Potential spawning grounds of phytophilic fish under a shifting hydrological regime in Poyang Lake, China

The quality and effectiveness of fish spawning grounds are of great significance to the conservation of freshwater systems, and the distribution of spawning grounds is critical to clearly identify. This study combines a hydrodynamic model and satellite imagery to determine potential spawning grounds in the largest freshwater lake in China. Results revealed that the increase in vegetation in Poyang Lake led to an expansion of potential spawning grounds towards the centre of the lake due to a water level decrease since 2000. The mean spawning grounds area in Poyang Lake declined from 482.51 to 814.40 km(2) after 2005 and average bathymetry decreased from 12.29 to 10.49 m. The current nature reserve holds 18.26% of the total spawning grounds, while sub-lakes hold 34.02% of the total. The constant area of spawning grounds under typical scenarios should be the baseline for future conservation.