Mapping the biodiversity conservation gaps in the East China sea.

Being one of the most productive China seas, the East China Sea is facing the challenge of unprecedented biodiversity loss and habitat degradation under the dual pressure of anthropogenic disturbance and climate change. Although marine protected areas (MPAs) are considered an effective conservation tool, it remains unclear whether existing MPAs adequately protect marine biodiversity. To investigate this issue, we first constructed a maximum entropy model to predict the distributions of 359 threatened species and identified its species richness hotspots in the East China Sea. Then we identified priority conservation areas (PCAs) under different protection scenarios. Since the actual conservation in the East China Sea is far from the goals proposed by Convention on Biological Diversity, we calculated a more realistic conservation goal by quantifying the relationship between the percentage of protected areas in the East China Sea and the average proportion of habitats covered for all species. Finally, we mapped conservation gaps by comparing the PCAs under the proposed goal and existing MPAs. Our results showed that these threatened species were very heterogeneously distributed, and their abundance was highest at low latitudes and in nearshore areas. The identified PCAs were distributed mainly in nearshore areas, especially in the Yangtze River estuary and along the Taiwan Strait. Based on the current distribution of threatened species, we suggest a minimum conservation goal of 20.4% of the total area of the East China Sea. Only 8.8% of the recommended PCAs are currently within the existing MPAs. We recommend expanding the MPAs in six areas to achieve the minimum conservation target. Our findings provide a solid scientific reference and a reasonable short-term target for China to realize the vision of protecting 30% of its oceans by 2030.