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- Carrying Capacity EvaluationPublication . Baltazar, João; Lamas, José; Vale, Nuno; Bandeira, Rui; Duarte, PedroBivalve culture is an important economic activity in several regions and it should be carefully managed towards its sustainability. In this context, carrying capacity (CC) evaluation of coastal ecosystems for bivalve culture became an important topic. Mathematical modelling is a common approach for CC estimation. The objective of this work is to evaluate the importance of spatial resolution of mathematical models for CC evaluation. Obtained results suggest that low resolution models may lead to CC overestimates.
- Biogeochemical Modelling of Ria Formosa (South Coast of Portugal) with EcoDynamo - Model descriptionPublication . Duarte, Pedro; Pereira, António; Falcão, Manuela; Serpa, Dalila; Ribeiro, Catarina; Bandeira, Rui; Azevedo, Bruno
- Scenario Analysis in Ria Formosa with EcoDynamoPublication . Duarte, Pedro; Azevedo, Bruno; Ribeiro, Catarina; Pereira, António; Falcão, Manuela; Serpa, Dalila; Bandeira, Rui; Reia, JoãoRia Formosa is a natural park managed partly by the Portuguese end-users of the DITTY project – Ria Formosa Natural Park authority, under “Instituto para a Conservação da Natureza (ICN)”. There are many conflicting interests over the management of this important coastal area: fishing, tourism, aquaculture, salt production, harbour activities, urban development and conservation. Furthermore, several institutions, such as the Natural Park Authority, municipalities, the Portuguese Navy, just to mention a few, are involved in decision-making over several areas of the natural park. Within DITTY, several scenarios were selected among those relevant for the management of this coastal ecosystem, considering available information from the end-users, relative importance of the mentioned scenarios, modelling and time constraints.
- Biogeochemical Modelling of Ria Formosa (South Portugal)Publication . Duarte, Pedro; Azevedo, Bruno; Guerreiro, Maria; Ribeiro, Catarina; Bandeira, Rui; Pereira, António; Falcão, Manuela; Serpa, Dalila; Reia, João; yesRia Formosa is a large (c.a. 100 km2) mesotidal lagunary system with intertidal areas with conflicting uses such as fisheries, aquaculture, tourism and nature conservation. Its watersheds cover an area of approximately 864 km2, with a perimeter of 166 km and a maximum altitude of 522 m. Land use may be classified into six major groups: 1) urban, 2) agricultural, 3) forest, 4) rangeland and pastures, 5) wetlands and 6) water bodies. The main objectives of this work are to: (i) Evaluate the relative importance of land drainage, waste water treatment plants (WTP) and water exchanges across the lagoon inlets, for nutrient dynamics; (ii) Analyse management scenarios related to changes in lagoon bathymetry and their potential effects on system dynamics. The Soil and Water Assessment Tool (SWAT model) has been applied to the catchment areas in order to simulate water discharges into Ria Formosa providing forcing to a twodimensional vertically integrated coupled physical-biogeochemical model, implemented with EcoDynamo – an object oriented modelling software. This model includes water column and sediment processes as well as their interactions and several biological sub-models (e.g. phytoplankton dynamics and bivalve growth). Obtained results suggest that the river network may have a significant effect on lagoon concentrations, in spite of the relatively low river flows, due to the high ammonium and nitrate loads. Scenarios reflecting increases in lagoon bathymetry through dredging operations suggest an increase in lagoon water washout time with potential impacts on water quality and impacts at a scale of tens of km. The obtained results are being used by the Ria Formosa Natural Park authority for management purposes and may be useful to feedback future updates of the watershed management plans, within the scope of the European Union Water Framework Directive. The use of a lagoon scale models is therefore justified in this work
- Avaliação da capacidade de carga para o cultivo de bivalves filtradoresPublication . Baltazar, João; Lamas, José; Vale, Nuno; Bandeira, Rui; Duarte, PedroA aquicultura de bivalves é uma actividade com uma grande importância económica em diversas regiões, pelo que deve ser dimensionada de modo correcto, para garantir a sua sustentabilidade. Nesse sentido, a determinação da capacidade de carga (CC ) dos ecossistemas costeiros para o cultivo de bivalves é um tema importante. A CC determina-se, geralmente, com recurso a modelos matemáticos. O objectivo deste trabalho é avaliar empiricamente a importância da resolução espacial desses modelos na determinação da CC . Os resultados obtidos põem em causa o desempenho de modelos com uma resolução espacial reduzida, tendentes a estimar por excesso a CC .