Feed aggregator

The second-noisiest animal in the ocean, the snapping shrimp. Dr Tullio Rossi, CC BY-SA

Despite appearances, the oceans are far from silent places. If you dunk your head underwater you’ll hear a cacophony of sounds from wildlife great and small, crashing waves, and even rain. And it’s louder still for creatures attuned to these sounds.

However, humans are changing these ocean soundscapes. Our recent research showed that changes caused by people, from ocean acidification to pollution, are silencing the seas' natural noises. (We’re also filling the oceans with human noise).

This is bad news for the species that depend on these noises to find their way.

Ocean soundscapes

All over the world you can hear a lively crackling sound made by thousands of snapping shrimp that live along coastlines.

These common shrimp, often referred to as pistol shrimp, have a large claw that they can close with such force that a cavitation bubble is formed. As this bubble implodes on itself a loud snap is created – like a pistol shot – which can be heard over long distances.

In fact, snapping shrimp are the loudest marine invertebrates, and second only to the noisest marine animals, which are sperm whales! Snapping shrimp are found all over the world, including in coral reefs, kelp forests, seagrass beds and mangroves.

Other types of animals create ocean noise too. Urchins and parrotfish make clearly audible chomping sounds as they scrape algae off rocks. Many fish are frequent and loud talkers and make an array of sounds such as chirps, burps, whistles, knocks and so on. They use these to mark out their territory, during fights and to locate mates.

These biological sounds, together with those from rain, crashing waves and seismic activities, form the so-called underwater soundscape.

Learn more about marine soundscapes watching this video.

Sounds that are emitted from temperate and tropical reefs are loud and quite constant. As such these sounds form a reliable source of information for animals, particularly for navigation.

Most animals in the sea let go of their fertilised eggs without providing any parental care. As these eggs hatch, small babies (larvae) are dispersed by ocean currents. Growing up away from coastal areas provides a safer place with fewer predators.

However, after growing for a few weeks or months in the open ocean, it is time for these young animals to return to the coast to find a home. How do they find their way in the vast and uniform open ocean? Sounds and odours from coastal habitats are key cues that allow marine animals to find their new homes and replenish adult populations.

Going quiet

Humans are increasingly dominating the physical and chemical environment. We are altering the carbon cycle through the burning of fossil fuels and the nitrogen cycle by extracting vast amounts of nitrogen for food production and releasing it as waste. Large amounts of this carbon and nitrogen liberation end up in the ocean.

About one-third of the carbon dioxide that humans emit into the atmosphere dissolves in the ocean, leading to increased seawater acidity (or ocean acidification). This is an obvious problem for animals that produce a calcium carbonate shell or skeleton (such as corals, some plankton, and snails). Remarkably, ocean acidification also alters the behaviour of many animals by messing up their brain functioning.

Earlier studies (see also here) have shown that ocean acidification can change the response of fish larvae to settlement habitat sounds by deterring them rather than attracting them.

Learn more about the effects of ocean acidification on fish behaviour watching this animation video.

Two of our recent studies (see also here) showed that ocean acidification not only affects sound reception, but also the sounds that ocean ecosystems produce. If we don’t reduce greenhouse gas emissions, rocky reefs could be much quieter in 2100 than now. And snapping shrimps are the reason.

Coastal discharge of nutrients from sewage plants and catchment runoff also degrades kelp forests and seagrass beds. These coasts are more silent than their healthy counterparts.

In many parts of the world, kelp forests, seagrass beds and coral reefs have been replaced by carpets of turf-forming or mat-forming algae. These weedy types of algae have much lower diversity of species and provide less shelter and feeding opportunities for shrimps and other noisy animals.

Degraded habitat means fewer animals, which means less noise. For larvae that use sound as a navigational cue, this means that fewer larvae will be able to successfully locate their home. And fewer returning larvae means less replenishment of fish stocks.

The effects of ocean acidification on fish orientation and soundscapes. Dr Tullio Rossi Options for restoration

Climate change and ocean acidification act at global scales and are difficult to stop in the short term. In contrast, nutrient pollution is a local stressor, which makes it more manageable.

Various options exist for local communities to reduce nutrient pollution of coastal areas. These include improved sewage treatment, restoration of coastal vegetation (such as mangroves) and swamps that extract sediment and nutrients from stormwater runoff, and decreasing the use of rivers as outlets for polluted waters.

Reducing the impacts of nutrient pollution on coastal ecosystems makes these systems more robust and provides them with increased resilience to cope with the impacts of ocean warming and acidification.

Ivan Nagelkerken receives funding from The Australian Research Council.

Sean Connell receives funding from The Australian Research Council.

Tullio Rossi owns the YouTube channel where the linked videos are hosted.

Redflow says first ZCell residential battery storage systems to be delivered to customers next month after first shipment of batteries arrived in Australia on Sunday.

Continued technological advancements are expected to continue reducing the cost of wind energy, according to a new survey of leading wind experts.

Tesla wins contract to install 20MW/80MWh Powerpack for Southern California Edison Mira Loma Substation.

What happens when a climate science denialist gets things badly, horribly, terribly, and embarrassingly wrong.

University of Queensland to add 200kW RedFlow zinc bromine battery to its world-leading solar research facility to test how it helps renewables interact with the grid.

Originally published in the Manchester Guardian on 25 September 1916

The serpentine stones which form the shingle on the Lizard peninsula are very tempting to collect, and we have had the happy idea of using them in bowls this winter, to grow narcissi in and Roman hyacinths. A child is the pure artist in collection. He needs no apology. The mere contemplating of his hoards, laying them out in array, counting and sorting, is amply enough joy for him. But we grown-ups are compelled to seek a plea of use, and, having found it, we may indulge our childishness. It is fortunate that the use we have hit upon allows, since we cannot learn to polish the stones, of the next best way of bringing out the colours – by wetting them.

They are very varied, these pebbles; veined or mottled, or netted, or broadly banded; colours laid one over the other or side by side. The greys sometimes get very near blue, mostly lilac or indigo blue. The greens are mostly yellowish or mossy, but there is a very handsome laurel green, not often found. The reds are mostly a rich and deep Indian red, but there are found occasional delicate pink shades. I have in my hand one pebble made up of broad bands of Indian red alternating with iron grey, a sombre combination; another dark one has a background of lavender with a fine network of the same red; more beautiful is the same lavender veined with purple.

Continue reading...

Forty years ago there were as many as 150 breeding pairs of whinchats on the Somerset Levels. Now there are none

Some birds pop up when you least expect it. On August bank holiday I went for a walk to my coastal patch, along with assorted relatives and a very boisterous dog. Bird-wise, apart from a high-tide roost of a thousand redshanks along the river Brue, things were relatively uneventful.

But as we were strolling back to the car, a small bird flew up onto a protruding twig along a hedgerow, and posed in a way that made its identity virtually certain.

Continue reading...

The fate of the Australian Antarctic Division’s research base on Macquarie Island hangs in the balance, after last week’s surprise announcement that it would close in March 2017 was followed on Friday by a suggestion that the government could yet reprieve it.

Why all the fuss over a scattering of buildings on a windswept island (admittedly a UNESCO World Heritage-listed one) perched on a tectonic ridge halfway between Australia and Antarctica?

Macquarie Island is the perfect natural laboratory for scientific research. Unique climate, geological, biological and astronomical measurements are collected year-round. The data is fed into many large-scale, international science programs and reports, including those published by the Intergovernmental Panel on Climate Change.

It is something of an anomaly in Australia’s national Antarctic program. Unlike Heard Island, Macquarie Island lies outside the areas covered by the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. The Tasmanian government manages the island.

The buildings at the island’s north end are home to research infrastructure and accommodation for various organisations. These include the Tasmanian Parks and Wildlife Service, the Bureau of Meteorology, and the Australian Radiation Protection and Nuclear Safety Agency, which monitors the Southern Ocean for evidence of nuclear events. These buildings are increasingly exposed to ocean inundation.

Death by a thousand cuts

Collaborations of this nature are common in Antarctic science. Budgetary decisions made in one section of the community have a direct impact on the programs of others.

This sudden closure announcement followed the harrowing CSIRO job cuts announcement earlier this year. Tasmanian Premier Will Hodgman, the Tasmanian and Antarctic science community and the Australian Greens understandably responded with dismay to last Tuesday’s announcement.

While funding to Australia’s Antarctic science program seemed assured with the long-awaited Australian Antarctic Strategy and 20-Year Action Plan this year, there is a reasonable correlation between previous successive cuts to the Antarctic program and the disrepair of Australian Antarctic infrastructure. Labor Senator Lisa Singh called this a “death of a thousand cuts”.

Competing interests

Given the huge scale of Australia’s interests in Antarctica and the Southern Ocean, there will always be competing budget priorities.

Environmental contamination from long-term human habitation, for example, is an issue common to Australia’s research infrastructure throughout the Antarctic region.

Any research in the Antarctic and sub-Antarctic must be done in a way that minimises the direct impact on the surrounding environment. Australian Antarctic Division director Nick Gales has cited the footprint of this research as one reason for withdrawal from Macquarie Island.

Environmentally sensitive replacements suited to such harsh and remote conditions are expensive. The ongoing remediation work on many old Antarctic and sub-Antarctic bases continues to cause further budgetary and logistical headaches.

Macquarie Island, Heard Island and Australia’s Antarctic Territory are notoriously difficult to access, particularly for long-term, logistically demanding tasks such as major remediation and refurbishment works. Access involves battling the increasingly unpredictable sea ice and ice airstrip conditions that already disrupt delicate resupply, search and rescue, and medical evacuation operations.

Given its position deep in the Southern Ocean, there remains a strong case for a small but permanent presence on Macquarie Island. For example, resident climate scientists have collected weekly ozone measurements for 20 years. There is a place for other Commonwealth departments, the Tasmanian government, private industry and research institutions to shoulder responsibility for maintaining this presence.

A silver lining for Tasmania?

Given successive budget cuts, precariously short-term funding of Antarctic research programs, the potential domino effect of budget cuts between collaborators and the doubt created within the community by the CSIRO climate job cuts saga, Tasmania needs to continue to build its capacity to ride out the vagaries of the federal political issues that have left it reeling over the past year.

Regardless of the current station’s fate, this could be seen as an opportunity for Tasmania’s Antarctic, climate and oceans science community to collaborate and innovate with various industries to ensure that crucial climate research and observations can continue.

By leveraging from existing programs such as the Antarctic Gateway Partnership, and with world-class scientific expertise, Tasmania is perfectly poised to innovate and invest in the areas of remote and autonomous scientific instruments, technology and data handling.

Private enterprise, including smaller non-icebreaking vessels that already operate as research and tourism platforms in the sub-Antarctic, also has a chance to fill the logistical gap.

The closure of the Macquarie Island station after almost 70 years would be sad and shocking for the generations of scientists who fondly visited “Macca”.

The continuation of a presence on the island, however, is largely a Tasmanian government responsibility. With innovation and collaboration, Tasmania can lead the way in a new, stable and less environmentally damaging era of science on Macquarie Island.

Indi Hodgson-Johnston is an Expert in Antarctic Law and Policy at the London-based Polar Research and Policy Initiative. She also works for the Integrated Marine Observing System at the University of Tasmania.

Rob Callender, who appeared in Sherlock and Game of Thrones, discusses The Incentive, his environmental call to arms

Rob Callender is talking about cheese. “My dad loves cheese, really loves it. So I’ve had to persuade him to cut down. Instead of leaping on every two-for-one in the supermarket, buy one really nice cheese once a week. Dairy farming is such a horrible industry.”

Callender’s passionate advocacy of veganism has made him an object of fun and curiosity on film sets, but he is now turning his environmentalism into art. In just over a month’s time, he he will begin shooting a short crowd-funded feature film on climate change.

Continue reading...

Roadsides are a haven for rare species, but council mowing is a threat. New schemes offer hope

Orchid-spotters have long-known that the best site in the UK to take in a display of pyramidal orchids is a roadside verge in Warwickshire, yet the role verges play in conservation isn’t widely appreciated. There are almost 251,000 acres of rural road verges across the country that are home to 703 species of wild plants – 87 of which are facing extinction.

Britain has lost 97% of its wildflower meadows since the 1930s as land has been turned over to grow food crops. Rural roadside verges and small, family-owned farms remain the only places left for species such as the crested cow-wheat, spiked rampion and man orchid to thrive. These roadside verges represent the last stronghold of British wildflowers yet they are being mown down by local councils because of budgetary pressures and a lack of guidance, conservationists have warned.

Continue reading...

Peace and quiet is an increasingly scarce commodity in the modern world

Silence is golden – or at least it should be. But according to the Noise Abatement Society (NAS), it’s increasingly rare. “Peace is a precious commodity,” says Poppy Szkiler, of Quiet Mark, part of the NAS.

Anti-noise campaigners suggest we have a “sliding baseline” in terms of our expectation of quiet time. This ecological term refers to an incremental lowering of standards as each generation progresses.

Continue reading...

With the Danes rebuffing Russia, and Canada laying further claim to the Northwest Passage, rising access to north pole reserves risks flashpoints

Kristian Jensen, Denmark’s foreign minister, gave a precise response last week to a request by Russia for the nations to enter bilateral talks over the ownership of the north pole. He flatly rejected the move. “We need to apply the international rules,” he told reporters.

The Russian request and the swift Danish response are intriguing. The United Nations is currently assessing Russian, Danish and Canadian claims to own sizeable chunks of the Arctic seabed. The Russian move was generally viewed as an attempt to strike a deal that would cut out Canada, while Denmark appears to believe its case is strong enough to exclude such manoeuvres.

Continue reading...

Licences for gamekeepers to kill the protected bird of prey will open the floodgates to illegal hunting, warn conservationists

Tim Boxall points at a shape in the field bordering the seven-acre wooded pen where he keeps 1,500 pheasants. “Here you are,” he says. “Look! There’s one over here.” He bends down and prises the remains of a pheasant from the long grass. “That’s a buzzard kill, you can tell by the way it’s been eaten.”

Boxall is a gamekeeper, raising 10,000 pheasants a year to be killed in commercial shoots on the land he rents in Gloucestershire. This year, however, the pheasants have something other than Boxall’s clients to fear: the buzzard.

Continue reading...

The ongoing violence in Syria, the Rio Paralympics, the anniversary of the 9/11 attacks, New York fashion week – the best photography in news, culture and sport from around the world this week

Continue reading...

New Forest The heather is studded with yellow tormentil, and mixed with dwarf gorse so tight to the turf that it’s knee-high to a grasshopper

A grey minibus pulls up behind me as I’m changing into my walking shoes. Five young people get out and hitch their packs. ”We’ll be there at five,” says the driver, and goes. They set off along the concrete perimeter road of the old airfield, with a two and a half hour walk ahead of them. I cut through some trees and, by the time I’m on the same road, they’re a speck in the distance.

It’s been too dry, and a little early yet, for autumn fungi to show, but a whitish dome in the grass under the trees suggests it will not be long before they do. It’s hot, the car thermometer registers 26°, and I’m hoping to find shade in the Inclosure.

Continue reading...

US scientists find possible new coral species and rare Dumbo octopus on expedition to previously unexplored extinct volcano off Hawaii

Scientists believe they have identified a new species of coral and found a rare Dumbo octopus during an expedition 3,000ft (900m) down in the Pacific Ocean.

Diving in a submersible to the previously unexplored Cook seamount, an extinct volcano at the bottom of the sea 100 miles south-west of Hawaii’s Big Island, the three-person team was hoping to examine the rich variety of marine life that collects around the nutrient-rich volcanic waters.

Continue reading...

‘I'd much rather be growing things than killing things,’ says Geoff Williams on the eve of a deer hunt. ‘I'd love to come down here and just walk around in the scrub, but I spend too many hours chasing these other bloody animals.’

A team of Australian scientists have won a prize to develop a portable 'electronic nose' that may be able to accurately and quickly identify trafficked animals and body parts in the field to assist in law enforcement.

As wildlife poaching pushes animals such as rhinos and elephants toward extinction, representatives from a record number of nations will gather in South Africa next week for a critical wildlife conference.