Astronauts living at the International Space Station are about to take their first bites of space-grown lettuce, in what scientists described as another step toward enabling human missions to Mars.

If space explorers can grow their own food while they are away from the Earth, they are more likely to survive the rigors of deep space exploration lasting months or even years, according to NASA.

The picture-perfect beaches and turquoise waters that people expect on their visits to the Caribbean are increasingly being fouled by mats of decaying seaweed that attract biting sand fleas and smell like rotten eggs.

Clumps of the brownish seaweed known as sargassum have long washed up on Caribbean coastlines, but researchers say the algae blooms have exploded in extent and frequency in recent years. The 2015 seaweed invasion appears to be a bumper crop, with a number of shorelines so severely hit that some tourists have canceled summer trips and lawmakers on Tobago have termed it a "natural disaster."

Seasonal rains have failed to materialize in some parts of Ethiopia, causing deaths of many cattle and other animals.

Witnesses say hundreds of cattle are dying daily, especially in the Afar Region.

Indonesian police have arrested four men for allegedly killing a Sumatran tiger and trying to sell its body parts, an official said Monday, the latest case of the critically endangered animals being targeted.

Acting on a tipoff, a group of police officers posing as potential buyers arrested the men on Saturday as they allegedly attempted to sell the tiger's skin, bones and teeth.

A seafood lunch in Hong Kong is enjoyed by locals and visitors alike, but with threatened species on the menu and fishing practices that endanger marine life, campaigners want to change the city's appetite.

Hong Kong is the second-largest consumer of seafood per capita in Asia -- an average resident consumes 71.2 kilos (157 pounds) of seafood each year, more than four times the global average, according to the World Wide Fund for Nature Hong Kong.

A comet streaking through space with a European robot lab riding piggyback will skirt the Sun this week, setting another landmark in an extraordinary quest to unravel the origins of life on Earth.

Scientists hope the heat of perihelion -- when the comet comes closest to the Sun in its orbit -- will cause the enigmatic traveler to shed more of its icy crust.

A prosecutor in South Africa's Kruger National Park says rhino poaching cases appear in court like "shoplifting cases in the city", casting doubt on the country's anti-poaching strategy as it suffers another year of rhino carnage.

For the past six years, prosecutor Ansie Venter has been working on rhino poaching cases in Skukuza Magistrates' Court, the legal heart of the world-famous park.

Mad as a hornet, a bumblebee buzzes her wings in vain against the walls of the vial holding her captive. She alights briefly on the paper tab indicating her number, and then resumes scuttling around her plastic prison.

Her warden is Shaina Helsel, one soldier in a citizen army that is taking a census of Maine's bumblebees in an effort to secure the future of the state's blueberries, cranberries and tomatoes amid concern about the population of pollinators.

It has long been thought that wealthy countries, bolstered with more money for infrastructure investment, face lower risks of flooding.

But new research Thursday found that rich countries face major risks as climate change and human activity render coastal populations increasingly vulnerable to devastating river delta floods.

A Florida aquarium has reached an agreement with one in Cuba to cooperate on coral conservation efforts -- the first such arrangement since Washington and Havana normalized relations, the American marine institute said Wednesday.

"Although Cuba's reefs are only 90 miles (145 kilometers) away from Key West, they are in much better condition than our local reefs systems," said Thom Stork, president and CEO of The Florida Aquarium.