Scientists from the United States are surprised at the extent of damage to marine life done by fishing boats engaged in bottom trawling in the Kermadec Trench north of New Zealand.
The New Zealand American Submarine Ring of Fire Expedition ended in Tauranga this week after exploring the Kermadec Arc for the last month.
The University of Hawaii research vessel Ka'imikai-o-Kanaloa used human-occupied submersibles to probe the largely unexplored sea trench.
The director of Hawaii's undersea research laboratory, Dr John Wiltshire, was surprised at the extent of damage done by fishing nets.
"We found that some of them have been very heavily dredged by fisheries trawlers, and there've been a lot of damage to the corals and other organisms on the bottom; much worse than had previously been thought."
Officials in Wellington estimate there are up to 30 New Zealand flagged vessels currently involved in bottom trawling on the high seas.