Composition, distribution, and diversity of pelagic fishes around the Canary Islands, Eastern Central Atlantic

Abstract

Oceanic islands of volcanic origin have a narrow shelf and a steep slope that should lead to considerable spatial overlap among coastal and oceanic fauna. During six pelagic surveys in the Canarian archipelago, Eastern Central Atlantic, over 65,000 fishes belonging to 211 species were collected at depths between 8 and 1035 m. The mesopelagic families of the lanternfishes (Myctophidae) and the bristlemouths (Gonostomatidae) accounted for about 50% of all specimens. By multivariate classification and ordination methods four different assemblages associated with mesopelagic, epipelagic–oceanic or coastal habitats could be identified. Two of these assemblages were coastal, differing in the proportion of meso- and epipelagic species. These data indicate intense horizontal migrations of mesopelagic fishes (mainly Myctophidae) into the neritic realm and increased interactions between coastal and oceanic habitats. Alpha diversity indices were higher and dominance was lower in oceanic habitats compared to the coastal realm. No marked differences among oceanographically similar areas of the entire archipelago were found. Beta diversity as a measure of similarity among sites or samples revealed variabilities between areas south of Gran Canaria and Fuerteventura islands. A considerable heterogeneity in species distribution was found off SE Fuerteventura in an area with high hydrographic variability. Therefore, both topography and hydrography are important factors influencing the distribution and abundance of pelagic fishes in this oceanic archipelago.

Keywords:

• Atlantic
• Canary Islands
• diel migrations
• diversity
• mesopelagic fishes
• myctophidae

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark

Acknowledgements

All surveys were carried out in projects supported by the Viceconsejería de Pesca del Gobierno de Canarias. Rupert Wienerroither got financial support from the ‘Stiftungs- und Förderungsgesellschaft der Paris-Lodron Universität Salzburg’. Sincere thanks to all colleagues at the Zoological Museum Copenhagen (ZMUC) and the University of Salzburg, especially A. Lametschwandtner and J. Strobl.

Notes

Published in collaboration with the University of Bergen and the Institute of Marine Research, Norway, and the Marine Biological Laboratory, University of Copenhagen, Denmark