William Bussing, Scott Smith, Jennifer Hales, Clarice Sandoval
Major Habitat Type
Tropical and subtropical coastal rivers
Drainages flowing into
Pacific Ocean, Golfo de Montijo, and Golfo de Panamá
Main rivers to other water bodies
This ecoregion includes the following drainage basins: Rio Cate, Quebrada Seca, Rio Santa Maria, Rio Tabasará, Rio San Pedro, Rio Ponuga, Rio Tebario, Rio Pavo, Rio Playita, Rio Tonosi, Rio Cana, Rio Oria, Rio Guarare, Rio Honda, Rio La Villa, Rio Parita, Rio Cocle del Sur, Rio Chorrera, Rio Estancia, Rio Anton, Rio Farallon, Rio Chame, and the Rio Sajalices (Smith & Bermingham 2005). The main rivers are the La Villa, Santa Maria, and Cocle del Sur.
This ecoregion lies on the Pacific side of Panama. The western border is formed by the Rio Santa Maria, Rio Tabasará, and Rio San Pedro drainage basins. The Soná Peninsula acts as an effective filter barrier separating this ecoregion with Chiriqui . The Santa Maria ecoregion continues eastward and encompasses the streams of the Azuero Peninsula. The ecoregion’s eastern boundary is situated between Rio Sajalices (Santa Maria ecoregion) and the Rio Capira (Tuira ecoregion ). The ecoregion includes Coiba Island, which lies just off the southwestern coast of Panama.
The north of this ecoregion is flanked by the Cordillera Central. Altitude varies from sea level to 1500 m above sea level, with the highest elevations and mountainous terrain concentrated along the western side (up to 2000 m) of the peninsula (Suzan et al. 2006). Further east is the volcano El Valle, which rises nearly 1200 m. Coiba Island is the largest Pacific coast island in Central America.
The Pacific-oriented rivers of this ecoregion are longer and slower than rivers on the Caribbean side. Their basins are also more extensive. Mostly unnavigable, many originate as swift highland streams, meander in valleys, and terminate in coastal deltas (Library of Congress 1987). The rivers are characterized in general by their abundant flow volume.
The Santa Maria basin is the third largest in Panama (MINSA 2007). The once extensive fresh and brackish coastal wetlands found in the lower courses of the Rio Santa Maria and Rio Villa have since been converted to rice and sugar plantations (Angehr 2005). Near the Rio Santa Maria, Ciénaga de Las Macanas is the largest freshwater wetland remaining in the driest region of Panama (Angehr 2005).
The Santa Maria ecoregion historically consisted of Isthmian-Pacific moist forest throughout the western half of the ecoregion and Panamanian dry forests along the eastern edge. Today, the Azuero Peninsula is a mostly transformed agricultural landscape with low human density and scattered remnants of tropical moist and dry forests. The native vegetation consists predominantly of deciduous trees with some perennial and succulent species, grasslands, and mangrove swamps near the coast (Tosi 1971).
Mature forest covers large expanses of the central and northern part of Coiba Island with over 230 recorded species of plants, a large majority of which are trees and shrubs. The most speciose families are Leguminosae, Rubiaceae, and Melastomataceae. Higher elevation forests are dominated by Calophyllum longifolium, Eschweilera pittieri, Cassipourea elliptica, and Ternstroemia tepezapote, whereas Calophyllum longifolium, Tetragastris panamensis, and Carapa guianensis dominate the surrounding, low-lying forest. Pelliciera rhizophora and Rhizophora mangle are the most common species of the mangrove forests along the southern shore of the island, and freshwater swamps are characterized by high concentrations of Prioria copaifera and Peltogyne purpurea (Perez et al 1996).
Description of endemic fishes
There is one endemic species of primary freshwater fishes in the Santa Maria ecoregion: a characid, Bryconamericus zeteki.
Justification for delineation
Fish provinces from Bussing (1976) were revised and subdivided on the basis of application of a similarity index to sub-basin fish presence/absence data.
Level of taxonomic exploration
The level of taxonomic exploration in this area of Panama is fair. More ichthyological work is required in the drainage basins of the Azuero Peninsula. This is particularly true of the Rio Playita, Rio Pavo, Rio Oria and the Rio Cana drainage basins.
- Bussing, W. A. (1976). "Geographic distribution of the San Juan ichthyofauna of Central America with remarks on its origin and ecology" T. B. Thorson (Ed.) Investigations of Nicaraguan lakes ( pp. 157-175 ) Lincoln, Nebraska: University of Nebraska.
- Smith, S. A. and Bermingham, E. (2005). "The biogeography of lower Mesoamerican freshwater fishes" Journal of Biogeography 32 (10) pp. 1835-1854.
- Angehr, G. R. (2005) \Final Report Waterbirds in Panama\ (Balboa, Panama)
- Delgado, F. (2005). "Informe del estado actual de las colonias de aves acuaticas y especies asociadas en la peninsula de Azuere" Chitre, Panama: Panama Audubon Society.
- Angehr, G.;Kushlan., J. A. (2007). "Seabird and colonial wading bird nesting in the Gulf of Panama" Waterbirds
- Global Amphibian Assessment (GAA) (2008) \Global Amphibian Assessment\ "<"http://www.globalamphibians.org">"
- Hijmans, R. J., S. Cameron and Parra., J. (2004) \WorldClim, Version 1.4 (release 3). A square kilometer resolution database of global terrestrial surface climate\ "<"[http://www.worldclim.org]">" (16 July 2009)
- Ministerio de Salud (MINSA) (2007) \Estudio Técnico – Financiero, Socioeconómico y de Identificacion de Proyectos para PASAP\ Buenos Aires, Venezuela. Halcrow Group Limited.
- Perez, R., R. Condit, S. Aguilar, et al. (1996). "Inventory of vegetation on Coiba Island, Panama: Composition and floristics" Revista de Biologia Tropical 44 (1) pp. 31-40.
- Suzan, G., J. Giermakowski, Thomasz;, J., et al. (2006). "Modeling Hantavirus reservoir species dominance in high seroprevalence areas on the Azuero Peninsula of Panama" American Journal of Tropical Medicine and Hygiene pp. 1103-1110.
- Tosi, J. (1971). "Zonas de Vida: Una base ecologica para investigaciones silvicolas e inventariacion forestal en la Republica de Panama" Rome, Italy: United Nations Development Programme.
- Library of Congress (1987) \Panama\ "<"http://countrystudies.us/panama">" (July 21, 2008)