Colorful sea hedgehogs starting to adapt to our souring oceans

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1 Colorful sea hedgehogs starting to adapt to our souring oceans By The Seattle Times, adapted by Newsela staff on Word Count 984 A sea urchin sits in a tank at the University of California, Santa Barbara marine science building where scientists are studying the creatures' adaptation to ocean acidification. Photo: Steve Ringman/Seattle Times/MCT SANTA BARBARA, Calif. Marine biologist Gretchen Hofmann has a number of sea urchins wriggling in the tank in her laboratory. These purple-colored spheres live underwater and are not really known for their speed. But these lowly sea urchins adapt very quickly to changes in the environment. So scientists are studying them to learn about how marine life will react to big changes in the ocean. Humans have made the seas more acidic by burning fuels like gasoline and oil. So the experts are looking at urchins to see how they change because of the new water around them. These hedgehogs of the sea show nature s amazing capacity to tough it out in the face of huge challenges. Many animals and fish are threatened by the rapidly souring seas. But few seem as likely as urchins to survive through the years ahead.

2 Not Everything Will Make It Hofmann is a marine biologist at the University of California. She has studied urchins for years. The animals can change very quickly but "concerns about extinction are very real," she said. Hofmann is concerned that sea creatures could be pushed beyond what they can handle and just die out. The oceans are absorbing a quarter of the carbon dioxide that results from people burning coal, oil and gas. This is making the water change faster than it has for tens of millions of years. Which plants and animals can survive these harsher seas and for how long will depend on many factors. These include where they live their population sizes, and how they handle warming temperatures and pollution. Survival will vary species by species. Not everything will make it. Stephen Palumbi, who works at Stanford University, said this process of evolution is not a "gentle sport." Palumbi added that when evolution happens, it is because the "unfit are dying" and it is "pretty brutal." In the late 2000s, urchin fisherman Bruce Steele feared things were not going very well for the animals. He had good reasons to think so. Urchins graze on seaweed and are eaten by sea otters and humans. Steele is a scuba diver who has made his living scooping up the animals from the seafloor since the 1970s. He sells the urchins to sushi restaurants. An Important Observation When he heard about sea acidification, he saw right away what it could mean for his business and the ocean he loves. So Steele dialed up Hofmann and she started looking into his concerns about the urchins' health. Her first experiment was to put urchin babies in water with high levels of carbon dioxide and observe what happened. She found that the babies often got smaller. Increasing carbon dioxide in the oceans reduces carbonate ions in the water. Scallops, crabs, coral and urchins use carbonate ions to build their shells and skeletons. Overall, their body size really matters in how well they swim and how much food they get, Hofmann said. So if you re smaller, it s really bad news if you re a baby sea urchin in the water. But the scientist noticed that while some of the babies had shrunk, some didn't change size at all. Also, not all of the urchins reacted to the water in the same way. Hofmann knew enough about science to know that this might be important.

3 A Moth Changes Color To Survive Animals can change to match their surroundings simply and quickly. In Manchester, England, a tree moth changed from mostly speckled ivory color to black in just a few years. Two hundred years ago in Manchester, there were two types of moths. The most common was ivory colored and the other was black. But when dirt from local factories darkened the light trees, white moths became very easy to see. The lighter insects were spotted by birds, but the black moths were more difficult to catch. The white moths were eaten while the black moths did well, so the most common color of the moth changed from ivory to black. But once smoke pollution was controlled, the tree trunks grew light again. After this, the ivory-colored moths returned to the trees, as they were once again more difficult to spot than the black moths. Like the moths, Hofmann suspected that some urchins were better able to handle changes than others. It all depends on the carbon dioxide, or CO2, levels in the water the animals are used to. Near to the shore, water moves around a lot and the CO2 levels can vary at different times of day. "Tough" Mixes With "Wimpy" The CO2 levels are also higher or lower in different parts of the ocean. In the oceans of Northern California and the Pacific Northwest, the urchins have spent millions of years in water with lots of CO2. But in Southern California, the animals have experienced much less CO2. So Hofmann and a co-worker mated wimpy Southern California sea urchins with "tougher" males from the north. They created babies that were more resistant to the acidic water. The kids of that father were much better at maintaining the size of their body, Hofmann said. At the same time, the Stanford researchers grew urchins in Southern Californian water and in water from high-co2 zones in Oregon. They also found that some animals started to adapt successfully to higher levels of carbon dioxide. The urchins have shown they can match their bodies to the changing oceans. It was really kind of surprising, and a little bit on the hopeful side, Hofmann said. But as the sea continues to fill up with carbon dioxide, the scientists still don't know how much the sea urchins can take before it is too much. Palumbi admitted that the experiments "don t tell us how long it will take for them to reach their limit." Another thing they don't know is how many urchins will shrink and suffer before they have adapted to the new ocean conditions.

4 Quiz 1 The survival of many plants and animals of the ocean depends on all of the following EXCEPT: their habitat their population their adaptability their place in the food chain 2 Carbonate ions in the ocean are important to all of the following EXCEPT: urchins crabs corals fish 3 Oceans absorb the CO2 produced as a result of the burning of all the following EXCEPT: oil gas coal electricity 4 Select the paragraph from the section, "Not Everything Will Make It," that shows the factors important for survival.

5 Answer Key 1 The survival of many plants and animals of the ocean depends on all of the following EXCEPT: their habitat their population their adaptability their place in the food chain 2 Carbonate ions in the ocean are important to all of the following EXCEPT: urchins crabs corals fish 3 Oceans absorb the CO2 produced as a result of the burning of all the following EXCEPT: oil gas coal electricity 4 Select the paragraph from the section, "Not Everything Will Make It," that shows the factors important for survival. Paragraph 6: Which plants and animals can survive these harsher seas and for how long will depend on many factors. These include where they live their population sizes, and how they handle warming temperatures and pollution. Survival will vary species by species. Not everything will make it.