Overview
- Peer-reviewed research in Communications Earth & Environment formalizes marine darkwaves as short-term, intense reductions in underwater light.
- Long-term records from New Zealand and California show events lasting days to more than two months, with near-complete loss of light at the seabed in some cases.
- Analyses link many events to sediment from storms and land use, with additional drivers including algal blooms, organic matter and excess nutrients.
- Impacts fall hardest near river mouths yet can spread tens of kilometres, threatening kelp forests, seagrass meadows and the behaviour and survival of fish and marine mammals.
- Researchers report 25–80 events along New Zealand’s East Cape since 2002 and note 2023 as an exceptionally active year, while new work tests soundscapes and calls for land-practice changes to curb sediment inputs.