Warmer oceans: 'We need to start planning for this now'

A report recommends sweeping changes to the recreational fishing sector.

 

New Zealand's fishing industry could hit a snag if it doesn't plan for warmer oceans significantly affecting marine life, say Niwa scientists.

As the ocean gets warmer it could affect phytoplankton - a key part of the oceans, seas and freshwater basin ecosystems - and could see a reduction in food supply for fish.

"This has already happened in the water just off Tasmania and the south-east corner of Australia, which is warming rapidly as the East Australian current pushes warmer water further south causing huge changes to the ecosystem," said Niwa marine biogeochemist​ Professor Cliff Law.

Tasmania's coastal ecosystems were changing with an increase in subtropical species, which can impact the economy, he said.

"The average warming around New Zealand is 2.5 degrees [Celsius] by the end of this century, which will affect how the ocean mixes and the nutrients available for plankton growth, with knock-on effects on the foodweb and fisheries.

"People tend to think of climate change from a terrestrial angle but obviously, as the ocean is a big part of the globe, there will be significant changes. As it's also a significant part of New Zealand's Exclusive Economic Zone we need to start planning for this now."

Near-record sea surface temperatures described as "off the charts" were reported on Monday.

A La Nina pattern and higher than normal atmospheric pressure are warming sea surface temperatures by more than 6 degrees Celsius in some areas, compared to the average for this time of year.

https://www.stuff.co.nz/business/industries/99538116/warmer-oceans-we-need-to-start-planning-for-this-now

Yellow-eyed penguins at risk due to set net fishery

Almost half the breeding population of yellow-eyed penguins on Codfish Island, west of Stewart Island, have disappeared at sea, most likely because of commercial set nets, Forest and Bird says.

Forest & Bird chief executive Kevin Hague said the group was calling on the Government to gather those who work to protect the penguins, but also the fishing industry to agree an immediate set of actions to eliminate the risks from set netting in the penguins' feeding area.

"Unlike previous years where disease and high temperatures caused deaths on land, this year birds have disappeared at sea. There is an active set net fishery within the penguins' Whenua Hou foraging ground, and the indications are that nearly half the Whenua Hou hoiho population has been drowned in one or more of these nets.

"We are asking DOC and MPI what they intend to do to save our hoiho from extinction, because at current rates of decline we are on track to lose hoiho completely from mainland New Zealand. We have also written to the Minister of Conservation, expressing our concern."

However, Ministry for Primary Industries (MPI) says it is stepping up monitoring of the set net fisheries.

Almost every penguin killed in the set net fishery was killed on a boat that had an official observer on board, Hague said.

The first step was to get more observers onto set net vessels and prioritise putting cameras on set netting boats, he said.

Department of Conservation information showed only 14 yellow-eyed penguins were found on Codfish Island, down from 24 the previous year.

Forest & Bird said yellow-eyed penguins had also declined elsewhere this year. The Catlins had seen a drop of 10 per cent in nests and Otago Peninsula saw a small decline but not all areas have been searched yet.

The estimate for the entire southern east coast of the South Island was down 6 per cent.

However, it's not just yellow-eyed penguins at risk.

https://www.stuff.co.nz/environment/99082357/yelloweyed-penguins-most-likely-disappearing-because-of-commercial-set-nets-forest--bird-say

Our scorching sea: Marine heatwave unfolding as hot temperatures continue

The warm weather is predicted to continue for the rest of the week as a ridge of high pressure sits over the country.

The first weekend of summer was marked by scorching temperatures nationwide, and Monday is expected to be even hotter.

Hanmer Springs was the hottest place in the country on Sunday at 31 degrees Celsius, according to MetService.

It's not just air temperatures that have been hot. According to NIWA's Ben Noll, ocean temperatures around New Zealand have been on average 2C warmer than usual - and up to 6C warmer off the West Coast. Water around the country has been warmer than average for more than a month now.

MetService Meteorologist Ciaran Doolin said: "It's good news for the working week. The (high pressure ridge across the country) is set to persist until Friday, which means a continuation of warm, settled weather."

https://www.stuff.co.nz/national/99491972/week-starts-with-a-scorcher-warm-weather-settled-in

What lies beneath: Why NZ's slice of Antarctica is at the centre of an eco-mystery

There's a problem in Antarctica.

Most climate change models say ice around the southern continent should be decreasing. It should be melting as the planet heats up.

But sea ice around Antarctica isn't shrinking. It's been growing.

"Since the satellites went up – and that's about 30 or 40 years of records – there's been a gradual trend toward more sea ice around Antarctica," say Dr Natalie Robinson, a marine physicist at Niwa, New Zealand's Institute for Water and Atmospheric Research. "Which is not what you'd predict in a warming ocean."

Frozen icebergs in the Ross Sea. "There's something particular going on with the Ross Sea," Robinson says.

This sort of thing makes climate change skeptics shout from the roof tops. Obviously the world isn't heating up!

https://www.stuff.co.nz/science/98902415/measuring-antarcticas-unpredictable-sea-ice-to-help-understand-climate-change