Ulva Island - Te Wharawhara

Ulva Island-Te Wharawhara Marine Reserve protects about 10.75 square kilometres of sea around Ulva Island in Paterson Inlet (Te Whaka a Te Wera), off the east coast of Stewart Island/Rakiura in southern New Zealand. ^[1] Established in 2004 and managed by the Department of Conservation, the marine reserve complements the famous predator-free open sanctuary of Ulva Island itself, where rats were eradicated to protect native birds. Lying just a few kilometres from the small township of Oban, the reserve safeguards sheltered subantarctic waters, seagrass beds and rocky reefs. Together the protected land and sea make Ulva one of New Zealand's most accessible showcases of restored island and marine ecosystems.

The cool, productive waters of Paterson Inlet support blue cod, trumpeter, butterfish, spotties and other temperate reef fish, alongside paua, kina and rock lobster on the reefs, with at least 56 marine fish species recorded in the reserve. ^[1] The inlet is also one of the richest and most accessible places in the world for brachiopods — ancient filter-feeding shellfish abundant in prehistoric oceans — that live on rocks and sediment at depths of less than 20 metres. ^[2] On adjacent Ulva Island, the predator-free forest shelters rare birds including South Island saddleback, Stewart Island robin, yellowhead and rifleman. The surrounding inlet is frequented by New Zealand fur seals, little blue penguins, shags and titi (sooty shearwaters), with occasional Hooker's sea lions also seen.

Below the surface, the reserve supports beds of seagrass (Zostera), kelp and mixed red and brown seaweeds that thrive in the inlet's sheltered, nutrient-rich waters and provide critical habitat for marine life. Stewart Island/Rakiura has more types of seaweed than anywhere else in New Zealand, and Paterson Inlet hosts 70% of the country's seaweed species, including 56 brown, 31 green, and 174 red species. ^[1] On Ulva Island the protected coastal forest is lush and largely unmodified, dominated by rimu, miro, southern rata and kamahi with a dense understory of ferns, mosses and broadleaf shrubs, representative of Rakiura's cool, wet temperate rainforest.

Stewart Island/Rakiura and Ulva Island are built largely on ancient granite and granodiorite, part of the Median Batholith that forms much of the region's bedrock. ^[1]) Paterson Inlet is a large, sheltered drowned valley system, flooded by post-glacial sea-level rise, giving the reserve its calm waters, complex shoreline and mix of rocky reef and soft-sediment habitats. ^[2] Weathering of the granite produces the pale sandy beaches found around Ulva Island, while submerged rock outcrops and boulder fields create the reef structures that support diverse marine communities.

The reserve has a cool, wet, oceanic climate strongly influenced by the surrounding Southern Ocean, with mild temperatures year-round, frequent rainfall and changeable, often windy conditions. Summers are cool and winters relatively mild for the latitude, and sea temperatures remain low, typically ranging from around 8 degrees Celsius in winter to the low teens in summer. Rakiura is renowned for its rapidly shifting weather, and calm, clear days are prized for boating and diving. The high rainfall and humidity sustain the area's lush rainforest and productive coastal waters.

Stewart Island/Rakiura holds deep significance for Maori, particularly Ngai Tahu, and Paterson Inlet (Te Whaka a Te Wera) has long been a place for gathering kaimoana and harvesting titi (muttonbirds) from surrounding islands. From 1872, early naturalist Charles Traill operated a small post office on Ulva Island, the first in the Stewart Island/Rakiura region, which served the scattered communities of the inlet until 1923. ^[1] The island takes its name from Ulva in the Inner Hebrides of Scotland, formerly having been called Coopers Island. ^[2]) The island and inlet have a history of small-scale settlement, fishing and tourism, and the nearby township of Oban remains the hub of the island's small permanent population.

The marine reserve was established in 2004 to protect a representative area of Paterson Inlet's sheltered marine habitats and to extend protection from Ulva Island's land sanctuary into the surrounding sea. ^[1] Ulva Island itself had earlier been cleared of introduced rats in 1997 and managed as an open predator-free sanctuary, allowing the reintroduction and recovery of threatened forest birds. ^[2]) Commercial fishing within Paterson Inlet had already been prohibited since 1994, and creating the adjoining marine reserve linked land and sea conservation, providing a no-take refuge for fish and invertebrates and reinforcing Ulva's role as a flagship for ecological restoration in southern New Zealand.

Ulva Island is one of New Zealand's premier birdwatching destinations, with a network of easy walking tracks leading through predator-free forest to sandy beaches such as Sydney Cove and Boulder Beach, where saddleback, robins, kaka and weka are readily seen. ^[1] The marine reserve itself is enjoyed by snorkellers, divers and kayakers exploring seagrass beds, reefs and clear inlet waters. Sea kayaking across Paterson Inlet from Oban is a popular way to combine the land sanctuary and marine reserve, and wildlife cruises offer chances to see seals, penguins and seabirds.

The reserve and island are reached by a short boat or water-taxi trip from Golden Bay wharf near Oban, the main settlement on Stewart Island/Rakiura, which is itself accessed by ferry or flight from Bluff and Invercargill. ^[1] Ulva Island has walking tracks, interpretive information and a wharf but no shops or accommodation, so visitors must bring their own supplies and carry out all rubbish. Oban provides accommodation, guiding services, kayak hire and charter operators. Visitors are asked to check gear for rodents and seeds to keep the island predator-free, and all fishing within the marine reserve is prohibited.

As a no-take marine reserve, fishing and the removal of marine life are prohibited, allowing fish and invertebrate populations to recover and protecting the inlet's seagrass and reef habitats. ^[1] The reserve works in tandem with the strict biosecurity and predator-free management of Ulva Island, where ongoing vigilance against rat incursions — including several detected since 1997 — safeguards reintroduced bird populations. ^[2]) Together these measures make Ulva a model of integrated land-and-sea conservation. Visitor education, biosecurity checks and monitoring by the Department of Conservation and partners, including Ngai Tahu, are central to sustaining the area's restored ecosystems.