Complex sentence: The Wadden Sea also has large numbers of young birds, fish, sealife, and a habitat for more than 500 species of plants and animal, of which, many are found nowhere else in the world.
Split into simpler sentences: The Wadden Sea also has large numbers of young birds, fish, and sealife. It provides habitat for more than 500 species of plants and animals, many of which are found nowhere else in the world.