Detailed maps are particularly lacking for submerged habitats, such as seagrasses, coral reefs, salt marshes, and tidal mudflats. Species diversity is not well inventoried and population assessments are only available for some keystone species, such as sea turtles and whales. Available information on the distribution of species needs to be consolidated and integrated with information on habitat distribution. Information on invasive species is limited because of difficulties in identifying and inventorying them. Assessing their impact on the native ecosystem is also necessary but currently lacking.
Limited information is available on the condition of ecosystems at the habitat level.
For example, anecdotal observations are available for the world's coral reefs, reflecting coral bleaching, disease, and human impacts, but little data have been compiled on coral condition, such as change in live coral cover. Indicators of change in ecosystem structure have not been fully explored. Spalding, M.D. 1998. Global and Local Scales. Marine Turtle Nesting Beaches .