A 20‐year census of a rocky littoral fish community in Lake Tanganyika

Abstract

Takeuchi Y, Ochi H, Kohda M, Sinyinza D, Hori M. A 20‐year census of a rocky littoral fish community in Lake Tanganyika. Ecology of Freshwater Fish 2010: 19: 239–248. © 2010 John Wiley & Sons A/SAbstract – Tropical fish communities are highly diverse with large numbers of allied species coexisting. Concerns have been raised about changes in such communities caused by anthropogenic disturbances, but little is known about long‐term changes. We investigated changes in the littoral fish community of Lake Tanganyika. A 10 × 40‐m quadrat was placed on a rocky shore in the southern part of the lake, and fish censuses were conducted once a year during most years in 1988–2008. In total, 54 cichlid and 6 non‐cichlid species were recorded. Aufwuch feeders were most abundant, followed by plankton feeders, detritus feeders, piscivores, shrimp eaters, zoo‐benthos eaters, and scale eaters. Species richness and abundance were sustained over the study period, with biodiversity, as evaluated by the Shannon–Wiener index, remaining high. However, Mantel tests between the Bray–Curtis index and the difference in years between compared censuses revealed that the species composition of the community gradually changed with time. The fish community gradually underwent a change that may be due to low anthropogenic impacts on food condition. Our results promote awareness about the conservation of diversity in Lake Tanganyika.