Harnessing Population Genomics, Gut Microbiota, and Environmental <scp>DNA</scp> Surveillance for the Conservation of Chinese Spotted Seals in a Changing World

The triple planetary crisis-encompassing climate change, biodiversity loss, and pollution-poses escalating threats to Earth's systems, particularly impacting marine mammals. The spotted seal (<i>Phoca largha</i> Pallas 1811), currently recognized as the only pinniped species known to breed in China, holds the status of a National Grade I protected species in China. To elucidate the genetic diversity of Chinese spotted seal populations and provide scientific foundations for their conservation and management, this review systematically summarized the fundamental biological characteristics and documented migration routes of spotted seal populations in China, with particular emphasis on reviewing molecular-level research advancements regarding population genetic structure. Early studies primarily employed molecular markers such as microsatellite DNA and mitochondrial DNA (mtDNA), revealing relatively low genetic diversity levels within Chinese spotted seal populations. In recent years, rapid developments in omics technologies have enabled comprehensive investigations into both genomic compositions, as well as gut microbial community diversity and functional profiles of this species. Furthermore, this review critically examined current research limitations and challenges while proposing the potential advantages and developmental trends of environmental DNA (eDNA) technology in future population studies. These technological and strategic advancements are anticipated to significantly enhance survey efficiency and conservation effectiveness for Chinese spotted seal populations.