Chapter 10
Echinoderm Research in Uruguay
Sergio Martínez
10.1 Introduction
The eastern 220 km of the Uruguayan coastline are considered marine (salinities
around 30–35 %), and the remaining ca. 350 km correspond to the Río de la Plata
estuary. The Río de la Plata is the second largest river system in South America
(drainage basin: 3.1 9 106 km
2 , sediment load: 91 9 106 t y
-1 , discharge of an
average of 22,000 m
3 s
-1 water to the ocean) (Framiñan and Brown 1996;
Guerrero et al. 1997; Syvitski et al. 2005). Along the coast there is a remarkable
salinity gradient, with changing fronts, caused by the discharge of fresh water from
the Paraná and Uruguay rivers into the Río de la Plata and from it into the Atlantic
Ocean (Fig. 10.1a). Winds change the location of the salinity and turbidity fronts
(Larrañaga 1894; Nagy et al. 1987). The Río de la Plata is extremely muddy
because of mud derived mainly by the Paraná River.
The Atlantic area is influenced by the warm coastal N–S Brazilian Current and
by the cold S–N Malvinas (Falkland) Current (Boltovskoy 1966; Podestá et al.
1991; Lentini et al. 2000; Piola et al. 2000). On the platform there are superficial
warm waters and deeper cold ones (Fig. 10.1b). The sub-tropical warm waters
converge and mix with the cold subantartic waters at about the isobaths of 100 and
200 m. Other factors such as topography, seasonality, and El Niño-Southern
Oscillation (ENSO) phenomena also contribute to the littoral environmental
conditions (Olson et al. 1988; Podestá et al. 1991; Lentini et al. 2000; Ortega and
Martínez 2007; Raicich 2008). In brief, the estuary and the adjunct platform have
complex horizontal and vertical structures complicated by a high degree of
S. Martínez (&)
Departamento Evolución de Cuencas, Facultad de Ciencias,
Iguá 4225, 11400, Montevideo, Uruguay
e-mail: smart@fcien.edu.uy
J. J. Alvarado and F. A. Solís-Marín (eds.), Echinoderm Research and Diversity
in Latin America, DOI: 10.1007/978-3-642-20051-9_10,
Ó Springer-Verlag Berlin Heidelberg 2013
345
Echinoderm Research in Uruguay
Sergio Martínez
10.1 Introduction
The eastern 220 km of the Uruguayan coastline are considered marine (salinities
around 30–35 %), and the remaining ca. 350 km correspond to the Río de la Plata
estuary. The Río de la Plata is the second largest river system in South America
(drainage basin: 3.1 9 106 km
2 , sediment load: 91 9 106 t y
-1 , discharge of an
average of 22,000 m
3 s
-1 water to the ocean) (Framiñan and Brown 1996;
Guerrero et al. 1997; Syvitski et al. 2005). Along the coast there is a remarkable
salinity gradient, with changing fronts, caused by the discharge of fresh water from
the Paraná and Uruguay rivers into the Río de la Plata and from it into the Atlantic
Ocean (Fig. 10.1a). Winds change the location of the salinity and turbidity fronts
(Larrañaga 1894; Nagy et al. 1987). The Río de la Plata is extremely muddy
because of mud derived mainly by the Paraná River.
The Atlantic area is influenced by the warm coastal N–S Brazilian Current and
by the cold S–N Malvinas (Falkland) Current (Boltovskoy 1966; Podestá et al.
1991; Lentini et al. 2000; Piola et al. 2000). On the platform there are superficial
warm waters and deeper cold ones (Fig. 10.1b). The sub-tropical warm waters
converge and mix with the cold subantartic waters at about the isobaths of 100 and
200 m. Other factors such as topography, seasonality, and El Niño-Southern
Oscillation (ENSO) phenomena also contribute to the littoral environmental
conditions (Olson et al. 1988; Podestá et al. 1991; Lentini et al. 2000; Ortega and
Martínez 2007; Raicich 2008). In brief, the estuary and the adjunct platform have
complex horizontal and vertical structures complicated by a high degree of
S. Martínez (&)
Departamento Evolución de Cuencas, Facultad de Ciencias,
Iguá 4225, 11400, Montevideo, Uruguay
e-mail: smart@fcien.edu.uy
J. J. Alvarado and F. A. Solís-Marín (eds.), Echinoderm Research and Diversity
in Latin America, DOI: 10.1007/978-3-642-20051-9_10,
Ó Springer-Verlag Berlin Heidelberg 2013
345