Aerial photograph of the Bocas del Toro Archipelago. Panama. Source: C.Michael Hogan

Bocas del Toro-San Bastimentos Island-San Blas mangroves is one of the ecoregions of Panama, situated on the Caribbean coast of northern Panama. Precipitation in this region, entirely in the form of rainfall, amounts to approximately 6000 mm per annum. This ecoregion is largely comprised of mangrove swamps and contains an extensive coral reef system ^[1] that protects the mangroves by moderating ocean wave action; in turn the mangroves trap sediment and promote water clarity than enhance coral reef development. Extensive submerged areas of this ecoregion are considered seagrass meadows, a highly biodiverse ;;marine biodiversity|marine ecosystem]] that has high primary productivity as well as considerable species richness In the shallower waters are found manatee along with numerous corals, sponges, pipefishes and baracuda. The deeper coastal waters are habitat for dolphins, most notably at Dolphin Bay, somewhat south of Bastimentos Island.

Coral reefs

The inshore reefs along the Bocas del Toro mainland have been severely impacted from sediment loading of surface runoff related to banana plantations, leading to a live coral fraction of about 25 percent. At least 64 different species of coral have been identified in the Bocas del Toro near shore mainland area. More than 120 species of sponge organisms are found in the shallow coastal region around the reefs. ^[2] West IndianManatees, Trichechus manatus, are found feeding in the shallow seagrass areas. Numerous fishes are found in the shallow reef waters including barracuda and pipefishes.

Terrestrial ecology

Spectacled Caiman in the wild on Bastimentos Island. Source: C. Michael Hogan

The dominant shoreline feature is the presence of Red Mangrove trees, whose submerged roots stabilize the shoreline. The near coastal zone and low elevation upland areas of this ecorefion also support a host of other flora, as well as birds, mammals, amphibians and arthropods.

Birdlife at the coastal upland and rich coastal riparian zone and other near shore upland habitats is quite diverse. ^[3] A notable terrestrial bird endemic to the Bocas del Toro region is the Brown Parakeet. ^[4] Another notable bird found in this ecoregion is the Pale-billed woodpecker, Campephilus guatemalensis, a large bird, who is found at the southern limit of his range here. The White-fronted nunbird, Monasa morphoeus, is a near passerine species found at the moist lowland forest edge, including secondary growth. Another bird found here that is tolerant of degraded forest is the Crimson-fronted parakeet, Aratinga finschi. A specialist bird to the mangroves and also dense somewhat upland areas of Bocas is the Rufous-necked wood-rail, Aramides axillaris. The Bare-necked umbrella bird is normally found at the higher elevation margin of the Bocas area, but can often be found in the near coastal fringe in non-breeding season. ^[5]

Mammalian species include the Collared-peccary, who may be found in mainland Bocas del Toro lowland moist forest or grasslands.^[6] Also found here is the critically endangered Pygmy three-toed sloth, Bradypus pygmaeus, ^[7] whose extant population of no more than a few hundred animals is restricted to the tiny (3.4 km²) island of Isla Escudo de Veraguas. There are also Central American red brocket, Mazama temama, a species of forest deer widespead in Mesoamerica.

Exploration history

Mangroves of leeward sheltered fringes of Bastimentos Island. Source: C.Michael Hogan

Christopher Columbus probed the coastal area at present day Bocas del Toro as early as the years 1501 to 1503 AD, while searching for a fabled passage to the Pacific Ocean. Damphier made detailed notes of the relentless hunting of manatee and marine tortoises by the Moskito Amerindians as early as 1698, noting that a canoe with two men would easily kill two manatees in one day with a harpooning technique. In colonial times, Bocas del Toro was considered a part of Veraguas. Later in the era of the union with Colombia, the government created a reservation with the name Bocas del Toro in 1834. In the year 1850, Bocas del Toro became a part of Chiriqui; thereafter, Bocas was separated from Chiriqui and became part of Colon. Josef von Warcewicz was a mid nineteenth century European biological explorer, whose specialties were orchids and hummingbirds. He ventured further into western Panama than any previous scientist, probing not only the Volcan Baru area, but reaching the Caribbean shores at Bocas del Toro, where he was one of the first to classify a large number of species in the Bocas del Toro area. ^[8]

Geology and hydrology

The geological formation of this portion of Mesoamerica is best explained as tectonic uplift associated with plate collisions between the Cocos and Caribbean plates and accompanied by a volcanic chain known as the Central American Arc. ^[9] This uplift conjoined with volcanic eruption created the subsequent land formation approximately 3.5 million years ago above an ancient seabed that once separated the North and South American continents. Some of the best evidence of dating the formation of this land is from the literature on brachiopod fossil recovery, where species date to the early Pleistocene. ^{[10] [11]} In particular species of Argyrotheca and Tichosina have been found within the Nancy Point Formation in Bocas del Toro.

References

1. ^ Mark Spalding, Corinna Ravilious and Edmund Peter Green. 2001. World Atlas of Coral Reefs. 424 pages
2. ^ Oceanoraphic literature review, Vol 53, Issues 289105800. page 557
3. ^ Burton Le Roy Gordon. 1982. A Panama forest and shore: natural history and Amerindian culture in Bocas del Toro. page 103
4. ^ Robert S. Ridgely and John A. Gwynne. 1992. A Guide to the Birds of Panama{ With Costa Rica, Nicaragua and Honduras. page 174
5. ^ Charles Gald Sibley and Burt Leavelle Monroe. 1990. Distribution and taxonomy of birds of the world. 1111 pages
6. ^ Rupert Leon Wenzel and Vernon J. Tipton. 1966. Ectoparasites of Panama. 861 pages
7. ^ Edward Alphonso Goldman. 1920. Mammals of Panama: (with thirty-nine plates). 309 pages
8. ^ S.Heckadon-Moreno. 2004. Naturalists of the Isthmus of Panama. Smithsonian Tropical Research Institute
9. ^ Yoshiyuki Tatsumi and Steve Eggins. 1995. Subduction zone magmatism. 211 pages
10. ^ Trevor A. Jackson. 2002. Caribbean geology: into the third millenium. 279 pages
11. ^ L.S. Collins. 1993. Neogene paleoenvironments of the Bocas del Toro Basin, Panama. Journal of Paleontology. 67:699-710