Ecological carrying capacity of shellfish aquaculture: An ecosystem-quality approach in the Changshan Archipelago, China

An assessment of ecological carrying capacity is crucial to the sustainable development of aquaculture, the protection of ecosystems, and the facilitation of regional development. We established a novel ecosystem quality-based method for assessing aquaculture capacity. This method involves first developing comprehensive ecosystem quality indicators through scenario simulations and then combining them with principal component analysis (PCA) to determine the aquaculture density for ecological carrying capacity. We found that different simulated shellfish stocking densities resulted in complex response patterns among ecosystem indicators rather than simple linear relationships. Specifically, energy flow diversity reached its maximum at 40 % of the current stocking density, and the information capacity was 1.1 times greater than the current stocking density value. The relative degree of polymerization index first decreased but then increased, with its lowest value (29.52 %) occurring when it was approximately 10 % lower than the current stocking density. Various scenarios revealed optimal stocking conditions that produced the highest ecosystem quality. By employing an ecosystem quality method, we determined the shellfish ecological carrying capacity in the Changshan Archipelago waters to be 33.58 t/km², which is approximately 73.3 % of the current stocking density. The connectivity index, diversity index, and information index increased significantly under the ecological carrying capacity scenario relative to their current values. This method incorporates the strengths of previous simulations while focusing on marine ecosystem quality. Therefore, the ambiguous impacts of shellfish stocking density, incomplete indicators, and subjective evaluation criteria for ecological carrying capacity can be addressed. • Exploring the impact of shellfish aquaculture through multi-scenario simulations. • Establishing a new ecosystem quality-based assessment method of aquaculture capacity. • The novel method was used to estimate the ecological carrying capacity.