6 resultados para New Castle (Del.)
em Aquatic Commons
Resumo:
The fishing resources of the Salado Basin are extraordinary important in the context of the inland waters of Argentina. However, the diversity of landscapes in the basin and the lack of continuity in the regional planning , have made difficult a proper management of the fishing resources. This paper has a general overview of the main aspects related to the fishing fauna of the region, with a natural point of view of the processes and mechanisms of the management. A description of the fishes basin community and the identification of the species with commercial and game interests is included . We describe the different fishing gears used in the province for game, commercial and scientific fishing. We review the criteria of diagnosis of the silver side population as a main resource of fishing interest and under this point of view we propose new outlooks to promote a proper management of the resources and its sustainable use. We identify the different kinds of fisheries that are common in the basin and we make a survey of the related socioeconomic aspects. Moreover, we analyze the development of a new institutional and regulatory frame in order to optimize the management of the fishing resources. Finally, we define criteria for ordering and conserving such resources and identify conflict points and requirements for its sustainable use in the context of new proposals for the public policies.
Resumo:
Distribution of the genus Anodontites (Mollusca: Bivalvia: Mycetopodidae) in Uruguay. Seven species of the freshwater mussel genus Anodontites were recorded from Uruguay. The populations of these bivalves suffer the negative effects of invasive bivalves, damming, industrial and urban discharges, and agrotoxic runoff. The distribution of these species is generally characterized at the level of basin or politic divisions, and precise geographic records are scarce. In order to detail the distribution of those species, the most representative collections of Uruguay were examined, the material of Anodontites was identified (612 records) and geographic coordenates were assigned at each locality (213 localities), using Geographic Information System (GIS) to obtain a distribution map for each species. Most of the localities with Anodontites were located in the left margin of Uruguay River and southwest of Uruguay, mainly in Soriano, Artigas, Salto and Colonia departments. The Salto Grande basin presented the highest species richness. The species with a highest number of records was A. patagonicus, which was also recorded in all basins. A. trapesialis and A. tenebricosus had a wide distribution and a high number of records. A. lucidus and A. ferrarisii, had a wide distribution (more than 6 basins) but comparatively lower number of records. Finally A. trapezeus and A. trigonus showed a limited distribution. There is a critical lack of samples in Merín Lagoon, Atlantic and Upper Negro River basins. It is necessary to carry out new sampling considering many variables in order to evaluate the current distribution and the ecologic preferences for each species.
Resumo:
A new species of mullet (Mugil) from Nipe Bay. North coast of Oriente Province, Cuba. The absence of axillary scale of pectoral fins, a very slender body and a notably elongated caudal peduncle are among the most diagnostic features of a new species.
Resumo:
The first part presents a general picture of the composition of the coastal plankton near Mar del Plata (Buenos Aires prov., Argentina) between August 1961-August 1962. Especially noted is the abundance of Noctiluca from October to the end of March. The second part deals with the plankton collected during a short cruise, named Operación Mar del Plata 1, planned to survey coastal waters. In the third part the author gives the descriptions of some new or interesting species. A chain-forming Gymnodinium is reported as G. catenatum; some differences with Graham description, could be due to the fact that he studied only preserved material. Oblea baculifera is a new species belonging to the new genus Oblea, of the Diplopsalis group, created for some species previ¬ously known as Peridiniopsis. A key of the included species is given. The other new species are Peridinium aspidiotum, P. anomaloplaxum, P. lipopodium and Gonyaulax fratercula, all of them carefully described and depicted. Sticholonche zanclea (Radiolaria), Calsiosolenia sinuosa (Coccolithophoridae) and Tintinnopsis levigata (Tintinnida) are reported for the first time in the South-Atlantic. For T. levigata ?, Balech, 1939, a new name has been created: T. tregouboffi. Some unknown details of the protoplasm of the silicoflagellate Dictyocha octonaria are described. In the fourth part the author compares the plankton taken in Mar del Plata with the previously studied at Pto. Quequén. The plankton of March-April points to an invasion of oceanic warm waters from the Brazilian Current System.