Niwa has discovered at least four new species of fish in its deepest exploration of New Zealand's surrounding ocean.
Working from their research vessel Tangaroa, scientists from the National Institute for Water and Atmospheric Research trawled down to 2730 metres northwest of the Graveyard Hills on the North Chatham Rise.
Over a series of eight trawls, ranging from depths of 1910 to 2730 metres, Niwa uncovered the specimens.
Within New Zealand's Exclusive Economic Zone (EEZ) the Chatham Rise stretches for about 1000km from near Christchurch out to the Chatham Islands. It is one of New Zealand's most productive fishing areas.
The EEZ is more than four million square kilometres and just over half of that area is deeper than 2000m.
A Niwa spokesperson said there were not many fish to be found below 2100 metres.
"Just a small numbers of skates, slickheads, rattails, and cusk-eels were caught there."
The trawls revealed some extremely rare fish - a Flabby Whalefish, three new Slickheads, a juvenile Richardson's Skate, large Warty Cusk-Eel, as well as new record of a white Rattail, and several unidentified species.
Ministry for Primary Industries spokeswoman Pamela Mace said the trawls revealed important information about the ecology of New Zealand's surrounding waters.
"We are interested in these results because they test whether our assumptions about the depth limits of commercial fish species are correct, and they also increase our knowledge about the inhabitants of our marine estate in this largely unexplored environment."
Niwa fisheries scientist Peter McMillan said it also provided an opportunity to gauge fish levels in the popular commercial fishing zone.
"We were fortunate to get an opportunity to explore this deep area on the Chatham Rise. It's great to know what we have, and how much."
He said it was also interesting because deep-sea fish often had bizarre body forms compared to more commonly study inshore fish.
Scientists sent nets to the bottom of the sea floor, in what was often painstakingly long work. Sending one to 2000m and getting it back could sometimes take more than three hours.
Shortly after fish were brought up from the depths of the ocean the scientists took photos to capture their fresh colour. The catch from each station was recorded and then specimens were labelled and frozen.
Niwa will gift the rare and the new-to-science fish to Te Papa where they will be preserved, researched and stored in the National Fish Collection.
In the Fishes Collection at Te Papa, preserved fish specimens are held from 28 sites below 2000 metres.
Of these, 120 specimens covering 34 species are represented.
The majority were caught by the New Zealand Oceanographic Institute and, more recently, by Niwa.