Biological, technical and socioeconomic aspects of the fishing activity in a Brazilian estuary

Abstract

BrazilTechnical, biological and socioeconomic factors act as obstacles in the development of fishing activity in the Guaratuba Bay, southern Brazil. Amongst the difficulties registered, the following stand out: there was little variety of fishing gear; the purchasing power of the fishermen was low; there was a lack of regularity in the presence of the target species in the estuary; legislation restricted the use of certain gear at particular times; the size of the individual fish was small when compared to those from the continental shelf. Aquaculture could offer an alternative to the revenue of the fishermen, but cultural tradition and the lack of financial resources make it difficult to introduce aquaculture as an activity for the fishermen. The pessimism encountered in the community indicates that the future of artisanal fishing in this estuary is uncertain.

Changes in the Microbiological Quality of Mangrove Oysters (Crassostrea brasiliana) during Different Storage Conditions

“…Oysters found in environments with large tidal amplitude and intermittent immersion, such as those extracted from mangroves in the Bay of Paranagua, have several physiological adaptations to survive out of seawater and under temperature variations (4,13,27). In most oyster cultivation systems, the shellfish are always completely immersed and, thus, lack the physiologic mechanisms to survive during long periods of exposure to air (6,19).…”

“…On the other hand, according to Fratini et al (25), submersed oysters in cultivations usually invest more energy in shell production, possibly to protect themselves against stressors of the environment, such as water currents and predators. This difference of nutritional status between cultivated and extracted oysters is even more affected by the age of the bivalves; whereas the cultivated oysters are young (less than 1 year, normally), it is almost impossible to precisely predict the age of oysters obtained from extraction, among which the larger, and probably older, specimens have much more commercial interest and value (13). The ability to withstand hypoxia during out-ofwater storage could be associated with the better nutritional status of oysters obtained from extraction, the trophic conditions of extraction sites, and the adaptation of the mollusks to a wide range of fluctuations in environmental parameters.…”

Microbiological quality assessment for oysters produced and traded in Paraná, Brazil

“…In addition to such factors, the water for this region includes less organic matter in the winter, which may also infl uence the bacterial biomass in the water and, consequently, oysters (MONTANHINI NETO et al, 2013). Another factor for consideration is the increased fl uctuating population on the coast of Paraná during the warm seasons, especially summer, which promotes an increase in domestic effl uent volume discharged into the environment (CHAVES et al, 2002). Altogether, these factors may explain the lower bacterial growth during the winter compared with the other seasons.…”

“…On the coast of the state of Paraná, a producer harvesting oysters from the Crassostrea genus (Sacco, 1897) generates income for fi shermen and their families. Further, this company increasingly promotes gastronomic tourism (CHAVES et al, 2002). However, producing such oysters is an artisanal practice, and the producers and handlers lack information about the appropriate processing and storage conditions to ensure microbiological quality and guarantee consumer safety (ANDRIGUETTO-FILHO et al, 2009).…”

Removals (Wild Harvesting) of the Biological Resources from Systems

“…Chaves et al (2002) stated that attempts to introduce aquaculture as an alternative source of revenue have not been very successful due to cultural resistance and lack of finance, and that the community is pessimistic about the future of their fishery. In many cases, they are unable to obtain financing for new fishing gear, and with the gradual decline in overall catch, seasonal legislative closures of the shrimp fishery, and low prices for fish, the fishers need to supplement their income from other sources.…”