n African Zoology - Movement behaviour of alien largemouth bass in the estuarine headwater region of the Kowie River, South Africa

Volume 50, Issue 4
  • ISSN : 1562-7020
  • E-ISSN: 2224-073X
This article is unavailable for purchase outside of Africa



The movement behaviour of largemouth bass Micropterus salmoides in the estuarine headwater region of the Kowie River, South Africa, was investigated using passive acoustic telemetry. Ten adult fish were tagged and released in four discrete pools below a weir that precluded possible upriver migration. Their residency and movement patterns were monitored using 27 moored acoustic receivers spanning both riverine and estuarine habitats between January and November 2013. Small-scale movements ranging from 50 to 400 m occurred between pools in the headwater region, where tagged fish remained resident (did not leave their tagging pool) during the warmer (summer) months. The onset of autumn and winter correlated with declining water temperatures and half of the tagged largemouth bass made downstream excursions into the slightly warmer upper reaches of the estuary. The penetration of the sealien piscivores into estuarine headwaters potentially provide additional predator pressure on the juveniles of migratory estuary-associated native marine fish species, which utilise these areas as nurseries. The presence of the alien fish in South African estuarine headwaters may impair the migration of juvenile fishes between the estuarine and freshwater environments.

Loading full text...

Full text loading...


Article metrics loading...


This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error