Ulva Island/Te Wharawhara Marine Reserve protects a large slice of Paterson Inlet on Stewart Island. The inlet is a shallow ria – an ancient river valley that has been submerged. Because the rivers that flow into it drain from pristine, undeveloped land they carry little sediment or nutrient run-off. As a result many species thrive in the inlet waters, including kina, sea cucumbers, starfish and brachiopods.Paterson Inlet is also an important habitat and nursery for at least 56 species of marine fish. The mixing of warm, subtropical and subantarctic waters in the currents around Stewart Island/Rakiura has added to the diversity of species found within the inlet.Brachiopods or lamp shells are the most ancient of filter feeding shellfish. They were abundant in prehistoric oceans at the dawn of life 300 to 550 million years ago, during the Palaeozoic period. Today their fossils are common but living examples are comparatively rare.Paterson Inlet is home to brachiopod species that live both on rock and sediment, thriving at depths of less than 20 metres. This makes the inlet one of the richest and most accessible brachiopod habitats in the world.Stewart Island/Rakiura has more varieties of seaweed than anywhere else in New Zealand. Paterson Inlet is home to 70% of them, including 56 brown, 31 green and 174 red kelp species. Seaweed forests provide habitat, protection and food to support diverse populations of fish and marine mammals.Dive trips can be arranged from Oban or Invercargill. You can also explore the area around Ulva Island on a sea kayak safari.