Biological variables are monitored every week by collecting information from all the species that live at the Punta San Juan reserve: fur seals, sea lions, sea birds, Humboldt penguins, gulls, vultures, sea otters, Inca tern, herons, falcons, etc.

Biological monitoring consists of two observers conducting surveys of the different species that live on the reserve. The censuses are made once a week during the nonbreeding season and daily during the breeding season. This information is to have a photo-like view of all the species that inhabit the Punta San Juan reserve.