Demography, fishery yield and potential management strategies of painted spiny lobster (Panulirus versicolor) at Northwest Island, Great Barrier Reef, Australia

2012 ◽  
Vol 63 (5) ◽  
pp. 387
Author(s):  
Ashley J. Frisch ◽  
Jean-Paul A. Hobbs
Keyword(s):  
Great Barrier Reef ◽  
Fishery Management ◽  
Spiny Lobster ◽  
Management Strategies ◽  
Minimum Size ◽  
Demographic Parameters ◽  
Barrier Reef ◽  
Minimal Impact ◽  
Demographic Processes ◽  
Yield Per Recruit

Quantification of demographic parameters is important for understanding how populations interact with their environment and for developing sustainable harvest strategies. Our aims were to quantify demographic parameters and yield of painted spiny lobster (Panulirus versicolor) at Northwest Island, Great Barrier Reef and review fishery management regulations in view of the findings. Using catch-curve analysis and an intensive mark–recapture program, the local lobster population was found to be sparsely distributed (~1.3 ha–1), with low rates of natural mortality (0.25–0.28 year–1) and immigration (0.05 ha–1 year–1). Under current management regulations (no minimum size limit; MSL), yield-per-recruit peaked at 0.38 kg when fishing mortality was 0.4 year–1. Implementation of a 100-mm (carapace length) MSL is recommended because it provides the best compromise between yield and stock size and has minimal impact on existing fishing practices. Revocation of the prohibition on possessing egg-bearing females is also recommended because it would reduce wastage of lobsters that are inadvertently killed by spear-fishers and because there appears to be little chance of localised recruitment overfishing. This study provides the first estimate of mortality rate for P. versicolor and highlights the importance of this parameter for understanding demographic processes and optimising management regulations.

Problems and Perspectives Regarding Recruitment of Spiny Lobsters, Panulirus argus, to the South Florida Fishery

1986 ◽  
Vol 43 (11) ◽  
pp. 2099-2106 ◽  
Author(s):  
William G. Lyons
Keyword(s):  
Carapace Length ◽  
Spiny Lobster ◽  
Fishing Effort ◽  
International Management ◽  
South Florida ◽  
Panulirus Argus ◽  
Minimum Size ◽  
Juvenile Growth ◽  
Larval Recruitment ◽  
Yield Per Recruit

Inappropriate minimum size, illegal harvest, fishery-induced juvenile growth retardation and mortality, and excessive effort have reduced reproductive contributions and depressed yield-per-recruit in the overcapitalized south Florida spiny lobster (Panulirus argus) fishery. Measures recommended to improve yield-per-recruit are as follows: increase minimum legal size to 85–90 mm carapace length; require escape gaps in traps; eliminate possession of sublegal lobsters aboard vessels; prohibit harvest in nurseries; reduce fishing effort; improve enforcement of fishery regulations; and initiate programs to educate fishermen regarding impacts of fishery practices. International management is recommended to assure larval recruitment among Pan-Caribbean stocks.

Geographic variation in the sex ratio, sex specific size, and age structure of Plectropomus leopardus (Serranidae) between reefs open and closed to fishing on the Great Barrier Reef

2000 ◽  
Vol 57 (7) ◽  
pp. 1448-1458 ◽  
Author(s):  
S Adams ◽  
B D Mapstone ◽  
G R Russ ◽  
C R Davies
Keyword(s):  
Sex Ratio ◽  
Great Barrier Reef ◽  
Age Structure ◽  
Spatial Scales ◽  
Geographic Region ◽  
Minimum Size ◽  
Barrier Reef ◽  
Reproductive Parameters ◽  
Size And Age Structure ◽  
Plectropomus Leopardus

Variation in reproductive parameters of Plectropomus leopardus populations between coral reefs open and closed to fishing was examined in two geographic regions (off Townsville (19°S) and in the Swains (22°S)) of the Great Barrier Reef, Australia. The reproductive parameters that were examined included the operational (reproductive) sex ratio and size and age structure of mature females, sex-changing individuals (transitionals), and mature males. There was a greater proportion of males above the minimum size and age of harvest on reefs closed to fishing for 8-10 years than on reefs open to fishing, although the effect varied with geographic region. Nevertheless, neither the sex ratio, mean age, nor mean size of males or transitionals varied significantly with reef closure status. Females, however, were significantly older and larger on closed than on open reefs in both regions. Marked regional variations in the sex ratio and average age of transitionals were found independent of reef closure status, suggesting regional variation in reproductive strategies. Controlled manipulations, inclusion of broad spatial scales, and detailed studies of intra- and inter-specific variation in serranid reproductive biology are necessary to resolve such complexities in the responses of protogynous serranids to fishing pressure and management strategies.

scholarly journals Evaluating catch and mitigating risk in a multispecies, tropical, inshore shark fishery within the Great Barrier Reef World Heritage Area

2011 ◽  
Vol 62 (6) ◽  
pp. 710 ◽  
Author(s):  
Alastair V. Harry ◽  
Andrew J. Tobin ◽  
Colin A. Simpfendorfer ◽  
David J. Welch ◽  
Amos Mapleston ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Management Strategies ◽  
World Heritage ◽  
Individual Species ◽  
Small Scale ◽  
Barrier Reef ◽  
Tropical Regions ◽  
Gill Net ◽  
World Heritage Area ◽  
Heritage Area

Small-scale and artisanal fisheries for sharks exist in most inshore, tropical regions of the world. Although often important in terms of food security, their low value and inherent complexity provides an imposing hurdle to sustainable management. An observer survey of a small-scale commercial gill-net fishery operating within the Great Barrier Reef World Heritage area revealed at least 38 species of elasmobranch were present in the catch. Of the total elasmobranch catch, 95% was 25 species of Carcharhiniformes from the families Carcharhinidae, Hemigaleidae and Sphyrnidae. Individual species were captured in a variety of ways by the fishery, often with strongly biased sex ratios and in a variety of life stages (e.g. neonates, juveniles, adult). Despite this, the main carcharhiniform taxa captured could be qualitatively categorised into four groups based on similar catch characteristics, body size and similarities in life history: small coastal (<1000 mm); medium coastal (1000–2000 mm); large coastal/semi-pelagic (>2000 mm); and hammerheads. Such groupings can potentially be useful for simplifying management of complex multispecies fisheries. The idiosyncrasies of elasmobranch populations and how fisheries interact with them provide a challenge for management but, if properly understood, potentially offer underutilised options for designing management strategies.

Catchment management and the Great Barrier Reef

2001 ◽  
Vol 43 (9) ◽  
pp. 203-211 ◽  
Author(s):  
J. Brodie ◽  
C. Christie ◽  
M. Devlin ◽  
D. Haynes ◽  
S. Morris ◽  
...  
Keyword(s):  
Great Barrier Reef ◽  
Management Strategies ◽  
Catchment Management ◽  
Positive Outcomes ◽  
Barrier Reef ◽  
Marine Animals ◽  
Current Management ◽  
Marine Park ◽  
World Heritage Area ◽  
Heritage Area

Pollution of coastal regions of the Great Barrier Reef is dominated by runoff from the adjacent catchment. Catchment land-use is dominated by beef grazing and cropping, largely sugarcane cultivation, with relatively minor urban development. Runoff of sediment, nutrients and pesticides is increasing and for nitrogen is now four times the natural amount discharged 150 years ago. Significant effects and potential threats are now evident on inshore reefs, seagrasses and marine animals. There is no effective legislation or processes in place to manage agricultural pollution. The Great Barrier Reef Marine Park Act does not provide effective jurisdiction on the catchment. Queensland legislation relies on voluntary codes and there is no assessment of the effectiveness of the codes. Integrated catchment management strategies, also voluntary, provide some positive outcomes but are of limited success. Pollutant loads are predicted to continue to increase and it is unlikely that current management regimes will prevent this. New mechanisms to prevent continued degradation of inshore ecosystems of the Great Barrier Reef World Heritage Area are urgently needed.

Managing Herring Fisheries Under Uncertainty

1985 ◽  
Vol 42 (S1) ◽  
pp. s245-s257 ◽  
Author(s):  
W. G. Doubleday
Keyword(s):  
Fishery Management ◽  
Management Strategies ◽  
Growth Patterns ◽  
Clupea Harengus ◽  
Growth Potential ◽  
Production Models ◽  
Abundance Indices ◽  
General Production ◽  
Clupea Harengus Harengus ◽  
Yield Per Recruit

The implications of the biological characteristics of the Atlantic herring (Clupea harengus harengus) on fishery management strategies are examined. Growth patterns and recruitment fluctuations limit opportunities to stabilize catches and stock biomasses without substantial loss of yield-per-recruit. The dynamics of herring stocks are much more dependent on recruitment than growth. Potential effectiveness of fishery management is also constrained by tendencies of herring populations to school, reducing self-regulatory possibilities by allowing catch rates to remain high when abundance is low, and to mix, complicating the estimation of catch-at-age and abundance indices. Given the vulnerability of herring to exploitation and the imprecision of abundance indices, achievement of relative stability of spawning stocks and catches requires adoption of fishing mortality rates near or below 0.2 in adult herring fisheries. Fisheries on immature herring reduce, and may destabilize, recruitment to spawning stocks and give lower yield-per-recruit than fisheries on mature herring although product prices may be higher. A simple stochastic model of the dynamics of an exploited herring population is examined. Analysis of this model demonstrated behaviour qualitatively similar to that observed in earlier studies of general production models subject to stochastic noise.

scholarly journals Mesophotic Coral Ecosystems of the Great Barrier Reef Are Understudied and Underexplored

2021 ◽  
Vol 8 ◽  
Author(s):  
Gal Eyal ◽  
Jack H. Laverick ◽  
Pim Bongaerts ◽  
Oren Levy ◽  
John M. Pandolfi
Keyword(s):  
Coral Reef ◽  
Great Barrier Reef ◽  
Fishery Management ◽  
Research Effort ◽  
Decision Makers ◽  
Barrier Reef ◽  
Mesophotic Coral Ecosystems ◽  
Deep Reef ◽  
The World ◽  
Coral Reef Ecosystems

Mesophotic coral ecosystems (MCEs) are characterized by the presence of photosynthetically active organisms such as corals and algae, and associated communities at depths ranging from 30 to 150 m in tropical and subtropical regions. Due to the increased awareness of the potential importance of these reefs as an integral part of coral reef ecosystems (i.e., deep reef refuge, specialized biodiversity, transition zone between shallow and deep-sea environments, and recreational and intrinsic values), interest from the scientific community has grown around the world over the last two decades. Several nations have already made management declarations and started to extend marine protected areas and fishery management to MCEs. The estimated area of Australian MCEs is likely equivalent to that of shallow reef ecosystems down to 30 m; however, Australian MCEs attract limited research effort compared to other major coral reef regions around the world. In this perspective, we briefly explore the reasons for this scarcity of research on mesophotic ecosystems of the Great Barrier Reef (GBR) of Australia (e.g., strict diving regulations, new researchers’ involvement, and logistics and cost). At present, research efforts on the mesophotic ecosystems of the GBR are in decline and if this trajectory is maintained, the global disparity in knowledge between MCEs near Australia and those from the other main coral reef regions worldwide will sharpen deeply. We call for action from the research community, grant agencies, and decision-makers toward a wider understanding of these important ecosystems in Australia.

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