14 The Bahia Blanca Estuary, Argentina
G.M.E. PERILLO, M.C. PICCOLO, E. PARODI, and R.H. FREIJE
14.1 Introduction
Bahia Blanca is a mesotidal coastal plain estuary in the southwest of the
Buenos Aires Province, Argentina. The estuary represents the remaining
part of a complex delta, formed by the Desaguadero river (Perillo 1989),
which once extended over almost 200 km from the northern coast of
Bahia Blanca to Bahia San Bias (Fig. 14.1). The Principal Channel of the
modern estuary approximately corresponds to the principal valley of the
late Pleistocene-early Holocene delta complex, which was formed by a
now vanished river and its tributary, the Colorado River (or one of its
arms). The southward migration of the Colorado River subsequently
carved the other major channels (i.e., Falsa, Verde, and Brightman bays)
of the estuary (Perillo 1989). The modern Bahia Blanca Estuary extends
over about 2,300km 2 and is formed by several tidal channels (740km 2 ),
extensive tidal flats (1, 150 km 2 ) with patches of low salt marshes, and
islands (410km 2 ; Montesarchio and Lizasoain 1981). Owing to marked
differences in surface morphology, the area can be divided along the northern shore of Falsa Bay into a funnel-shaped northern part, characterized by the Principal Channel and many small tidal creeks, and a
southern part, dominated by the Falsa, Verde, and Brightman bays (Perillo
and Piccolo 1999; Fig. 14.1).
14.2 Geomorphology
The Principal Channel of the Bahia Blanca Estuary has a total length of
60 km and varies in width from about 3-4 km at the mouth (22-m depth) to
200m at the head (3-m depth); both depth and width increase almost
exponentially from head to mouth. Like other major channels (bays) that
flow towards the inner shelf, the Principal Channel is partly closed by a
Ecological Studies, Vol. 144
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
©Springer-Verlag Berlin Heidelberg 2001
G.M.E. PERILLO, M.C. PICCOLO, E. PARODI, and R.H. FREIJE
14.1 Introduction
Bahia Blanca is a mesotidal coastal plain estuary in the southwest of the
Buenos Aires Province, Argentina. The estuary represents the remaining
part of a complex delta, formed by the Desaguadero river (Perillo 1989),
which once extended over almost 200 km from the northern coast of
Bahia Blanca to Bahia San Bias (Fig. 14.1). The Principal Channel of the
modern estuary approximately corresponds to the principal valley of the
late Pleistocene-early Holocene delta complex, which was formed by a
now vanished river and its tributary, the Colorado River (or one of its
arms). The southward migration of the Colorado River subsequently
carved the other major channels (i.e., Falsa, Verde, and Brightman bays)
of the estuary (Perillo 1989). The modern Bahia Blanca Estuary extends
over about 2,300km 2 and is formed by several tidal channels (740km 2 ),
extensive tidal flats (1, 150 km 2 ) with patches of low salt marshes, and
islands (410km 2 ; Montesarchio and Lizasoain 1981). Owing to marked
differences in surface morphology, the area can be divided along the northern shore of Falsa Bay into a funnel-shaped northern part, characterized by the Principal Channel and many small tidal creeks, and a
southern part, dominated by the Falsa, Verde, and Brightman bays (Perillo
and Piccolo 1999; Fig. 14.1).
14.2 Geomorphology
The Principal Channel of the Bahia Blanca Estuary has a total length of
60 km and varies in width from about 3-4 km at the mouth (22-m depth) to
200m at the head (3-m depth); both depth and width increase almost
exponentially from head to mouth. Like other major channels (bays) that
flow towards the inner shelf, the Principal Channel is partly closed by a
Ecological Studies, Vol. 144
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
©Springer-Verlag Berlin Heidelberg 2001