What Penguins Tell Us About Ocean Warming

Two African Penguins swimming at the National Aviary

One of the featured attractions at the National Aviary is the Penguin Point exhibit. The African penguins on display are used to a warmer climate. (1) In the winter, the Pittsburgh National Aviary provides them with heated areas. The penguins hate having to walk across any snow that accumulates in their enclosure.

While African (and many other species of) penguins are used to warmer climates, they all live in areas where cold water flows near land, and it’s because of chemistry. That little quirk–that penguins live near currents of cold ocean water–is a clue to something profound about the ocean and warns us of a danger of global warming.

Everyone knows that if you want clear ice cubes, you boil your water before you freeze it. While higher temperatures make it easier to dissolve sugar and salt and other chemicals in water, gasses are the opposite. The higher the temperature, the less gas will dissolve in water. The lower the temperature, the more gas will dissolve in water. As a result, cold sea water contains more carbon dioxide and oxygen.

On TV, the commercials point out that drinking soda pop (2) will damage your teeth. Why? Besides the sugar giving bad bacteria in your mouth something to grow on, the fizz in soda pop comes from carbon dioxide dissolved into the water to make carbonic acid:

Water plus Carbon Dioxide produces Carbonic Acid

Water plus Carbon Dioxide produces Carbonic Acid

 

Acids make it easier to dissolve a lot of chemicals in the water, like calcium. So soda pop helps dissolve the calcium out of your teeth, and CO2 in ocean water helps dissolve calcium and other nutrients into the water.

Colder water is richer in calcium, potassium, oxygen and other chemicals–chemicals that are nutrients for the zooplankton (tiny microscopic and near-microscopic animals) and phytoplankton (tiny microscopic and near-microscopic plants) in water. Fish need food and oxygen, so the smaller fish eat the plankton and phytoplankton. The larger fish eat the smaller fish. The penguins eat the larger fish.

So the penguins hang out near cold ocean streams because that’s where the food is. Unfortunately for the penguins, leopard seals hang out in cold water because that’s where the food is, and and one of their foods is penguins. Great white sharks gather to feed in cold water areas because, once again, that’s where the food is. Whales feed in cold water for the same reason.

Cold water provides nutrients for life in the oceans.

Now, Rush Limbaugh (3) and others are claiming the Earth hasn’t been warming due to global warming for 7-15 years (depending on where they pick their numbers and sometimes, I think they just make things up). If you actually look at the temperature record, you’ll notice that the temperature increase takes a number of steps up and then a couple back, but the progression is upward:

Two Views of Global Warming

Skeptical Science Graphics (Skeptical Science) / CC BY 3.0
But it’s worth remembering that the above graph is about atmospheric temperatures. Real Climate posts the graph for ocean temperatures:
Heat Content of the Earth's Oceans

Heat Content of the Earth’s Oceans

The average pH of the ocean water is going down, As more CO2 enters into the atmosphere, more CO2 gets dissolved into the ocean, absorbed by the cold water. While this will increase the nutrients in the water, it will also decalcify the phytoplankton and zooplankton. Weakened plankton will mean less plankton and thus less food for small fish and the animals that depend upon them–including penguins and humans.

The rising ocean temperatures will raise the ocean levels and currents, which will also affect the penguins. If a cold ocean stream is diverted, the penguins there will starve–as is happening already with the Humbolt Penguins.

And they’re not going to be the only species to starve as a result.

 

  1. This is one reason African penguins are popular in zoos–you don’t have to keep them refrigerated all year! []
  2. I went to Washington University in St. Louis, where half the people said “pop” and half said “soda.” To cut down on confusion, I took to saying “soda pop.” Redundancy provides error correction in communication! []
  3. Someone once told me I didn’t know what I was talking about with regard to global warming, that I was an artist and not a scientist, and I should listen to scientists like Rush Limbaugh. I really need to let that particular incident go. []

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