This Perspective introduces the “Mariana Trench Environment and Ecology Research (MEER)”, the first systematic study of hadal ecosystems (>6,000m) in the Mariana Trench. Using China’s “Fendouzhe” submersible (2021), 33 dives collected 227 sediment cores, seawater, and macrofauna (amphipods, snailfish). Key findings: (1) Microbial diversity—extreme novelty and adaptation to ultrahigh pressure, revealed by 92 Tb metagenomic data; (2) Macrofauna evolution—horizontal gene flow in amphipods and vertebrate colonization by snailfish; (3) Ecosystem connectivity—trenches link surface oceans and Earth’s interior, hosting microbial hotspots driving biogeochemical cycles. MEER’s open-access databases and methodologies redefine the hadal zone as a dynamic, biodiverse frontier critical to Earth’s processes.
MEER microorganisms: All data can be viewed in NODE (http://www.biosino.org/node) by pasting the accession OEP004067 into the text search box or through the URL: https://www.biosino.org/node/project/detail/OEP004067 and has been deposited at CNSA with the accession CNP0004890 (https://db.cngb.org/search/project/CNP0004890/)
Amphipod: The raw genomic data, genome assemblies, and annotations have been deposited to the China National GeneBank (CNGB) Sequence Archive (CNSA) with accession numbers CNP0003471 and CNP0005374 (https://db.cngb.org/search/project/CNP0003471/ & https://db.cngb.org/search/project/CNP0005374/)
Fishes: The raw data have been deposited at NCBI with the accession number PRJNA1138967 (https://www.ncbi.nlm.nih.gov/bioproject/PRJNA1138967)
Xiao, X., Wang, J., & Ding, K. (2025). MEER: Extraordinary flourishing ecosystem in the deepest ocean. Cell, 188(5), 1175-1177. DOI: 10.1016/j.cell.2024.12.037