The researchers studied the underwater environment in San Ignacio Lagoon to see how human activities and environmental changes affect the plants and animals living there. They looked at the types of plants and animals in the water and on the seafloor, and how they are distributed. They found that certain types of animals were more common in specific areas, like mollusks near eel grass and worms in muddy areas. They also discovered that the physical and biological conditions in the water and on the seafloor varied a lot between different parts of the lagoon. Overall, they found 11 different groups of animals, with annelids and arthropods being the most common.