A influência da sazonalidade turística e de fatores climáticos na qualidade microbiológica da água e areia de praias urbanas de Fortaleza-Ceará

Abstract

The coastal cities of the Northeast are attractive to national and international tourism. However, the environmental quality of urban beaches for users is often suboptimal, a problem closely related to the basic sanitation of cities, their uses and pressures on these coastal environments. The city of Fortaleza, in the state of Ceará, is a prime example of a tourist destination of significant popularity in Brazil. The primary objective of the present study was to monitor the microbiological quality of the water and sand on the beaches, with particular attention to granulometry, in addition to climatic factors and the frequency of tourists. The secondary variables considered were: air temperature, insolation and radiation indices; rainfall index; and published bathing indices. The collection period was from April to October 2023, encompassing the tourist periods Before the High Season (BHS), High Season (HS) and After High Season (AHS) in the city of Fortaleza-CE. The collection points included the beaches with high tourist traffic, namely Praia Caça e Pesca, Praia do Futuro, Praia de Iracema and Praia do Meireles. Water and sand samples were collected at each site. The highest estimates of thermotolerant coliforms were observed in the water samples collected from points P1 (Caça e Pesca) and P3 (Iracema). The same concentration pattern of thermotolerant coliform bacteria was found in the sand of these beaches, mainly aggregated in the larger granules at the bottom. . It appears that contamination by thermotolerant coliforms on Fortaleza's urban beaches is more related to the action of climatic factors, such as the power of rainfall to carry microorganisms, than to tourist seasonality. The analysis of secondary data revealed that Fortaleza maintains a significant tourist flow throughout the year, with high occupancy rates in April (71.8% in the Observatory and 58.6% in the Forum of Hotel Operators of Brazil - FOHB) and July (74.2% in the Observatory and 71.4% in the FOHB). It is evident that even outside the conventional high season, the city continues to receive a substantial number of visitors. Furthermore, it was determined that the sand exhibited higher concentrations of coliforms in comparison to the water, predominantly within medium-grained particles. This observation signifies the sand's potential function as a microbial reservoir. It was observed that an increase in rainfall led to the dispersion of contaminants in the coastal zone. It is recommended that the sanitation infrastructure be strengthened, that water and sand quality be monitored, and that further studies be conducted to enhance our understanding of the dynamics of microorganisms in the sediment, thereby contributing to the updating of national bathing legislation.