Impacts of trout on aquatic macroinvertebrates in three Drakensberg rivers in KwaZulu-Natal, South Africa

  • NA Rivers-Moore
  • B Fowles
  • B Fowles
  • RJ Karssing
  • RJ Karssing

Abstract

Global literature suggests that trout, when introduced as alien species into local streams, have had deleterious impacts on aquatic community structure and function. Prior to defining management actions regarding trout in the rivers of the Ukhahlamba-Drakensberg Park (UDP), data are required on their impacts on local aquatic communities. In February 2007, aquatic macroinvertebrate communities were sampled at three locations in streams in the UDP. Paired sites were separated by waterfalls, with no trout occurring upstream but occurring at low densities downstream. Differences in aquatic macroinvertebrate communities between upstream and downstream sites were apparent but, within the constraints of this study, such differences could not be directly attributed to trout predation. Further studies are recommended in order to provide additional information on seasonal variation in these patterns, as well as on density-dependent effects of trout on aquatic macroinvertebrate communities.

Keywords: management, Oncorhynchus mykiss, Salmo trutta, Ukhahlamba-Drakensberg Park, waterfalls

African Journal of Aquatic Science 2013, 38(1): 93–99

Author Biographies

NA Rivers-Moore
Centre for Water Resources Research, University of KwaZulu-Natal, Private Bag X01, Scottsville 3209, South Africa
B Fowles
Envirocare Environmental Consultants, 6 Shortlands Ave, Hillcrest 3610, South Africa
B Fowles
Envirocare Environmental Consultants, 6 Shortlands Ave, Hillcrest 3610, South Africa
RJ Karssing
Ezemvelo KZN Wildlife, PO Box 13053, Cascades 3202, South Africa
RJ Karssing
Ezemvelo KZN Wildlife, PO Box 13053, Cascades 3202, South Africa
Published
2013-03-06
Section
Articles

Journal Identifiers


eISSN: 1727-9364
print ISSN: 1608-5914