Short-Term Effects of Artificial Reef Construction on Surface Sediment and Seawater Properties in Daya Bay, China

The degradation and modification of habitats are dominant drivers of biodiversity fluctuation, which is increasingly threatened in marine ecosystems (especially coral reefs) and can be mitigated by the construction of artificial reefs (ARs). Environmental indices are considered excellent indicators of how disturbances affect organisms, but the effects of AR construction on nearby sediment and seawater environments remain unclear. In the current study, changes in the properties of surface sediment and seawater (surface and bottom) for 2 years following AR construction were investigated in Daya Bay, China. The reef habitat and the nearby nonreef habitat were sampled. The results indicated that surface sediment organic matter significantly increased but sediment texture did not change following AR construction, regardless of habitat. The pH, dissolved oxygen, and salinity significantly declined, but chemical oxygen demand, inorganic nitrogen, and suspended particulate organic matter significantly increased in both surface and bottom seawater, regardless of habitat; temperature, nitrogen/phosphorus ratio, and available phosphate were not consistently altered by AR construction. Considering the intimate relationships between abiotic factors and organisms, these results indicate that long-term assessment of multiple environmental properties is needed to evaluate and predict the effects of AR construction on marine wildlife.