WELLINGTON, Jan. 13 (Xinhua) -- A New Zealand-led study has created the first framework to detect short but intense underwater darkness events, or "marine darkwaves," that can harm marine ecosystems.
The study shows evidence of sudden underwater darkness events from California, U.S., to New Zealand that disrupt marine ecosystems and reveal how coasts respond to changing conditions like Cyclone Gabrielle, according to a news release from New Zealand's University of Waikato on Tuesday.
The research, published in Communications Earth & Environment, introduces marine darkwaves as an event-based framework for detecting and comparing episodes of unusually low underwater light, the release said.
Marine darkwaves lasted from a few days to more than two months, it said, adding that some events caused the seabed to receive almost no light compared with normal conditions.
While long-term coastal darkening has been documented globally, the study showed that short-lived but intense darkness events can be highly damaging to marine ecosystems and may have ecological impacts that rival longer-term declines in underwater light.
"Light is a fundamental driver of marine productivity all the way up to the upper food chain, yet until now we have not had a consistent way to measure extreme reductions in underwater light," said Francois Thoral, lead author and marine scientist at the University of Waikato.
"Marine darkwaves allow us to identify when and where these events occur, shedding new light on a critical but often overlooked phenomenon," Thoral said.
"Even short periods of reduced light can impair photosynthesis in kelp forests, seagrass and corals," affecting the behavior of fish, sharks and marine mammals, he added.
Using over two decades of light and satellite data, the marine darkwave framework offers a standardized way to compare underwater darkening across depths, regions and years, providing a more complete picture of how environmental change affects coastal ecosystems, the release said.
