<- Back to: News

The Tasman Sea is warming at one of the fastest rates on Earth, four times the global average.

That alarming fact was presented to last week’s Seafood NZ annual conference in Wellington by MetOcean chief scientist Dr Moninya Roughan.

Surface temperatures were as much as 6 degrees C above the norm last summer, with the increase the most marked in the Tasman Sea.

Such dramatic shifts have profound implications for the marine environment as heatwaves become more frequent and more intense.

The most obvious are the geographic redistribution of species such as tropical fish ranging as much as 3000km south of their normal habitat, such as Queensland groper found off the northern New Zealand coast this year.

Less visible but equally as significant is impact on larval flows. Tiny rock lobster, for instance, are carried across the Tasman from Australia to our shores and could be displaced by hundreds of kilometres.

Temperature peaks can also cause habitat destruction to kelp and corals, diminish paua recruitment, sharply increase farmed salmon mortalities and alter species distributions and abundance, even in deep water.

Despite the seriousness of such changes, there remains a paucity of open ocean data, Dr Roughan says.

“We have under invested in our ability to comprehensively measure, monitor and predict the state of New Zealand’s coastal oceans.

“Marine industries are operating in the dark without accurate ocean circulation and temperature information.

“We have a poor understanding of temperature trends, variability and climate change scenarios. New Zealand is lagging a decade, if not two, behind other developed nations in this regard.”

Dr Roughan and her colleagues are seeking to address that through an ambitious programme termed the Moana Project.

It includes the widespread use of low cost temperature sensors, with the data recorded added to an open access data base.

The seafood sector is central to this. Fishing vessels crisscross the oceans and could readily attach sensors to trawls, integrated with satellite communications.

Data from a single float off the west coast of New Zealand on March 15 this year showed that the temperature anomaly went as deep as 1200 metres.

The research also aims to improve ocean circulation modelling.

MetOcean, acquired by State-owned MetService earlier this year, is seeking funding of $10 million from the Ministry of Business, Industry and Employment’s Endeavour Fund for the project.

The assessment is demanding, as it should be with so much public money at stake.

Proposals are first ranked for their scientific excellence and then on impact and benefit to New Zealand.

The Moana Project has easily cleared that first hurdle and is one of 60 proposals to advance to round two.

“We have strong industry support (including Seafood NZ) and we are confident of the value of the project to the growth of our Blue Economy,” Dr Roughan says.

Confirmation on successful projects is due by the end of September.

In parallel with this project, the industry-owned Trident Solutions research body in partnership with research funder Seafood Innovations Limited is exploring what types of information can be collected by the seafood sector that is likely to be required for future fisheries management, and could include salinity, currents, turbidity and chlorophyll as well as temperature.

These projects are small first steps towards a comprehensive ocean observing and modelling programme for NZ that will support an ecosystems based approach for better management of our marine resources.