Kaikōura/Te Tai-o-Marokura marine management area

Hikurangi is managed under Kaikōura/Te Tai-o-Marokura marine management.

Read the Kaikōura marine management summary 

Kaikōura Canyon

The Kaikōura canyon is 1000 m deep and is a food basket for many of the whale, dolphin and seabird species found in New Zealand's waters. Visiting the reserve is an unparalleled opportunity to see them up close, and often in large numbers.

The canyon is a side branch of the Hikurangi Trench, an underwater trough thousands of kilometres long extending northwards up the east coast of New Zealand and beyond.

Several small rivers and streams meet the ocean at or near Hikurangi Marine Reserve, bringing nutrients from the mountains to the sea. At the same time, the Southland Current brings cold water from the Southern Ocean and the East Cape Current brings warm water from the subtropics. These water masses converge off Kaikōura, creating a nutrient rich, highly productive environment which can support many marine mammals and seabirds.

Wildlife

A variety of marine mammals may be seen year-round at Kaikōura, though the region is best known for its sperm whales, dusky dolphins and New Zealand fur seals. The Kaikōura Canyon is the only place around New Zealand's mainland where the majestic sperm whale can be regularly found so close to shore.

Orca are regular visitors and humpback whales pass through on their northern winter migration. Many other whale species also visit the area from time to time. Large pods of dusky dolphins live in the vicinity of the Kaikōura Canyon and small groups of Hector's dolphins are also found closer to shore.

New Zealand fur seals are widespread, with significant colonies at Ohua Point north of Kaikōura and on the peninsula. Many species of albatross, petrel, shearwater and prion gather at Kaikōura. Kaikōura is the only place in the world where Hutton's shearwaters breed.

Landform

The shoreline connection of the marine reserve is broadly representative of Kaikōura 's southern rocky coastline. Three offshore islands (Panau Island and two smaller islets) are located just offshore.

Greywacke boulder and bedrock reefs dominate the shoreline, interspersed with small gravel/cobble beaches. Reefs extend sub tidally for several hundred metres or more offshore, often as patchy outcrops or as a mosaic of low relief reef with or without a veneer of silt or sand.

Amongst the offshore reef areas, and extending beyond, are areas of pebbles/gravels, coarse sand and, in deeper areas, mud. Muddy sediments dominate offshore, across the deeper parts of the continental shelf and down into the abyss of the Kaikōura Canyon. Patches of reef occur on the sides of the canyon where it is thought localised currents and the steep slope prevent the accumulation of sediment.

Marine invertebrates and fish species

Encrusting and mobile invertebrates (including various molluscs, crustaceans, echinoderms, anemones and sponges) are common over the intertidal reefs, especially towards the lower shore. A rich seaweed community is also present, again increasing in abundance and diversity towards the lower shore where bull kelp forms a distinctive band.

Luxuriant stands of seaweeds – large brown seaweeds and red algae often forming a diverse understory – are conspicuous close to shore. Encrusting invertebrates (e.g. sponges, ascidians, anemones and hydroids) are also common, particularly deeper down where the seaweeds start to thin out.

Paua, kina and rock lobster are the most well known macro-invertebrates inhabiting the reefs; however, numerous other mobile species are also present including various starfish, molluscs and crustaceans. A common array of fish species inhabit coastal areas including butterfish, blue cod, tarakihi, marblefish, blue and red moki, sea perch, and several species of wrasse and triplefin.

While seafloor communities over the continental shelf are not well understood, more is known about the biota inhabiting the floor of the Kaikōura canyon. 

Sponge gardens occur on the northern edge of the canyon. Burrowing sea cucumbers, worms, urchins and other invertebrates inhabit the canyon floor, numbering in their thousands per square metre. Total biomass in the base of the canyon is estimated to be 100-times higher than similar deep-sea canyon habitats around the world, making Kaikōura Canyon a known biodiversity hotspot.

Species such as hapuku, tarakihi, ling, hoki, lantern fish, and various sharks, rays, skates and squid inhabit the deeper waters. Benthic feeding fishes (notably rattails) are especially abundant in the depths of the Kaikōura canyon.

The 2016 Kaikōura earthquake caused submarine landslides and devastating sediment flows down the length of the Kaikōura Canyon. Despite the huge impact on the canyon floor ecosystem, very good signs of recovery occurred over the months and years following the earthquake. This suggests the canyon is reasonably resilient to periodic sediment flow events.

Uplift of the seabed during the earthquake also had very large impacts on rocky shore ecosystems along the Kaikōura Coast. Uplift of intertidal and subtidal reefs was greatest northwards from the Peninsula.

In comparison, uplift at Hikurangi Marine Reserve was relatively small, and combined with the reserve’s high wave exposure, appears to have had limited lasting effect on the reserve.

Read more about the deep ocean and its unusual biodiversity.