Macroalgae play an important role in nutrient extraction in coastal environments, and their role in carbon sequestration resisting global warming are promoted. At the same time they are affected by the environmental factors impacted by climate change. Zhang et al. found Sargassum fusiforme cultivation could increase DO and pH levels and decrease nitrogen and phosphorus levels in addition to enhancing phytoplankton community biodiversity, which was an effective approach for mitigating environmental problems in marine ecosystems. Broch et al. used a high resolution coastal and ocean hydrodynamic model system to investigate the transport and deposition patterns of Particulate Organic Matter (POM) from kelp farm. They underscore the dispersal and deposition of detritus from kelp cultivation associated environmental risks posed by organic loading, and the potential for seafloor carbon sequestration by kelp farming as a nature based climate solution. Endo and Gao reviewed the interactive effects of warming and nutrient enrichment on macroalgae production. They predicted that global warming would enhance bottom-up effects on primary production in cold seasons and areas, and there would be a negative warming effect on production in hot seasons and areas, but it might be possible to mitigate this effect by appropriate levels of nutrient enrichment.

Shellfish aquaculture interacts with marine ecosystems through processes like nutrient cycling, trophic recourses, substrate engineering etc. Sean et al. proved that the mussel farm enriched benthic communities at line- and bay-scales Îles de la Madeleine, eastern Canada. Spatial structure in the distribution of macrofauna was evident within the aquaculture lease as most species were more abundant directly below and close to mussel lines and anchor blocks. At the same time, oyster farm can provide habitat for marine organisms and increase the biodiversity of microbenthic animals. Chan et al. assessed the biodiversity associated with an abandoned benthic oyster farm. The oyster farm provided habitat and trophic support for associated benthic macrofauna. It showed that oyster aquaculture could improve the restoration potential of oyster reefs. There is also other impacts of aquaculture on the wild animals. Drolet et al. found the aquaculture-related diets from shellfish farm and salmonid farm had different effects on the long-term performance and condition of the rock crab (Cancer irroratus). The mussel-only diet impact little on the crabs, whereas the salmonid feed diet resulted in negative impacts on condition. However, the impacts should be investigated in wild environment in the future.

Bivalve aquaculture plays a role in nitrogen extraction. Guyondet et al. used coupled hydro-biogeochemical modeling to integrate all relevant interactions in the assessment of bivalve culture as a nitrogen extraction solution, which provided a new method to assess the eutrophication mitigation. Bivalve culture was shown to provide a net nitrogen removal in the majority of the tested scenarios. Mussel rather than oyster farming provided the strongest potential for nutrient loading mitigation.

The buried bivalve could increase sediment mineralization process. However, they were adversely affected by decreased dissolved oxygen and increased hydrogen sulfide in the sediment induced by marine heat wave, which was proved by Liu et al. from the behavior and physiological metabolism aspects of Manila clam (Ruditapes philippinarum).

Artificial reefs are popularly used in the enhancement of sea cucumber (Apostichopus japonicus). Xu et al. found that the sea cucumber farm provided spawning and first-year nursery grounds for wild black rockfish (Sebastes schlegelii) in Bohai sea, China. The same time, the increased black rockfish could affect other organisms, including crustacea, mollusk and Hexagrammos otakii, in both positive and negative way. So, the interaction effects between sea ranching and wild organisms need further research.

Polyculture is an important concept in acheiving sustainable development of aquaculture. The well known and successful polyculture example is the shellfish-macroalgae integrated multi-trophic aquaculture (IMTA) (Fang et al., 2016). Liu et al. found the macroalgae and shellfish-macroalgae aquaculture waters absorbed CO₂ from atmosphere by determined the carbonate system and pCO₂ in Sanggou Bay, China. Jiang et al. found that the presence of kelp in integrated aquaculture may help shield oyster from the negative effects of elevated seawater pCO₂, which was due to the kelp improving pHNBS in the enriched CO₂ experimental system, and then the oyster could keep a relevant normal clearance rate and scope for growth. In the polyculture pond, Feng et al. constructed three Ecopath models representing the early, middle, and late culture periods of a Portunus trituberculatus polyculture ecosystem, respectively. The results demonstrated that detritus was the main energy source in this polyculture ecosystem. R. philippinarum had a dominant influence on phytoplankton community dynamics which changed from nano- to pico-phytoplankton predominance, from the middle to the late period. The ecosystem stability was decreasing during the culturing period, but it can be optimized by stocking more R. philippinarum and involving macro-algae in the pond.

JF and FW wrote the editorial. ØS and DL contributed to review and correct the editorial. All authors approved the submitted manuscript for publication.

The editorial was funded by the National Key Research and Development Program of China (Grant number 2019YFD0900803), the National Natural Science Foundation of China (Grant number 42276123, 41876185) and the Environment and Aquaculture Governance—EAG phase III (Norwegian Ministry of Foreign Affairs, Grant number CHN-17/0033).

Authors are grateful to Thimedi Hetti for the help of organizing the Research Topic.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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