Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



SHAKE AND BLOW
Tsunami reveals human noise pollution in Hawaiian waters
by Staff Writers
Durham NC (SPX) Nov 02, 2017


Using passive acoustic recorders, Heenehan and her colleagues measured and identified the sources of sound pollution in four shallow bays along the Kona Coast that are home to populations of spinner dolphins, a major eco-tourism draw. Conservationists have long feared that interactions caused by dolphin-encounter boat tours and other human activities disrupt the sleeping behaviors of the dolphins, who rest in the bays during the day to gain energy to hunt for food in offshore waters at night.

A tsunami that struck Hawaii in 2011 and caused a temporary halt to boat traffic has provided scientists a rare glimpse into what the bays might sound like without human activities.

The tsunami, triggered by the same earthquake that caused the Fukushima nuclear disaster in Japan, reached waters along the island of Hawaii's Kona Coast while a Duke University-lead team was recording underwater sound in four bays there.

"On the tsunami day, underwater sound levels during the loudest part of the day measured 98.8 decibels (re 1 uPa). On days when human activities in and near the bays weren't halted, we recorded sound pulses more than 16 times louder than that," said Heather L. Heenehan, a postdoctoral scientist at NOAA's Northeast Fisheries Science Center, who led the study as part of her doctoral dissertation at Duke's Nicholas School of the Environment.

Because sound waves travel and are amplified differently in water than in air, scientists use the reference "(re 1 uPa)" to express the relative loudness of sounds recorded underwater.

Noise from boat traffic in the four bays reached up to 125 decibels (re 1 uPa), while pulses from nearby sonar exercises reached 143 decibels (re 1 uPa). "Keep in mind that every increase of 10 decibels is perceived as a doubling in loudness," Heenehan said.

The new peer-reviewed paper was published online Oct. 24 in the journal Marine Pollution Bulletin.

Using passive acoustic recorders, Heenehan and her colleagues measured and identified the sources of sound pollution in four shallow bays along the Kona Coast that are home to populations of spinner dolphins, a major eco-tourism draw. Conservationists have long feared that interactions caused by dolphin-encounter boat tours and other human activities disrupt the sleeping behaviors of the dolphins, who rest in the bays during the day to gain energy to hunt for food in offshore waters at night.

The new study validated these concerns by showing that humans create the loudest disruptions in each of the four bays. Boat traffic and sonar were significant causes of noise in all four bays. Sounds from boats involved in recreational activities in the bays and nearby fish farms also contributed to the daytime din to varying degrees.

Because different combinations of human noises affected each bay's soundscape differently, policy solutions will have to be tailored to individual situations, said David W. Johnston, a co-author on the study and associate professor of the practice of marine conservation ecology at Duke's Nicholas School.

"No one-size-fits-all approach will work," he said.

The new tsunami-enabled benchmark of what the bays sound like without human disruptions gives policymakers, conservationists and local communities an aspirational target to aim for when implementing future measures to reduce underwater sound levels, Heenehan said.

"This shows just how much human activities interrupt the acoustic environment of these animals at a critical resting time," she said.

Research Report: "Natural and Anthropogenic Events Influence the Soundscapes of Four Bays on Hawaii Island,"

SHAKE AND BLOW
Tsunami enabled hundreds of aquatic species to raft across Pacific
Washington DC (SPX) Oct 02, 2017
The 2011 Japanese tsunami set the stage for something unprecedented. For the first time in recorded history, scientists have detected entire communities of coastal species crossing the ocean by floating on makeshift rafts. Nearly 300 species have appeared on the shores of Hawaii and the U.S. West Coast attached to tsunami debris, marine biologists from the Smithsonian Environmental Research Cent ... read more

Related Links
Duke University
Bringing Order To A World Of Disasters
When the Earth Quakes
A world of storm and tempest


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SHAKE AND BLOW
$129 bn in extreme weather losses last year: climate report

Displaced Puerto Ricans find refuge in New York

Puerto Rico 'heartbreaking' five weeks post-storm

Five years on, New Yorkers still live with the scars of Hurricane Sandy

SHAKE AND BLOW
Turning a material upside down can sometimes make it softer

Nanoscale textures make glass invisible

Discovery of a new structure family of oxide-ion conductors SrYbInO4

Technique offers advance in testing micro-scale compressive strength of cement

SHAKE AND BLOW
Mass seal deaths in Russia's Lake Baikal

Fossil coral reefs show sea level rose in bursts during last warming

Devices assembled from 2D materials separate different salts in seawater

The oceans were colder than we thought

SHAKE AND BLOW
Hopes dashed for giant new Antarctic marine sanctuary

Canada caribou herds, habitat continue to decline: report

'Scars' left by icebergs record West Antarctic ice retreat

Groundwater and tundra fires may work together to thaw permafrost

SHAKE AND BLOW
Crops evolving 10 millennia before experts thought

Rainy summer puts Germans off their beer

EU member states to vote on five-year weedkiller renewal next month

Cowpea protected from a devastating pest, free for smallholder African farmers

SHAKE AND BLOW
Anticipating aftershocks

Japanese earthquake zone strongly influenced by the effects of friction

Tropical Storm Philippe crosses Cuba towards Florida

Authorities lower Bali volcano alert status

SHAKE AND BLOW
Death of soldiers highlights US military presence in Niger

Pentagon looks at stepped-up Africa role to counter IS

US military to pursue Niger operations after deadly attack

Niger raid highlights US forces' growing Africa role

SHAKE AND BLOW
Older Neandertal survived with a little help from his friends

Researchers demonstrate 'mind-reading' brain-decoding tech

Remote Amazon tribe tries to straddle two worlds

Determining when humans started impacting the planet on a large scale




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement