A Supremely Gigantic Aquarium

The "Kuroshio Sea" is a super-gigantic fish tank located at the Okinawa Churaumi Aquarium in Japan. It's the second-largest tank in the world (second only to the Georgia Aquarium), holding nearly 2 million gallons of water, and housing four whale sharks (the world's biggest fish), among others. The video below shows spectators watching the action, and divers are visible inside the tank -- dwarfed by the fish, sharks, and manta rays. From the filmmaker's description:

The main tank called the "Kuroshio Sea" holds 7,500-cubic meters (1,981,290 gallons) of water and features the world's second largest acrylic glass panel, measuring 8.2 meters by 22.5 meters with a thickness of 60 centimeters. Whale sharks and manta rays are kept amongst many other fish species in the main tank.

Kuroshio Sea - 2nd largest aquarium tank in the world - (song is Please don't go by Barcelona) from Jon Rawlinson on Vimeo.

The song is "Please Don't Go" by Barcelona. You can also download a desktop wallpaper of the aquarium, or read more about the aquarium (includes some impressive photos).

Joe Raedle, Getty Images
Why Scientists Are Hunting Down Iguanas in Florida
Joe Raedle, Getty Images
Joe Raedle, Getty Images

In South Florida, iguanas had better watch their backs. That's because scientists are on an unusual hunt to kill them, with the help of captive bolt guns and a $63,000 research grant, according to the Sun Sentinel.

It's not as cruel as it might seem at first glance. The green iguana, native to Central and South America, is an invasive species in Florida. The large lizards—which can grow up to 6 feet long—first made it to Florida in the 1960s, and as their population has exploded, they have expanded farther north. The reptiles damage roads, sidewalks, sea walls, and flood-control canals with their burrows; chomp their way through landscaping; spread Salmonella, largely by pooping in people's backyard pools; and compete with the endangered Miami blue butterfly for precious food resources.

The population boom has caused an uptick in complaints from residents, Florida Fish and Wildlife's Sarah Funck told the Sun Sentinel in 2017, pushing the state to find new strategies to deal with the reptiles. One approach? Hire scientists to hunt them down and kill them.

As part of the Florida Fish and Wildlife research project, 15 University of Florida biologists have been tasked with executing as many iguanas as possible in Broward County (home to Fort Lauderdale and parts of the Miami metropolitan area), setting out in teams of two at night. Armed with flashlights and captive bolt guns—which are often used on animals in slaughterhouses and are considered a humane way of killing an animal instantly and painlessly—the researchers attempt to sneak up on sleeping lizards and shoot them before they can scurry away. They also sometimes dispatch the iguanas by smashing their heads against a hard surface, including the side of a truck or a boat.

They've exterminated 249 lizards so far. They take the dead animals back to the lab to be weighed and measured for their dataset, then deposit the carcasses in a landfill. The iguana killing spree is expected to last into May.

While they have tried trapping the iguanas in county parks, they haven't succeeded in capturing any with that method.

As part of the Fish and Wildlife Conservation Commission's iguana-eradicating efforts, the agency has also been hosting public workshops on how to deter and trap iguanas and has hired a dedicated trapper to control populations on public lands in the Florida Keys. 

[h/t Sun Sentinel]

Rachael Herman, Louisiana State University, © Stony Brook University
Poop Visible From Space Helped Scientists Find a Remote 'Supercolony' of Penguins
Rachael Herman, Louisiana State University, © Stony Brook University
Rachael Herman, Louisiana State University, © Stony Brook University

Penguin poop visible from space just helped scientists discover a previously unknown, massive colony of Adélie penguins on a chain of remote Antarctic islands, according to a new study published in Scientific Reports.

In 2014, Stony Brook University's Heather Lynch and NASA's Mathew Schwaller identified guano stains in satellite images of the Danger Islands, a rocky archipelago off the Antarctic Peninsula. The visible guano marks signaled that a large population of penguins was living there. When the scientists launched an expedition to the islands to learn more, and counted birds by hand and with a camera-equipped drone, they discovered a "supercolony" of more than 1.5 million Adélies.

"Until recently, the Danger Islands weren't known to be an important penguin habitat," Lynch said in a press release. By this count, the islands are actually home to the largest population of the species on the Antarctic Peninsula.

The Danger Islands were discovered by British explorer James Clark Ross in 1842, and got their name from the fact that they are often hidden under ice. Ross and his crew almost crashed their ships on them—"appearing among heavy fragments of ice, they were almost completely concealed until the ship was nearly upon them," as the USGS's Geographic Names Information System explains. They're still hard to access and dangerous to visit because of the thick ice that surrounds them. And that makes them perfect for penguins.

Aerial shot from a quadcopter of penguin populations on Heroina Island.
Thomas Sayre McChord, Hanumant Singh, Northeastern University, © Woods Hole Oceanographic Institution

Penguins depend on sea ice for survival, and in places where sea ice is disappearing, their populations are declining. The western Antarctic Peninsula has seen huge declines in Adélie penguin populations as the ice has melted—up to 80 percent in some colonies since 1981, by one estimate. But because of the geographic variation in how climate change has affected temperatures, the population decline hasn't been the same everywhere, and other colonies have even grown. This new discovery tracks with Lynch's previous research, which has found that the impact of climate change on Antarctic penguins will be highly variable depending on the location.

“Just because a huge colony was just found doesn't mean that colonies in areas where sea ice isn't great aren't declining," University of Minnesota ecologist Michelle LaRue wrote in an email to Mental Floss. “If the sea ice conditions at the Danger Islands colony all of a sudden saw similar trends in sea ice decline, I would still expect that colony to decline, too." LaRue has worked with Lynch to study penguin populations before, but wasn't involved with this latest study.

The paper also shows how useful the combination of satellite, ground observation, and drones can be in counting penguins in remote areas. The drone was able to capture images like the one above every second as it flew over the island, creating 2D and 3D views of the whole area. This made their overall population count more accurate, which will aid researchers in tracking changes in the colony as time goes on.


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