Ferns Although fairly common and abundant in surrounding areas, ferns are not that numerous in terms of species around the Estuary, but several can be seen in close proximity including the specialist Water Fern. A checklist of ferns recorded from the area is included here . Information is basic and continually up-dated with links given by the usual method to a wealth of additional information. Headings and columns A and B are locked, so are always visible. This checklist does not follow a recognised format as one doesn't appear to exist for species recorded in Aotearoa New Zealand. Web address links are edited to fit within the static species columns. List can be downloaded and additions for personal use be "save as". These will not be saved to the web. Retoreto/Red Azolla Rauarahu/Austral Bracken Petako/Sickle Spleenwort

Water Quality The quality of water flowing through the estuary from the adjacent towns and land and from the entire upstream length of the Manawatū River and its tributaries has a profound effect on the health of the habitat for all forms of life in the estuary. The Manawatū Estuary Management Team has formed a Water Quality group that is looking into gaining a good understanding of the water quality and what is going on that could improve it. As solid information is gained, it will be referenced on this page. There are four regularly monitored swimming spots within the area and testing runs from November to the end of April. These are carried out by Horizons Regional Council and results given on the LAWA website. To view a particular spot, click on each site picture to view details, bearing in mind that they are not monitored outside of the summer/autumn period. Once on the site, click on the weekly/long term button to see if there is any update. Other useful information is also viewable once on this site is open. The HDC Local Waters Combined Bylaw 2025 came into effect on 1 July 2025 and means there is now one Bylaw covering all local Horowhenua water services. Previously there were three different Bylaws (Water Supply, Wastewater and Trade Waste) and no Stormwater Bylaw. All previous Bylaws can be viewed through Local Bylaws and Policies.

Ngutu pare/Wrybill Anarhynchus frontalis Endemic. Threatened-naturally increasing. One percent of the Aotearoa New Zealand population of Wrybills overwinters in the Manawatū Estuary, making this an important location for these waders. The best place to see them in the estuary is from the Dawick Street viewing platform at high tide, when they roost on the sandspit. They're usually seen only in winter, since in summer they're breeding on South Islands braided river systems. The Wrybill is the only bird in the world to have a beak that is bent to one side and is its most easily identifiable feature. Its grey colour makes it distinct from the majority of waders. A stocky shorebird, it has a pale grey back and white underparts and, in the breeding season, a thin black band across its breast. The black bill curves to the right. Its legs are grey green and not long. A gregarious bird in winter, it's usually seen in flocks on the Estuary. It feeds on mudflats by sieving tiny crustacea out of the water and mud, making sweeping motions with its bill. It also stalks and seizes polychaete worms and crabs, as well as probing the mud for worms and bivalves. nzbirdsonline-Wrybill Armitage, I. 2007. Wrybills (Anarhynchus frontalis) at the Manawatu River Estuary, North Island, New Zealand. Notornis 54 118-119.

About the estuary The Manawatū Estuary is a very special place in Aotearoa New Zealand. So special in fact, that it has been designated as a Wetland of International Importance (a Ramsar site), one of only seven in Aotearoa New Zealand. Bar-tailed Godwits feeding at the Estuary The importance of the area lies partly in its role as permanent or temporary home to 23 threatened species: thirteen species of bird, six species of fish, and four species of plants. The estuary is an important habitat for migratory native fish living upriver, as many Aotearoa New Zealand species need to go to sea at some point in their life cycle. The mudflats serve as a feeding ground for many migratory birds each year. A very high diversity of birds and fish is supported by these waters; 95 species of birds have been recorded here, meaning the estuary holds one of the greatest diversities of bird species in the country. As the largest (over 200 ha) and most significant estuary in the southern half of the North Island, the Manawatū Estuary offers important habitat for many different wildlife species, including the migratory Bar-tailed Godwit, which flies all the way from Alaska to spend our summer here before returning to the Arctic for the northern summer to breed. The Land Air Water Aotearoa website (LAWA) has some more interesting information about estuaries, including what can be found at the Manawatū Estuary. More on the history of the estuary and river can be found here .

Plants A checklist of species recorded from the area is included here . Information is basic and continually updated with links given by the usual method to a wealth of additional information. Headings and columns A and B are locked, so are always visible. Web address links are edited to fit within the static species columns. List can be downloaded, and additions added for personal use be “save as”. These will not be saved to the web. Much of the estuary vegetation near Foxton Beach township consists of exotic, salt tolerant vegetation of a grassy or scrubby nature, with the occasional stand of exotic trees. But a few native plants are still common and easily spotted. They tend to occur in the wetter areas, or closest to the coast. Some of the plant species you might see when you are at the estuary are described below. Estuarine Vegetation A significant portion of the estuarine vegetation found within the Ramsar site is native, in some cases endemic. Weeds are present - they must be addressed to conserve the biodiversity of the estuary. The most accessible portion of this estuarine vegetation is in the salt marsh area surrounding the Dawick Street viewing platform. This area is home to many of the native estuarine plants found in this Estuary. Map showing main areas of vegetation Native and endemic Estuarine vegetation Maakoako/Sea Primrose Glasswort Shore Cotula Piripiri/Biddy-biddy Taupata/Mirror Bush Three-ribbed Arrow Grass Wīwī/ Sea Rush Purua Grass Oioi/Jointed Wire Rush Wiwi/Knobby Club Rush Slender Clubrush Remuremu/Swampweed New Zealand Celery Māori Musk Three-square Bulrush Goosefoot Ephemeral Dune Wetland Vegetation The United Nations Convention on Wetlands, signed in Ramsar Iran, covers wetlands and their preservation. The estuary of the Manawatū river is one such wetland of international importance according to this, but the geophysical situation here, where the river crosses a large sand plain en route to the sea, adds another dimension to the wetland biodiversity, in the form of an ephemeral (temporary) dune wetland, with a notably different range of vegetation than the adjacent estuarine environment. The dunes of the west coast of the lower North Island are heavily defined by the dynamic environment, driven by the wind, and the accumulating sand from the beach. Plants in this dynamic environment must cope with high levels of water in the winter half of the year, and long periods with a low water table in the summer half of the year. In the summer, the drying out of the sand plains lets the wind excavate the slacks between the dunes, carrying the sand inland. The water table can drop dramatically by autumn The winter rains raise the water table, creating wetlands generally only present for part of the year. This enforces challenging requirements for plants to thrive and reflects in the fact that this ecosystem contains a disproportionate number of species on the threatened species list. Through fortuitous circumstances, the ephemeral dune wetland contained within the Ramsar site, has less weeds than any other dune wetland zone on this coast, and is maintained in that state by a community team. The area within the Manawatū Estuary Ramsar site that is an ephemeral dune wetland, is known locally and wider as the Dune Garden. Vegetation of the ephemeral dune wetlands Jersey Cudweed Harakeke/New Zealand Flax Tātaraheke/Sand Coprosma Sand Gunnera Half-star Autetaranga/Sand Daphne Strand Sedge Sand Wind Grass Shiny Bog-rush Punakuru/Angled Lobelia Pingao/Golden Sand Sedge Mudwort Kōwhangatara/Spinifex Sand Buttercup Grasswort Rauparaha/Shore Bindweed Smooth Willowherb Maikaika/Onion-leaved Orchid Tauhinu/Cottonwood

Punakuru/Angled Lobelia Lobelia anceps Native. Not threatened. Punakuru/Angled Lobelia has a tiny but prominent presence in the Dune Garden, not least because it flowers for much of the year. Besides Aotearoa New Zealand, it is also found in Australia, South Africa and Chile. It is a coastal and lowland plant that is generally found in exposed places that includes riversides and near lakes. Among it’s characteristics, in the Dune Garden it grows mostly prostrate (along the surface), but when it grows amongst other vegetation such as Kōwhangatara/Spinifex or Marram Grass, stretches upwards impressively, occasionally exceeding 30cm in height. Flowers are blue to purple. NZPCN-Lobelia anceps iNaturalist-Punakuru

Maakoako/Sea Primrose Samolus repens Native. Not threatened. A common estuarine plant around Aotearoa New Zealand, in many situations it can be a pioneer species moving in after an area has suffered a natural disaster. Afterward, other species move in, often overgrowing it, but even then, Maakoako survives under taller vegetation. For example, at the time of writing, at the end of Carter Crescent there is a patch of ‘lawn’ mowed by Council staff down to tide level. There is also a small patch easily seen from the viewing platform. Maakoako is a principal constituent of this patch of estuarine lawn. There is also a small patch easily seen from the viewing platform. It has pretty white flowers which show from well before Christmas until the start of winter, a long growing season. Besides Aotearoa New Zealand, it can be found in Australia, some Pacific Islands and Chile in South America. NZPCN-Samolus repens var repens iNaturalist-Samolus repens

Pohowera/Banded Dotterel Charadrius bicintus Native. At risk-declining. Pohowere/Banded Dotterel breed mainly inland, moving to coastal regions in late December and are at their greatest numbers in February. From mid-July they begin to return to their breeding grounds. Most years at least one attempt is made to nest in the sand dunes. Usual clutch size is three with incubation reputed to be around four weeks. Young are active from hatching and take a further 6 weeks to become independent. Plumage is variable with non-breeding livery pictured opposite. Two distinctive dark brown and chestnut bands cross the breast in breeding plumage, which fade as winter approaches. These active little birds are visual feeders, running across the mudflats and stopping when they see something interesting. Their diet consists of crustacea, worms, flies and berries from species such as Muehlenbeckia and Coprosma. nzbirdsonline-Banded Dotterel

Beetles This page is under contruction and will be continually up-dated with additional information added as it becomes available. A checklist of species recorded from the area is included here . Information is basic and continually updated with links given by the usual method to a wealth of additional information. Headings and columns A and B are locked, so are always visible. Web address links are edited to fit within the static species columns. List can be downloaded, and additions added for personal use be "save as". These will not be saved to web. Broun"s Sand Beetle Lagrioda brouni Endemic. Not assessed. Very little is known about this reasonably common species of beetle. It is mainly associated with driftwood, being found either beneath it or inside crevices. Mainly observed either as solitary individuals, small groups or, on occasions, congregating in groups of a dozen or so. Recorded from both islands, mainly in coastal regions with a number of observations between Otaki and Himatangi Beach with the summer months providing the most observations although it can be found at most times of the year. Naturalist-Broun's Sand Beetle

Pekapeka/Indo-pacific Comb Star Astropectin polyacanthus As its name suggests, this species inhabits the Indo-Pacific region being found from around Africa to Hawaii and from Japan, the Indonesian Islands to Australia and Aotearoa New Zealand. This species is typically found in shallow estuaries and harbors, at depths reaching 185 metres.. It is often a victim of dragnet fishing, which could explain why they are occasionally discovered deceased on beaches, sometimes in significant numbers. In life, they exhibit a dark purple hue on their upper side and orange on their underparts. Their common name originates from the "spines" located on both sides of their five arms which resembles a comb. Food consists mainly of shellfish which are swallowed whole. iNaturalist-Indo-pacific Comb Star finger sponge Pūngorungoru/Finger Sponge Callyspongis nuda Very little is known about this frequently washed-up Sponge Although there are records of this species being found globally in locations off East Africa, Madagascar, Indonesia and North and South America, it is Aotearoa New Zealand which seems to have the most records (see GBIF reference). Food in the form of plankton and dissolved organic material is drawn in through pores (clearly visible in the photograph) and the nutrients filtered from the water by cell walls as it was pumped through. Waste is also expelled through these pores. The life cycle of Sponges in general is complex. Most are hermaphroditic with both male and female cells. Larva produced find places to attach themselves to which can be rocks, marine debris or as in the picture, the shell of a mollusc. GBIF-Callyspongia nuda Wikipedia-Sponges by-the-wind-sailor By-the-wind Sailor Velella velella Not every summer but most, there are strandings of By-the-wind-sailor, although not in the numbers that are found for Bluebottles. Often called Jellyfish, they are actually a group of organisms each with a particular part to play in ensuring its survival and are termed Siphonophores. Unlike true jellyfish which are mobile in their own right, By-the-wind-sailors have no mechanism by which to achieve this and rely solely on wind and currents for their movement. A thin semicircular fin is set diagonally across the float and this acts like a sail which catches the wind and moves these creatures over great distances. The sting of this species is not that strong, but handling should be avoided. Jellywatch-Velella velella

Tauhinu/Cottonwood Ozothamnus leptophyllus Endemic. Not threatened. Principally a dry dune species on this coast, and in the Dune Garden sometimes appears in the ephemeral wetland area. There it builds dry islands by accumulating sand, but not as effectively as Pingao and Kōwhangatara. It is found from coastal areas generally up to subalpine regions and can attain a height of over 2m. One of the pleasant defining characteristics of this endemic species is that when the white flower is fully active, the aroma is quite reminiscent of Manuka honey. It is pleasant to be downwind of a large number of these plants when in bloom. It is reputed to be the larval food plant of the endemic moth Homoeosomo anaspoia . NZPCN-Tauhinu iNaturalist-Tauhinu

Pūkeko/Australasian Swamp Hen Porphyrio melanotus Native. Not threatened. With their large size, bright blue plumage and raucous behaviour, Pūkeko are a familiar bird around the area. They are an abundant species throughout most regions of Aotearoa New Zealand. They have a growing presence being observed in margins bordering the estuary. They are numerous in the damp paddocks in and around Foxton Beach, often forming groups of six to ten birds out of the breeding season. Their breeding system make them a very interesting species to study. Many form monogamous pairs (1 male/1 female) while others are can be polygynandy where both males and females have multiple partners. Pūkeko are known to breed at any time of the year if conditions are favourable and it is not uncommon to see chicks during the winter months. Clutch size is up to six eggs but can be many more if additional females lay in the same nest. Mainly vegetarian, feeding on a variety of grasses, sedges and rushes, they also catch small animals and will feed on carrion. If items can't be swallowed whole, they will be gripped in a foot and ripped apart. nzbirdsonline-Pukeko