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Laguna de Tacarigua, located on the central-eastern portion of the Venezuelan coast (10 degrees 16 ’N - 65 degrees 48 ’W), is a shallow (average depth: 1.2 m), estuarine system with an approximate area of 72 km(2). Formed during the Holocene, the lagoon, with a length of 28 km and a maximum width of 5 km, runs parallel, in a southeast-northwest direction, to the Caribbean Sea, from which it is separated by a permanent, continuous sand bar with a width of 300 to 1,000 m. In its north-western area, there is an inlet that connects this body of water to the ocean. Annual precipitation in this area averages 990.0 mm with a marked seasonality. Eighty-five percent of the precipitation occurs from June to December and the maximum is in November with an average of 169.5 mm. Evaporation is intense, averaging 2,003.5 mm/year. Salinity fluctuates spatially and seasonally from 0.5 to 54.0 parts per thousand. Depending on the zone of the lagoon and time of the year dissolved oxygen can vary substantially, ranging from 0.0 to 20.5 ml/l for the whole lagoon. Variations are higher at El Guapo embayment (1.54 - 8.54 ml/l). Water temperature varies monthly between 26.6 (February and April) and 33.8 degrees C (August and September) and spatially: the lowest temperatures have been registered at El Guapo. The lagoon’s water is rich in nutrients which vary in seasonally and spatially. Productivity is also periodic: the maximum (187.76 mgC/m(3)/h) coincides with the rain peaks, during the middle and the end of the year. Mangrove forests, which cover about 4,000 ha, line almost all the lagoon’s perimeter. The dominant mangrove species is Rhizophora mangle, with a coverage of 71%. Avicennia germinans (6%), and Laguncularia racemosa (2%) are also present. The rest corresponds to Conocarpus erectus and mixed mangrove forests. The surrounding vegetation includes arid and semiarid littoral communities, where xerophilous scrubs and psammophilous or halophilous meadows prevail, but tropophilous basimontane deciduous forests are also present. The plankton is dominated by a few species: the copepod Oithona hebes, the rotifer Brachionus plicatilis, the tintinnid Favella panamensis and the algae Ceratium fusus v. seta. The population dynamics of the mangrove crab Aratus pisonii echo some of the abiotic processes that could be cardinal in the lagoon dynamics, mainly the rainfall regime and tital cycles. The diversity and densities of birds in and around this body of water are noteworthy: 136 aquatic species have been reported, ranking as the third wetland in Venezuela in number of species. Eighty of these species are residents, including 58 which nest in this area. With 117 boats registered in 1982 and some 300 fisherman, this estuary sustains important subsistence and marginally commercial fisheries that averaged 383,282 kg/year from 1975 to 1982, and which are mostly based on the exploitation of Mugil liza, which represents 56% of the landings. Other species caught are Centropomus ensiferus, C. pectinatus and C. undecimalis (15%), M. curema (12%), and Eugerres plumieri (11%). Until a few years ago, shrimp fisheries were also a main staple in the lagoon villagers economy. The major freshwater influx comes from the Guapo River which discharges through the Madre Casanas Canal. The main processes in the dynamics of Laguna de Tacarigua seem to be rainfall patterns, the Guapo River discharge, and circulation patterns, as modulated through the narrow tidal pass.

During recent years, rechanneling of this river and also of the Cupira River, mismanagement of the catchment basin, and of several creeks that flow into the lagoon induced a decrease of freshwater input and an increment in the rate of sedimentation, thus blocking the connection with the open sea for long periods of time up to one year. Additionally, a delta, which grew 1.1 km(2) from 1963 to 1975, has been formed at he mouth of the Madre Casanas Canal. Since 1974, Laguna de Tacarigua is legally protected by a National Park status (area: 184 km(2)); however, threats on the lagoon persevere due to the exclusion of the western bar from the preservation regime.