Ruth Kassinger

Behind the Book by

For most people, the word algae conjures up images of slimy green goo, pond scum or seaweed. But Ruth Kassinger will change your mind. In her new book, Slime: How Algae Created Us, Plague Us, and Just Might Save Us, she takes an obscure topic that seems boring, even gross, and makes it fascinating and relevant.

Still don’t believe us? Don’t take our word for it. From Ruth Kassinger herself, here are 12 interesting facts about algae to convince even the sternest slime skeptics.


1. Take a breath. Half the oxygen you breathed in was made by algae. We don’t think much about algae, except when we see yucky, slimy scum on a pond. But algae first oxygenated Earth’s atmosphere. If all Earth’s algae died tomorrow, we would soon expire, too.

2. Swallow a single drop of ocean water, and you’ll swallow thousands of microscopic algae. There are more algae in the oceans than stars in the universe.

3. Algae are the base of the marine food chain. Without algae, there would be no fish or any other sea animals.

4. All plants evolved from algae. Without plants to eat, fish would never have evolved to become land animals—including, of course, us.

5. Coral reefs depend on algae. Symbiotic algae that live inside corals (which are animals) create sugars through photosynthesis. Those sugars meet 90% of the corals’ energy needs.

6. Our brains are dependent on the iodine and omega-3 oils that algae contain. When we don’t eat algae (or sea creatures that dined on algae), we run the risk of thyroid deficiency and lower IQs. Some scientists attribute the expansion of the hominid brain to access to seaweed and algae-eating fish.

7. Algae are in your kitchen and bathroom. Listed as carrageenan or alginate, you’ll find them in ice cream (where they prevent ice crystals from forming), chocolate milk (to keep cocoa suspended) and salad dressing (to keep the components mixed). Algae gel your toothpaste, thicken your body lotion and coat tablets to hold the ingredients together. And that’s just the start!

8. The U.S. Navy has run ships and planes on nonpolluting fuel made from the oils in algae. The price of algae oil has dropped radically, and new technology will drive it down further. If the price of fossil fuels even partially reflected the cost of their environmental damage, we would be flying jets on algae fuel.

9. Algae can substitute for oil and natural gas in plastics. A Mississippi company is making the soles of running shoes and other products with EVA made from algae. In 2019, Algix will use more than 12 million pounds of pond scum. Ten billion pairs of running shoes are made annually; the potential for algae plastics is big.

10. Harmful algae blooms are getting bigger and lasting longer in our era of climate change and fertilizer runoff. The blooms already cause hundreds of millions of dollars in annual losses for fishermen and tourist economies around the world.

11. Red algae living on the Greenland ice sheet account for 5 to 10% of the ice sheet’s shrinkage. The algae turn the snow pink when the slightest melt occurs. This “watermelon snow” absorbs light, which heats the snow and creates a feedback loop that hastens the disappearance of snow.

12. Livestock burps and flatulence are responsible for 15% of greenhouse gas emissions. Scientists recently discovered a seaweed that, when added in small amounts to livestock feed, reduces livestock methane emissions by 50 to 85%.

ALSO IN BOOKPAGE: Read our review of Slime.

Ruth Kassinger gives us 12 interesting facts about algae to convince even the sternest slime skeptics.

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