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 The orientation and migratory dynamics of the western rock lobster, Panulirus cygnus, in Western Australia

2014 ◽  
Vol 71 (5) ◽  
pp. 1052-1063 ◽  
Author(s):  
Simon de Lestang
Keyword(s):  
Large Scale ◽  
Economic Benefits ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Breeding Grounds ◽  
Mean Size ◽  
Catch Rates ◽  
Panulirus Cygnus ◽  
The Impact ◽  
Oceanic Currents

Abstract Large-scale migrations are known to occur in numerous species, and in the case of the Western Rock Lobster, Panulirus cygnus, result in juveniles moving from nursery areas into deeper offshore breeding grounds. In 2008 the Western Rock Lobster fishery reduced harvest rates to increase legal and spawning biomass throughout the fishery, which also allowed greater numbers of lobsters to migrate. Increased lobster migration could potentially reduce biomass in some areas, thus adversely impacting commercial catch rates. Over 20 000 tag–recaptured lobsters were analysed to determine the dynamics underlying migration in this species and to assess the impact reduced harvest rates may have had on catches. This study showed that P. cygnus migration was associated with body size and water depth, and that magnetism and oceanic currents appear to be the most likely guideposts used for orientation. Size at migration varied in a constant fashion along the coast, being larger towards the southern end of the fishery and smallest at the offshore Abrolhos Islands. During the migration period, up to 50% of lobsters at their mean size of migration moved from coastal areas out towards deeper waters (>40 m), whereas <15% of those in deeper water at the same size moved significant distances northward. This behaviour appears to be contranatant, counteracting the downstream redistribution of larvae after their 9–11 month larval life. Reduced harvest rates and catches being focussed onto higher valued sedentary lobsters have allowed more lobsters to migrate. However, the numbers moving between management areas are relatively small, with the biological and economic benefits of fishing at a reduced exploitation rate outweighing losses to catches.

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.

Prediction of Commercial Catches of the Western Rock Lobster Panulirus cygnus

1986 ◽  
Vol 43 (11) ◽  
pp. 2126-2130 ◽  
Author(s):  
B. F. Phillips
Keyword(s):  
Single Species ◽  
Total Catch ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Life History Stages ◽  
Last Stage ◽  
Panulirus Cygnus ◽  
Western Australian ◽  
Term Data

Predictions of the size of the Western Australian commercial catch of the western rock lobster Panulirus cygnus have been successfully made 4 yr ahead. The predictive system, which has operated for 9 yr has been recognized by industry and government as an important tool in the management of Australia's most valuable single-species fishery. The accurate prediction depends on demonstrated relationships between the number of rock lobsters at the puerulus stage of their development (the last stage of its pelagic existence) and the level of recruitment to the fishery, and the total catch of the fishery, 4 yr after settlement. Since 1980, predictions of the catches have been based on settlement data from a single site, Seven Mile Beach, which is near the centre of the distribution of the species. The catches of the fishery from 1961–62 to 1983–84 ranged from 6.8 × 106 kg in 1973–74 to 12.4 × 106 kg in 1982–83. Based on a regression of total catches from 1969 to 1979 on puerulus settlement, and allowing for a trend of increasing catch with time, the total catch is predicted to fall to about 7.72 × 106 kg in 1986–87 because of the low level of puerulus settlement in 1982–83. However, increased settlement in 1983–84 and the highest settlement ever recorded in 1984–85 indicate that catches should increase for the 1987–88 fishing season. Similar relationships between life history stages can be discerned for other crustacean species, provided accurate, long-term data are available.

Regional Prediction of the Western Rock Lobster, Panulirus Cygnus, Commercial Catch in Western Australia

Crustaceana ◽  
1995 ◽  
Vol 68 (2) ◽  
pp. 245-256 ◽  
Author(s):  
Nicolavito Caputi ◽  
Christopher F. Chubb ◽  
Rhys S. Brown
Keyword(s):  
Western Australia ◽  
Rock Lobster ◽  
Commercial Catch ◽  
Regional Prediction ◽  
Panulirus Cygnus

scholarly journals The Social Balance Sheet as Part of the Annual Report in Financial Institutions. A Case Study: Banco Bilbao Vizcaya Argentaria (BBVA)

2021 ◽  
Vol 13 (6) ◽  
pp. 3075
Author(s):  
Miguel Ángel Martín Valmayor ◽  
Beatriz Duarte Monedero ◽  
Luis A. Gil-Alana
Keyword(s):  
Annual Report ◽  
Economic Value ◽  
Balance Sheet ◽  
Value Added ◽  
Social Value ◽  
Economic Value Added ◽  
The Social ◽  
Social Balance ◽  
Corporate Social

In this paper, we examine the concept of the social balance sheet (SBS) and its evolution in corporate social reports that large companies have to issue today in their yearly statements. The SBS allows companies to evaluate their compliance with corporate social responsibility during a specific period and quantify its level of accomplishment. From a methodological perspective, this research analyzed the information that should be contained in the SBS report comparing economic value added (EVA) with other social value added statements (SVA), analyzing also in detail the case of Spain’s Banco Bilbao Vizcaya Argentaria (BBVA) bank as one of the pioneers in offering social reports. Along with this study, their metrics following EVA were recalculated and a more academic SVA statement was proposed for this specific case.

scholarly journals Performance Management for Growth: A Framework Based on EVA

2021 ◽  
Vol 14 (3) ◽  
pp. 102
Author(s):  
Mihaela Brindusa Tudose ◽  
Valentina Diana Rusu ◽  
Silvia Avasilcai
Keyword(s):  
Statistical Analysis ◽  
Performance Management ◽  
Performance Appraisal ◽  
Business Performance ◽  
Reference Model ◽  
Corporate Sustainability ◽  
Economic Value ◽  
Value Added ◽  
Research Perspectives

Some of the constructs in the field of performance management are intuitive or not empirically validated. This study provides a data-driven framework for measuring and improving the performance through synchronized strategies. The ultimate goal was to provide support for increasing business performance. Empirical research materializes in an exploratory case study and a statistical analysis with econometric models. The case study revealed that a company can improve its performance, even in periods of growth, being characterized by consistent investments. The statistical analysis, performed on a restricted sample of companies, confirmed the results that were provided by the case study. The measurement of performance was made by capitalizing on financial and non-financial data precisely to intensify the interest for corporate sustainability. The obtained results, contrary to previous research that showed that economic value added (EVA) is negatively influenced by the increase in invested capital, open up new research perspectives to find out whether, at the industry level, performance appraisal that is based on EVA stimulates the development of a business’s economic capital. The research has a double utility: scientific (by providing an overview of the state of the art in the field of performance management) and practical (by providing a reference model for measuring and monitoring performance).

scholarly journals Changes in the lease and permanent sale quota markets of a rock lobster fishery in response to stock abundance

2015 ◽  
Vol 72 (5) ◽  
pp. 1555-1564 ◽  
Author(s):  
Rafael León ◽  
Caleb Gardner ◽  
Ingrid van Putten ◽  
Klaas Hartmann
Keyword(s):  
Granger Causality Test ◽  
Economic Rent ◽  
Rock Lobster ◽  
Markov Modelling ◽  
Causality Test ◽  
Individual Transferable Quotas ◽  
Theoretical Pattern ◽  
Lobster Fishery ◽  
Trade Market ◽  
Stock Abundance

AbstractEffective individual transferable quotas (ITQ) systems rebuild stocks and allow transfer of quotas to more efficient operators. This process requires functional markets for both quota sales and temporary quota leases. These markets are expected to respond to changes in economic rent from the fishery, which is influenced by stock abundance and the international rock lobster price. This research used multistate Markov modelling and Granger causality test to examine changes in the permanent and temporary quota trade in the Tasmanian rock lobster fishery quota market, during periods of both increasing and decreasing stock abundance. The permanent quota trade market was more active during the period of stock growth, while the quota lease market was active in both periods of stock growth and decline. In contrast to theoretical trends in ITQ fisheries, trades in both markets were not linked to the technical efficiency (i.e. catching capability) of operators, but were more driven by the quota owners' financial capacity (i.e. number of owned quotas). Prolonged and unexpected stock decline affected the quota market so that it deviated from the theoretical pattern of ITQ fisheries. Operators previously active in the market reduced their activity, while smaller operators and firms that previously had not traded became more active, so the fleet expanded with smaller operators entering.

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