Estructura de la comunidad y distribución vertical de la macrofauna de fondos blandos en isla Gorgona, Pacífico Colombiano

Abstract

Community structure and vertical distribution of the soft bottom macrofauna on Isla Gorgona, Colombian Pacific. Soft bottoms are important in marine ecosystems but their ecology have been less studied in the tropics than in temperate areas. This article describes the temporal, spatial, and vertical distribution of the community structure of subtidal soft bottom macrofauna on Isla Gorgona, Colombian Pacific. Samples were collected in March and June 2011 by corers at 10m depth at five points around the island. Seventy-three species were recorded; polychaetes (55%) and crustaceans (30%) were the dominant groups in number of individuals. The community structure assessed by classification and ordination analysis did not change temporarily, but it shows differences between sampling points, due to the structure of the substrate. The highest abundances of macrofauna were recorded at points with dominance of fine particles (Farallones). However, another point with a similar substrate (Planchón) showed low abundance, apparently due to bioturbation exerted by the fish Heteroconger sp. The presence of Heteroconger sp. in El Planchón could also affect the vertical distribution of the macrofauna, where their relative abundance was homogeneous across the analyzed layers (1-2-3-4-5-10cm). In the other four sites, the abundance of the macrofauna was mainly limited to the first two centimeters of the sediment. Playa Blanca and Remanso showed substrates composed mainly of gravel, recording at the last sampling point the lowest richness, diversity and abundance. Rev. Biol. Trop. 62 (Suppl. 1): 169-188. Epub 2014 February 01.

Landscape context and nutrients modify the effects of coastal urbanisation

“…Los peces capturados hacen parte de la fauna acompañante de la pesca de arrastre artesanal cuyo principal objetivo es el camarón (Díaz-Ochoa et al, 1997;Diaz-Ochoa, 1997). Sin embargo, la pesca en la bahía de Tumaco se clasifica como multiespecífica, caracterizada por una alta diversidad de especies de peces que pueden explotarse comercialmente Velasco & Wolff, 2000). Se evidenció que las familias más representativas en cuanto a número de individuos para la pesca artesanal fueron Sciaenidae, Haemulidae, Ariidae, Engraulidae y Achiridae.…”

“…Se evidenció que las familias más representativas en cuanto a número de individuos para la pesca artesanal fueron Sciaenidae, Haemulidae, Ariidae, Engraulidae y Achiridae. Una característica común de estas familias es que presentan hábitos costeros y de poca profundidad, la familia Engraulidae (pelágica-nerítica), Sciaenidae y Haemulidae (demesarpelagicas) y finalmente Ariidae y Achiridae (bentónicas) (Ayala-Perez et al, 2017;Velasco & Wolff, 2000). Estos resultados difieren un poco a los encontrados en desembarques de la pesca artesanal en la bahía de Tumaco, donde las familias Sciaenidae, Ariidae y…”

New record of Hyachelia tortugae Barnard, 1967, an amphipod epibiont on green turtles Chelonia mydas (LINNAEUS, 1758) from Gorgona island (colombian pacific)

“…Knowledge of gammarid amphipod diversity in Colombia and in particular in the Colombian Pacific is scarce. Gammarids of Gorgona Island (2° 58' 00" N and 78° 11' 24" W), a protected area in the Colombian Pacific belonging to the Eastern Tropical Pacific Marine Corridor, have been mainly identified to family level (CORTÉS et al, 2012;VALENCIA et al, 2014), and only a few studies have reached lower taxonomic levels (BARNARD, 1967a;VALENCIA et al, 2014). We present a new record for the Colombian Pacific of the gammarid amphipod Hyachelia tortugae Barnard, 1967.…”