Several of the bays and lagoons in the Dutch Caribbean contain examples of one or more of the three threatened marine ecosystems: coral reefs, seagrass beds and mangroves. Coral reefs at the entrance of a bay serve as a protection against high seas. The seagrass beds form a critical nursery ground for countless species of coral reef fish and invertebrates and a foraging ground for green turtles. In some bays, cushion stars and conch can still be found amongst the seagrasses as well as fields of pulsating Upside-down Jellyfish (Cassiopea spp.) or ‘Cassiopeia’. The mangroves provide a safe haven and roosting place for herons, egrets, stilts, terns, flamingos, frigate birds, endangered ospreys and pelicans. They are also important nesting and breeding grounds for various species of birds and – between the roots of the mangroves – fish and other marine life.