Segmentation and fishery characteristics of the mixed-species multi-gear portuguese fleet

Fleet segmentation and knowledge of fishing fleet dynamics are essential to move from single species to fishery/fleet-based advice. The coastal mixed-species multi-gear Portuguese fleet comprises medium-sized (> 12m) vessels, using a diversity of passive gears, and is economically important. For hake (under a recovery plan) and monkfish (overexploited), it contributes > 50% to their total annuel landings. Commercial daily landings in 2005 from 271 vessels were analysed by region using non-hierarchical cluster analysis and multi-variate regression trees. The cluster analysis allowed the identification of regional fleet segments with a low mixture of species through-out the year. The multivariate regression trees were applied to clusters of vessels with a high mixture of species, to explain weekly landing profiles (species) by vessel technical characteristics, fishing license, and main landing port. The results showed a link between exploited species and geographic location, and in the north between vessel size and depth and an inshore/offshore range. Finally, from the analysis and for the most important species exploited by the Portuguese multi-gear fleet, it was possible to define two or three vessel groups that accounted for at least 50% of the landed value.NeoMAv "New Assessment Methodologies"; Portuguese General Directorate for Fisheries and Aquaculture (DGPA); Sarah Walmsley (Cefas); Pedro de Barros of the University of the Algarveinfo:eu-repo/semantics/publishedVersio

Yield per recruit of the peacock bass Cichla monoculus (Spix and Agassiz, 1831) caught in Lago Grande at Manacapuru (Amazonas – Brazil)

We evaluated the stock of peacock bass Cichla monoculus caught by a small-scale fishing fleet in Lago Grande at Manacapuru. The database was constructed by monthly samplings of 200 fish between February 2007 and January 2008. We measured the total length (cm) and total weight (gr) of each fish. We employed previously estimated growth parameters to run a yield per recruit model and analyse scenarios changing the values of the age of the first catch (Tc), natural mortality (M), and fishing mortality (F). Our model indicated an occurrence of overfishing because the fishing effort applied to catch peacock in Lago Grande at Manacapuru is greater than that associated with the maximum sustainable yield. In addition, the actual size of the first catch is almost half of the estimated value. Although there are difficulties in enforcing a minimum size of the catch, our results show that an increase in the size of the first catch to at least 25 cm would be a good strategy for management of this fishery.</jats:p

Yield per recruit of the peacock bass Cichla monoculus (Spix and Agassiz, 1831) caught in Lago Grande at Manacapuru (Amazonas – Brazil)

We evaluated the stock of peacock bass Cichla monoculus caught by a small-scale fishing fleet in Lago Grande at Manacapuru. The database was constructed by monthly samplings of 200 fish between February 2007 and January 2008. We measured the total length (cm) and total weight (gr) of each fish. We employed previously estimated growth parameters to run a yield per recruit model and analyse scenarios changing the values of the age of the first catch (Tc), natural mortality (M), and fishing mortality (F). Our model indicated an occurrence of overfishing because the fishing effort applied to catch peacock in Lago Grande at Manacapuru is greater than that associated with the maximum sustainable yield. In addition, the actual size of the first catch is almost half of the estimated value. Although there are difficulties in enforcing a minimum size of the catch, our results show that an increase in the size of the first catch to at least 25 cm would be a good strategy for management of this fishery

Yield per recruit of the peacock bass Cichla monoculus (Spix and Agassiz, 1831) caught in Lago Grande at Manacapuru (Amazonas &#8211; Brazil)

We evaluated the stock of peacock bass Cichla monoculus caught by a small-scale fishing fleet in Lago Grande at Manacapuru. The database was constructed by monthly samplings of 200 fish between February 2007 and January 2008. We measured the total length (cm) and total weight (gr) of each fish. We employed previously estimated growth parameters to run a yield per recruit model and analyse scenarios changing the values of the age of the first catch (Tc), natural mortality (M), and fishing mortality (F). Our model indicated an occurrence of overfishing because the fishing effort applied to catch peacock in Lago Grande at Manacapuru is greater than that associated with the maximum sustainable yield. In addition, the actual size of the first catch is almost half of the estimated value. Although there are difficulties in enforcing a minimum size of the catch, our results show that an increase in the size of the first catch to at least 25 cm would be a good strategy for management of this fishery