20-year census of Lake Tanganyika fish


Japanese scientists carrying out a two-decade survey of a patch of rocky shoreline in Lake Tanganyika have recorded significant changes in the fish community, according to a paper published in the most recent issue of the journal Ecology of Freshwater Fish.

Yuichi Takeuchi and coauthors arrived at this conclusion surveying the diversity and abundance of the fish community in Kasenga Point at the southern end of Lake Tanganyika from 1988–2008. 

The authors recorded a total of 54 cichlid and six non-cichlid fish species over the entire period of the survey, with aufwuchs feeders being the most abundant type of fish present. 

Although the species richness and abundance of fishes were relatively constant over the study period, the authors found the density of the aufwuchs feeders and invertebrate eaters to decline over the survey period, followed by a concomitant increase in the density of detritus feeders. 

The authors hypothesise that this change in composition might be due to anthropogenic disturbance such as deforestation and agriculture causing sediment loading in Lake Tanganyika to increase, although they could not rule out natural variation in the community structure as the primary cause.

For more information, see the paper: Takeuchi Y, H Ochi, M Kohda, D Sinyinza and M Hori (2010) A 20-year census of a rocky littoral fish community in Lake Tanganyika. Ecology of Freshwater Fish 19, pp. 239–248.6001