Regno di Nettuno

Regno di Nettuno (Kingdom of Neptune) Marine Protected Area encompasses approximately 11,256 hectares of Tyrrhenian Sea surrounding the volcanic islands of Ischia, Procida, and Vivara in the Gulf of Naples. Established in 2007, it is one of Italy's larger marine reserves, protecting waters that combine volcanic geological interest with exceptional biodiversity. The underwater volcanic features, thermal vents, and varied substrates create unique habitats found nowhere else in the Gulf of Naples.

The volcanic substrate and thermal springs create unique ecological niches supporting specialized communities alongside typical Mediterranean marine fauna. Seahorses inhabit the seagrass meadows, while large groupers and corvina have recovered in protected zones. The warm water vents attract thermophilic bacteria and unique invertebrate assemblages. Loggerhead sea turtles frequent the area, and bottlenose dolphins are regular visitors. The cliffs of Vivara, a strict nature reserve, host important seabird colonies including Cory's shearwaters and Mediterranean storm petrels.

Posidonia oceanica meadows form extensive underwater prairies around all three islands, particularly well-developed in the shallower waters between Procida and Ischia. Near underwater thermal vents, specialized algal communities adapted to elevated temperatures and altered chemistry occur alongside typical Mediterranean species. The volcanic rocky substrates support diverse macroalgal forests in shallow waters. Cymodocea nodosa beds occupy sandier areas. Terrestrial vegetation on the islands includes Mediterranean maquis and, on Vivara, pristine holm oak forest.

The islands of Ischia and Procida are volcanic in origin, part of the Campanian volcanic arc that includes Vesuvius and the Campi Flegrei. Ischia's Monte Epomeo (788m) is a volcanic horst of green tuff, and the island has experienced eruptions as recently as 1302. Underwater fumaroles and thermal springs release heated water and gases from the seabed, particularly around Ischia's southern coast. Procida is built from tuff and lava deposits from multiple eruption centers. The varied volcanic lithology creates diverse underwater landscapes with arches, caves, and boulder fields.

The Gulf of Naples enjoys a Mediterranean climate with hot dry summers and mild winters. Sea temperatures around the islands range from about 14 degrees Celsius in winter to 27 degrees in summer, though areas near thermal vents may be significantly warmer locally. The islands moderate temperature extremes compared to the mainland coast. Prevailing winds from the west and northwest are strongest in winter, while summer conditions are typically calm with afternoon sea breezes. Visibility underwater is best from June through November.

These islands have been inhabited since the Neolithic era. Greek colonists from Euboea established Pithecusae on Ischia around 770 BCE, making it one of the earliest Greek colonies in the western Mediterranean. Procida has been continuously inhabited since Mycenaean times. The Romans prized Ischia's thermal springs, building elaborate bath complexes. Throughout the medieval period, the islands served alternately as refuges from mainland conflict and targets of Saracen raids. Traditional fishing communities maintained sustainable practices until modern industrial fishing disrupted local ecosystems.

Regno di Nettuno Marine Protected Area was established in 2007 after extensive scientific surveys documenting the unique combination of volcanic geology and marine biodiversity. The designation process was complex, involving three island municipalities and balancing tourism, fishing, and conservation interests. The reserve's name evokes the mythological ruler of the seas, reflecting the area's maritime heritage. Management has focused on establishing effective monitoring and enforcement while building local stakeholder support for conservation objectives.

Diving around Ischia's southern coast reveals underwater fumaroles releasing streams of gas bubbles from volcanic vents. The Banco d'Ischia, an offshore seamount, attracts large pelagic fish and offers advanced diving on its deep walls. The waters around Castello Aragonese feature forests of bubbling CO2 vents studied as natural laboratories for ocean acidification research. Snorkeling at Procida's Chiaiolella Bay reveals seagrass meadows with seahorses. The uninhabited island of Vivara offers guided nature walks through pristine Mediterranean vegetation.

The islands are reached by frequent ferry and hydrofoil services from Naples (approximately 40-60 minutes) and Pozzuoli. Ischia has numerous diving centers offering excursions within the marine protected area. Procida offers smaller-scale diving operations. The reserve's administrative office coordinates permits and provides information about zonation and permitted activities. Tourism infrastructure on both islands is well-developed, with accommodation ranging from hotels to vacation rentals. Glass-bottom boat tours offer non-diving access to underwater sites.

The reserve implements zonation balancing strict protection of sensitive volcanic vent communities with sustainable access for diving tourism and traditional fishing. Monitoring programs track the unique vent ecosystems as indicators of volcanic activity and study the effects of natural CO2 emissions on marine organisms. Anti-trawling enforcement protects seabed habitats from destructive fishing practices. The reserve promotes the islands' marine environment as a sustainable tourism asset, developing blue economy alternatives to extractive resource use.