Context Wetland loss threatens global biodiversity. Peri-urban wetlands face acute pressures from urban expansion. Aims Investigate biodiversity and land-cover changes in two wetlands undergoing suburbanisation near Hangzhou, China. Methods Seasonal field surveys of birds, fish and amphibians, coupled with remote-sensing analysis of land-cover changes from 2009 to 2020. Key results Suburban wetlands exhibited unique degradation patterns, including reduced species diversity, simplified community structures and proliferation of invasive species, with 91 bird species being recorded, dominated by common residents, 25 still-water fish species with few carnivores and migratory species, and 5 ubiquitous amphibian species detected. Species richness was lower than in nearby conserved wetlands. From 2009 to 2020, 6–7% of the wetlands were lost to urban expansion and converted to artificial vegetation or infrastructure. Conclusions Ecological degradation is driven by rapid urbanisation, with habitats being fragmented by roads and converted to artificial land covers. Water pollution from insufficient treatment and abandoned aquaculture further impairs habitats. Implications Innovative integrated-management framework was proposed for wetlands biodiversity restoration in suburban area. Key strategies include (1) modernising traditional circular economies to sustain wise use, (2) wildlife-friendly infrastructure design, (3) targeted invasive species control, and (4) adaptive co-management informed by ongoing monitoring. This socio-ecological systems approach aims to harmonise biodiversity conservation, cultural heritage and sustainable development in threatened suburban wetlands.