6.1 Introduction
6.1.1 Ecuadorian Continental Shelf
Geography and Climate
The continental coastal territory of Ecuador extends 4,403 km from north to south,
including islands, islets, and estuarine borders. The width of the continental shelf
exceeds 100 km, particularly off the Gulf of Guayaquil (associated with the most
important watershed from the Guayas River basin). The influence of the Guayas
River extends over two-thirds of the surface along the continental coast. This
causes coastal sedimentation, and a complex estuarine-deltaic system, that extends
close to the edge of the continental shelf (Benítez 1995 in Morante-Carballo 2004).
Approximately one-third of the coastline in Ecuador consists of stretches of
mangroves on mudflats, with major concentrations along the southern half of the
northern Ecuadorian coast and in the Gulf of Guayaquil. There are substantial
stretches of rocky shores scattered throughout the coast. The longest uninterrupted
areas occur in the central coast of Ecuador. Long stretches of sandy beaches are
mostly concentrated along the northern-central Ecuadorian shorelines. Coral reef
development in this region is prevented by unfavorable conditions that result from
freshwater input from river runoff, siltation, nutrient enrichment, and upwelling
influences. The majority of reef habitat in this region consists of rocky reefs.
Suitable conditions for coral development and persistence are found around islands
and rocky promontories located away from the central mainland coast, such as Isla
de la Plata, Isla Salango, and Bajo Montañita.
According to the classification of climate and life zones proposed by Cañadas
(1983) and Sierra (1999) there is a gradient in rainfall levels from north to south,
with a complex spatial and temporal variation. The northern part is a wet tropical
region (with [2,000 mm yr
-1 of rainfall and without ecologically-dry months
throughout the year) and the central and southern regions, range from a dry
tropical desert to a sub-tropical desert (with \1.9 mm yr
-1 of rainfall). The
monthly maximum temperatures are higher in the central and northern Ecuador
and decrease to the south, at the entrance to the Gulf of Guayaquil. Overall, the
average annual temperature is above 22 °C. The maximum temperatures fluctuate
between 32 and 38 °C and the minimum is around 15 °C. The relative humidity is
above 80 % and with considerable cloudiness. The rainy season runs from January
to April, with temperatures averaging 28 °C. The rest of year includes short rainy
summers and relatively dry seasons.
Oceanography
Ecuador is located at the confluence of two major marine ecosystems: the Pacific
Central American Coastal System and the Humboldt System. The Ecuadorian
184
J. Sonnenholzner et al.
6.1.1 Ecuadorian Continental Shelf
Geography and Climate
The continental coastal territory of Ecuador extends 4,403 km from north to south,
including islands, islets, and estuarine borders. The width of the continental shelf
exceeds 100 km, particularly off the Gulf of Guayaquil (associated with the most
important watershed from the Guayas River basin). The influence of the Guayas
River extends over two-thirds of the surface along the continental coast. This
causes coastal sedimentation, and a complex estuarine-deltaic system, that extends
close to the edge of the continental shelf (Benítez 1995 in Morante-Carballo 2004).
Approximately one-third of the coastline in Ecuador consists of stretches of
mangroves on mudflats, with major concentrations along the southern half of the
northern Ecuadorian coast and in the Gulf of Guayaquil. There are substantial
stretches of rocky shores scattered throughout the coast. The longest uninterrupted
areas occur in the central coast of Ecuador. Long stretches of sandy beaches are
mostly concentrated along the northern-central Ecuadorian shorelines. Coral reef
development in this region is prevented by unfavorable conditions that result from
freshwater input from river runoff, siltation, nutrient enrichment, and upwelling
influences. The majority of reef habitat in this region consists of rocky reefs.
Suitable conditions for coral development and persistence are found around islands
and rocky promontories located away from the central mainland coast, such as Isla
de la Plata, Isla Salango, and Bajo Montañita.
According to the classification of climate and life zones proposed by Cañadas
(1983) and Sierra (1999) there is a gradient in rainfall levels from north to south,
with a complex spatial and temporal variation. The northern part is a wet tropical
region (with [2,000 mm yr
-1 of rainfall and without ecologically-dry months
throughout the year) and the central and southern regions, range from a dry
tropical desert to a sub-tropical desert (with \1.9 mm yr
-1 of rainfall). The
monthly maximum temperatures are higher in the central and northern Ecuador
and decrease to the south, at the entrance to the Gulf of Guayaquil. Overall, the
average annual temperature is above 22 °C. The maximum temperatures fluctuate
between 32 and 38 °C and the minimum is around 15 °C. The relative humidity is
above 80 % and with considerable cloudiness. The rainy season runs from January
to April, with temperatures averaging 28 °C. The rest of year includes short rainy
summers and relatively dry seasons.
Oceanography
Ecuador is located at the confluence of two major marine ecosystems: the Pacific
Central American Coastal System and the Humboldt System. The Ecuadorian
184
J. Sonnenholzner et al.