2 resultados para Estágios do ciclo de vida
em Instituto Politécnico de Bragança
Resumo:
Freshwater mussel (Mollusca, Bivalvia, Unionoida) populations are one of the most endangered faunistic groups. Mussels play an important role in the functioning of aquatic ecosystems, because they are responsible for the filtration and purification of water. They have a complex life cycle, with a parasitic larvae and usually limited host fish species. The real status of these populations is still poorly understood worldwide. The objectives of the present work were the study of bioecology of duck mussel (Anodonta anatina L.) populations of Tua Basin (NE Portugal). It was made the characterization of the ecological status of Rabaçal, Tuela and Tua Rivers, selecting 15 sampling sites, equally distributed by the three rivers. Samplings were made in the winter of 2016, and several physico-chemical water parameters measured and two habitat quality indexes calculated (GQC and QBR indexes). Benthic macroinvertebrate communities were sampled based on the protocols established by the Water Framework Directive. Host fish populations for duck mussel were determined in laboratorial conditions, testing several native and exotic fish species. The results showed that several water quality variables (e.g. dissolved oxygen, conductivity, pH, total dissolved solids, and nutrients) can be used for the classification of river typology. Other responsive metrics were also determined to identify environmental degradation. For instances, hydromorphological conditions (GQC and QBR indexes) and biota related metrics (e.g. composition, distribution, abundance, diversity of invertebrate communities) contributed to the evaluation of the ecological integrity. The upper zones of Rabaçal and Tuela rivers were classified with excellent and good ecological integrity, while less quality was found in downstream zones. The host fish tests showed that only native species are effective hosts, essential for the conservation purposes of this mussel species. Threats, like pollution, sedimentation and river regularization (3 big dams are in construction or in filling phase), are the main cause of habitat loss for native mussel and fish populations in the future. Rehabilitation and mitigation measures are essential for these lotic ecosystems in order to preserve the prioritary habitats and the native species heavily threatened.
Resumo:
The research is orientated to the actual issues of strategic management of industrial enterprises. The theoretical aspects of strategic management are generalized, its role is certain in organization development, methods and processes of strategic management are investigational. In this context the main objective of study is based on the strategic analysis of PJSC «Elektrotermometriya», formation ways to improve the strategic management of the company with regard to the readiness of the company to strategic changes and conducting of developments and recommendations for improvement activity of the enterprise. To answer to the main objective it was conducted the strategic analysis of activity of PJSC «Elektrotermometriya». The results proved the basic strategy to achieve the strategic goal of PJSC «Elektrotermometriya». According to the life cycle, and based on the current conditions of its functioning, is appropriate to use the strategy of gradual growth. Forecast implementing strategies defined by the optimistic, probable and pessimistic forecasts. According to the pessimistic forecast the company should use a strategy of stabilization, while to the optimistic and the most likely scenario - moderate growth strategy. Thus to achieve the main strategic goals according to each scenario PJSC «Elektrotermometriya» should use set of functional strategies and define the business strategy.