Study on attraction effect of artificial reefs vertical plate with different square apertures on Sparus macrocephalus

Construction of artificial reefs is an important measure to restore marine habitats and conserve fishery resources. Reinforced concrete reefs are commonly-used artificial reefs. The square apertures of the reef vertical plates (Side plates and spacer plate) are made of reinforced concrete reefs. The main structure, the square aperture of the vertical plate is an important factor that affects the fish trapping. In order to observe the attractive effects of different square apertures of reef vertical plates for juvenile black sea bream (Sparus macrocephalus), we used different square pore-size to study the attractive effect on the juveniles. The results show that the average occurrence rate of the juveniles was 2.56% in A1 area of blank reef area in the control group, and that of Group B1 (aperture 8 cm) was 9.89%, followed by 9.01% in B3 (aperture 24 m), 7.65% in B2 (aperture 16 cm), 6.80% in B5 (aperture 40 cm) and 5.25% in B4 (aperture 32 cm) after the reef vertical plate was placed. The fish fins were about 2, 6, 4, 10 and 8 times, respectively. Statistical analysis shows that five groups of square aperture vertical plates have certain trapping effect, among which Group B1 with 8 cm hole diameter of reef vertical plate has the best effect, but there is no obvious difference between the square hole diameters of reef vertical plate.