3 The Maracaibo System, Venezuela
G. RODRIGUEZ
3.1 Introduction
The Maracaibo Basin was formed during the Mio- Pliocene when the Venezuelan Andes and the Sierra de Perija attained their maximum development (Gonzalez de Juana et al. 1980). Within this basin, the Maracaibo
System acts as an assemblage of interactive brackish water bodies
(> 220 km 2 ), comprised of the Gulf of Venezuela, Tablazo Bay and the Maracaibo Strait, which connect Lake Maracaibo in the interior of the basin to
the Caribbean Sea (Fig. 3.1). Eustatic sea level changes during the Holocene
have induced either fresh or brackish water conditions in the lake. After the
last transgression (about 9,000 years B.P.), when sea levels were about 20m
above present levels, numerous islands and bars were formed at the mouth
of the estuary.
3.2 Environmental Factors
The topographic features of the Maracaibo Basin strongly determine the
airflow of trade winds and convergence processes over the lake and consequently influence the regional climate. The mean annual air temperature in
the basin is 28.3 °C with a difference of approximately 40 oc between the
hottest and coldest month. The arid and semiarid zones around the Gulf of
Venezuela have distinct dry and rainy seasons, with 90% of the rainfall
(about 200 mm) occurring from May to October when the trade winds
decrease. Further inside the basin, differences between dry and rainy seasons decrease and rainfall increases (annual mean 1,400 mm), owing to
almost permanent low pressure over the Catatumbo River mouth. The
highest precipitation (annual mean 3,500 mm) is recorded in the upper
Catatumbo River watershed.
Ecological Studies, Vol. 144
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
© Springer-Verlag Berlin Heidelberg 2001
G. RODRIGUEZ
3.1 Introduction
The Maracaibo Basin was formed during the Mio- Pliocene when the Venezuelan Andes and the Sierra de Perija attained their maximum development (Gonzalez de Juana et al. 1980). Within this basin, the Maracaibo
System acts as an assemblage of interactive brackish water bodies
(> 220 km 2 ), comprised of the Gulf of Venezuela, Tablazo Bay and the Maracaibo Strait, which connect Lake Maracaibo in the interior of the basin to
the Caribbean Sea (Fig. 3.1). Eustatic sea level changes during the Holocene
have induced either fresh or brackish water conditions in the lake. After the
last transgression (about 9,000 years B.P.), when sea levels were about 20m
above present levels, numerous islands and bars were formed at the mouth
of the estuary.
3.2 Environmental Factors
The topographic features of the Maracaibo Basin strongly determine the
airflow of trade winds and convergence processes over the lake and consequently influence the regional climate. The mean annual air temperature in
the basin is 28.3 °C with a difference of approximately 40 oc between the
hottest and coldest month. The arid and semiarid zones around the Gulf of
Venezuela have distinct dry and rainy seasons, with 90% of the rainfall
(about 200 mm) occurring from May to October when the trade winds
decrease. Further inside the basin, differences between dry and rainy seasons decrease and rainfall increases (annual mean 1,400 mm), owing to
almost permanent low pressure over the Catatumbo River mouth. The
highest precipitation (annual mean 3,500 mm) is recorded in the upper
Catatumbo River watershed.
Ecological Studies, Vol. 144
U. Seeliger and B. Kjerfve (eds.)
Coastal Marine Ecosystems of Latin America
© Springer-Verlag Berlin Heidelberg 2001