Shocking images released on Wednesday show the damage Cyclone Gabrielle has caused to New Zealand's sea floor.
Research, conducted by NIWA scientists on behalf of Fisheries New Zealand, discovered evidence of significant impacts to the ecosystem.
"Analysis of satellite images suggest that the influence of Cyclone Gabrielle on water quality lasted approximately two to three months across the two regions," NIWA benthic ecologist Dr Daniel Leduc said in a statement.
He said of 36 locations surveyed with an underwater camera, 11 showed signs of sediment impact.
The damage can't officially be attributed to the cyclone, but only because there are no pre-cyclone camera observations taken to compare the data with.
"Extreme weather events can create sediment deposits in the ocean because of accelerated soil erosion and transport from rivers into the sea," he explained.
He said sedimentation is one of the main threats to our marine ecosystems.
Two research surveys were conducted in June and October last year, across Hawke's Bay and Tairāwhiti.
They involved the use of satellite imagery, sea floor mapping, and underwater cameras.
NIWA also explored the impacts of cyclone disturbance to animals living on the sea floor, by adapting an existing seafloor model.
"We fed the model lots of information, including history of bottom trawling and sedimentation prior to the cyclone, biological characteristics of sea floor organisms, and how much sediment was deposited after the cyclone."
Leduc said the model suggested habitat-forming organisms were impacted by pre-cyclone fishing and sedimentation.
It also found additional declines to those organisms, such as sponges, were predicted from the cyclone.
"We also took sediment core samples and saw evidence of cyclone impacts on seafloor animal communities off Poverty Bay, where small fauna sampled four months after the cyclone had decreased markedly compared to samples dating back to 2010," he said.
However, Ludac said while there were noticeable impacts on the seafloor, some areas are already showing positive signs of recovery.
Nine months after the cyclone, fauna populations on the sea floor recovered to pre-cyclone levels.
Fisheries NZ director of science and information Simon Lawrence admitted "marine ecosystems are complex."
Lawrence said they are impacted by a range of factors including direct human impacts, extreme weather events such as the recent cyclones and the effects of climate change.
"The results of this survey provide an important baseline for understanding the impacts of these cyclones on our coastal marine environment and help us plan for, and respond to, future events like this."
Some of the early observations from this research have already been used for management settings."
He said the research will prove useful for ongoing fisheries decisions.
