Quirks & Quarks

August 13: Best of Quirks & Quarks - Stories from our water world

We’re bringing you stories from our past season about the water on our planet, like an innovative experiment in Australia to protect the wondrous Great Barrier Reef, the sweet secret of seagrass meadows, historic Indigenous oyster fisheries, and more.

How whales fertilize the ocean, why car tires are bad for salmon, and more.

Scientists investigate a humpback whale by boat and drone in the surface waters near the West Antarctic Peninsula. (Duke University Marine Robotics and Remote Sensing under NOAA permit 14809-03 and ACA permits 2015-011 and 2020-016)

On this week's episode of The Best of Quirks & Quarks with Bob McDonald:

Cloud-based sunscreen could help protect the Great Barrier Reef from future heat damage
Originally broadcast Oct. 9, 2021

Scientists in Australia have started testing a radical idea to brighten clouds over the Great Barrier reef to protect it from future heat damage. They hope to enhance low-lying marine clouds over the reef to make them reflective so they bounce more of the sun's energy away from Earth to cool the water. Daniel Harrison, a senior lecturer at the National Institute of Marine Science at Southern Cross University in Australia, led experiments that he said would produce a localized effect over the Great Barrier Reef.
Australian scientists test radical idea to prevent future coral bleaching by artificially brightening clouds by spraying a fine mist of seawater into the atmosphere. (Brendan Kelaher / Southern Cross University / Reuters)

Whale researchers do autopsy with heavy machinery to understand why whales don't choke on their food
Originally broadcast Jan. 22, 2022

The largest whales, the giant filter feeders like the blue and fin whales, feed by lunging at concentrations of prey and taking in vast quantities of food and water. Scientists have puzzled over how these massive animals can dive so quickly, with their mouths wide open, without choking. Researchers including zoologist Kelsey Gil from the University of British Columbia made the surprising discovery of a fatty "oral plug" that acts to block the whales' windpipe to allow them to feed with ease.

Rubber dust from car tires can poison freshwater fish 
Originally broadcast March 19, 2022

Fish die offs are common in waterways around roads after a storm and rubber dust from car tires may be one reason why. A team led by Markus Brinkmann at the University of Saskatchewan found that a chemical called 6PPD-quinone, found in most car tires, is incredibly toxic to two trout species. Half of the rainbow and brook trout in the research tank would die when exposed to low concentrations of the chemical, much lower than is found in many rivers. Curiously, the chemical did not have an effect on two other species studied: Arctic char and white sturgeon. The research was published in Environmental Science & Technology Letters.

Seagrass is hiding a submerged sweet CO2 secret
Originally broadcast May 14, 2022
Seagrass meadows around the world absorb carbon dioxide at a prodigious rate. Now researchers have discovered that they're converting and storing the carbon in marine sediments in a surprising form – as ordinary table sugar. Nicole Dubilier, Director at the Max Planck Institute for Marine Microbiology in Bremen, Germany, led a team that detected the sugar-rich sediments. They also found the seagrass also produced antimicrobials that prevent the sugar being consumed by 'sweet-toothed' microorganisms, and its carbon safely locked away. Her research was published in Nature Ecology and Evolution.
Seagrass meadows like this one convert and store carbon into massive amounts of sugar which they deposit through their roots into marine sediment. Researchers estimate that world-wide, seagrass produces an amount of sugar equal to that of 32 billion cans of soda-pop. (HYDRA Marine Sciences GmbH)

Oyster shell mountains show history of sustainable Indigenous fisheries
Originally broadcast May 14, 2022

At sites around the world, ancient people disposed of oyster shells in piles that, over many hundreds of years, reached metres high. In a new study published in the journal Nature, a team of archaeologists including Torben Rick examined these massive oyster shell piles around the world and found that they revealed a history of sustainable oyster harvesting practices that modern scientists think we can learn from.

Read more: Indigenous people harvested huge amounts of oysters sustainably through history, study finds

How whales' gigantic appetites can help the ocean
Originally broadcast November 6, 2021

In the most detailed study of their diets yet, researchers studying 321 different whales across seven different species found that baleen whales — which includes the world's largest animal, the blue whale — eat an average of three times more each year than previously estimated. All that food turns into iron-rich feces, which is important in the ocean's nutrient cycle. The research was published in the journal Nature.

Read more: Baleen whales eat much more than we thought — and fertilize the oceans doing it