doctoralThesis
Impactos do mergulho recreativo em ambientes recifais tropicais do Brasil
Fecha
2018-02-26Registro en:
CALADO, Janaina Freitas. Impactos do mergulho recreativo em ambientes recifais tropicais do Brasil. 2018. 161f. Tese (Doutorado em Ecologia) - Centro de Biociências, Universidade Federal do Rio Grande do Norte, Natal, 2018.
Autor
Calado, Janaina Freitas
Resumen
Recreational diving (RD) is one of the fastest growing tourist activities in the world, generating
employment, income and contributing with the conservation of reef environments. This boosts the
creation of protected areas (PA) and helps with financial inputs to the maintenance of existing PAs.
Despite the socioeconomic advantages, when carried out uncontrolled RD can cause negative impacts to
reef ecosystems, such as changes in community structure, physical damage and reduction of reef’s
resilience. Several studies on coral reefs worldwide have proposed management strategies and biological
indicators for monitoring RD impacts. The peculiarities of Brazilian reefs, with low coral and high
seaweed and sponge cover, make it necessary to identify and define management strategies appropriate to
this type of use. The present study evaluated the impact of recreational diving on tropical reefs of Brazil.
The first chapter is a scientometric analysis that indicates trends in the impact of RD on Brazilian reefs.
Results show growth of publications over time but a lack of an integrated analysis of the impacts that RD
causes on the reef biota. In addition, it was observed the necessity of delineation of the profile,
preferences and the behavior of the divers. Our work also indicates that Ceará’s reefs and urban reefs of
Paraíba and Alagoas are areas with greater lack of studies. In the second chapter, the behavior of
recreational divers in a Marine Environmental Protection Area (MPA) in the Brazilian northeast was
characterized, quantifying the frequency of touches on the reef substrate related to the profile of the diver
and characteristics of the type of diving performed. The average frequency of touches (FT) observed was
markedly lower in the studied reef when compared to other studies on coral reefs in the world. The
variables that influenced FT were: type of diving (scuba> snorkel), sex (men> women) and in the age
group (above 50 years, higher than in the other age groups). The discussion in this chapter discusses how
the physical characteristics of the place of study may have influenced the reduction of FT, as well as the
posture of tourism professionals. The third chapter deals with the RD impacts on the ichthyofauna and the
benthic community in a Brazilian reef environment. In this chapter, an integrated analysis of multiple
variables of the marine biota revealed important changes in the structure of the reef community as a
function of RD. This approach allowed the observation of possible cause and effect relationships, that the
assessment of only one biological group could not detect. The main changes documented were: higher
relative frequency of sand and gravel in the substrate cover and lower values of hard coral, soft coral and
filamentous algae in High Use areas. The average density of corals did not vary among the areas,
however, the species of coral Favia gravida showed lower density in the tourist areas. Areas of high use
exhibited even greater relative abundance of black urchin and sessile invertebrates. The Low Use areas
presented greater coverage of foliose algae. In relation to ichthyofauna, in High Use areas the species
Haemulon aurolineatum showed greater abundance but lower diversity. In these areas, the highest
abundance of the mobile, omnivorous and carnivorous invertivorous trophic groups was observed,
predominantly fish of the size category between 11 - 20 cm. The Control areas presented a different
pattern with lower total fish abundance, greater diversity and homogeneity, and greater abundance of
herbivores, especially the territorial ones, within the categories of size of 6 - 10 cm and of 21 - 30 cm. In
the Low Use areas, we observed intermediate values and of greater similarity with the Control areas.
These changes can be caused directly by RD or by indirect effects, which is a result of the complex way
in which the different taxa respond to damages from the tourist activity. Despite this, these modifications
are spatially punctual and with more studies, monitoring, supervision and proper management, the
impacts could be reduced in the tourist areas. In this work, we suggest management measures to reduce
the impact of RD and biological indicators that can optimize the monitoring of reef areas under tourism
activity. The fourth and final chapter reports how uses of multiple methodologies in an Environmental
Education (EE) project, whose main theme was "Impacts of recreational diving", was effective on a
public school in the surroundings of MPA, which is a target area for tourism speculation. Results indicate
that combinations of scientific and local knowledge, the use of media and visits to non-formal
environments are fundamental to the effectiveness of an EE project. This thesis presents pioneering data
about impacts that the recreational diving causes to Brazilian’s reefs, effectively contributing to
management actions and development of sustainable tourism in marine protected areas.