We can assess the health of coral reefs by the sounds algae make

Tiny bubbles talk photosynthesis.

  • During photosynthesis, algae produces a symphony of little "pings."
  • The sounds are produced by oxygen bubbles breaking away from the plants.
  • Monitoring reef health through its sound is a new avenue for acoustic ecology.

When oceanographers Lauren and Simon Freeman, a couple who work with the U.S. Naval Undersea Warfare Center in Rhode Island, first mentioned what they'd heard to others, the response was not exactly positive. They'd been listening to sounds they were certain had been made by marine macroalgae covering underwater coral reefs in Hawaii. Simon recalls, "We were told the sound was from snapping shrimp, end of story." But, listening at a few locations, they saw a correlation between the amount of sound and the quantity of algae. Further research has pretty much confirmed their hunch, and they've introduced a new avenue for marine acoustic ecology: Assessing the health of reefs according to the sounds they make.

Back up. Sounds the algae make?

An oxygen bubble about to ping and float upward. (Freeman, et al)

Algae, like plants on dry land, convert sunlight and carbon dioxide to energy via photosynthesis. The process releases tiny bubbles of oxygen to the surface. As each bubble lets go of the plant that produced it, there's a little "ping." As the Freemans' research states, "Many such bubbles create a large, distributed sound source over the sea floor." This 2 kHz – 20kHz hiss made of pings is what the Freemans have been hearing and recording from reefs.

There's actually quite a lot of acoustic goings-on underwater, between animal noises, human noises, waves, other bubbles and so on. Acoustic ecologist Erica Staaterman, not involved in the Freemans' research, says, "When I put a recorder in the water, I'm usually surprised by some cool new fish sound that I've never heard before. There's so much to discover."

As a result, recording and listening to algae in the wild is challenging.

To verify that the telltale pings were indeed coming from algae and not some other source, the Freemans set up a tank containing the invasive Hawaiian algae Gracilaria salicornia — no fish or crustaceans welcome. Upon listening, they heard the same high-pitched noise they'd witnessed at degraded reefs that no longer supported fish or other animals.

The value of this discovery

(Rich Carey/Shutterstock)

"Right now," says Simon, "reefs are evaluated visually by divers." Thorough research is an expensive and time-intensive endeavor, and findings are limited to what divers can see. The Freemans are hopeful that acoustic analysis of these environments will eventually reveal much more about reefs' conditions.

"In the future, it might be possible to quickly listen to a coral reef soundscape, perhaps by using an autonomous vehicle, and evaluate how it may have changed from the previous year."

Even now, a snapshot of a reef's algae cover can be quickly gleaned from its sound. (Other researchers are acoustically monitoring beds of sea grass in Australia.)

As Staaterman sees it, "Making these kind of links between bioacoustics and biodiversity is an exciting field with a lot of promise."

LinkedIn meets Tinder in this mindful networking app

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No, we aren't talking about Tinder. Introducing Shapr, a free app that helps people with synergistic professional goals and skill sets easily meet and collaborate.

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Kosovo land swap could end conflict - or restart war

Best case: redrawing borders leads to peace, prosperity and EU membership. But there's also a worst case

Image: SRF
Strange Maps
  • The Yugoslav Wars started in 1991, but never really ended
  • Kosovo and Serbia are still enemies, and they're getting worse
  • A proposed land swap could create peace - or reignite the conflict

The death of Old Yugoslavia

Image: public domain

United Yugoslavia on a CIA map from 1990.

Wars are harder to finish than to start. Take for instance the Yugoslav Wars, which raged through most of the 1990s.

The first shot was fired at 2.30 pm on June 27th, 1991, when an officer in the Yugoslav People's Army took aim at Slovenian separatists. When the YPA retreated on July 7th, Slovenia was the first of Yugoslavia's republics to have won its independence.

After the wars

Image: Ijanderson977, CC BY-SA 3.0 / Wikimedia Commons

Map of former Yugoslavia in 2008, when Kosovo declared its independence. The geopolitical situation remains the same today.

The Ten-Day War cost less than 100 casualties. The other wars – in Croatia, Bosnia and Kosovo (1) – lasted much longer and were a lot bloodier. By early 1999, when NATO had forced Serbia to concede defeat in Kosovo, close to 140,000 people had been killed and four million civilians displaced.

So when was the last shot fired? Perhaps it wasn't: it's debatable whether the Yugoslav Wars are actually over. That's because Kosovo is a special case. Although inhabited by an overwhelming ethnic-Albanian majority, Serbians are historically very attached to it. More importantly, from a legalistic point of view: Kosovo was never a separate republic within Yugoslavia but rather a (nominally) autonomous province within Serbia.

Kosovo divides the world

Image: public domain

In red: states that recognise the independence of Kosovo (most EU member states – with the notable exceptions of Spain, Greece, Romania and Slovakia; and the U.S., Japan, Turkey and Egypt, among many others). In blue: states that recognise Serbia's sovereignty over Kosovo (most notably Russia and China, but also other major countries such as India, Brazil, Mexico, South Africa and Iran).

The government of Serbia has made its peace and established diplomatic relations with all other former Yugoslav countries, but not with Kosovo. In Serbian eyes, Kosovo's declaration of independence in 2008 was a unilateral and therefore legally invalid change of state borders. Belgrade officially still considers Kosovo a 'renegade province', and it actually has a lot of international support for that position (2).

The irony is that on the longer term, both Kosovo and Serbia want the same thing: EU membership. Ironically, that wish could lead to Yugoslav reunification some years down the road – within the EU. Slovenia and Croatia have already joined, and all other ex-Yugoslav states would like to follow their example. Macedonia, Montenegro and Serbia have already submitted an official application. The EU considers Bosnia and Kosovo 'potential candidates'.

Kosovo is the main stumbling block on Serbia's road to EU membership. Even after the end of hostilities, skirmishes continued, between the ethnically Albanian majority and the ethnically Serbian minority within Kosovo, and vice versa in Serbian territories directly adjacent. Tensions are dormant at best. A renewed outbreak of armed conflict is not unthinkable.

Land for peace?

Image: BBC

Mitrovica isn't the only area majority-Serb area in Kosovo, but the others are enclaved and fear being abandoned in a land swap.

In fact, relations between Kosovo and Serbia have deteriorated spectacularly in the past few months. At the end of November, Kosovo was refused membership of Interpol, mainly on the insistence of Serbia. In retaliation, Kosovo imposed a 100% tariff on all imports from Serbia. After which Serbia's prime minister Ana Brnabic refused to exclude her country's "option" to intervene militarily in Kosovo. Upon which Kosovo's government decided to start setting up its own army – despite its prohibition to do so as one of the conditions of its continued NATO-protected independence.

The protracted death of Yugoslavia will be over only when this conflict is finally resolved. The best way to do that, politicians on both sides have suggested, is for the borders reflect the ethnic makeup of the frontier between Kosovo and Serbia.

The biggest and most obvious pieces of the puzzle are the Serbian-majority district of Mitrovica in northern Kosovo, and the Albanian-majority Presevo Valley, in southwestern Serbia. That land swap was suggested previous summer by Hashim Thaci and Aleksandar Vucic, presidents of Kosovo and Serbia respectively. Best-case scenario: that would eliminate the main obstacle to mutual recognition, joint EU membership and future prosperity.

If others can do it...

Image: Ruland Kolen

Belgium and the Netherlands recently adjusted out their common border to conform to the straightened Meuse River.

Sceptics and not a few locals warn that there also is a worst-case scenario: the swap could rekindle animosities and restart the war. A deal along those lines would almost certainly exclude six Serbian-majority municipalities enclaved deep within Kosovo. While Serbian Mitrovica, which borders Serbia proper, is home to some 40,000 inhabitants, those enclaves represent a further 80,000 ethnic Serbs – who fear being totally abandoned in a land swap, and eventually forced out of their homes.

Western powers, which sponsored Kosovar independence, are divided over the plan. U.S. officials back the idea, as do some within the EU. But the Germans are against – they are concerned about the plan's potential to fire up regional tensions rather than eliminate them.

In principle, countries consider their borders inviolate and unchanging, but land swaps are not unheard of. Quite recently, Belgium and the Netherlands exchanged territories so their joint border would again match up with the straightened course of the Meuse river (3). But those bits of land were tiny, and uninhabited. And as the past has amply shown, borders carry a lot more weight in the Balkans.

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Scientists claim the Bible is written in code that predicts future events

The controversy around the Torah codes gets a new life.

Michael Drosnin
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  • Mathematicians claim to see a predictive pattern in the ancient Torah texts.
  • The code is revealed by a method found with special computer software.
  • Some events described by reading the code took place after the code was written.
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  • Facebook and Google began as companies with supposedly noble purposes.
  • Creating a more connected world and indexing the world's information: what could be better than that?
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