Artificial reefs can mimic natural habitats for fish and macroinvertebrates in temperate coastal waters of the Yellow Sea

Abstract

The deployment of artificial reefs to enhance the abundance of reef-associated species in the coastal waters of China occurs on a very large scale. However, the ability of these artificial structures to mimic natural habitats for fauna has not been evaluated. This study examined the benthic fish and macroinvertebrates assemblages (sampled using trap nets) of artificial reef complexes deployed in shallow, nearshore (9–11 m) and deeper, offshore waters (20–30 m) in the Lidao artificial reef zone (Yellow Sea, China) to determine whether they differed from assemblages on adjacent habitats: i.e. natural reefs in nearshore and bare substratum in offshore waters. It also investigated the extent of any temporal variation in these assemblages. A greater total number of taxa were identified in offshore than nearshore waters, but nearshore waters supported higher total mean numbers and biomass. No significant differences were detected in the characteristics of the benthic fish and macroinvertebrate fauna between artificial reefs and their corresponding natural habitats in both depths. Faunal composition in both depths showed strong patterns of temporal variation, mainly due to changes in the abundance of some transient fish species such as Conger myriaster and Pseudopleuronectes herzenstein, which matched seasonal patterns in water temperature and clarity. The similarity of community structure between nearshore artificial reefs and natural habitats implies that the artificial reefs are mimicking natural habitats, which facilitates functional connectivity. Thus, in the Lidao artificial reef zone, artificial reefs and natural habitats can be considered as integrated habitat management units. In the offshore waters, however, the lack of a difference in composition between habitats possibly reflects the observed sinking of the artificial reefs. This highlights the importance of detailed site assessments before the deployment of artificial reefs, particularly in silty sediments.