Lake Worth Lagoon is an urban estuary and the primary estuarine water body in Palm Beach County, Florida. It has been estimated that over 87% of the natural shoreline vegetation has been disturbed in some way – in many cases replaced by seawalls, bulkheads, or subject to dredging or development. A portion of northern Lake Worth Lagoon is protected, located within the boundaries of John D. MacArthur Beach State Park, including the nearly 40 ha, semi-enclosed Lake Worth Cove. In an ongoing project conducted by a variety of stakeholders, including university faculty, undergraduate research assistants, park staff, scientists and volunteers, nondestructive field surveys of submerged aquatic vegetation were initiated within the Cove in 2010. All seven of Florida's seagrass species were found in the Cove, including the federally threatened species Halophila johnsonii (Johnson's seagrass) as well as Ruppia maritima (wigeongrass), a species which has never been documented within the Cove and rarely documented within the lagoon remote from freshwater sources. Within a particular 2 ha zone in the southern cove, all seven species were present. Lake Worth Cove has the highest seagrass diversity of any area in Lake Worth Lagoon and, along with the Indian River Lagoon, has the greatest seagrass diversity of any estuary in the Western Hemisphere. This diversity may be due to the semi-enclosed morphology of the estuary, and likely influenced by the variety of sediment types, depths and currents found within the cove. The protected nature of the area and the natural resource management efforts of the Florida Park Service likely enhance the community makeup and integrity of the submerged habitats. In many other natural areas, the biodiversity and value may not yet be documented, nor even known. Under current developmental pressure, the remnant natural areas within Lake Worth Lagoon are threatened. The ecological loss of these patches within urban landscapes would far outweigh the temporary economic benefit.