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1 INTRODUCTION
Mangroves are wetlands that occur in tropical and
subtropical areas, bathed by tidal movements, by the
exchange of organic matter between fresh and salty
water. It receives debris from soils, rocks, and mainly
organic matter, usually brought by rivers. A portion is
transformed into smaller particles by the action of
crabs and other animals, serving as food for snails,
larvae, and soil microorganisms, which supply
nutrients to water flora, which will later serve as food
for several animals [9].
Santos’s mangroves are important wetlands
located on the Brazilian coast, in an estuarine rural
tropical area within Santos (Figure 1). The most
extensive mangrove study in the Santos Estuary [9]
classified their characteristics in 1985 as high: 67.85%;
low: 4.14%; degraded: 8.53%; amended: 19.48%. High
mangrove is the vegetation with trunks that support
large leaf mass. Low mangrove is the vegetation with
smaller diameter of tree cup. Degraded mangrove is
partial or total cut areas, exposing dark substrate
(dominance of decomposed organic matter exposure)
with cut logs or small regeneration shrubs. Amended
mangrove presents structural modifications of total or
partial character by the installation of paths or roads,
constructions, or embankments and even agricultural
or aquaculture activity. The study was developed by
means of remote sensing techniques from satellite and
orthophoto images.
Therefore, in this paper only healthy mangroves
were considered, that is, degraded and amended were
disregarded. The overall mangroves area of healthy
mangroves (high and low) along the riparian zones
influencing the Santos Estuary was around 25.20 km
2
.
The study informs the areas of each mangrove swamp
according to its characteristics.
According to [1], it is concluded that mean sea
level rise will have a considerable impact upon the
mangrove areas, with approximately 1.0 m rise
Prediction of Wetland Loss Due to Sea Level Rise
A
round the Largest Port Area in Latin America
P
. Alfredini & E. Arasaki
Polytechnic School of São Paulo University, São Paulo, Brazil
ABSTRACT: Santos’s mangroves are important wetlands located in Brazilian coast, a fishing area inside Santos
Bay. The overall healthy mangroves area along the riparian zones influencing the Santos Estuary is around
25.20 km
2
. The resulting tidal level recorded from Port of Santos tide gauge (from 1940 to 2014), also located in
the estuary, shows consistent increasing trend. One healthy mangrove was selected for a previous qualitative
biological survey to better understand the characteristics of the habitat to be monitored and evaluated about the
possible impacts in the next decades. The mangroves situated a few meters upper from the sea level and some
other areas have the risk to be submerged till 2085 which will seriously affect the riparian mangroves biome.
Indeed, the mangrove area is confined downward by the low tide level and upward by existing structures,
roads, rural and urban areas.
http://www.transnav.eu
the
International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 15
Number 3
September 2021
DOI: 10.12716/1001.15.03.23