Library Creek is a usually crystal clear creek that runs behind the Islamorada Library. It is bordered on its west side by a wall of thick mangrove trees and on its east side by several marinas and a mobile home park. The creek has three of the four marine ecosystems: mangrove, hardbottom and seagrass beds. The fourth marine ecosystem, the coral reef, is in the Atlantic Ocean. As we cruise slowly through the creek, we often see parrot fish, angelfish, snapper, nurse shark, slender mojarras, silversides, and mosquito fish. Sometimes we are very lucky to see manatee.