Ocean ‘twilight’ zone reveals new species

A small orange seahorse is among three new fish species discovered by New Zealand scientists in a survey of the Kermadec Islands.

The survey, which incorporated marine mammal sampling as well as diving and offshore sampling, is the first of its kind and was conducted over 19 days on NIWA’s research vessel, Tangaroa.

Seven organisations including NIWA, Auckland Museum, and Te Papa collaborated on the survey, which was conducted between October and November last year.

The objective of the survey was to improve the knowledge of the area for the 620,000 square kilometre marine sanctuary the government has proposed creating.

In total, 88 coastal and 166 offshore invertebrate species were provisionally identified, and 236 fish species.

However, many could not be properly identified onboard and that would be done over the next year.

Head of Natural Sciences at the Auckland Museum Tom Trnski, who was one of the co-leaders of the survey, said there were a number of fish that did not match known species.

At the moment they knew at least three of the species were new.

They included the cusk eel, which Dr Trnski said looked like a minature version of a ling, “if you can imagine a sort of eel-shaped fish that’s only about 5cm long but with a very big eye”.

There was also a new type of dragonet – a bottom fish that Dr Trnski described as “very colourful with big fins and … about 15cm long”.

The researchers also found a small orange seahorse, which was both the first seahorse ever surveyed in the Kermadecs and also a probable new species.

Associate Professor of biological sciences at the Univeristy of Auckland, Rochelle Constantine – another co-leader – said the Kermedec Islands had amazing ecosystems.

“They’re filled with these black grouper which can be one, two metres in length – they’re an enormous fish – and then you’ve got Galapagos sharks swimming around, so it’s quite a different place.”

Dr Constantine said the deep sea was like twilight, “and they’re we’re getting all of these amazing fishes that are sort of small and very loose muscles – quite watery in structure with enormous eyes, the lantern fishes and the fishes with the big sort of scary jaws”.

NIWA principal fisheries scientist Malcolm Clark said studying the Kermadecs would allow scientists to better manage the environment in future because it was so pristine.

“It gives us a natural baseline and benchmark against which to try and evaluate what changes are occurring naturally, versus those closer to mainland New Zealand [which] are driven by human activities, pollution, fishing.”

The Kermadec Ocean Sanctuary will mean 15 percent of New Zealand’s ocean environment will be fully protected.

The law to establish the sanctuary has been delayed. The Maori Fisheries Trust, Te Ohu Kaimoana, has launched legal action over the proposal.