President Barack Obama announced on Monday the opening of two new American marine sanctuaries, one in Lake Michigan, and another in Maryland’s tidal waters. These sanctuaries are the first to be opened in 15 years.

“Our economies, our livelihoods and our food all depend on our oceans,” said Obama. “Yet, we know that our actions are changing them. Greenhouse gas emissions are making our seas warmer and more acidic. Marine pollution harms fish and wildlife, affecting the entire food chain. Illegal fishing depletes the world’s fisheries.”

The Lake Michigan sanctuary covers 875-square miles and extends from Port Washington to Two Rivers. The Maryland sanctuary covers a 14-square mile area of the tidal Potomac River near Charles County.

Watch Obama’s message.

For more on this story, visit PBS NewsHour Obama announces new marine sanctuaries, a first in 15 years”