Biology and conservation of elasmobranchs: an introduction to the collection

Elasmobranchs, the taxonomic group comprising sharks, skates and rays, play important roles in society and marine ecology but several species in this subclass are under threat. This collection aims to be an open access hub for articles concerning all areas of elasmobranch biology and conservation. The collection is indefinitely open to further submissions and so will continue to grow as additional articles are added

Ανάπτυξη και χαρακτηρισμός ικριωμάτων νανοϋδροξυαπατίτη με την τεχνική της λυοφιλίωσης

Post-trawl survival (PTS) is an important metric used in determining the ecological risk posed by prawn (shrimp) trawling on discarded elasmobranchs. Despite this, PTS of elasmobranchs is poorly understood. The present study quantified the PTS of two small batoids caught incidentally by prawn trawlers in southern Queensland, Australia, namely the common stingaree (Trygonoptera testacea) and the eastern shovelnose ray (Aptychotrema rostrata). Field studies using on-board tanks revealed that A. rostrata were more resilient to trawl capture and release than T. testacea. For both species, survival was found to increase with size, whereas increasing time on deck resulted in lower survival. Female T. testacea were found to be more resilient than males, and increased tow duration resulted in lower survival for A. rostrata. The mean (+/- s.e.m.) PTS for female and male T. testacea was 33.5 +/- 6.0 and 17.3 +/- 5.5% respectively, compared with a mean PTS for A. rostrata of 86.8 +/- 3.2%. The survival estimates derived in the present study provide an insight into the effects of trawling on these species and will improve their ecological risk assessment and management

Stock structure of exploited shark species in north-eastern Australia

The project has provided management and other stakeholders with information necessary to make informed decisions about the management of four of the key exploited shark species caught in the Queensland inshore net fishery and northern New South Wales line fishery. The project has determined that spatial management of milk sharks within Queensland, and scalloped hammerhead, common black tip and Australian black tip sharks within Queensland and New South Wales is appropriate. The project has determined that both black tip shark species are likely to require co-operative management arrangements between Queensland and New South Wales. For scalloped hammerheads separate stocks between the two jurisdictions were identified from the fisheriesdependent samples, however genetic exchange across borders is likely to be facilitated by movement of adult females and perhaps larger males to a lesser extent. This information will greatly assist compliance with the Commonwealth Environment Protection and Biodiversity Conservation Act (1999) for shark fisheries in north-eastern Australia by providing the necessary basis for robust assessment of the status of stocks of the study species, thereby helping to deliver their sustainable harvest. It also helps to achieve objectives of the Australian National Shark Plan. The project provides the appropriate spatial framework for future monitoring and assessment of the study species. This is at a time when shark fisheries are receiving close attention from all sectors and when monitoring programs are being implemented, aimed at better assessment of stock status. This project has provided the crucial information for developing an appropriate monitoring design as well as the necessary basis for making statements about stock status. The project has addressed research priorities identified by the Queensland Fisheries Research Advisory Board, Great Barrier Reef Marine Park Authority and Queensland Fisheries. Previously management has assumed a single stock for each species on the east coast of Queensland, and management of shark fisheries in New South Wales (NSW) and Queensland has been independent of one another. The project has been able to enhance and develop links between research, management and industry. Strong positive relationships with commercial fishers were crucial in the collection of samples throughout the study area and fisheries managers were part of the project team throughout the study period. During the project the study area was extended to include both Queensland and NSW waters, creating mutualistic and positive links between the States’ research and management agencies. Extension of project results included management representatives from NSW and Queensland, as well as the Northern Territory where similar shark fisheries operate and similar species are targeted. The project was able to provide significant human capital development opportunities providing considerable value to the project outcomes. Use of vertebral microchemistry and life history characteristics as stock determination methods provided material for two PhD students based at James Cook University: Ron Schroeder, vertebral chemistry; and Alastair Harry, life history characteristic. The project has developed novel research methods that have great capacity for future application, including: • Development of a simple and rapid genetic diagnostic tool (RT-HRM-PCR assay) for differentiating among the black tip shark species, for which no simple morphological identifier exists; and • Development of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) methods for analysing and interpreting microchemical composition of shark vertebrae. The study has provided further confirmation of the effectiveness of using a holistic approach in stock structure studies and justifies investment into such studies

Demography of a deep-sea lantern shark (Etmopterus spinax) caught in trawl fisheries of the northeastern Atlantic: Application of Leslie matrices with incorporated uncertainties

The deep-sea lantern shark Etmopterus spinax occurs in the northeast Atlantic on or near the bottoms of the outer continental shelves and slopes, and is regularly captured as bycatch in deep-water commercial fisheries. Given the lack of knowledge on the impacts of fisheries on this species, a demographic analysis using age-based Leslie matrices was carried out. Given the uncertainties in the mortality estimates and in the available life history parameters, several different scenarios, some incorporating stochasticity in the life history parameters (using Monte Carlo simulation), were analyzed. If only natural mortality were considered, even after introducing uncertainties in all parameters, the estimated population growth rate (A) suggested an increasing population. However, if fishing mortality from trawl fisheries is considered, the estimates of A either indicated increasing or declining populations. In these latter cases, the uncertainties in the species reproductive cycle seemed to be particularly relevant, as a 2-year reproductive cycle indicated a stable population, while a longer (3-year cycle) indicated a declining population. The estimated matrix elasticities were in general higher for the survivorship parameters of the younger age classes and tended to decrease for the older ages. This highlights the susceptibility of this deep-sea squaloid to increasing fishing mortality, emphasizing that even though this is a small-sized species, it shows population dynamics patterns more typical of the larger-sized and in general more vulnerable species. (C) 2014 Elsevier Ltd. All rights reserved

Gillnet size selectivity of shark and ray species from Queensland, Australia

Gillnets are size-selective fishing gears commonly used by industrial and small-scale fishers, so understanding selectivity can aid fisheries management by identifying suitable mesh sizes to optimize catches of target species while reducing bycatch. Few size selectivity parameters have been estimated for sharks, with even fewer for rays. Size selection parameters were estimated for seven species of sharks and two species of rays from the Queensland East Coast Inshore Finfish Fishery (ECIFF). Size frequency data from a fishery observer program on ECIFF vessels was used to fit a standard size selection model. Mesh size independent parameters, θ1 and θ2, were estimated for each species to define selectivity curves for different mesh sizes for each species. Parameter values were compared with previous studies that used the same method. Estimates of θ1 were similar among species within the same genus, such as Carcharhinus, Rhizoprionodon, and Sphyrna. Anoxypristis cuspidata had the largest θ1 and θ2 values, likely because of its toothed rostrum that affected catchability in gillnets. Our findings can be used for the ECIFF and other gillnet fisheries to aid in mesh size recommendations and risk mitigation

Reactions of durum wheats to Fusarium pseudograminearum in the Northern grain growing region of Australia

Dissertação de mestrado em Marketing, apresentada à Faculdade de Economia da Universidade de Coimbra, sob a orientação de Arnaldo Coelho.Há quem defenda que o estudo do comportamento do consumidor está demasiado focado na fase de aquisição, deixando para segundo plano a compreensão da origem do desejo do consumidor (Pham, 2013). A cultura influencia a forma como o ser humano vive e se relaciona (Salomon et al., 2013). A literatura já há muito reconheceu que o comportamento do consumidor varia entre culturas. Porém os mecanismos por trás desta variação continuam pouco claros (Parker & Tavassoli, 2000). Esta dissertação pretende aclarar alguns desses mecanismos. O objetivo principal desta dissertação é estudar o impacto da cultura no comportamento do consumidor de uma forma geral. A cultura será avaliada tendo por base a teoria das dimensões culturais de Hofstede (Hofstede, 2003), através da CVSCALE – Individual Cultural Value Scale (Yoo, Donthu, & Lenartowicz, 2010). Os consumidores são parte de uma cultura e a cultura é o sistema global em que todos os outros sistemas estão organizados (Salomon et al., 2013). Relativamente ao comportamento do consumidor pretende-se ter uma visão geral, pelo que serão avaliadas áreas do comportamento do consumidor, já descritas na literatura como sendo influenciadas pela cultura: a compra por impulso (Kacen & Lee, 2002), a atitude face ao luxo (Shukla & Purani, 2012) e a atitude face às promoções (McNeill, 2006). Os resultados dos 385 questionários preenchidos na totalidade por consumidores de Portugal e do Brasil permitiram corroborar a teoria de que a cultura tem impacto no comportamento do consumidor, com relevância diferente dentro de cada área do comportamento do consumidor analisada. Também foram identificados alguns mecanismos que permitem perceber de que forma a cultura exerce influência no comportamento do consumidor

Extinction risk and conservation of the world\u27s sharks and rays

The rapid expansion of human activities threatens ocean-wide biodiversity. Numerous marine animal populations have declined, yet it remains unclear whether these trends are symptomatic of a chronic accumulation of global marine extinction risk. We present the first systematic analysis of threat for a globally distributed lineage of 1,041 chondrichthyan fishes—sharks, rays, and chimaeras. We estimate that one-quarter are threatened according to IUCN Red List criteria due to overfishing (targeted and incidental). Large-bodied, shallow-water species are at greatest risk and five out of the seven most threatened families are rays. Overall chondrichthyan extinction risk is substantially higher than for most other vertebrates, and only one-third of species are considered safe. Population depletion has occurred throughout the world’s ice-free waters, but is particularly prevalent in the Indo-Pacific Biodiversity Triangle and Mediterranean Sea. Improved management of fisheries and trade is urgently needed to avoid extinctions and promote population recovery