With many fish stocks subject to over-fishing and marine fisheries in decline around the world, marine ranching is rapidly growing in China as an alternative method to re-establish coastal fisheries and conserve aquatic biodiversity. In China and East Asia, marine ranching has concentrated on a concept of aquaculture-based, artificial habitat-based marine ranching (e.g., buoyant rafts and artificial reefs) and rehabilitation-based marine ranching (e.g., seaweed beds and seagrass). Studies reported that some species of fish feed primarily on zooplankton, which may play an essential role in the future development of marine ranching. To evaluate the effects of facilities associated with marine ranching on zooplankton communities, a case study was conducted in Xiangshan Bay investigating the spatial heterogeneity of zooplankton communities in four different areas: an artificial reef, a kelp (Laminaria japonica)-suspended farming area, a Kumamoto oyster (Crassostrea sikamea)-suspended farm, and a neighboring natural rock reef habitat (control area). The results demonstrated that there were significant differences among the zooplankton communities in different areas. Both the Pielou’s evenness index (J′) and Shannon–Wiener diversity index (H′) in the artificial reef area were lower than those in the control area, while an approximately 134% increase in zooplanktonic numerical abundance was observed in the artificial area compared with that in the control area. The abundance of Centropages abdominalis (Copepoda) in the artificial reef area was 2.28 times higher than in the control area. The artificial reef area was characterized by a dense distribution of eggs and larvae of the Dotted gizzard shad (Konosirus punctatus) and Blackhead seabream (Acanthopagrus schlegelii), which indicated that the artificial reefs did have a positive role in promoting the enhancement of the above species. A decrease in nutrient concentration and an increase in chlorophyll a were detected in the kelp farming area. The concentrations of dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphate (DIP) were significantly lower in the kelp farming area than in control area, which indicated that kelp farming was an effective measure to lessen eutrophication. No measurements of diversity or total zooplankton abundance exhibited significant differences between the kelp farming and control areas. However, a significant regional difference in zooplankton community composition was found. The abundance of Amphipoda (Gammaridae sp. and Caprellidae sp.) was higher in the kelp farming area compared with those of the control area, whereas ichthyoplankton abundance was low in kelp farming. Since oyster cultivation increased the concentration of both DIN and DIP, eutrophication tended to be elevated in the oyster farming area. The abundance of copepods, particularly that of C. abdominalis, was low in the oyster farming area; consequently, the total zooplankton abundance was low. However, the abundances of Caprellidae sp. and Blackhead seabream larvae and eggs were higher in the oyster farming area than in the control area.