edwardsii (Hutton, 1875), are known to migrate over long distances from oceanic water and settle on coastal reefs using a combination of onshore transport and active nocturnal swimming. In laboratory experiments, we examined environmental cues used for this migration, specifically whether chemical cues in coastal vs oceanic seawater influenced their swimming orientation and their rate of development to juveniles. In total, 66% of pueruli actively swam toward coastal water rather than oceanic water (n = 41), indicating that they may use chemical cues in their settlement processes. Holding pueruli in coastal water vs artificial seawater did not expedite the development of pueruli to benthic juvenile stage, indicating that other cues could be important to the final settlement process. The present study suggests that chemical cues are being used in settlement processes during the onshore migration to settlement sites in this ecologically and economically important species.

  • Outlier SNPs enable food traceability of the southern rock lobster, Jasus edwardsii
    Marine Biology, 2016
    Co-Authors: Cecilia Villacorta-rath, Nicholas P. Murphy, Jan M. Strugnell, Bridget S Green, Irina Ilyushkina, Stephen R. Doyle, Nathan E. Hall, Andrew J. Robinson, James J. Bell
    Abstract:

    Recent advances in next-generation sequencing have enhanced the resolution of population genetic studies of non-model organisms through increased marker generation and sample throughput. Using double digest restriction site-associated DNA sequencing (ddRADseq), we investigated the population structure of the commercially important southern rock lobster, Jasus edwardsii, in Australia and New Zealand with the aim of identifying a panel of SNP markers that could be used to trace country of origin. Four ddRADseq libraries comprising a total of 88 individuals were sequenced on the Illumina MiSeq platform, and demultiplexed reads were used to create a reference catalog of loci. Individual reads were then mapped to the reference catalog, and variant calling was performed. We have characterized two single-nucleotide polymorphism (SNP) panels comprised in total of 656 SNPs. The first panel contained 535 neutral SNPs and the second, 121 outlier SNPs that were characteristic of being putatively under selection. Both neutral and outlier SNP panels showed significant differentiation between the two countries, with the outlier loci demonstrating much larger F _ST values ( F _ST outlier SNP panel = 0.134, P  

  • outlier snps enable food traceability of the southern rock lobster Jasus edwardsii
    Marine Biology, 2016
    Co-Authors: Cecilia Villacortarath, Nicholas P. Murphy, Jan M. Strugnell, Bridget S Green, Irina Ilyushkina, Stephen R. Doyle, Nathan E. Hall, Andrew J. Robinson
    Abstract:

    Recent advances in next-generation sequencing have enhanced the resolution of population genetic studies of non-model organisms through increased marker generation and sample throughput. Using double digest restriction site-associated DNA sequencing (ddRADseq), we investigated the population structure of the commercially important southern rock lobster, Jasus edwardsii, in Australia and New Zealand with the aim of identifying a panel of SNP markers that could be used to trace country of origin. Four ddRADseq libraries comprising a total of 88 individuals were sequenced on the Illumina MiSeq platform, and demultiplexed reads were used to create a reference catalog of loci. Individual reads were then mapped to the reference catalog, and variant calling was performed. We have characterized two single-nucleotide polymorphism (SNP) panels comprised in total of 656 SNPs. The first panel contained 535 neutral SNPs and the second, 121 outlier SNPs that were characteristic of being putatively under selection. Both neutral and outlier SNP panels showed significant differentiation between the two countries, with the outlier loci demonstrating much larger F ST values (F ST outlier SNP panel = 0.134, P < 0.0001; F ST neutral SNP panel = 0.022, P < 0.0001). Assignment tests performed with the outlier SNP panel allocated 100 % of the individuals to country of origin, demonstrating the usefulness of these markers for food traceability of J. edwardsii.

  • Conversion of southern rock lobster (Jasus edwardsii) carapace length to tail width for enforcement of size limits
    New Zealand Journal of Marine and Freshwater Research, 2013
    Co-Authors: Bridget S Green, Caleb Gardner
    Abstract:

    The morphometric relationship of carapace length (CL) to tail width (TW) of southern rock lobster (Jasus edwardsii) was determined to assist enforcement of existing minimum size limits and also to enable the development of an upper size limit in Tasmania. Data were collected from southern rock lobsters in the wild and at processors and used to develop a system for measuring TW which reduces measurement error. Linear regression was used to define the relationship between CL and TW for males (TW = 0.4107x+14.058, R2=.9236, n=1003) and females (TW=0.5756x+2.2884, R2=.9323, n=503). Logistic regressions provide the TWs associated with the probability (0.5, 50 and 95%) of a lobster having a carapace equal to or more than the theoretical size limits. Regional differences in the morphometric relationship were evident but would not prevent the use of size limit based on TW if a conservative probability value were used.

  • growth rate of adult rock lobsters Jasus edwardsii increased through translocation
    Fisheries Research, 2010
    Co-Authors: Arani Chandrapavan, C Gardner, Bridget S Green
    Abstract:

    Growth rates of southern rock lobster, Jasus edwardsii, decrease from north to south of Tasmania and also decrease with depth. Slow-growing lobsters from deep-water regions were translocated to shallow-water, inshore areas to examine the potential of translocation to increase yield for the Tasmanian rock lobster industry. Within their first moult, translocated lobsters increased their growth rates, exceeding that of resident deep-water lobsters from the original site. Growth of translocated females increased to the extent that it exceeded resident shallow-water females in the first year post-release. The increased growth rate of deep-water southern rock lobsters after translocation and the magnitude of the growth increments achieved in a short period highlight the plasticity in growth of this species. Growth, and therefore size-at-age, are potentially determined by density effects, food availability or other unidentified environmental factors. Rapid increases in lobster growth achieved through translocation suggest that translocation could be applied to increase the productivity of the fishery.

C Gardner - One of the best experts on this subject based on the ideXlab platform.

  • coastal chemical cues for settlement of the southern rock lobster Jasus edwardsii
    11th International Conference and Workshop on Lobster Biology & Management, 2018
    Co-Authors: Ivan A Hinojosa, Bridget S Green, C Gardner, Andrew G Jeffs
    Abstract:

    Larval behavior plays an important role in dispersal and settlement of marine organisms with cues from the environment often providing crucial guidance for facilitating these processes. The post-larvae, or pueruli, of the southern rock lobster, Jasus edwardsii (Hutton, 1875), are known to migrate over long distances from oceanic water and settle on coastal reefs using a combination of onshore transport and active nocturnal swimming. In laboratory experiments, we examined environmental cues used for this migration, specifically whether chemical cues in coastal vs oceanic seawater influenced their swimming orientation and their rate of development to juveniles. In total, 66% of pueruli actively swam toward coastal water rather than oceanic water (n = 41), indicating that they may use chemical cues in their settlement processes. Holding pueruli in coastal water vs artificial seawater did not expedite the development of pueruli to benthic juvenile stage, indicating that other cues could be important to the final settlement process. The present study suggests that chemical cues are being used in settlement processes during the onshore migration to settlement sites in this ecologically and economically important species.

  • growth rate of adult rock lobsters Jasus edwardsii increased through translocation
    Fisheries Research, 2010
    Co-Authors: Arani Chandrapavan, C Gardner, Bridget S Green
    Abstract:

    Growth rates of southern rock lobster, Jasus edwardsii, decrease from north to south of Tasmania and also decrease with depth. Slow-growing lobsters from deep-water regions were translocated to shallow-water, inshore areas to examine the potential of translocation to increase yield for the Tasmanian rock lobster industry. Within their first moult, translocated lobsters increased their growth rates, exceeding that of resident deep-water lobsters from the original site. Growth of translocated females increased to the extent that it exceeded resident shallow-water females in the first year post-release. The increased growth rate of deep-water southern rock lobsters after translocation and the magnitude of the growth increments achieved in a short period highlight the plasticity in growth of this species. Growth, and therefore size-at-age, are potentially determined by density effects, food availability or other unidentified environmental factors. Rapid increases in lobster growth achieved through translocation suggest that translocation could be applied to increase the productivity of the fishery.

  • surviving a sea change survival of southern rock lobster Jasus edwardsii translocated to a site of fast growth
    Ices Journal of Marine Science, 2009
    Co-Authors: Bridget S Green, C Gardner
    Abstract:

    Green, B. S., and Gardner, C. 2009. Surviving a sea-change: survival of southern rock lobster (Jasus edwardsii) translocated to a site of fast growth. - ICES Journal of Marine Science, 66: 656-664.In an experiment aimed at increasing the yield and value of the fishery for southern rock lobster (Jasus edwardsii), 1998 pale and slow-growing lobsters were translocated to sites where lobsters grow faster naturally and develop higher value market traits. Survival of lobsters in their new habitat was critical to the viability of this experiment. To estimate survival, the release site was surveyed every 1-3 months for 2 years. Apparent survival of translocated lobsters was compared with survival of resident lobsters tagged in a similar period using Cormack-Jolly-Seber modelling on mark-recapture data. Lobster survival was not influenced by size, gender, or origin (translocated or resident) alone. The four most parsimonious models suggested slightly lower apparent survival in translocated lobsters immediately after release compared with all other lobsters, but support for these models was weak (∑QAIC c weights 62%). The differences in apparent survival were not likely to be significant because of large variance when averaged over all the models. Apparent survival of newly released translocated lobsters was 92% (72-98, 95% CI) compared with 97% (95-98, 95% CI) for all other lobsters. Potential sources of differences in survival are movement from the release site or greater predation on pale lobsters. Losses of lobster through release mortality were low and unlikely to influence the feasibility of translocation as a tool to enhance the value of the fishery, although it would be prudent to include 5% mortality of translocated lobsters in future models of translocation feasibility.

  • colour variation in the southern rock lobster Jasus edwardsii and its economic impact on the commercial industry
    New Zealand Journal of Marine and Freshwater Research, 2009
    Co-Authors: Arani Chandrapavan, Adrian Linnane, C Gardner, David Hobday
    Abstract:

    Abstract Southern rock lobster Jasus edwardsii varies in shell coloration throughout southern Australia. Predominantly exported as a live product to Asian markets, price is influenced by colour with prices higher for dark red than paler coloured lobsters, which are discounted. This paper explores spatial and depth variation in shell colour for the Tasmanian, South Australian and Victorian fisheries using catch sampling data. The proportion of red lobsters decreased with depth and was prevalent at depths less than 30 m, whereas paler coloured lobsters dominated the deeper depth ranges. The depth of transition where 50% of lobsters were classified as red showed a weak trend of increase with latitude from southern Tasmania to northern South Australia. Under quota management, lobster colour was a significant driver of fleet dynamics as fishers target areas of high price per unit. Consequently, catches of pale lobsters from greater depths remain low despite the high catch rates in these areas. The colour price...

  • movements of the southern rock lobster Jasus edwardsii in tasmania australia
    Bulletin of Marine Science, 2003
    Co-Authors: C Gardner, S D Frusher, M Haddon, Colin Buxton
    Abstract:

    The magnitude and direction of movements of spiny lobsters Jasus edwardsii (Hutton, 1875) around Tasmania were examined from 39,000 tag- recapture events that occurred between 1973 and 2001. There was no evidence of large-scale, unidirectional migration, as observed elsewhere in the same species. Tag-recaptures indicated high site fidelity with the majority of animals moving no detectable distance after periods of one-two yrs between capture events. Sex, female maturity, and geography influenced the magnitude of lobster movement with significant interaction between these factors. Site had a pronounced influence on the magnitude of movement with consistently greater movement in the north of the state. The lowest magnitude of movement occurred in southern areas, which are known to have highest lobster density. The effect of female maturity on the magnitude of movement was influenced by site, with greater movement by immature females than mature in the northeast, but not the northwest. The direction of movement of animals recaptured on at least five occasions (n = 434) was not significantly unidirectional, although about 20% of these animals exhibited axial bi-directional movement. Significantly unidirectional movement from single recapture events was detected in the majority of areas for males in summer and females in spring, which may be associated with biological events of molting and larval release, respectively.

Adrian Linnane - One of the best experts on this subject based on the ideXlab platform.

  • High levels of site fidelity in movement patterns of Southern Rock Lobster (Jasus edwardsii) in Victoria, Australia
    New Zealand Journal of Marine and Freshwater Research, 2019
    Co-Authors: Alexandra Skeer, Adrian Linnane, David Reilly, Charlie Huveneers
    Abstract:

    ABSTRACTMovement patterns of the Southern Rock Lobster Jasus edwardsii in Victoria, Australia were investigated from 8,533 tag-recapture events across a 20-year period (1992–2012). In total, 83% of...

  • Trends in productivity of Southern Rock Lobster Jasus edwardsii, across south-eastern Australia: Evidence of a regime shift?
    Fisheries Research, 2019
    Co-Authors: Adrian Linnane, John E Feenstra, Richard Mcgarvey, Anthony D.m. Smith, Janet M. Matthews, Klaas Hartmann, Caleb Gardner
    Abstract:

    In south-eastern Australia, Southern Rock Lobster Jasus edwardsii supports important regional fisheries across the States of South Australia, Victoria and Tasmania. Previous studies across the region have identified considerable synchrony in both larval settlement and recruitment, suggesting that the mechanisms driving these processes occur across broad spatial scales. This study aimed to further examine cross-jurisdictional fishery patterns by analysing long-term trends in Surplus Production (SP) as a measure of annual stock productivity. The results showed evidence of a common trend across south-eastern Australia. Specifically, a substantially rapid decline in SP was observed around the late 1990s and early to mid-2000s period. This decline was particularity evident in both the Northern Zone of South Australia and the Tasmanian fishery. It is suggested that these results may reflect a regime shift in Southern Rock Lobster productivity across south-eastern Australia, which should be considered in terms of future management of the resource.

  • In situ video monitoring of by-catch interactions within commercial rock lobster (Jasus edwardsii) fishing traps
    Marine Biology Research, 2017
    Co-Authors: Christina H. Asanopoulos, Matthew Hoare, Adrian Linnane, Charlie Huveneers
    Abstract:

    ABSTRACTThe incidental capture of non-target and undersized target species during commercial fishing operations has been identified as a major issue and ongoing challenge for fisheries management. In the Northern Zone rock lobster (Jasus edwardsii) fishery (NZRLF) of South Australia, escape gaps have been mandatory in all commercial fishing traps since 2002 to reduce non-target species (by-catch) catch rates and juvenile lobster mortality. This study used in situ video monitoring of by-catch species in traps with and without escape gaps to understand how by-catch species interact within commercial fishing traps. Twenty-two different by-catch species were observed entering commercial rock lobster traps, 20 of which were temperate reef finfish. Overall, on-board by-catch rates were significantly higher in hauled traps without escape gaps and were dominated by reef-dwelling finfish species, particularly Meuschenia hippocrepis and Notolabrus tetricus. However, in situ video monitoring within traps showed no d...

  • Residency and movement dynamics of southern rock lobster (Jasus edwardsii) after a translocation event
    Marine and Freshwater Research, 2015
    Co-Authors: Adrian Linnane, Shane Penny, Peter Hawthorne, Matthew Hoare
    Abstract:

    Previous movement studies on the southern rock lobster (Jasus edwardsii) have all involved releasing tagged animalsatthepointofcapture.In2007,5298lobsters,intotal,weretaggedandtranslocatedfromanoffshoresite(.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.

  • Abnormal reproductive morphology in two species of spiny lobster: Jasus edwardsii and Jasus paulensis
    Marine Biodiversity Records, 2015
    Co-Authors: Adrian Linnane, Caleb Gardner, Anthony Pere, Thibaut Thellier
    Abstract:

    Jasus edwardsii and Jasus paulensis are two species of spiny lobster that are distributed across south-eastern Australia and isolated islands of the southern Indian Ocean, respectively. We present rare examples of abnormal reproductive morphology in both species. For Jasus edwardsii , this included a female lobster captured in South Australia, which, in addition to the normal pair of gonopores at the base of the third pair of pereiopods, also exhibited a second a pair of gonopores on the coxopodites of the fourth pair of pereiopods. In Tasmania, a male individual exhibited the specialized pincer on the right propopodite, normally only observed in females. The frequency of abnormal morphological reproductive characteristics appeared higher in Jasus paulensis . This included 14 individuals that exhibited a range of additional and abnormal gonopore locations in both males and females. We discuss the findings in relation to rare cases of gynandromorphism in crustaceans.