- Mbappe on target as Real Madrid cruise to Leganes win
- Israel records 250 launches from Lebanon as Hezbollah targets Tel Aviv, south
- Australia coach Schmidt still positive about Lions after Scotland loss
- Man Utd 'confused' and 'afraid' as Ipswich hold Amorim to debut draw
- Sinner completes year to remember as Italy retain Davis Cup
- Climate finance's 'new era' shows new political realities
- Lukaku keeps Napoli top of Serie A with Roma winner
- Man Utd held by Ipswich in Amorim's first match in charge
- 'Gladiator II', 'Wicked' battle for N. American box office honors
- England thrash Japan 59-14 to snap five-match losing streak
- S.Africa's Breyten Breytenbach, writer and anti-apartheid activist
- Concern as climate talks stalls on fossil fuels pledge
- Breyten Breytenbach, writer who challenged apartheid, dies at 85
- Truce called after 82 killed in Pakistan sectarian clashes
- Salah wants Liverpool to pile on misery for Man City after sinking Saints
- Berrettini takes Italy to brink of Davis Cup defence
- Lille condemn Sampaoli to defeat on Rennes debut
- Leicester sack manager Steve Cooper
- Salah sends Liverpool eight points clear after Southampton scare
- Key Trump pick calls for end to escalation in Ukraine
- Tuipulotu try helps Scotland end Australia's bid for a Grand Slam
- Davis Cup organisers hit back at critics of Nadal retirement ceremony
- Noel in a 'league of his own' as he wins Gurgl slalom
- A dip or deeper decline? Guardiola seeks response to Man City slump
- Germany goes nuts for viral pistachio chocolate
- EU urges immediate halt to Israel-Hezbollah war
- Basel votes to stump up bucks to host Eurovision
- Ukraine shows fragments of new Russian missile after 'Oreshnik' strike
- Six face trial in Paris for blackmailing Paul Pogba
- Olympic champion An wins China crown in style
- It's party time for Las Vegas victor Russell on 'dream weekend'
- Norris applauds 'deserved' champion Verstappen
- Kohli blasts century as India declare against Australia
- Verstappen 'never thought' he'd win four world titles
- Former Masters champion Reed wins Hong Kong Open
- Awesome foursomes: Formula One's exclusive club of four-time world champions
- Smylie beats 'idol' Cameron Smith to win Australian PGA Championship
- Five key races in Max Verstappen's 2024 title season
- Max Verstappen: Young, gifted and single-minded four-time F1 champion
- 'Star is born': From homeless to Test hero for India's Jaiswal
- Verstappen wins fourth consecutive Formula One world title
- Survivors, sniffing dogs join anti-mine march at Cambodia's Angkor Wat
- Far right eye breakthrough in Romania presidential vote
- Jaiswal slams majestic 161 but Australia fight back in Perth
- Edinburgh's alternative tour guides show 'more real' side of city
- IPL teams set to splash the cash at 'mega-auction' in Saudi Arabia
- Olympics in India a 'dream' facing many hurdles
- Wounded Bangladesh protesters receive robotic helping hand
- Majestic Jaiswal 141 not out as India pile pain on Australia
- Giannis, Lillard lead Bucks over Hornets as Spurs beat Warriors
Mysteries and music: listening in to underwater life
When marine researchers started recording sounds in the seagrass meadows of the Mediterranean Sea they picked up a mysterious sound, like the croak of a frog, that resounded within the dense foliage -- and nowhere else.
"We recorded over 30 seagrasses and it was always there and no-one knew the species that was producing this kwa! kwa! kwa!" said Lucia Di Iorio, a researcher in ecoacoustics at France's CEFREM.
"It took us three years to find out the species that was producing that sound."
The melodious songs of whales might be familiar music of the world's underwater habitats but few people will have heard the hoarse growl of a streaked gurnard or the rhythmical drumbeat of a red piranha.
Scientists are now calling for those sounds and many thousands more to become more widely accessible.
They say a global database of the booms, whistles and chatter of the sea will help to monitor diversity in aquatic life -- and help put a name to mystery sounds like the one Di Iorio and her colleagues investigated.
Experts from nine countries are working to create what they have dubbed the Global Library of Underwater Biological Sounds -- or "GLUBS".
This would gather together recordings held all over the world and open them up to artificial intelligence learning and mobile phone apps used by citizen scientists.
While experts have been listening to life underwater for decades, the team behind GLUBS say that audio collections tend to be narrowly focused on a specific species or geographical area.
Their initiative is part of burgeoning work on marine "soundscapes" -- collecting all the sounds in a particular area to discern information about species types, behaviour and overall biological diversity.
Scientists say these soundscapes are a non-invasive way to "spy on" life underwater.
In a paper published recently in the journal Frontiers in Ecology and Evolution, the GLUBS team said many fish and aquatic invertebrates are mainly nocturnal or hard to find, so acoustic monitoring could help conservation efforts.
"With biodiversity in decline worldwide and humans relentlessly altering underwater soundscapes, there is a need to document, quantify and understand the sources of underwater animal sounds before they potentially disappear," said lead author Miles Parsons of the Australian Institute of Marine Science.
- Sonic 'barcode' -
Scientists believe that all 126 marine mammal species emit sounds, as do at least 100 aquatic invertebrates and some 1,000 fish species.
The sounds can convey a wide range of messages -- acting as a defence mechanism, to warn others of danger, as part of mating and reproduction -- or just be the passive noise of an animal munching a meal.
Di Iorio, a co-author on the GLUBS paper, said while marine mammals, like humans, learn their language of communication, the sounds made by invertebrates and fish are "just their anatomy".
Many fish produce a distinctive drumming sound using a muscle that contracts around their swim bladder.
"This dum-dum-dum-dum-dum, the frequency, the rhythm and the number of pulses vary from one species to another. It's very specific," Di Iorio told AFP.
"It's like a barcode."
Scientists can recognise families of fish just from these sounds, so with a global library they might be able to compare, for example, the thrumming calls of different grouper fish in the Mediterranean to those off the coast of Florida.
But another key use for the library, they say, could be to help identify the many unknown sounds in the world's seas and freshwater habitats.
- Mystery music -
After many months investigating the strange seagrass croaker, Di Iorio and her colleagues were able to point the finger of suspicion at the scorpionfish.
But they struggled to explain how it was making such an unusual noise -- and it refused to perform for them.
They tried catching the fish and recording it in a carrier. They sunk sound equipment onto the seabed next to the fish. They even listened in to aquariums that contained scorpionfish.
"Nothing," she said.
Eventually colleagues from Belgium took a camera that could record at low light and staked out some seagrass in Corsica.
They were able to capture the kwa! kwa! sound as well as video of the fish making a shimmying motion.
Back in the lab, they dissected a scorpionfish and found that they have tendons strung along their bodies.
Their hypothesis is that the fish contracts these muscles to produce the sound.
"It's a guitar, an underwater guitar," said Di Iorio.
But there are many more mysteries where that came from.
Di Iorio said in the Mediterranean, up to 90 percent of noises in a given recording might be unknown.
"Every time we put a hydrophone in the water we're discovering new sounds," she added.
F.Santana--PC