{"id":356511,"date":"2026-03-31T08:11:10","date_gmt":"2026-03-31T08:11:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/356511\/"},"modified":"2026-03-31T08:11:10","modified_gmt":"2026-03-31T08:11:10","slug":"the-hauraki-gulf-is-getting-noisier-pushing-sea-life-to-the-brink","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/356511\/","title":{"rendered":"The Hauraki Gulf is getting noisier, pushing sea life to the brink"},"content":{"rendered":"

The Hauraki Gulf is doing it tough. This summer, shearwaters struggled to find enough food to feed their chicks, and koror\u0101\/little blue penguins washed up malnourished. This marine region \u2013 considered a p\u0101taka kai, or food cupboard \u2013 is under extreme stress.<\/p>\n

Some of the reasons for this stress are large and complex \u2013 marine heatwaves, climate change, the long-term effects of dredging and overfishing. But one of them is very simple: human activity makes a lot of noise underwater.<\/p>\n

Noise is stressful, but it also makes it more difficult for fish and other marine species to communicate with each other, to find places to settle down and breed, or to avoid predators. Even seagrass is harmed by too much noise. Over time, stress has a cumulative effect: animals that are continuously stressed tend to live shorter lives and have fewer offspring.<\/p>\n

Parts of the Hauraki Gulf, as well as other marine areas around New Zealand, are protected from some types of fishing, but not from other kinds of human impact. \u201cSound is a big one,\u201d says Craig Radford, a professor of marine science at Waipapa Taumata Rau, University of Auckland. \u201cWe could really make a huge impact in terms of how we design marine reserves.\u201d<\/p>\n

Put in some noise restrictions, for instance. Humans have them: no partying after 10pm, or quiet hour in the supermarket on Wednesdays. Radford and two colleagues recently published a paper describing exactly how marine reserves could incorporate quiet zones, too<\/a>.<\/p>\n

Why sound is crucial in the ocean<\/p>\n

Sound travels extremely well through water, so marine species use it to communicate and sense their surroundings. They use it in the same way that we rely on light to perceive the world around us.<\/p>\n

On a clear day, you might be able to see all the way to the horizon. Whales and dolphins can hear sounds all the way to the horizon and beyond \u2013 no matter what time of day it is. \u201cSound works even in the dark,\u201d says Radford. \u201cAnd it travels in all directions equally. It\u2019s not affected by water currents and things like that. So, it really is quite a widely used sensory cue by a whole range of different animals under the sea.\u201d<\/p>\n

At least, they\u2019re trying to use it. Increasingly, human sounds drown out whatever fish and crustaceans and dolphins and whales are trying to say. \u201cThat\u2019s why we\u2019re really interested in noise effects,\u201d says Radford. \u201cThe world is getting noisier, and it\u2019s the same underwater.\u201d<\/p>\n

Noise affects not only communication: larvae floating in the water column listen for the sound of reefs to find somewhere to live, orienting themselves towards the chorus from other animals there.<\/p>\n

What happens when things get too loud?<\/p>\n

Loud noises close to animals can physically harm them, says University of Auckland research fellow Louise Wilson, who co-authored the paper. \u201cThere are studies that have shown sound pollution can rupture the swim bladder of fishes. They can also experience either permanent or temporary hearing damage.\u201d<\/p>\n

A bigger problem is \u2018masking,\u2019 otherwise known as the cocktail party effect: a reduction in the distance over which species can communicate. \u201cJust like being at a party, right?\u201d says Radford, \u201cIf you want to talk to someone and it\u2019s a loud party, you\u2019ve got to be really close together.\u201d<\/p>\n

If the sound drowns out that animal\u2019s natural hearing range, it makes it harder for it to avoid predators, find prey, or breed. \u201cAnd that has implications for the survival of that animal,\u201d says Wilson. \u201cIf an animal is having to spend more time looking for food and less time resting, that\u2019s less time that they\u2019re able to spend breeding \u2013 and can have knock-on effects for fitness and survival.\u201d<\/p>\n

Various types of marine protection ban fishing from certain areas but don\u2019t put any restrictions on cruise ships motoring through the middle of them. \u201cYou can\u2019t fish, but you can drive an oil tanker through there if you want,\u201d says Radford.<\/p>\n

Ships in general are really loud, he says. Small boats are loud but quick. Large boats are loud but slow. And in the Hauraki Gulf, there can be a lot of them. <\/p>\n

The scientists know what happens when the boats are absent. During the Covid lockdowns, University of Auckland hydrophones recorded a momentous change in the seascape. The number of marine species that were audible increased dramatically. They heard seals, fish, invertebrates, Bryde\u2019s whales, dolphins. \u201cWe showed that when you reduce the impact of pleasure craft, all of a sudden the range the animals can hear expands,\u201d says Radford. \u201cSo that was quite serendipitous and quite cool.\u201d<\/p>\n

The communication range of fish and dolphins increased by an estimated 65 percent<\/a>, according to a paper Radford, Wilson and colleagues published about their lockdown research. With greater communication, the natural behaviours of sea life have a chance to return.<\/p>\n

It\u2019s a problem, but with a simple fix<\/p>\n

When politicians are crafting marine-reserve legislation \u2013 much of which has been modified or changed over the past few years \u2013 they could consider the impacts of noise. \u201cYou can just do things as simple as having quiet zones, or restricting speed to reduce noise,\u201d says Radford.<\/p>\n

Even considering the amount of noisy recreational activity that\u2019s allowed to happen in a marine protected area would be a start, says Wilson. \u201cOr simply limiting it at specific times of year when you know from existing research that specific species which use sound are going to be more vulnerable to sound pollution,\u201d she says.<\/p>\n

There are currently a few noise restrictions in the sea so far, particularly where construction is concerned. Marine construction, mining, and surveying all involve a noise-impact assessment, \u201cwhich is relatively new for New Zealand,\u201d says Radford.<\/p>\n

But we don\u2019t consider the noise impact of ships travelling 24\/7 through our waters. Or other craft: Radford points out that helicopter pads along the coast can lead to a great deal of noise pollution underwater. His research hydrophones capture the sound of drones and airplanes: all audible underwater.<\/p>\n

To save our seas, the researchers are clear: human-made sound is a factor that should be an important part of the criteria deciding marine protection legislation.<\/p>\n

The world is facing unprecedented environmental challenges. Planetary Solutions, an initiative of the Sustainability Hub at Waipapa Taumata Rau, University of Auckland, and Newsroom, explores these issues \u2013 and the practical ways we can all be part of the solution.<\/p>\n","protected":false},"excerpt":{"rendered":"The Hauraki Gulf is doing it tough. This summer, shearwaters struggled to find enough food to feed their…\n","protected":false},"author":2,"featured_media":356512,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[22],"tags":[273,111,139,69,84870,147,11219,22190],"class_list":["post-356511","post","type-post","status-publish","format-standard","has-post-thumbnail","category-environment","tag-environment","tag-new-zealand","tag-newzealand","tag-nz","tag-planetary-solutions","tag-science","tag-sustainable-future","tag-university-of-auckland"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/356511","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=356511"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/356511\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/356512"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=356511"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=356511"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=356511"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}