They could not live in a sandy beach habitat. The mangrove marsh habitat is perhaps the most productive section of the lagoon ecosystem. The mangrove is a salt- tolerant tree that grows in intertidal areas of tropical and subtropical oceans. Mangrove marshes are a critically important resting and feeding grounds for numerous migratory bird species, and a home to several resident species of birds. The mangrove marshes, like all ocean marshes, are also the nurseries for many different species of ocean fishes and the homes to many different species of invertebrates.
Fishes move into the marsh to lay their eggs.
When the young hatch, they use the quiet waters of the marsh to gain strength before they venture out into the open ocean. Marine Habitat Laguna San Ignacio is one of the few remaining undisturbed marine lagoon habitats in North America. It supports a large number of vertebrate and invertebrate species different from the ones that live in the lagoon's other habitats. Imagine the tides flushing and recharging the lagoon ecosystem. Each rising tide stirs up nutrients from the bottom sediment and recharges areas of stagnant water with oxygen.