Marcelo Vasconcellos

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Dynamic simulations of 18 ECOPATH mass-balance marine trophic models are used to explore the stability of systems when briefly impacted by a fishery on the key 'wasp-waist' populations occurring at intermediate trophic levels. The results are related to different ecosystem goal functions previously identified as representative of three attributes of(More)
An efficient protocol for colchicine mediated production of in vitro autotetetraploids from Ponkan mandarin using cell suspension cultures is described. Cells were treated with 1 g l−1 colchicine for 4 or 8 days before transfer into solid EME medium supplemented with 5% maltose. Colchicine treated cells were placed in medium with or without an overlay of(More)
Sea cucumbers are important resources for coastal livelihoods and ecosystems. At least 60 species are fished from more than 40 countries and most of the harvests are processed then exported to Asian markets. Sea cucumbers generally appear to have slow rates of population turnover and are easily harvested in shallow waters in the tropics. With retail prices(More)
This paper analyses the impact of the activities of distant water fleets on Namibia’s marine ecosystem through the use of simulation modeling. Mass-balance trophic models and economic valuation techniques are combined to simulate the ‘with’ and ‘without’ distant water fleet (DWF) scenarios for two decades prior to Namibia’s independence in 1990. Our(More)
Four antioxidants including glycine betaine, glutathione, lipoic acid, and polyvinylpyrrolidone were evaluated to improve transformation efficiency of Mexican lime, a precocious but recalcitrant citrus cultivar to Agrobacterium mediated transformation. Lipoic acid substantially improved the transformation efficiency of Mexican lime by aiding in callus(More)
Policy may be defined as an approach towards reaching a broadly defined goal. In fisheries, policies are often implemented via total allowable catches, TACs, that are recalculated annually, and through regulations that affect fleet and deployment. The task of fisheries scientists should be to advise both on policy formulation and on its implementation.(More)
We estimate biomass trends for demersal and large pelagic fishes, (i.e., excluding small pelagic and mesopelagic fishes) based on 17 Ecopath models from Mauritania, Cape Verde, Senegal, the Gambia, Guinea, and Guinea-Bissau, Sierra Leone and the open waters of the central east Atlantic, made to represent various time periods during the second half of the(More)
This paper analyses the ecological knowledge of small-scale fishers in the estuary of Patos Lagoon, obtained from interviews and questionnaire surveys, and discusses its potential role in the local co-management of artisanal fisheries. This study demonstrates that fishers' knowledge can provide a valuable set of information about the characteristics of(More)
During the last decades there has been a substantial increase in the trade with seafood, as the world’s markets have become more integrated. A large part of this increased trade is increased exports from developing countries to industrialised countries. In this paper some stylised facts about the trade is given, and a discussion of the causes and effects of(More)