Life in the ocean – the unknown last frontier


What is known about life in the ocean? Even though it’s the biggest habitat on the planet, most of the ocean remains unexplored biologically. So what do we know? And how does New Zealand’s biodiversity compare with the rest of the world?

“We are still in the discovery phase for life in the ocean and that’s especially true for New Zealand. Even as recently as 2003 a new species of whale, two metres long, was discovered by the Japanese. In New Zealand, we are discovering new marine species faster than we have the capacity to name and classify them,” says NIWA principal scientist Dr Dennis Gordon.

An assessment of total biodiversity throughout the New Zealand Exclusive Economic Zone (EEZ) and the Ross Sea commenced a decade ago. The results so far reveal more than 17000 species. This is only about 30% of the entire known land and water biodiversity of New Zealand.

New Zealand’s marine biodiversity is very high. For example, within our best studied groups, (sponges, corals and anemones, shellfish, lamp shells, bryozoans, sea stars and their spiny relatives, and fish).

“We are still in the discovery phase, unlike Britain, and Europe. The European marine region is five and a half times as big as our (EEZ). But what is interesting, is that they have only got twice as many species. On a proportional basis our marine life is much richer than the northeastern Atlantic.”

The management and conservation responsibility of our region, is great. “But we don’t yet have 10% of our mainland coast in marine reserves”.

Because of our geographical position, we can’t be reliant on our neighbouring nations to look after our marine species. There are a significant number of highly migratory species within New Zealand waters that are dependent on safe access to either breeding or feeding grounds in environments and habitat well beyond New Zealand’s EEZ.

New Zealand’s capacity to name, describe, and classify marine species is low and declining. . There’s a staggering number of still-undescribed species in many groups, and the rate of new discovery underscores the need for increased effort to fully document New Zealand’s biodiversity. For example, in natural history collections there are more than 4400 known but undescribed species.

“You have to know what’s out there, where it is and in what numbers, only then can you really say ‘this is where we should put a marine reserve’, because of what is representative or because it’s rare and special,” says Dr Gordon.

New Zealand has a National Biodiversity Strategy. It was launched in 2000 with a twenty-year-timeframe. The purpose of the strategy is to restore our biodiversity, to conserve that for posterity and to ensure that our ecosystems are functioning well.


NIWA is proud to support the United Nations International Year of Biodiversity. Biological diversity is essential to sustaining the living networks and systems that provide all of us with health, wealth, food, fuel, and other vital services our lives depend on. Our own biodiversity is especially important because many of New Zealand’s species are not found anywhere else in the world. NIWA’s biodiversity and biosecurity experts are leading science to safeguard this irreplaceable natural resource and reduce biodiversity loss. For more information about the International Year of Biodiversity or to find out how you can help go to\

The major marine data repository is kept at the National Institute of Water and Atmospheric Research, which is involved in several Census of Marine Life field projects.


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Emeritus Researcher – Marine Biodiversity