Exploring the effects of spatial closures in a temperate marine ecosystem in Western Australia: A case study of the western rock lobster (Panulirus cygnus) fishery

2012 ◽  
Vol 245 ◽  
pp. 31-40 ◽  
Author(s):  
Hector M. Lozano-Montes ◽  
Russ Babcock ◽  
Neil R. Loneragan
Keyword(s):  
Western Australia ◽  
Marine Ecosystem ◽  
Rock Lobster ◽  
Panulirus Cygnus

Genetic structure of the western rock lobster, Panulirus cygnus, with the benefit of hindsight

1996 ◽  
Vol 47 (7) ◽  
pp. 889 ◽  
Author(s):  
AP Thompson ◽  
JR Hanley ◽  
MS Johnson
Keyword(s):  
Genetic Structure ◽  
Western Australia ◽  
Allozyme Variation ◽  
Genetic Homogeneity ◽  
Latitudinal Variation ◽  
Rock Lobster ◽  
Polymorphic Loci ◽  
Allelic Frequencies ◽  
Genetic Subdivision ◽  
Panulirus Cygnus

Allozyme variation was used to investigate the genetic structure of the western rock lobster, Panulirus cygnus, along the coast of Western Australia. The study involved genetic surveys in 1980 and 1994. The first survey showed strong suggestions of latitudinal variation at two polymorphic loci, EST and GPI, but these suggestions were statistically suspect. With the benefit of hindsight gained from 1980, the 1994 survey was designed to examine more directly the suggestion of latitudinal genetic subdivision in this species. No evidence of genetic subdivision was found at either the EST or the GPI locus. In addition, the average FST value over nine polymorphic loci was a very low 0.0002. The evidence is consistent with current interpretations that P. cygnus is a single, panmictic population. In contrast with this spatial genetic homogeneity, however, there were significant changes in allelic frequencies at the GPI locus between 1980 and 1994, indicating genetic differences among cohorts.

scholarly journals Identifying indicators of the effects of fishing using alternative models, uncertainty, and aggregation error

2011 ◽  
Vol 68 (7) ◽  
pp. 1417-1425 ◽  
Author(s):  
Sarah J. Metcalf ◽  
Matthew B. Pember ◽  
Lynda M. Bellchambers
Keyword(s):  
Economic Value ◽  
Ecosystem Change ◽  
Small Fish ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Alternative Models ◽  
Qualitative Models ◽  
Lobster Fishery ◽  
Panulirus Cygnus

Abstract Metcalf, S. J., Pember, M. B., and Bellchambers, L. M. 2011. Identifying indicators of the effects of fishing using alternative models, uncertainty, and aggregation error. – ICES Journal of Marine Science, 68: 1417–1425. The identification of indicators of the indirect effects of fishing is often an issue for fisheries management, particularly if just commercial catch data are available. Complex, intermediate, and simplified qualitative models were produced for a fishery case study off Western Australia to identify potential indicators of ecosystem change attributable to western rock lobster (Panulirus cygnus) extraction and bait input. Models of intermediate complexity were used to identify indicators because they produced the least aggregation error. Structural uncertainty was considered through a series of structurally different intermediate models. These alternate models consistently predicted that extraction of rock lobster may positively impact small fish of low economic value, such as old wife (Enoplosus armatus), footballer sweep (Neatypus obliquus), and king wrasse (Coris auricularis). These small fish were therefore identified as potential indicators of the effects of rock lobster extraction. Small crustaceans (amphipods and isopods) also displayed positive impacts attributable to bait input from the rock lobster fishery and were identified as potential indicators of bait effects. Monitoring of these indicators may aid the detection of ecosystem change caused by the rock lobster fishery.

scholarly journals Interannual variation in the moult cycle and size at double breeding of mature female western rock lobster (Panulirus cygnus)

2006 ◽  
Vol 63 (9) ◽  
pp. 1631-1639 ◽  
Author(s):  
Simon de Lestang ◽  
Roy Melville-Smith
Keyword(s):  
Breeding Season ◽  
Western Australia ◽  
Interannual Variation ◽  
Carapace Width ◽  
Mature Female ◽  
Moult Cycle ◽  
Rock Lobster ◽  
Management Measures ◽  
Panulirus Cygnus

Abstract The moult cycle of mature female Panulirus cygnus was examined from data recorded over 32 years at four sites along the coast of Western Australia. A repeating trend for mature females was inferred from samples taken between 15 November and 15 August. Setae were present on the endopodites of all large females from June until February–March; between March and June the proportions of females with setae declined sharply as about 80% moulted into a non-setose phase. Females that did not undergo this moult in February remained setose throughout the “normal” non-setose period before moulting and producing a new set of setae by midwinter. New or eroded spermatophores were present on most large females between November and January, but their presence declined sharply during the February–March moult, to be absent by May. The percentage of mature females that bypassed the non-setose moult varied markedly from 1% to 40%, and was well correlated with mean water temperatures in January and February. The proportion that did not undergo a moult increased when these months were cool but decreased when they were warm. The size (carapace width) at which females carry two batches of eggs in one breeding season (double breeder) declined progressively from 96.6 mm to 84.1 mm with decreasing latitude (32°S to 28°S), and further declined at the offshore Abrolhos Islands (29°S) to 78.7 mm. The implications of these findings are discussed in relation to management measures designed to protect females in a setose condition.

The diet of post-puerulus western rock lobster, Panulirus cygnus George, at Seven Mile Beach, Western Australia

1993 ◽  
Vol 44 (4) ◽  
pp. 649 ◽  
Author(s):  
P Jernakoff ◽  
BF Phillips ◽  
JJ Fitzpatrick
Keyword(s):  
Western Australia ◽  
Natural Environment ◽  
Coralline Algae ◽  
First Year ◽  
Rock Lobster ◽  
Natural Habitats ◽  
Moult Stage ◽  
Food Items ◽  
Animal Material ◽  
Panulirus Cygnus

Post-puerulus western rock lobsters (juveniles within their first year after settlement), taken from natural habitats and artificial collectors at Seven Mile Beach, had consumed a variety of plant and animal material. Post-pueruli in the natural environment foraged amongst seagrass and macroalgae on limestone reefs, and animals on the collectors probably foraged only on the collectors. The major components in the diet were coralline algae, molluscs and crustaceans. The ratios of these in the contents of the fore-gut were related to moult stage. Although the dietary spectrum of the post-pueruli was similar to that of larger juveniles at the same site, the ratios of food items were different.

Increased density, biomass and egg production in an unfished population of Western Rock Lobster (Panulirus cygnus) at Rottnest Island, Western Australia

2007 ◽  
Vol 58 (3) ◽  
pp. 286 ◽  
Author(s):  
R. C. Babcock ◽  
J. C. Phillips ◽  
M. Lourey ◽  
G. Clapin
Keyword(s):  
Western Australia ◽  
Carrying Capacity ◽  
Egg Production ◽  
Carapace Length ◽  
Spiny Lobster ◽  
Shallow Waters ◽  
Recreational Fishing ◽  
Total Biomass ◽  
Rock Lobster ◽  
Panulirus Cygnus

Surveys of spiny lobster (Panulirus cygnus) populations in shallow waters surrounding Rottnest Island in Western Australia revealed much higher levels of density, biomass and egg production in no-take than in fished areas. Density of lobsters was ~34 times higher in the sanctuary, and density of lobsters above minimum legal size around 50 times higher than in other areas around the island where recreational fishing is allowed. Mean carapace length (CL), total biomass and egg production of lobsters in the sanctuary zone were significantly higher than in adjacent fished areas. Large individuals (≥100 mm CL), especially large males, were found almost exclusively within the sanctuary. The abundance of mature animals in these shallow waters indicates that not all P. cygnus migrate to deep water and that shallow water habitats may currently be well below carrying capacity in terms of biomass and egg production. If implemented in a systematic way, unfished areas such as the Kingston Reefs could also provide a useful fisheries-independent tool for assessing trophic interactions and the structure and density of unfished populations, and for estimating parameters such as growth of larger individuals that may be rare or absent in more widely fished populations.

Optimizing an oceanographic-larval model for assessment of the puerulus settlement of the western rock lobster, Panulirus cygnus, in Western Australia

2018 ◽  
Vol 94 (3) ◽  
pp. 775-800
Author(s):  
Nick Caputi ◽  
Ming Feng ◽  
Ainslie Denham ◽  
Simon de Lestang ◽  
James Penn ◽  
...  
Keyword(s):  
Western Australia ◽  
Rock Lobster ◽  
Panulirus Cygnus

Predicting the recreational western rock lobster (Panulirus cygnus) catch in Western Australia

2001 ◽  
Vol 52 (8) ◽  
pp. 1527 ◽  
Author(s):  
Roy Melville-Smith ◽  
Sonia M. Anderton ◽  
Nick Caputi
Keyword(s):  
Western Australia ◽  
Coastal Management ◽  
Southern Region ◽  
Recreational Fishing ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Mail Surveys ◽  
Panulirus Cygnus ◽  
Multipleregression Analysis ◽  
Better Than

The number of fishers purchasing recreational rock-lobster licences in Western Australia increased from ~15 000 during 1986–87 to 33 000 during 1998–99. The quantity landed was estimated from mail surveys conducted during this period. The recreational catch of western rock lobster increased from approximately 220 to 630 tonnes, or from 1.8% to 4.8% of the commercial catch. This study has shown that total recreational catches of western rock lobster in Western Australia are correlated with licence usage rates (r2 = 0.81) and puerulus settlement indices at Alkimos, in the southern region of the fishery, 3 to 4 years earlier (r2 = 0.59). A multipleregression analysis using both of these variables (r2 = 0.91) was used to predict future recreational lobster catches. If future usage were to remain at 1998–99 levels, it is predicted that the recreational catch would be 700 t in 1999–2000, 650 t in 2000–01, and 550 t in 2001–02. We attempted to improve predictions by analysing the data according to puerulus settlement and licence usage in the two coastal management regions. The correlation for the southern region (where most of the recreational fishing is concentrated) was marginally better than that for the total fishery (r2 = 0.93), but the correlation was poor for the northern coastal zone (r2 = 0.55), where licence usage has been relatively steady and where the recreational catch has consistently remained at around 98 t per annum over the last decade.

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