Browsing by Author "Parente, Joaquim"
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- AUMENTO DA EFICIÊNCIA ENERGÉTICA EM ARRASTÕES COSTEIROS ATRAVÉS DA UTILIZAÇÃO DE REDES DE ARRASTO COM FIBRAS DE ELEVADA TENACIDADEPublication . Parente, Joaquim; Fonseca, Paulo; Henriques, Victor; Campos, Aida; Instituto Português do Mar e da AtmosferaTrawling is a fishing technique associated with an intensive consumption of fuel and, consequently, the profit margin of a commercial trawling vessel is very dependent on the variations in the price of diesel. The share of fuel in the total costs of Portuguese coastal trawlers may be as high as 40%. One way of reducing consumption is to decrease the overall drag resistance of the trawl by introducing changes to the trawl gear. Within the framework of the project CONSUPESCA - Reduction of Energy Consumption in Trawling Fisheries, financed by the PROMAR program, changes were introduced in a gear typically used by coastal trawlers operating off the main port (Aveiro) of the centre region of Portugal. The trawl gear originally built in braided polyethylene was redone, incorporating high-tenacity fibres and slightly increasing the front panels’ mesh size. The immediate result was a 30% decrease in twine area, leading to a significant reduction in fuel consumption per unit area of the gear’s mouth, ranging from 13 to 21% for trawl velocities ranging from 3.6 to 4.4 knots. The qualitative assessment made by the captain on the performance of the modified gear was very positive, with a less demanding engine effort within the range of commercial trawling speeds.
- FROTA COSTEIRA DE CERCO CARACTERIZAÇÃO TECNOLÓGICA E TIPOLOGIAS DE EMBARCAÇÕESPublication . Parente, Joaquim; Feijó, Diana; Silva, Alexandra; Instituto Português do Mar e da Atmosfera, I.P.It is intended to characterize coastal seine vessels with an active license in 2016, operating in ICES zone 9a, depending on the shape of the hull and structures on the deck, as well as on the type of equipment used for hauling and handling the seine gear on board. The grouping of vessels into typologies will depend on that characterization and on the degree of modernization of the vessels. Most vessels have a high degree of modernization of the deck, promoting the speed of fishing operations and improving the quality and safety of work on board. Currently, there are few vessels operating without a purse line reel or that do not have at least one crane to facilitate the handling of cargo and aid in fishing maneuvers, which was very infrequent to observe 15 years ago. The placement of a gantry on the stern deck, aims to facilitate maneuvers with the seine skiff and to improve the working conditions and safety of the crew, being more common in larger vessels due to the larger spaces on deck. Five typologies were identified in the current composition of the coastal seine fleet operating off the Portuguese mainland coast, each one presenting different degrees of modernization. The greater the size of the vessel, the greater will be the deck space available for the deployment of structures and fishing equipment that increase both the vessel's fishing power and the comfort and safety of the crew on board.