1.Ocean University of China;2.Zhejiang Ocean University
National Key R & D Program
Artificial reef is an effective practice for improving benthic habitat, benthos diversity, and resource richness. Its ecological effects are closely related to the construction time. In order to explore the effects of construction time on the trophic relationship of macrobenthos, stable isotope technique was used in this study to analyze the trophic structures of macrobenthos and their potential food sources in an artificial reef area based in Furong Island, Laizhou Bay. The trophic level of macrobenthos was also calculated. The results showed that: (1) The δ13C values in macrobenthos from long-age reef area, short-age reef area and control area ranged from -25.08 ‰ to -13.34 ‰, -25.86 ‰ to -17.80 ‰, and -25.39 ‰ to -11.06 ‰, respectively. The δ15N values ranged from 10.73 ‰ to 15.78 ‰, 10.02 ‰ to 14.89 ‰, and 10.17 ‰ to 15.80 ‰, respectively. (2) Compared to short-age reef and control area, the macrobenthos community in the long-age reef area has higher trophic diversity, more diverse trophic niches and more stable of community structures. (3) Macrobenthos were divided into four functional groups based on their feeding habits, including planktophagous group (Pl), carnivourous group (C), detritivorous group (D) and omnivorous group (O). Among the four potential food sources (phytoplankton, zooplankton, particulate organic matter (POM) and sediment organic matter (SOM)), phytoplankton had the highest average contribution (31.40%) rates to the three types of consumers, except for carnivourous group. (4) The trophic levels of consumers in long, short, and control area were 2.0 – 3.83, 2.00 – 3.49 and 2.00 – 3.87, respectively. In addition, higher trophic level predators were observed in long-age reef area, which indicated more complex trophic structure in long-age reef. The results of this study indicated that the construction of artificial reefs could enhance the utilization of carbon sources of phytoplankton by macrobenthos, increase the trophic diversity and richness of macrobenthos community, and increase the numbers of higher trophic animals in the community. Our results provide basic data for the material cycle and energy flow of food web in benthic habitats, and contribute to understand the ecological effects of artificial reef construction and the trophic structure of macrobenthos communities.