RESUMO
The tiger shark (Galeocerdo cuvier) has been relatively well assessed concerning biology and ecology aspects in both Atlantic and Pacific North America and in Caribbean waters. The amount of data in these regions has led to the species protection under capture quotas and with the creation of sanctuaries. The reality in developing countries, however, is the exact opposite, with scarce information on the species in the southern hemisphere, namely South American and African waters. In these regions, protection measures are insufficient, and studies on tiger shark biology and ecology are scarce, significantly hindering conservation and management efforts. Thus, the aim of this study was to compile scientific literature on the tiger shark in the South Atlantic and discuss the impact of these data (or lack thereof) distributed within a total of ten research categories for guiding management plans. In total, 41 scientific publications on different G. cuvier biology and ecology aspects were obtained. The most studied topics were Feeding Ecology (n = 12), followed by Human Interactions (n = 8), and Movements and Migration (n = 7). Northeastern Brazil (Southwest Atlantic) was the most researched area, probably due to the higher coastal abundance of tiger sharks in this area, alongside a high number of recorded attacks, justifying funding for studies in the region. No studies carried out in other South American or African countries were found. It is important to mention that even though some research topics are relatively well covered, a severe knowledge gap is noted for risk assessments and fisheries management, with a proposition for the implementation of sanctuaries noted. This is, however, particularly worrisome, as the South Atlantic is mostly unexplored in this regard for tiger sharks. It is also important to note how different the attention given to this species is in the North Atlantic when compared to the South region. Lastly, we highlight that the existence of sub-populations, the lack of migratory corridors geographically connecting distinct areas used by the species, and the lack of fisheries statistics on tiger shark landings, all increase the vulnerability of this species in the South Atlantic.
Assuntos
Ecologia , Tubarões , Animais , Humanos , Pesqueiros , Brasil , ÁfricaRESUMO
In this study we analyzed data on fishing landings of Genidens barbus in the state of São Paulo, Brazil, from 2000 to 2014. An estimation of the total production was obtained through the analysis of 781,856 landings, among which 87% were categorized as artisanal and 13% as industrial. The abundance index showed some stability in the period. However, due to the high number of production units, the fishing effort need to be maintained, given that there is a risk that increased production might affect the abundance of G. barbus. Thus, as alternatives to maintaining marine catfish exploitation in southeastern Brazil under control, the following management actions can be suggested: i) prohibition of fishing activity by the industrial sector; ii) strengthening of inspection of the fleet that is not allowed to participate in the marine catfish fisheries, with emphasis on purse seiners; and iii) maintenance of a closed season for G. barbus, performing an adaptive management of fishing prohibition according to the reproductive biology of the species and with the support of artisanal fishers. These measures have the aim of promoting sustainable exploitation of G. barbus, especially through small-scale fisheries in southeastern Brazil.