Guanglong Qiu

Blue carbon ecosystems are critical biodiversity hotspots facing escalating threats. Coastal and Marine Spatial Planning (CMSP) is a key policy tool for protecting their biodiversity and enhancing ecosystem services, resilience, climate action, and sustainable development. We performed a systematic bibliometric analysis (1981–2025) using the Web of Science Core Collection. The results indicated that global CMSP–blue carbon ecosystems collaborative research exhibits a three-stage evolutionary pattern: the initial phase (2008–2012) of blue carbon concept introduction; the development phase (2013–2018), where research focus shifted to carbon sinks and ecology driven by policy initiatives; and the growth phase (2019–2025), where research focused on precision systematic governance. Research has evolved from baseline ecosystem assessments to policy governance integration, which emerged as a core component of Marine Spatial Planning to advance sustainable development. Research networks exhibit a “center–periphery” pattern. However, the international influence of China’s research output remains limited. Future CMSP collaborative governance will require refining planning frameworks, addressing regional technical adaptation challenges, and establishing a multidimensional policy system to reconcile the effective conservation of blue carbon ecosystems in order to reconcile biodiversity, resilience, and sustainable development. This study maps the CMSP–blue carbon ecosystems research landscape, informing improved climate-friendly marine and coastal spatial planning for enhanced coastal wetland biodiversity and ecological resilience.

Summary: The importance of marine angiosperms, or seagrasses, as foundation species for marine coastal ecosystems is in marked contrast to their low species number of only 70 described taxa. Seagrass species tend to have very similar overall morphologies dictated by hydrodynamic forces of the ocean environment. Moreover, they have inconspicuous and simple flowers, probably due to the absence of flower–pollinator interactions in the sea. We hypothesized that the seagrass species Nanozostera japonica, distributed from tropical to temperate latitudes in the North‐Western Pacific, contains cryptic species. To test this, we assembled two chromosome‐level reference genomes and conducted whole‐genome resequencing at 17 locations throughout its native distribution. We identified two genetically divergent clades in the north and south of its range (hereafter Nj_N and Nj_S) that diverged some 4.16 million years ago. Hybrid individuals at a contact zone were either diploid F1‐crosses or featured triploidy, indicating reproductive isolation. A large (42 Mb) reciprocally fixed chromosomal inversion between Nj_N and Nj_S possibly contributed to the formation of the reproductive isolation. We conclude that the N. japonica species complex is actually consisting of two different species. Further population genomic studies may reveal additional cryptic species, solving the conundrum why there are so few described seagrass species today.

Halophila beccarii is one of the oldest two generations of seagrass plants and one of the 10 species of seagrass currently at risk of extinction worldwide. Therefore, how to effectively protect the H. beccarii resources from extinction is a huge challenge. Molecular biology research can provide a scientific basis for species conservation. So far, there has been no detailed analysis of the mitochondrial genome of the genus Halophila. The mitochondrial genome of H. beccarii was assembled into 28 circular chromosomes, ranging in length from 41,738 bp to 104,744 bp, with a total length of 1,964,072 bp and a GC content of 46.71%. It contains 39 genes, including 26 protein coding genes, 10 tRNA genes, and 3 rRNA genes. Repeat sequence analysis and prediction of RNA editing sites revealed a total of 850 dispersed repeats, 1,205 simple repeats, 61 tandem repeats, and 120 RNA editing sites. Analysis of codon usage indicates that codons ending in A/U are preferred. Gene migration between the mitochondrial genome and the chloroplast genome was observed through homologous fragment detection. In addition, Ka/Ks analysis showed that most protein coding genes in the mitochondrial genome experienced negative selection, while only the nad3 gene experienced potential positive selection in most Alismatales. Nucleotide polymorphism analysis revealed variations in each gene, with rpl10 being the most significant. In addition, comparative analysis shows that the GC content is conserved, but there are significant differences in the size and structure of mitochondrial genomes among different species of Alismatales. The phylogenetic analysis based on the mitochondrial genome reflects the exact evolutionary and taxonomic status of H. beccarii. In this study, we sequenced and annotated the mitochondrial genome of H. beccarii, and compared it with the mitochondrial genomes of other plants in Alismatales. Our findings enrich the mitogenome database of seagrass plants and highlight the potential for mitochondrial genes to help decipher plant evolutionary history.

Ecologically, Halophila beccarii Asch. is considered as a colonizing or a pioneer seagrass species and a “tiny but mighty” seagrass species, since it may recover quickly from disturbance generally. The use of transcriptome technology can provide a better understanding of the physiological processes of seagrasses. To date, little is known about the genome and transcriptome information of H. beccarii. In this study, we used single molecule real-time (SMRT) sequencing to obtain full-length transcriptome data and characterize the transcriptome structure. A total of 11,773 of the 15,348 transcripts were successfully annotated in seven databases. In addition, 1573 long non-coding RNAs, 8402 simple sequence repeats and 2567 transcription factors were predicted in all the transcripts. A GO analysis showed that 5843 transcripts were divided into three categories, including biological process (BP), cellular component (CC) and molecular function (MF). In these three categories, metabolic process (1603 transcripts), protein-containing complex (515 transcripts) and binding (3233 transcripts) were the primary terms in BP, CC, and MF, respectively. The major types of transcription factors were involved in MYB-related and NF-YB families. To the best of our knowledge, this is the first report of the transcriptome of H. beccarii using SMRT sequencing technology.