All animals breath out carbon dioxide and plants ‘inhale it.’ There is always carbon dioxide in the air and water but too much is a bad thing. Excess carbon dioxide is created by burning fossil fuels such as gas in our cars.
Carbon dioxide is what is causing ocean acidification. The ocean absorbs a lot of carbon dioxide from the atmosphere. The more carbon dioxide in the atmosphere the more carbon dioxide that gets absorbed into the ocean. CO2 affects pH or acids and bases. The more carbon dioxide the lower the pH or the more acidic something is. Higher levels of carbon dioxide and in exchange lower ph can have harmful effects on life in the ocean. For example, shell building creatures cannot build thick, strong shells. Without thick strong shells they cannot reproduce, live as long, and be very healthy. Many of the shell builders are at the bottom of the food chain and affect large large creatures at the top of the food chain. Also, many marine animals use chemical signals for finding a home, spotting predators, and choosing a mate. The increase in carbon dioxide and in the water can make it hard to use those chemical signals. A good example of this is a clownfish being unable to smell.
