Esmeraldas-Pacific Colombia mangroves


The Esmeraldas-Pacific Colombia mangroves is an ecoregion of mangrove forests along the Pacific coast of Colombia and Ecuador.
It is threatened by human population growth, leading to over-exploitation for wood and clearance for farming and aquaculture.

Geography

Location

Mangroves are found along the coast of Colombia and Ecuador from the Gulf of Tribugá in the north to Mompiche Bay in the south.
Between these bays there are extensive stands of mangroves in the mouths of the San Juan, Naya, Guapi, Mira and Esmeraldas rivers.
The mangroves cover.
The largest block is the almost continuous strip from the Mataje River to Chanzará bay near Guapi.
In 1996 it was estimated that of mangroves were growing in the four Colombian Pacific coast departments.
The mangroves border the Chocó-Darién moist forests ecoregion along most of the Pacific coast of Colombia.
In the extreme south they border the Western Ecuador moist forests.

Terrain

The ecoregion may be divided into two large zones to the north and south of Cabo Corrientes.
In the northern section the continental shelf is narrow, with the land rising steeply from the shore to around above sea level.
Many small rivers supply clear water to the ecoregion year round.
There are strong low-intensity upwellings along the coast.
The southern section fringes a flat sedimentary coastal plain with a broad continental shelf. There are no coastal upwellings.
Rocks are mostly lutite, sandstone and conglomerates, with some limestone.
The mangroves along the low, alluvial coast that stretches over from Cabo Corrientes into Esmeraldas Province are the largest mangrove area in northwest South America, forming the tidal fringe of the coastal plain wide.
There are large river deltas at the mouths of the Mataje, Mira, Patía, Sanquianga and Guapi rivers, and smaller deltas at the mouths of about 25 smaller rivers.
There provide more fresh water than in the north, and often carry much more sediment.
The mangrove forest strips run parallel to the coast in the southern section and may extend inland for as much as due to the tides.

Climate

The mangroves adjoin wet tropical forest with temperatures over and very high rainfall.
The climate is influenced by the Intertropical Convergence Zone.
Annual rainfall in the northern section is from, while the southern section receives.

Ecology

The mangrove forests may release 8 to 15 tons of organic material per hectare each year, providing food to many other organisms.
The forests play a crucial role as nurseries and food sources for fish, and also protect the coastline from erosion.
The ecoregion is in the neotropical realm, in the mangroves biome.
The Panama Bight Mangroves, a Global ecoregion, contains the Gulf of Panama mangroves, Esmeraldas-Pacific Colombia mangroves, Manabí mangroves and Gulf of Guayaquil-Tumbes mangroves.

Flora

Depending on the local topography and climate, mangrove formations include bar, inverse estuary, coastal, dwarf, border and small island.
Compared to the Caribbean, the Pacific mangroves of Colombia have lower salinity due to the high rainfall and tidal action, and their zoning may be more dependent on stability of the substrate.
The abundant nutrient-rich fresh water results in exuberant growth, with heights over, and high production of organic detritus.
Bromeliads and orchids grow on the trunks of the mangroves, and their branches hold water and falling material.
Mangrove species include mangle caballero, red mangrove, Rhizophora racemosa, Samoan mangrove, nato mangrove, black mangrove, Avicennia tonduzzii, buttonwood, white mangrove and tea mangrove.
The Conocarpus erectus mangroves are rare, found as isolated individuals.
Most of the mangrove forest is a transition zone in which Mora oleifera and Euterpe species dominate.
Mora oleifera is endemic to the Pacific Coast from Parrita in Costa Rica to Esmeraldas in Ecuador.
Further inland there are freshwater marshes with plants such as golden leather fern, Campnosperma panamensis, milk tree and palms such as Mauritiella pacifica, sheath palm and Euterpe cuatrecasa.
Common plants include Amphitecna Gentry, black calabash, Crenea patentinervis, açaí palm, coast cottonwood, Lonchocarpus monilis, Mora oleifera, Pavonia rhizophorae, Phryganocydia phellosperma, mangle marica, Tuberostylis axillaris and Tuberostylis rhizophorae.
Sandy areas have field sandbur, Homolepis aturensis, and climbers such as beach bean, bayhops, fiddle-leaf morning glory, Pectis arenaria and St. Augustine grass.
Bromeliaceae and Orchidaceae epiphytes that invade the canopy include Vrissia grandioliflora, Guzmania musaica and Heliconia bihai.
Core samples have shown that in the south of the Gulf of Tribugá dominant populations of Rhizophora mangroves have been relatively stable for the last 4,500 years.
In recent years abundant Acrostichum aureum have appeared, probably introduced by humans.
In one area of the northern gulf there have been populations of Pelliciera rhizophorae for about 2,600 years, but in another area the mangroves are from recent colonization.

Fauna

The mangroves host invertebrates, shellfish, fish, reptiles, birds and mammals.
The mangrove cockle is important for artisanal fisheries in the south-central region.
Reptiles include iguanas and snakes. Mammals include oncilla, coypu, deer, lowland paca and white-lipped peccary.
The mangroves are refuges for locally or regionally threatened species including bare-throated tiger heron, American yellow warbler, crab-eating raccoon, American crocodile and spectacled caiman.
Common bivalves include Anomia fidenas, Gould's shipworm, pleasure oyster, thin purse-oyster, striate piddock and brown falsejingle.
Common gastropods include mangrove periwinkle, Littorina fasciata, Littorina varia, Littorina zebra, great pond snail, Melampus carolinus, Nassarius wilsoni, ornate nerite, Thais kiosquiformis and Theodoxus luteofasciatus.
Common crustaceans include grapsid crab, Callodes gibbosus, Eurypanopeus transversus, Eurytium tristani, Glyptograpsus impressus, Latreutes antiborealis, Macrocoeloma villosum, Notolopas lamellatus, Panopeus chilensis, Panopeus purpureus, Pinnotheres angelicus, Cangrejo de pantano, Sholometopus occidentalis and Sholometopus rhizophorae''.
The mangrove tree crab is very common.

Status

The World Wide Fund for Nature gives the ecoregion the status "Critical/Endangered".
Mangroves are traditionally used for fuel, construction material, fishing equipment and as a source of tannin.
They are threatened by expansion of towns, aquaculture, unsustainable extraction of wood, overfishing and clearance for farms or coconut plantations.
Domestic and industrial pollution is a growing problem.
The ecoregion is protected in Colombia by the Sanquianga National Natural Park and the Utría National Natural Park.
Civil Society Natural Reserves are also starting to protect parts of northern Colombia.