It is a direct impact of excessive production of CO2. 25% of CO2 produced by humans. The ocean acidity has increased by the last 250 years but by 2100, it may shoot up by 150%. The main impact is on shellfish and plankton in the same way as human osteoporosis.
Humans are inextricably linked to the health of the ocean. We have always relied on the ocean's resources for food, recreation, transportation and medicines. From an interpretive standpoint, the important thing is to help people realize how they are personally connected to the ocean, and then to be able to explain to them how that connection is being jeopardized by ocean acidification. One of the most obvious connections people have with the ocean is seafood. Most of the shellfish we eat are going to be negatively impacted by ocean acidification due to the fact that they will be unable to build sturdy shells. Some oyster hatcheries in the Pacific Northwest have already been impacted, and have seen declines in larval settlement and survival rates. Pteropods may seem insignificant to many people, but since they are a major food source for fish, their survival is very important to us.