Hello Australia!! - The warming oceans are rapidly losing oxygen - The US and Iran swap prisoners - The macabre "dinner party" preceding a mass shooting - And more in your CareerSpot Global News Briefs:

Climate change is causing the world's oceans to lose precious oxygen, and threatening many species of fish.  The biggest study of its kind conducted by the International Union for the Conservation of Nature (IUCN) said that about 700 sites had been identified globally with low oxygen levels.  That's up from only 45 in the 1960s.  "What we are seeing is a decline of two percent in the global oxygen level (in the oceans).  It doesn't sound like a lot but this small change will have enormous ramifications," said the IUCN's Minna Epps.  "Deoxygenation will have an impact on biodiversity, on biomass of commercially important species and on vulnerable rare species."

The worst drought in a century has reduced Africa's Victoria Falls from one of the most majestic waterfalls on earth to a mere trickle.  The Zambezi River - which feeds the falls on the border of Zimbabwe and Zambia - has fallen so low that hydroelectric dams cannot produce electricity and the two countries are instituting widespread power cuts.  Previous climate models had predicted more drought years as the earth warms, but this is happening even faster than predicted - the last drought was only three years ago.

US Defense Secretary Mark Esper won't call the shooting at Florida's Pensacola Naval Air Station a terrorist attack just yet.  But there are troubling details coming out about the events that preceded Saudi Arabian military officer Mohammed Saeed Alshamrani's attack in which he killed three people before he was shot dead by a local Sheriff's deputy.  Alshamrani had invited friends to a dinner party the night before Friday's attack, and showed them videos of mass shootings.  Associates said Alshamrani had recently returned from a visit to his homeland, and appeared to be more pious and didn't want to go out with them anymore.  

Government forces and Russian allies have pounded the last rebel stronghold in Syria with a series of air raids that killed at least 18 people in Idlib province - eight children are reportedly among the dead.  Forces loyal to President Bashar al-Assad are softening-up the area before an anticipated offensive to recapture the main highway that links the capital Damascus with the northern city of Aleppo, Syria's largest and once a commercial center.  The last rebels are mostly al Qaeda-linked fighters.  The eight-year Syrian Civil War - seemingly forever in its final days - has killed more than 400,000 people, wounded more than a million, and displaced half the country's pre-war population.

Representatives from the US and Iran met in Switzerland to work out a prisoner swap, although each side is loath to characterize it as such.  Iran released US-citizen and Princeton University PhD candidate Xiyue Wang, who was jailed for alleged espionage since 2016 when he traveled to the country to research the Qajar Dynasty of the 19th Century.  The US sent back Iranian scientist Massoud Soleimani, who had been accused of violating trade sanctions.