There are a total of 33 species of marine mammals in Peru ranging from the tiniest salt-water marine otters or chingungos, that inhabit inaccessible beaches to the large whales and sperm-whales that roam the open sea. Scientists group them into nine taxonomic families, with the most important being the otariidae and the delphinus, that group the sea lions and southern fur seals and the dolphins, respectively.
Undoubtedly the most widely-seen mammals on the Peruvian coast, are the sea lions. Two different species share the coast bathed by the cold Peruvian ocean current: the large South American Sea Lion (Otaria byronia) weighing up to 300 kg, which prefers to gather on sandy beaches, and the smaller South American Fur Seal (Arctocephalus australis), which tends to group on outcrops of inaccessible rocks along the coast. Both species reproduce between November and March, ideal months for observation.
The best spots for finding them is along the southern coast: Paracas (250 km from Lima) features major breeding grounds on the Ballestas Islands (a one-and-a-half hour boat-ride from the El Chaco dock or from the Hotel Paracas), Punta Arquillo (15 minutes on a rough-grade road that runs through the peninsula) and Morro Quemado (a three-hour drive in an all-terrain vehicle) where possibly the largest number of sea lions and southern fur seals in the country congregate.
The coastal beaches of the Paracas National Reserve are also the best spots for viewing the elusive chingungo or marine otter, a marmot that inhabits the rarely-visited rocks and beaches of the central and southern Peruvian coast. The beaches of Mendieta and La Catedral have the greatest number of recorded endangered species.
A bit further south (480 km from Lima via the Pan-American Highway) is Punta San Juan, a Reserve established to protect the nesting grounds of guano birds, Humboldt penguins and a large colony of sea lions.
Cetaceans are well represented in Peruvian waters. Observing them, however, is rather difficult since there is a lack of tourist infrastructure for this end. Several species of dolphins, such as the Bottlenose Dolphin and the Short-Beaked Common Dolphin, as well as Porpoise, are habitual residents of the relatively shallow coastal waters. The best way to observe these creatures is to rent a boat in the larger coves or ports and then to request information on the best spots and times for viewing. In Peru, all cetacean species are protected by law. The capture, consumption or sale of these animals or any product derived thereof, is strictly prohibited.