|Macrozoobenthos diversity in an oxygen minimum zone off northern Namibia|Zettler, M.L.; Bochert, R.; Pollehne, F. (2009). Macrozoobenthos diversity in an oxygen minimum zone off northern Namibia. Mar. Biol. (Berl.) 156(9): 1949-1961. hdl.handle.net/10.1007/s00227-009-1227-9
In: Marine Biology. Springer: Heidelberg; Berlin. ISSN 0025-3162, more
|Authors|| || Top |
- Zettler, M.L., more
- Bochert, R.
- Pollehne, F., more
A benthological survey in the Benguela upwelling area off northern Namibia (located at 17.3°S and water depth ranging between 26 and 117 m) showed the concentration of dissolved oxygen and the accumulation of organic-rich sediments to control macrozoobenthic community patterns. In contrast to highly biodiverse nearshore areas with well-structured shell deposits of the brachiopod Discinisca tenuis (Sowerby 1847), the benthic community in the oxygen minimum zone (OMZ) decreased strongly in species numbers. Nevertheless, a well-established community ranging from 13 to 31 species persisted. Species densities (300–3,350 ind m-2) and biomass (4–109 g afdw/m2) were surprisingly high for areas with near bottom oxygen concentrations from 0.06 to 0.88 ml l-1. In contrast to OMZ’s of other upwelling areas, where the benthic macrofauna is generally dominated by small-bodied polychaetes, off Namibia larger key organisms like the bivalve Nuculana bicuspidata (Gould 1845) and the snail Nassarius vinctus (Marrett 1877) accounted for a large proportion of the macrozoobenthos >1 mm. This is supposed to have a distinct effect on the functional properties of the sediments.