19
(Diegues 1987) and is considered as an internationally sanctuary that needs to be
preserved (Mendonça and Katsuragawa 2001). According to IUCN (1984), this
regions is one of the five most productive and less disturbed estuary in the world and
is a priority to conservation according to the World Conservation Strategy. The estuary is legally protected by several federal, state and municipal protected areas,
which together create a mosaic of conservation units that aims the conservation of
local biodiversity (Schaeffer-Novelli et al. 1990). Besides that, is stated as “The
Mata Atlântica Biosphere Reserve” and “World Heritage Site” by UNESCO at 1991
and 1999 (UNESCO 1992, 1999).
Cananéia estuary (24°40′S; 47°25′W and 25°05′S; 48°02′W; Fig. 2.2a) has
110 km of extension, consisting of a large protected channel (Mar Pequeno), one
bay (Baía de Trapandé) and three islands (Ilha Comprida at east, Ilha do Cardoso at
south and Ilha de Cananéia at west). Which communicate with the Atlantic Ocean
by two inlets (Barra do Icapara at north and Barra de Cananéia at south). The channels are composed by brackish water, bordered by mangrove vegetation. The three
main species of mangroves are Rhizophora mangle (red mangrove), Laguncularia
racemosa (white mangrove) and Avicennia schaueriana (black mangrove)
(Schaeffer-Novelli et al. 1990).
Paranaguá estuary (25°13′S; 48°06′W and 25°45′S; 48°44′W; Fig. 2.2b) shows
two distinct components. The first one is represented by sandbars and many lagoons.
The second one is more affected by the fluvial system. The flow of the water inside
the estuary is regulated mainly by tidal currents, commonly found in estuarine systems. The fresh water and salt wedge interacts with each other creating a great distinctness during low and high tide (Bigarella 1978). The vegetation is mainly
composed by mangroves, salt marshes and “restingas” (Lana 1986).
Both regions show a high variation of the bathymetry. Sand and mud banks are
commonly found, which increases heterogeneity of underwater landscape. This
ground depth variation builts many different coastal formations, flooded marshals and
floodplains. The formation of vegetation islands enforces the water currents to narrow
channels, creating a strong flow of water during tidal currents, which impacts water
dynamics (Miyao and Sarti 1986). All complexity of this system receives high influence of tides, fluvial flow, and ocean winds (Miranda et al. 1995). The salinity patterns
change seasonally, according to fresh water outflow, being higher during the Austral
winter (dry season) and lower at Austral summer (rain season) (Miyao and Sarti
1986). Consequently, all these features are suitable to build a high heterogeneity habitat, which supports the presence of several species, including the Guiana dolphin.
2.4 Morphology
As part of our efforts, some studies started almost at the same time because of the
necessity of collecting carcasses along the beach shores. One example of carcassbased study is described above, with the use of geometric morphometric (MonteiroFilho et al. 2002), counting with great support of other institutions’ scientific
2 Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern…
(Diegues 1987) and is considered as an internationally sanctuary that needs to be
preserved (Mendonça and Katsuragawa 2001). According to IUCN (1984), this
regions is one of the five most productive and less disturbed estuary in the world and
is a priority to conservation according to the World Conservation Strategy. The estuary is legally protected by several federal, state and municipal protected areas,
which together create a mosaic of conservation units that aims the conservation of
local biodiversity (Schaeffer-Novelli et al. 1990). Besides that, is stated as “The
Mata Atlântica Biosphere Reserve” and “World Heritage Site” by UNESCO at 1991
and 1999 (UNESCO 1992, 1999).
Cananéia estuary (24°40′S; 47°25′W and 25°05′S; 48°02′W; Fig. 2.2a) has
110 km of extension, consisting of a large protected channel (Mar Pequeno), one
bay (Baía de Trapandé) and three islands (Ilha Comprida at east, Ilha do Cardoso at
south and Ilha de Cananéia at west). Which communicate with the Atlantic Ocean
by two inlets (Barra do Icapara at north and Barra de Cananéia at south). The channels are composed by brackish water, bordered by mangrove vegetation. The three
main species of mangroves are Rhizophora mangle (red mangrove), Laguncularia
racemosa (white mangrove) and Avicennia schaueriana (black mangrove)
(Schaeffer-Novelli et al. 1990).
Paranaguá estuary (25°13′S; 48°06′W and 25°45′S; 48°44′W; Fig. 2.2b) shows
two distinct components. The first one is represented by sandbars and many lagoons.
The second one is more affected by the fluvial system. The flow of the water inside
the estuary is regulated mainly by tidal currents, commonly found in estuarine systems. The fresh water and salt wedge interacts with each other creating a great distinctness during low and high tide (Bigarella 1978). The vegetation is mainly
composed by mangroves, salt marshes and “restingas” (Lana 1986).
Both regions show a high variation of the bathymetry. Sand and mud banks are
commonly found, which increases heterogeneity of underwater landscape. This
ground depth variation builts many different coastal formations, flooded marshals and
floodplains. The formation of vegetation islands enforces the water currents to narrow
channels, creating a strong flow of water during tidal currents, which impacts water
dynamics (Miyao and Sarti 1986). All complexity of this system receives high influence of tides, fluvial flow, and ocean winds (Miranda et al. 1995). The salinity patterns
change seasonally, according to fresh water outflow, being higher during the Austral
winter (dry season) and lower at Austral summer (rain season) (Miyao and Sarti
1986). Consequently, all these features are suitable to build a high heterogeneity habitat, which supports the presence of several species, including the Guiana dolphin.
2.4 Morphology
As part of our efforts, some studies started almost at the same time because of the
necessity of collecting carcasses along the beach shores. One example of carcassbased study is described above, with the use of geometric morphometric (MonteiroFilho et al. 2002), counting with great support of other institutions’ scientific
2 Long-Term Monitoring of Dolphins in a Large Estuarine System of Southeastern…