Gestão ambiental na Zona Costeira Fluminense: avaliação do potencial de resiliência ambiental e da potencialidade de serviços ecossistêmicos da Baía de Ilha Grande (BIG)

Abstract

Ilha Grande Bay is officially considered a hotspot of marine biodiversity on the Brazilian coast, and is characterized by its status of preserving coastal marine ecosystems, with emphasis on mangroves, restingas, rocky shores and beaches. The evolution of threats to the Ilha Grande Bay ecosystem is highlighted and documented in a range of publications. Among these threats, the presence of an oil and oil derivatives transfer and storage terminal (TEBIG), two nuclear plants (Angra I and Angra II) and a shipyard stand out, in addition to a growing human occupation on the coastline. The Bay in question, despite the various environmental challenges, presents potential ecological resilience in the face of existing environmental maintenance challenges. The present study sought to generate a roadmap to evaluate the potential of ecological resilience for coastal areas that allow contributing to coastal ecosystem management processes and applying it in Ilha Grande Bay, characterizing its state of health and environmental resistance, in the face of various ecosystem pressures. which has suffered over decades of use. The methodology applied consisted of two main approaches: the development of the roadmap to assess the resilience potential in coastal areas and its application in Ilha Grande Bay. The itinerary consists of six stages, namely: survey of the region's historical characteristics and sources of pressure; survey of primary and secondary indicators; generation of environmental alerts; construction of scenarios of increasing environmental impacts and proposing strategies to combat them. The biodiversity characterization resulted in environmental alerts for reef fish, impossex percentage in gastropods, coral health and difference in CO2 partial pressure, directly linked to ocean acidification, and availability of microplastics in the water column. Based on the analysis of the matrix of aspects and impacts, their relationships with the environmental quality of Ilha Grande Bay and the notes made on resilience, 3 development scenarios were constructed that address growth in sources of ecosystem pressure and breakdowns of protection barriers. The first scenario illustrates the current characteristics of the Bay, as a system with potential for resilience, which persists in ecosystem services and marine biodiversity, despite numerous environmental forces. The second scenario points to the growth of Pressure Sources for Ilha Grande Bay, but still with the existence of barriers/defenses in the system. In the third scenario, Ilha Grande Bay would face a series of challenges. The lack of barriers and defenses in the system, together with the growth of environmental pressure forces, would lead to the destruction of its ecosystems and the significant loss of biodiversity. Depending on the sources of pressure raised, environmental alerts generated and scenarios constructed, the region needs comprehensive and sustainable environmental management strategies, in the short and long term, that strengthen and add barriers to maintaining local resilience.