Prince William got a first-hand look at the waters of New York City on Monday on a visit to an oyster reef restoration project, after arriving in the United States for an environmental summit connected to a global competition for solutions to climate change challenges.

William was taken to Governors Island in New York Harbor to see the efforts of the Billion Oyster Project. The organization is trying to rebuild the oyster reefs that were once abundant in New York waters, and which can help with water filtration and protect against storm damage.

William also met Monday with U.N. Secretary-General António GuterresAntonio Guterres, according to the U.N. It said the two discussed efforts needed to step up the fight against climate change, as well as ways to finance development and improve implementation of key U.N. goals.

On Tuesday, William is scheduled to speak at the Earthshot Prize Innovation Summit. He founded the prize, which looks for ways to address problems created by climate change, and is announcing a second group of finalists.

The summit is taking place during New York Climate Week and the 78th convening of world leaders at the United Nations General Assembly.