Small-Scale Effects of Offshore Wind-Turbine Foundations on Macrobenthic Assemblages in Pinghai Bay, China

In recent years, offshore wind farms in China have developed rapidly, especially in SE coastal regions. The construction of wind-turbine foundations (WTFs) introduces new artificial structures into coastal ecosystems, influencing the surrounding macrobenthos. Small-scale effects on macrobenthic assemblages around a high-rise cap pile WTF in Pinghai Bay, China, were investigated in November 2017 and May 2018, along SW and SE gradients. The macrobenthic abundance increased from 220 +/- 92 individuals (ind) m(-2) at 200 m to 547 +/- 103 ind m(-2) at 25 m from the foundation, and the species number increased from 8 +/- 3 at 200 m to 16 +/- 6 per sample at 25 m from the foundation, whereas the biomass decreased from 17.2 +/- 2 g m(-2) at 200 m to 3.1 +/- 1.4 g m(-2) at 25 m from the foundation. The macrobenthic abundance increased by 94.75% compared with that before the WTF construction. Abundance significantly increased from 179 +/- 115 to 463 +/- 255 ind m(-2) for Annelida, from 62 +/- 56 to 99 +/- 77 ind m(-2) for Arthropoda, and from 4 +/- 3 to 22 +/- 25 ind m(-2) for Echinodermata. However, the abundance of Mollusca decreased from 65 +/- 100 to 14 +/- 22 ind m(-2). Thus, it is likely that most macrobenthos were able to recover quickly after the deployment of WTF, whereas more time might be needed for Mollusca to recover. There was also an obvious shift in species dominance, with Annelida becoming the dominant group (73.28-77.78%) in the macrobenthic community.