Application of ecological indicators in coastal watershed under high pressure during summer period

Aichely Rodrigues Da Silva,Alessandra Larissa D’ Oliveira Fonseca,Ângela Da Veiga Beltrame,Claudinei José Rodrigues

doi:10.1590/2318-0331.011615106

Aichely Rodrigues Da Silva, Alessandra Larissa D’ Oliveira Fonseca + Show 2 more

Open Access

https://doi.org/10.1590/2318-0331.011615106

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Abstract

ABSTRACT Water bodies located in coastal areas are subject to human pressures and the loss of environmental quality. The objective of this study was to evaluate the environmental quality of the river Papaquara through water quality and river landscape, using the Trophic Index (TRIX) and Rapid Assessment Protocol (RAP). The study was developed in the watershed located in the north of the island of Santa Catarina, Florianópolis – SC, whose population increase in the summer is around 280%. The Trophic Index and the Rapid Assessment Protocol were evaluated in the pre-summer period, summer and after-summer in seven sample points along the inner areas (higher population density), median and outside the Papaquara river, plus two points in affluent. The river Papaquara showed up in great stress state, is classified as eutrophic, 77% of the samples and changed in 50% of the sampled area, as the TRIX index and RAP, respectively. The internal area registered up eutrophic and impacted in all periods analyzed. The median area and the outer decreased their water quality, due to summer activity, while there was no change in environmental quality by RAP. A significant correlation between the indices used indicated that the RAP should be used with caution to describe the condition of water quality. This analysis has submitted be more appropriate when used in river scale as a whole, but not isolated segments.

Highlights

Worldwide coastal zones cover 40% of the population who live less than 100km from the seashore and those areas are under persistent demographic, economic and ecological pressure (STATHAM, 2012)
Eutrophication is the result of the excess of nutrients in bodies of water and it favors the increase of phytoplankton biomass and proliferation of aquatic macrophytes (CHAMBERS; PREPAS, 1994; BALDY et al, 2007)
The decomposition of this biomass promotes the decrease in the dissolved oxygen concentration in aquatic environments, which results in a decrease of water quality and the reduction of aerobic organism

Summary

Introduction

Worldwide coastal zones cover 40% of the population who live less than 100km from the seashore and those areas are under persistent demographic, economic and ecological pressure (STATHAM, 2012). The coastal river basins show high environmental vulnerability and significant anthropic interventions. Eutrophication is the result of the excess of nutrients in bodies of water and it favors the increase of phytoplankton biomass and proliferation of aquatic macrophytes (CHAMBERS; PREPAS, 1994; BALDY et al, 2007). The decomposition of this biomass promotes the decrease in the dissolved oxygen concentration in aquatic environments, which results in a decrease of water quality and the reduction of aerobic organism. The researches involving the eutrophication of aquatic ecosystems aim at estimating the trophic state by the application of water quality and environmental index, i.e. by the development of applications methodology available to researchers and environmental managers (CUDOWSKI, 2015)

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