Relation between Aggregating Effect of Artificial Fish Reef and Flow Pattern around Reef

The aggregation effect of the artificial fish reef was investigated through numerical simulation and experiments in the field and the laboratory. When compared with the measured probability of existence of young red seabream and black seabream around the model fish reef in the laboratory with the calculated flow pattern, it is found that the provability of existence of black seabream in the upstream side is higher than that of red sea bream. This comes from the difference in the swimming ability of both fishes. Around the artificial fish reef in the field, it was observed various fishes of all types more than 25 species. Each species exists in a specific region of the reef that toughly corresponds to the calculated flow velocity.