Dorsal de Nasca

Dorsal de Nasca National Reserve is a marine protected area in the Pacific Ocean off the southern coast of Peru, in the Ica region. Established in 2021, the reserve covers approximately 65,000 km² of open ocean centered on the Nazca Ridge — a submarine volcanic chain extending from southern Peru westward into the South Pacific. The reserve is Peru's largest marine protected area and one of the largest in South America, protecting a section of one of the most productive marine ecosystems in the world. Administered by SERNANP (Service for Protected Natural Areas by the State), the reserve was created to safeguard the exceptional biodiversity associated with the Nazca Ridge seamounts and the surrounding Humboldt Current marine ecosystem.

The Nazca Ridge and surrounding waters constitute a globally important marine biodiversity hotspot. The Humboldt Current system, combined with the topographic effects of the ridge causing upwelling of cold, nutrient-rich deep water, supports extraordinary concentrations of marine life. Sperm whales, blue whales, humpback whales, and sei whales forage in these waters. Large aggregations of bottlenose dolphins, common dolphins, and striped dolphins are frequently encountered. The reserve supports important populations of the critically endangered short-tailed albatross and multiple other seabird species including Peruvian boobies, Nazca boobies, sooty shearwaters, and several petrel species. Whale sharks and Mola mola (ocean sunfish) are seasonally present. Giant manta rays congregate near seamount peaks.

The marine ecosystem of the reserve is driven by phytoplankton communities sustained by nutrient upwelling from the Humboldt Current. Phytoplankton blooms support enormous zooplankton populations — particularly krill and copepods — that form the base of the food web sustaining the reserve's spectacular megafauna. The seamount peaks of the Nazca Ridge, rising from abyssal depths to within 300 to 600 meters of the surface in some locations, create oases of concentrated marine life where deep-water nutrients intersect with sufficient light. Cold-water coral communities and sponge gardens have been documented on the upper seamount slopes, forming structural habitat for deep-sea fish and invertebrate communities. These habitats remain poorly characterized given the extreme logistical challenges of deep-sea research.

The Nazca Ridge is a submarine aseismic volcanic ridge created approximately 25 to 10 million years ago by the passage of the Nazca tectonic plate over the Easter Island Hotspot in the South Pacific. The ridge has been carried eastward by plate motion toward the South American subduction zone. Seamounts along the ridge represent eroded submarine volcanoes that never breached sea level or were subsequently submerged. The collision of the Nazca Plate — and the Nazca Ridge specifically — with the South American continent is contributing to the ongoing uplift of the Andes and is seismically active. The ridge system extends from near the Peru coast westward for approximately 1,000 km, with the protected area covering a section of the eastern portion closer to the Peruvian continental shelf.

The ocean environment of the Dorsal de Nasca reserve is dominated by the Humboldt Current system, which brings cold upwelled water from depths to the South Pacific surface, creating one of the most productive marine environments on Earth but also one of the most meteorologically distinctive. Sea surface temperatures in the reserve average 14 to 18°C — exceptionally cold for a tropical latitude. The Peruvian coast and adjacent ocean are influenced by periodic El Niño Southern Oscillation events, during which warm water intrudes from the north, dramatically reducing upwelling productivity, affecting seabird and whale distribution, and causing significant disruption to the food web. La Niña years produce enhanced upwelling and higher productivity. The reserve lies within the trade wind belt with predominantly southerly surface winds.

The Nazca Ridge and surrounding waters have been important fishing grounds for coastal Peruvian communities since pre-Columbian times, when the Nazca civilization and later the Chincha kingdom built maritime cultures along the southern Peruvian coast. The Humboldt Current was a key resource for the Nazca culture (100 BCE to 800 CE), whose people conducted offshore fishing voyages using reed boats. Industrial fisheries exploiting the Humboldt Current anchovy and tuna resources expanded dramatically in the 20th century, making Peru one of the world's top fishing nations by catch volume. The broader Humboldt Current ecosystem has been subject to intensive industrial exploitation, providing the impetus for establishing marine protected areas including the Dorsal de Nasca reserve.

The Dorsal de Nasca National Reserve was established by Supreme Decree No. 005-2021-MINAM on March 18, 2021, making it one of the newest protected areas in Peru. The reserve's creation resulted from years of lobbying by Peruvian conservation organizations, marine scientists, and international NGOs who documented the exceptional biodiversity of the Nazca Ridge ecosystem. IUCN and National Geographic Society research expeditions to the ridge contributed scientific evidence supporting the designation. The reserve was established as part of Peru's commitment to protect 30 percent of its ocean territory. Concurrent with national protected area status, the Peruvian government has pursued international recognition for the reserve as part of broader high-seas conservation frameworks.

As an open-ocean marine reserve, Dorsal de Nasca is not a conventional tourism destination with land-based trails or visitor centers. The reserve is accessible to scientific research expeditions, and some specialized whale-watching and pelagic birdwatching tours from ports in Ica and Lima operate near the reserve margins. The town of Paracas, approximately 200 km northwest on the coast, is the primary gateway for marine tourism to the Humboldt Current ecosystem generally, with the adjacent Paracas National Reserve providing complementary marine and coastal protected areas. Pelagic birdwatching tours out of Paracas occasionally reach waters adjacent to the Dorsal de Nasca reserve, offering opportunities to observe albatrosses, petrels, and cetaceans in the productive offshore environment.

There are no visitor facilities within the reserve itself, which is an open-ocean environment managed for conservation and sustainable resource use. The gateway city of Ica (population approximately 400,000) is located about 60 km inland from the coast and has full urban services, an airport with flights to Lima, and connections to the coastal town of Paracas. SERNANP maintains an administrative office in Ica that can provide information on research permits and conservation programs. For general visitors interested in the Humboldt Current marine ecosystem, the Paracas National Reserve and the Ballestas Islands (accessible from Paracas) offer accessible encounters with the same biological community — seabirds, sea lions, Humboldt penguins — that characterize this productive marine region.

The primary conservation challenge for Dorsal de Nasca is the management of industrial fishing activities within and adjacent to the reserve. High-seas fishing for tuna, swordfish, and other pelagic species by Peruvian and international fleets operates throughout the region, and enforcement in a 65,000 km² offshore reserve requires satellite monitoring, aerial surveillance, and international cooperation. Illegal, unreported, and unregulated (IUU) fishing is a significant threat. Climate change and El Niño intensification threaten to shift the productivity of the Humboldt Current system. Deep-sea mining interests in Pacific seamount environments represent a future threat to the benthic communities of the Nazca Ridge. SERNANP works with the Navy of Peru and international organizations to monitor vessel traffic and enforce conservation measures within the reserve.