The Galapagos coastal area is the most studied of the Galapagos Marine Reserve (GMR) and also the most vulnerable to impacts since it is where the greatest part of human activities takes place (fishing, tourism, leisure, etc.). Edgar et al. (2004) analysed shallow subtidal rocky reef coastal biodiversity data (fish and macro-invertebrate communities) collected in 2000-2001 in order to derive regional biogeography areas. Sampling units consisted of 50 m x 10 m line transects for fish and 50 m x 2 m line transects for macro-invertebrate species (sea cucumbers, sea urchins, octopus, lobsters, large gastropods, etc.) at various depths between - 2 and - 20 m and distributed along the coastal subtidal area of 50 islands and islets of the Galapagos. A multivariate analysis of the data resulted in the identification of three major biogeographical regions: the Far-northern islands of Darwin and Wolf; the Central-south-eastern islands, including the east coast of Isabela; and the Western region, comprising Fernandina and the west coast of Isabela. The Central-south-eastern region could be further divided in two, namely the Northern region, including the islands of Pinta, Marchena and Genovesa; and the Central-south-eastern region, including the islands of Santiago, Rábida, Pinzón, Santa Cruz, Baltra, Santa Fe, San Cristóbal, Floreana, Española and the eastern side of Isabela. Another region could be further identified in the Western region, the Elizabeth region, covering an area comprising the Bolivar channel and Urbina and Elizabeth bays down to Punta Moreno in Isabela and Punta Mangle in Fernandina. Edgar et al.'s study is one of the most cited marine studies in the Galapagos. However, the authors only included a small scale map and a written description of the bioregions geographical limits within the GMR but did not include a detailed paper or digital map. Here, I provide an interpretation of the bioregions identified in Edgar et al.'s study based on the figure and the descriptions included in it. The resulting data set is a GIS layer in ArcGIS shapefile format, EPSG 32715 (WGS 1984/UTM Zone 15S) and a Google Earth layer in KMZ format of the GMR shallow subtidal rocky reef bioregions based on fish and macro-invertebrate data. The layers include attribute information on bioregion name and area (in square km). This dataset will be of most utility to those attempting to use Edgar et al.'s Galapagos bioregions in their analyses since it provides for a consistent use of bioregion boundaries.
Reference: Edgar, G. J., Banks, S., Fariña, J. M., Calvopiña, M., and Martínez, C. (2004, doi:10.1111/j.1365-2699.2004.01055.x).
This publication is contribution number 2294DS of the Charles Darwin Foundation for the Galapagos Islands.
