An ecological element for selecting enhancement stock based on the stability of nekton community structure

The abundance-biomass comparison curves (ABC curves) method was adopted to analyze the temporal stability of the fish and nekton community structure in Laoshan Bay, China, during the spring and summer seasons from 2013 to 2015. This study aimed to explore the feasibility of using stable species in the nekton structure as stock enhancement candidates and to enrich the guidelines for responsible stock enhancement. Results showed that the W-statistic values of ABC curves for nekton were generally higher than those for fish across the three years’ spring and summer seasons. For fish, the biomass curves were often located below their abundance curves; in contrast, the biomass curves of nekton were generally positioned above their abundance curves or intersected with them. These findings indicated that the nekton community structure was more complex and stable than that of the fish community. Portunus trituberculatus played an important role in maintaining the stability of nekton community structure during spring and summer. Therefore, stock enhancement of P. trituberculatus in Laoshan Bay every spring could improve the stability of nekton community structure in the subsequent summer through trophic relationships. Given that ABC curves have a solid ecological theoretical basis, the stability of nekton structure could be one of joint ecological elements for selecting stock enhancement species.