Analysis of permanent magnets as elasmobranch bycatch reduction devices in hook-and-line and longline trials

Previous studies indicate that elasmobranch fishes (sharks, skates and rays) detect the Earth’s geomagnetic field by indirect magnetoreception through electromagnetic induction, using their ampullae of Lorenzini. Applying this concept, we evaluated the capture of elasmobranchs in the presence of permanent magnets in hook-and-line and inshore longline fishing experiments. Hooks with neodymium-iron-boron magnets significantly reduced the capture of elasmobranchs overall in comparison with control and procedural control hooks in the hook-and-line experiment. Catches of Atlantic sharpnose shark (Rhizoprionodon terraenovae) and smooth dogfish (Mustelus canis) were signif icantly reduced with magnetic hook-and-line treatments, whereas catches of spiny dogfish (Squalus acanthias) and clearnose skate (Raja eglanteria) were not. Longline hooks with barium-ferrite magnets significantly reduced total elasmobranch capture when compared with control hooks. In the longline study, capture of blacktip sharks (Carcharhinus limbatus) and southern stingrays (Dasyatis americana) was reduced on magnetic hooks, whereas capture of sandbar shark (Carcharhinus plumbeus) was not affected. Teleosts, such as red drum (Sciaenops ocellatus), Atlantic croaker (Micropogonias undulatus), oyster toadfish (Opsanus tau), black sea bass (Centropristis striata), and the bluefish (Pomatomas saltatrix), showed no hook preference in either hook-and-line or longline studies. These results indicate that permanent magnets, although eliciting species-specific capture trends, warrant further investigation in commercial longline and recreational fisheries, where bycatch mortality is a leading contributor to declines in elasmobranch populations.

Gestão de Custos através do Custeio Baseado em Atividades (ABC): um estudo de caso em um projeto de desenvolvimento de software

O contexto da era da informação exige novas habilidades para competir com sucesso, tanto para empresas industriais como para as de serviços. Desde o seu surgimento, a Engenharia de Software tem enfrentado o desafio em estimar, controlar e gerenciar custos no processo de desenvolvimento de software. Os custos são parte de um projeto de software e nem sempre são claramente mensurados. Algumas desenvolvedoras de software são caracterizadas como prestadoras de serviços e as organizações que prestam serviços possuem as mesmas dificuldades em termos gerenciais que as indústrias, elas precisam de sistemas de gestão adequados para gerir seus custos, logo seus recursos. Nesse contexto é que os sistemas de informações contábeis estão inseridos, fornecendo respostas que os gestores necessitam para tomar decisões. Os custos são exemplos desse tipo de informação, pois o seu conhecimento é indispensável para uma boa gerência dos recursos organizacionais. O Custeio Baseado em Atividades (ABC) é uma ferramenta contábil útil para o gerenciamento estratégico dos custos uma vez que os sistemas de custeio tradicionais já não atendem essa necessidade das organizações. Diante desse cenário, o objetivo geral dessa dissertação é aplicar a metodologia de custeio baseado em atividades em um projeto de desenvolvimento de software com a finalidade de gestão de custos. Este pesquisa caracteriza-se como qualitativa descritiva e faz uso do método do estudo de caso. Através desse estudo foi possível comprovar a utilidade do ABC como instrumento de auxílio na gestão de custos nas organizações que prestam serviços em desenvolvimento de software, pois possibilita a visualização da maneira que os recursos são consumidos pelas atividades que agregam e não agregam valor ao negócio e ao cliente.

Dividing population genetic distance data with the software Partitioning Optimization with Restricted Growth Strings (PORGS): an application for Chinook salmon (Oncorhynchus tshawytscha), Vancouver Island, British Columbia

A new method of finding the optimal group membership and number of groupings to partition population genetic distance data is presented. The software program Partitioning Optimization with Restricted Growth Strings (PORGS), visits all possible set partitions and deems acceptable partitions to be those that reduce mean intracluster distance. The optimal number of groups is determined with the gap statistic which compares PORGS results with a reference distribution. The PORGS method was validated by a simulated data set with a known distribution. For efficiency, where values of n were larger, restricted growth strings (RGS) were used to bipartition populations during a nested search (bi-PORGS). Bi-PORGS was applied to a set of genetic data from 18 Chinook salmon (Oncorhynchus tshawytscha) populations from the west coast of Vancouver Island. The optimal grouping of these populations corresponded to four geographic locations: 1) Quatsino Sound, 2) Nootka Sound, 3) Clayoquot +Barkley sounds, and 4) southwest Vancouver Island. However, assignment of populations to groups did not strictly reflect the geographical divisions; fish of Barkley Sound origin that had strayed into the Gold River and close genetic similarity between transferred and donor populations meant groupings crossed geographic boundaries. Overall, stock structure determined by this partitioning method was similar to that determined by the unweighted pair-group method with arithmetic averages (UPGMA), an agglomerative clustering algorithm.

The ECOPATH II software

Problems involved in the development of ecosystem models are discussed, considering in particular the use of the ECOPATH II software and the approach used at ICLARM in the project Global comparisons of trophic aquatic ecosystem models designed to support modelling efforts of research groups throughout the world.

ICLARM software projects: back to the future

The different computer softwares developed by the International Center for Living Aquatic Resources (ICLARM) and its functions and uses in fisheries science are presented.

A computer software package for assessing and managing risks posed by experiments with genetically modified fish and shellfish

Assessment and management of risk is needed for sustainable use of genetically modified aquatic organisms (aquatic GMOs). A computer software package for safely conducting research with genetically modified fish and shellfish is described. By answering a series of questions about the organism and the accessible aquatic ecosystem, a researcher or oversight authority can either identify specific risks or conclude that there is a specific reason for safety of the experiment. Risk assessment protocols with examples involving transgenic coho salmon, triploid grass carp and hybrid tilapia are described. In case a specific risk is identified, the user is led to consider risk management measures, involving culture methods, facilities design and operations management, to minimize the risk. Key features of the software are its user-friendly organization; easy access to explanatory text, literature citations and glossary; and automated completion of a worksheet. Documented completion of the Performance Standards can facilitate approval of a well designed experiment by oversight authorities.