West Coast Marine and Coastal Localities:
a Detailed Description of 14 Segments

5.3 Karamea
(Kohaihai River – Gentle Annie Point, 47 km)

5.2.1 Summary
The Karamea segment includes the Karamea coastal sand plain and tidal estuaries in the north and coastal hill country in the south. The Oparara, Karamea and Little Wanganui Rivers flow out to sea in this segment. The seabed is mostly of a uniform shelf grading out to fine sediments but with inshore rocky reefs in the south and a variety of beach types. Marine life is typical of northern West Coast habitats but with the addition of some more northern influences. Access to and use of this area is greatest in the Karamea plains area. Dairy farming and residential development are predominant uses of the coastal sand plain.

Notable features of this segment include: its accessibility from Karamea and SH 67, extensive coastal wetlands, relatively unmodified and remote coastal forest in the north and south, coastal wildlife, natural landscapes and protected catchments, diverse marine habitats, cultural and historic heritage and a variety of recreational uses.

Existing protection include: small areas of conservation lands associated with coastal wetlands and other parts of the Karamea sand plain. Virtually all the forested hill country lies within Kahurangi National Park. There are several areas closed to whitebaiting, and specified areas under the Regional Coastal Plan.

5.2.2 Natural Features

Coastal Land and Islands
The Karamea segment coastal landscape can be divided into two main parts, with a boundary at the Little Wanganui River mouth. To the north, the coastline consists entirely of sandy beaches, backed mostly by estuaries, broad river plains, coastal wetlands and low-lying sand dunes. To the south the coastline is predominantly rocky, with some coarse sand and cobble beaches backed by very steep gullied hillslopes with small streams running down to the coast.

Most of the Karamea coastal sand plain and river flats have been modified by farming and other land development. Coastal sand plain forest remnants are small, but natural vegetation cover has been retained on much of the coastal hillslopes. Between Kohaihai and Oparara the coastal hills are much closer to the coastline, rising above a narrow coastal plain of fixed dunes and a sandy beach with a steeper profile. The Oparara Estuary and the Karamea/Otumahana Estuary are prominent wetland features in this coastal segment. The Karamea settlement and Kongahu Swamp both lie a little further inland on the broad coastal and alluvial plain. Dairy farming is the main land use on the coastal plain.

Little Wanganui beach.
Photo: T Hume, NIWA 		North towards Kohaihai Point
Photo: T Hume, NIWA

Between the Little Wanganui River mouth and Kongahu Point, the coastal hillslopes are composed of erodible mudstone and sandstone with large landslips reaching down to the shore. South of Kongahu Point the narrow coastal strip consists of more stable Paparoa granite.

Johnson (1992) ranked the Kahurangi – Oparara coast as the most botanically-significant coastal dune vegetation system between Farewell Spit and Saltwater Lagoon Pouerua. However, although the dune form is still largely intact, marram grass and other weed species are present. Dune blowouts are common along the beach between Oparara and Little Wanganui (partly intensified by stock grazing and farm development) and are mostly edged with introduced plant species such as marram grass and pasture grasses. The threatened red katipo spider has been recorded in significant numbers at Karamea Beach41. The threatened coastal cress Lepidium flexicaule occurs in significant abundance at the seal colony site on Kongahu Point42.

The coastline from Little Wanganui River to Gentle Annie Point is listed in the Regional Coastal Plan43 as an outstanding natural feature and landscape. It is described as a “highly natural section of coast adjoining a large area of land administered by the Department of Conservation. [It has] high amenity, landscape and scenic values enhanced by natural coastal landforms.” Indigenous forests in the Karamea Bluffs area are under a sustained possum control programme.

Sites of geological interest include a fossil site of regional importance at Little Wanganui Head (notable for its large fossil brachiopods) and geological structures at Gentle Annie Point44. Coastal erosion including slumping caused by the Murchison earthquake, is a feature of this southern part of the Karamea coastal segment (see Henderson 1937).

Coastal Wetlands and Waterways
The largest waterways are the Kohaihai, Oparara, Karamea and Little Wanganui Rivers and Falls Creek. The Karamea River has an estimated annual suspended sediment discharge of 0.15 million tonnes45.

The Karamea plain is an important area for coastal wetlands. The main ones are described below:

Karamea Aerodrome Lagoon is a freshwater wetland of moderate wildlife value46, and is used at high tide by birds feeding on the Karamea River estuary.

Karamea-Otumahana Estuary (400 ha) and Oparara Estuary (110 ha) are considered wetlands of national importance47 because of their high wildlife value (especially a high diversity of birds, particularly waterfowl and some migratory waders). These estuaries are fed by the Oparara and Karamea Rivers respectively, and are surrounded mostly by grazed pasture. The Karamea-Otumahana Estuary is one of the largest and more diverse estuarine habitats in the West Coast region. It comprises sand and mud flats with extensive areas of saltmarsh dominated by sea rush, saltmarsh ribbonwood and jointed rush. Large shellfish beds of cockles, pipi and other bivalve species occupy extensive areas of the estuary’s mudflats and tidal channels.

A very high diversity of about 40 bird species occur here, including shorebirds, waterfowl and wetland birds48. The estuaries provide spawning and rearing habitat for indigenous fish species, including giant kokopu and inanga49. The southern lagoon draining Kongahu Swamp is a particularly important whitebait spawning area50. Marginal saltmarsh vegetation provides good cover for wildlife and the barrier beaches and dunes provide high tide roosts for birds. White-fronted terns nest on the north spit of the Karamea River estuary and black-backed gulls and red-billed gulls nest on the north spit of the Oparara Estuary. The Otumahana Estuary is the southern known limit on New Zealand’s west coast for the bubble shell51 (a snail) and the glasswort (a saltmarsh plant)52. The Oparara Estuary has not been studied in as much detail, but it also has extensive sand flats and its proximity to the larger Karamea-Otumahana Estuary is important to its natural values, by adding to the total area expanse of these habitats available to plants and animals on the Karamea plain.

Inanga spawning sites have been recorded in Granite and Blackwater Creeks at the south end of the Otumahana Estuary, in Baker Creek at the north end of the Karamea Estuary, and in the Oparara River and an unnamed tributary of the Oparara Estuary53. Small patches of the exotic cord grass (Spartina sp.)have been controlled in Karamea estuary since the 1980s.

The coastline north from Six Mile Creek
Photo: T Hume, NIWA 		One of the earthquake slips on the coastline between Little Wanganui Head and Kongahu Point
Photo: T Hume, NIWA

Kongahu Swamp and Little Wanganui River mouth are considered wetlands of moderate-to-high wildlife interest because they support some threatened wildlife species, and provide habitat for indigenous fish, including spawning sites for inanga54. Kongahu Swamp lies just outside the coastal marine area. It is a large freshwater peat swamp of flax, Carex, and kahikatea on the coastal plain; it drains northwards into the Otumahana Estuary and provides habitat for brown mudfish, giant kokopu and inanga. Prior to drainage works and on-going land development for dairy farming since the 1980s, Kongahu Swamp was the most extensive wetland of its kind in the northwest of the South Island. It was then regarded as a nationally important wetland habitat55 but this is now unlikely given the environmental changes. The adjacent whitebaiting closed area provides some protection for the whitebait population.

The Little Wanganui River rises in Kahurangi National Park and crosses the southern end of the Karamea coastal sand plain, flowing quietly over a shingle bed56. The proximity of the tidal sandflat roosts at the river mouth to the intertidal reef at Little Wanganui Head makes it a habitat for coastal birds like variable oystercatchers.

Little Wanganui River
Photo: T Hume, NIWA 		Karamea-Otumahana Estuary
Photo: T Hume, NIWA

Seashore and Marine Areas
The Karamea coastal segment contains the most extensive continuous sand beaches on the West Coast, stretching from Kohaihai to Little Wanganui.

Intertidal rock platforms and shallow reefs occur at several sites south of Little Wanganui River, with the largest at Gentle Annie Point and others at Little Wanganui Head, Falls Creek and Kongahu Point. Coastal bluffs of erodible sedimentary rock occur between Little Wanganui Head and Kongahu Point. Rocky shores are relatively common in this section. These platforms and reefs are typical of northern West Coast rocky coastal habitats, being significantly influenced by sedimentation and dominated by mussels, other filter-feeding invertebrates and robust seaweeds. In most cases the coastal reefs appear to bottom out to sand very close to shore at depths of around 10 metres or less. There is no documented evidence of deep reefs within territorial waters in this segment, but there is reportedly a large area of foul ground further out, about 40 km offshore57.

Offshore, the seabed slopes gradually out across the Karamea Bight towards the Challenger Plateau at a gradient of less than one degree, reaching a depth of about 100 metres at the territorial limit. Seabed sediments grade from sandy and cobble beaches to muddy sediments offshore.

Coastal currents vary with sea and weather conditions, but the hydrographic chart indicates an average 0.3 knot southward current off the Oparara River mouth and a 1.0 knot northward current off Gentle Annie Point.

Karamea River mouth, Otumahana Esturay
and adjacent coastal areas
Photo: T Hume, NIWA 		The coastline south from Kohaihai Bluff
Photo: T Hume, NIWA

Coastal and Marine Wildlife
Wetland and wading birds occur in the estuaries and wetlands, especially the Karamea-Otumahana Estuary, but few detailed records of their occurrence are available.

A seal rookery at Kongahu Point appears to have increased in size over recent years, with about 30 pups reported in 2006.

Hector’s dolphins occur in the inshore waters in moderate to low densities,58 and several whale and dolphin species as well as vagrant New Zealand fur seals have been recorded in inshore waters or beachcast.

Marine Fish and Other Species
This coastal segment like the whole western coast of the South Island, supports a rich diversity of fish and invertebrate species that are fished both commercially and recreationally by a number of fishing methods including trawl, longlining, potting and set netting.

Inshore trawl fisheries are multi-species and are primarly based on flatfish (several species), red gurnard, red cod, giant stargazer, tarakihi and blue warehou. Other species taken as bycatch include arrow squid, dark ghost shark, ling, barracouta, jack mackerel, spiny dogfish, rig, school shark, sea perch, rough skate and smooth skate59.

Intertidal shore platforms and reefs in this area (e.g. Little Wanganui Head, Falls Creek, Kongahu Point, Grenadier Rocks, Gentle Annie Point) have extensive mussel beds and a variety of other marine species. The Gentle Annie Point mussel bed appears to support a moderate diversity of fish species that is typical of the Buller area. This locality is the southern known limit on New Zealand’s west coast for an agar weed, Pterocladia lucida60. Shells of the endemic toheroa are sometimes found on the beach near Kongahu (specimens collected in 1992 are held in the Te Papa collection), suggesting this species should be in the locality but live specimens are yet to be found.

5.2.3 Historical and Archaeological Heritage
There is extensive evidence of early Maori occupation at numerous coastal archaeological sites on the Karamea sand plain, but beach ecresion following the Murchison earthquake has destroyed some of these sites61.

5.2.4 Recreation and Tourism
Recreational fishing occurs throughout the Karamea segment and includes surfcasting and rod fishing (at any accessible location), set netting (especially at accessible points south of Otumahana Estuary), cockle gathering (especially in Otumahana Estuary), and whitebaiting (most coastal rivers and streams, including from whitebait stands in the Karamea and Little Wanganui Rivers). Waterfowl shooting and recreational boating occurs in the Oparara and Karamea-Otumahana Estuaries.

Uses of the area south of Little Wanganui relate mostly to recreational walking and fishing activities and to the baches at Falls Creek and Kongahu Point. Much of this coastline is quite difficult for recreational users to access, but some visit for SCUBA-diving and line fishing, travelling by boat out of the main rivers in the area (e.g. Little Wanganui) or Westport. Recreational fishers also access the area by walking along the coastline from Little Wanganui and Mokihinui. Mussel gathering is possible in the vicinity of the beds at Gentle Annie Point, Little Wanganui Head and Falls Creek. Diving and potting (e.g. for rock lobsters) is most likely in the deeper and more complex reefs around Kongahu Point.

Scenery and landscape appreciation are relevant at a number of locations – such as the estuaries, the road corridor, and sites in the vicinity of Karamea and other small settlements. The Kohaihai roadend picnic area at the southern entrance to the Heaphy Track is of regional recreational significance and receives high public use62. Other access points along the coast are used for beachwalking and other coastal recreational activities. Other recreation and tourism facilities include a small fishing/launching wharf near the Little Wanganui River mouth, a camping ground adjoining the Otumahana Estuary and a golf course on the beach frontage to the north of Karamea.

5.2.5 Commercial Use
Much of the coastal sand plain and estuary margins as well as some of the lower hill country south from Little Wanganui Head have been developed for dairying and sheep farming.

This segment, as for the rest of the inshore western coast of the South Island, is fished by commercial fishers using a variety of methods and by vessels that operate out of Nelson, Motueka, Westhaven and Westport. As well as fishing on the inner continental shelf, some rock lobster fishing occurs on the rocky reefs in this region.

A blacksand gold mining licence covers the beach between Karamea and Little Wanganui. The coastal marine area out to the territorial limit is part of a marine gold exploration proposal presently being sought by Seafield Resources Ltd.

A dairy factory at Karamea that is presently closed for operation has an effluent discharge pipe on the Karamea beach.

5.2.6 Other Public Uses and Facilities
Public access (including vehicle access) to and along the coastal marine area occurs at several sites along the Karamea plain, including Kohaihai River mouth, Oparara Estuary, Flagstaff (out from Karamea), Otumahana Estuary and Little Wanganui River mouth. Most of these access points run out from State Highway 67 as far as Karamea township, and then from a gravelled road that continues northward along the coast to the start of the Heaphy Track at Kohaihai.

Access south of Little Wanganui River is limited to a gravel road (de Malmanches Rd) at the southern end of this segment and walking tracks and coastal routes in the north and south. Access across waterways and along the coast is possible along the full length, but restricted by the tide at several points, especially between Falls Creek and Kongahu Point and at major river mouths.

Shore platform at Gentle Annie Point, north to Kongahu Point in the distance
Photo: D Neale, DOC 		North of Kongahu Point
Photo: D Neale, DOC

The main settlement is at Karamea, but smaller settlements and private dwellings occur at Little Wanganui and Falls Creek. Single houses and baches occur at numerous locations along the Karamea plain, as well as a bach at Kongahu Point. Sewage ponds for the Little Wanganui settlement are located just upstream of the coastal marine area at Glasseye Creek. In response to upstream flooding concerns, some channel excavation has occurred in Granite Creek and the southern reaches of Otumahana Estuary.

An airstrip is located near the coast just north of Karamea.

Canterbury University periodically use the mussel bed at Gentle Annie Point for research into larval settlement of mussels and other marine species.
There are Resource Management Act coastal permits issued in this segment63 for:

5.2.7 Existing Protection and Management Areas
On the Karamea sand plain most of the immediate coastal strip of land above MHWS is private land and/or legal road, but small portions of land within and adjacent to Karamea and Oparara estuaries (including a large area of saltmarsh within the coastal marine area of Otumahana Estuary), Kongahu Swamp and Little Wanganui River mouth are conservation lands administered by the Department of Conservation.

Some of the coastal hillslopes in the northern portion of this segment are part of Kahurangi National Park, fronted by formed legal road and/or private land.

South of Little Wanganui, much of the coast is in conservation lands administered by the Department of Conservation, but significant areas of private land exist north from Falls Creek, north of Kongahu Point, and around Gentle Annie Point. The Hiwinui Scenic Reserve (12.9 ha) extends along the coast for about two kilometres south from Falls Creek64, and the Karamea Bluff Ecological Area extends from north of Kongahu Point to about Gentle Annie Point.

The area lies within Fisheries Statistical Area FSA 35, which is part of the Challenger Fishery Management Area (FMA 7). The adjoining land area is within the Buller District.

Looking south from Kongahu Point, to Gentle Annie Point in the distance.
Photo: D Neale, DOC

Several waterways in this segment are closed to whitebaiting:65

The operative West Coast Regional Coastal Plan recognises: 41 Patrick 2002
42 Neale & Geritzlehner 2006
43 WCRC 2000
44 Hayward & Kenny 1999
45 Hicks & Shankar 2003
46 Davis 1987, Morse 1981, DOC unpublished wetland inventory
47 Partridge 2004, Cromarty & Scott 1995, Neale et al 1992, Davis 1987, Morse 1981
48 Cromarty & Scott 1995
49 Davis 1987
50 Kelly 1988
51 B. Marshall pers comm 1992
52 D. Norton pers comm 1992
53 Taylor et al 1992
54 Partridge 2004, Davis 1987, Morse 1981
55 DOC unpublished wetland inventory, Davis 1987; Morse 1981,
56 Kelly 1988
57 Stevenson 2004
58 Dawson 2001
59 Stevenson & Hanchet 2000
60 W. Nelson pers comm 1998
61 Hooker 1990
62 Groome 1990
63 www.wcrc.govt.nz “Maps on the Web”, June 2006
64 Kelly 1974
65 Whitebait Fishing (West Coast) Regulations 1994

Karamea MapHabitats & Ecosystems People & UseAnimals & Plants Existing Protection & Management Plans Submission Form