Quantitative Biological Assessment of a Newly Installed Artificial Reef in Yenne, Senegal

An artificial reef project was initiated in the coastal area of Yenne Village on the central coast of Senegal in June 2004 in response to a strong demand for coastal fisheries management and resource conservation in Senegal. The artificial reef consisted of 400 gabions and 75 concrete cubes installed in a 570 m super(2) area. We used a modified point-stationary census method with video analysis to quantify fish abundance over a summer and winter season. The results showed a strong tendency for fish aggregation around the artificial reef, while fish aggregation was negligible at the control site. Estimated fish biomass at the artificial reef increased from 0 to 1.7 tn only 1 mo after construction of the artificial reef. The biomass then decreased to around 300 kg in winter. The total fish biomass significantly differed over time (H = 11.674, p < 0.05). At the control site, the biomass was very low in July 2004 (0.8 plus or minus 0.3 kg), and this trend was maintained throughout the study period. This is the 1st study to quantify fish abundances on an artificial reef in the West African region. Such information is important for assessing the effectiveness of artificial reefs in enhancing marine resources in habitat-limited coastal areas.