300
J.E. Conde . G. Rodriguez
16.2
General Description
The aquatic component of the Maracaibo System and the drainage basin cover approximately 120000 km\ that spread through a latitudinal band of approximately six degrees (Fig. 16.1). Located in northern South America, the Maracaibo System comprises
two main bodies of water, Lake Maracaibo, the largest in South America and 17th in
the world, and the Gulf of Venezuela, interconnected by the Strait of Maracaibo and EI
Tablazo Bay (Fig. 16.1). The lake, approximately oval in shape and 155 km long, is part
of an extensive (89800 km 2 ) watershed area located on Colombia and Venezuela. The
lake itself occupies 12000 km 2 , and the inlet and bay connecting the lake to the Caribbean Sea cover an additional 1 000 km 2 • Depth in the lake averages 25 m, with a maxim.um of 33 m. The strait and the bay have 39 km in length. The bay, square in shape,
opens into the Gulf of Venezuela through two narrow inlets sprinkled by a number of
islets and shoals (Rodriguez 1973,1974,1984). Overall, the coastline of the Maracaibo
System extends through approximately 1 700 km.
The distinct bodies of water form a continuum that includes euhaline waters, in the
Gulf of Venezuela; the limnetic waters of the lake proper; and the mixohaline waters of
the Strait of Maracaibo and EI Tablazo Bay (Rodriguez 1973). The lake's water discharge
into the Caribbean Sea at a rate of 49000 million m 3 a-I (Rodriguez 1974), after spending 5.99 years in the lake (ESCAM 1991). The freshwater volume has been estimated at
50600 million m 3 • The hydraulic balance, even during the dry season, is positive from
the lake to the sea.
Due to the large area encompassed by the Maracaibo System, a great variety of climates occurs. Thirteen climates have been recognized, ranging from semiarid tropical
(DA' in the Thornthwaite's classification) in the shoreline of the Gulf of Venezuela, to
arid mesothermal (EB'), perhumid mesothermal (AB') and semiarid microthermal
(DC') at the western and southern watersheds.
The biota and ecosystems of Lake Maracaibo has been thoroughly documented
(Rodriguez 1963, 1967, 1973, 1974; Ewald 1967; Taissoun 1969, 1972; Pannier and Pannier 1985; MARNR 1985, 1986, 1990, 1991; Huber and Alarcon 1988; Conde and
Alarcon 1993; amol)g others). It is composed of species with quite a variable geographical range, that include pantropical, pantemperate, West Indian, tropical American, and
Northern South American distributions, and also several endemisms (Rodriguez 1974).
In addition to some endemic species, most of the fishes are typical northern South
American forms, while most of the decapod crustacea are West Indian. Most of the crabs
from the southeastern coast of the Gulf of Venezuela have a wide distribution
(Carmona-Suarez and Conde 1996). Carmona and Conde (1989) have described the
principal coastal biotopes and physiographic features of the southeastern and eastern
shorelines of the Gulf of Venezuela.
Among the aquatic vertebrates, five species of cetaceans have been confirmed for the
Gulf of Venezuela: Turpsiops truncatus;Stenella frontalis, Orcinus orca, Ziphius cavirostris
and Balaenoptera edeni. Another species, Sotalia jluviatilis, has been observed at numerous localities, ranging from the southern perimeter of the lake to the Strait of Maracaibo;
there are also several sightings in the Gulf of Venezuela (Rodriguez, in press). A subspecies of cayman, Cayman sclerops fuscus, has been reported from several rivers of
the Serrania de Perija and from the swamps ~n the southwestern coast of the lake.
J.E. Conde . G. Rodriguez
16.2
General Description
The aquatic component of the Maracaibo System and the drainage basin cover approximately 120000 km\ that spread through a latitudinal band of approximately six degrees (Fig. 16.1). Located in northern South America, the Maracaibo System comprises
two main bodies of water, Lake Maracaibo, the largest in South America and 17th in
the world, and the Gulf of Venezuela, interconnected by the Strait of Maracaibo and EI
Tablazo Bay (Fig. 16.1). The lake, approximately oval in shape and 155 km long, is part
of an extensive (89800 km 2 ) watershed area located on Colombia and Venezuela. The
lake itself occupies 12000 km 2 , and the inlet and bay connecting the lake to the Caribbean Sea cover an additional 1 000 km 2 • Depth in the lake averages 25 m, with a maxim.um of 33 m. The strait and the bay have 39 km in length. The bay, square in shape,
opens into the Gulf of Venezuela through two narrow inlets sprinkled by a number of
islets and shoals (Rodriguez 1973,1974,1984). Overall, the coastline of the Maracaibo
System extends through approximately 1 700 km.
The distinct bodies of water form a continuum that includes euhaline waters, in the
Gulf of Venezuela; the limnetic waters of the lake proper; and the mixohaline waters of
the Strait of Maracaibo and EI Tablazo Bay (Rodriguez 1973). The lake's water discharge
into the Caribbean Sea at a rate of 49000 million m 3 a-I (Rodriguez 1974), after spending 5.99 years in the lake (ESCAM 1991). The freshwater volume has been estimated at
50600 million m 3 • The hydraulic balance, even during the dry season, is positive from
the lake to the sea.
Due to the large area encompassed by the Maracaibo System, a great variety of climates occurs. Thirteen climates have been recognized, ranging from semiarid tropical
(DA' in the Thornthwaite's classification) in the shoreline of the Gulf of Venezuela, to
arid mesothermal (EB'), perhumid mesothermal (AB') and semiarid microthermal
(DC') at the western and southern watersheds.
The biota and ecosystems of Lake Maracaibo has been thoroughly documented
(Rodriguez 1963, 1967, 1973, 1974; Ewald 1967; Taissoun 1969, 1972; Pannier and Pannier 1985; MARNR 1985, 1986, 1990, 1991; Huber and Alarcon 1988; Conde and
Alarcon 1993; amol)g others). It is composed of species with quite a variable geographical range, that include pantropical, pantemperate, West Indian, tropical American, and
Northern South American distributions, and also several endemisms (Rodriguez 1974).
In addition to some endemic species, most of the fishes are typical northern South
American forms, while most of the decapod crustacea are West Indian. Most of the crabs
from the southeastern coast of the Gulf of Venezuela have a wide distribution
(Carmona-Suarez and Conde 1996). Carmona and Conde (1989) have described the
principal coastal biotopes and physiographic features of the southeastern and eastern
shorelines of the Gulf of Venezuela.
Among the aquatic vertebrates, five species of cetaceans have been confirmed for the
Gulf of Venezuela: Turpsiops truncatus;Stenella frontalis, Orcinus orca, Ziphius cavirostris
and Balaenoptera edeni. Another species, Sotalia jluviatilis, has been observed at numerous localities, ranging from the southern perimeter of the lake to the Strait of Maracaibo;
there are also several sightings in the Gulf of Venezuela (Rodriguez, in press). A subspecies of cayman, Cayman sclerops fuscus, has been reported from several rivers of
the Serrania de Perija and from the swamps ~n the southwestern coast of the lake.