Crustacea Crustacea are a diverse group of animals with at least 65000 species worldwide but here at the estuary there are less than twenty to be found. While some are residents, many are washed up after storms or arrive hitching a lift on either debris or seaweed. Most are free-living in either freshwater or a marine environment but one group, the familiar slater or woodlouse are terrestrial (land) based. Other species include crabs, crayfish, shrimps and barnacles. More information on Crustacea can be found on the following links here and here . 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. Tunnelling Mud Crab Titan Acorn Barnacle

Remuremu/Swampweed Goodenia radicans Native. Not threatened. Found throughout the Southern Hemisphere, this species common name originates here. Routinely found in estuarine situations, it can also be found in wetland habitats with little saline component. In summer it produces a lovely white half-star flower indistinguishable from its rare cousin, Goodenia heenanii , which is known only from this coast. Another defining characteristic of Remuremu is the production of wonderfully large, soft carpets of vivid green overlaying estuarine mud flats. This plant occurs on both sides of the river on the Ramsar site. It has been hypothesised to be the main host plant for the moth species Asaphodes frivola, a critically endangered species, currently known from only two small colonies near Invercargill but would certainly be worth further investigation locally. NZPCN-S elliera radicans iNaturalist-Selliera radicans

Poaka/Pied Stilt Himantopus leucocephalus Native. Not threatened. Poaka/Pied Stilts can be seen on the mudflats at the estuary and mix readily with other feeding shorebirds such as oystercatchers and godwits. It is more abundant in winter when flocks of over a hundred can regularly be encountered from the viewing platform.at Dawick Street. They are a stunning, slender black and white wader that stalks through the water on long, red, stilt-like legs which trail behind them when flying. Plumage can be variable, especially around the head and neck. The long, slim beak is black and the eye red. Diet consists of water insects and crustacea which are taken from the water or the mud. When wading through water, it may take food from the surface or put its head underwater. On the mudflats it probes or scythes soft mud with its beak. Pied stilts are usually seen in groups, and also breed in small colonies. The bird has a distinctive yapping call which it utters while both on the ground and in flight, nzbirdsonline-Pied Stilt

Slender Clubrush Isolepis cernua Native. Not threatened. Routinely found in estuarine situations, this species is adaptable and can also be found in freshwater and brackish wetland environments with little or no saline component. This wee rush appears to be fruiting much of the year, losing the head only for the winter. It can be found on both sides of the river of the Ramsar site. In the Dune Garden, this species appeared around 2020, and spread widely across the wetland area within two years and is now an abundant species. Very widespread on a global scale being found throughout Australasia, Europe, Africa and North and South America. NZPCN-Isolepis cernua iNaturalist-Isolepis cernua

Molluscs Globally, there are around 85,000 species. They are a diverse group of both familiar and unfamiliar species including snails, slugs, clams, barnacles, mussels, squid, octopus plus many unfamiliar species. An excellent article is linked here and this also has a number of links to other avenues of mollusc information. A more in-depth outline of species in given here . 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. Mudflat Snail Saltmarch Snail Toheroa Photo Tangatawhenua iNaturalist

Tuna kuwharuwharu/Longfin Eel Anguilla dieffenbachii Native. At risk-declining. Mainly a nocturnal species, they live in rivers and lakes but can also be found in most types of water, usually inland from the coast but can equally survive in farm drains, dams and large ponds even if the water is quite murky water. Most habitats would have some bank shading. A second species, Tuna Hinahina/Shortfin Eel A. australis is also found in our rivers but is not as abundant. Breeding takes place only once in their lifetime when they migrate some 5000 km across the Pacific to lay their eggs off the coast of Tonga, after which they die. Spawn drifts back to Aotearoa New Zealand on sea currents, hatching en route. On entering freshwater to start their migration up-stream they change into "glass eel" and it could be up to 80 years before these repeat the journey. The Department of Conservation produces an excellent information sheet which includes links to an activity book and many other aspects of their lives.

Pukatea/Jersey Cudweed Helichrysum luteoalbum Native. Not threatened. Despite its common English name, it is regarded as having arrived in Aotearoa New Zealand before human settlement. Growing around the periphery of the wet areas of the Dune Garden, it can also grow in a variety of other different habitats such as meadows, road verges and waste ground. In fact, it can thrive adequately in most dry conditions, even in poor soil but if found growing in fertile areas they can be very prolific and become invasive over time. It is an easily distinguished plant that can reach 50cm in height and has greyish-green leaves which can be furry. Flower buds develop in spring and have a reddish tip before opening and are borne mostly on the top of the plant and are yellow-white. These are attractive to many insects which pollinate them, and the mass of seed produced translates into a good number of seedlings, but most unfortunately don’t seem to reach maturity in the dunes. iNaturalist-Jersey Cudweed NZPCN-Jersy Cudweed

Strand Sedge Carex pumila Native. Not threatened. Nowhere is this clearer than in the Dune Garden, that this is a foundational plant for ephemeral dune wetlands on this coast, where it shelters many of the smaller species found there. It is a common species in coastal regions of Aotearoa New Zealand, Australia, Chile, China and Japan where it can also be found growing near coastal lagoons and rivers. Is also a lawn weed in some locations. It is a low growing sedge reaching 0.4m with distinctively channeled, smooth-edged, blue-grey leaves. Delicate white flowers produced during summer are followed by robust seed heads through autumn which develop into oval shaped nut-like structures up to 3mm in length. iNaturalist-Strand Sedge NZPCN-Strand Sedge

Fauna and Flora The Manawatū Estuary offers important habitat for many different wildlife species, and has one of the highest bird diversities in New Zealand. In addition, it is home to a number of threatened fish and plant species. Click on the links below to learn more about some of the species you might see here. Birds Fish Plants Mammals Crusta cea Spiders Molluscs Beach Mysteries Beetles Fungi, Mosses and Lichens Other marine species Invertebrates Amphibians and Reptiles Ferns

Pest Fauna It is a well-known fact that Aotearoa New Zealand has a disproportionate number of introduced animal species, many of which are detrimental to the survival of native wildlife. Many species, such as rodents (rats and mice) and mustelids (weasels, stoats and ferrets) are well documented and present around this area. This page will introduce some of these species, plus others that are not so well known. Brief introductions and a list of organisations where these can be reported will be included, as are some control methods. iNaturalist has a list of exotic species for the Ramsar site but this is a little vague in terms of information. Best to search for the individual species in this link . Before commencing any trapping of Mustelids, Rats or Possums please consult Department of Conservation booklet Practical Guide to Trapping 3rd edition . One of the most comprehensive coverages of what is required to start and expand a successful pest control program is contained in a publication by Predator Free Miramar and titled How to kill rats and engage a community . It contains a detailed account of what is needed from trap building to engaging public and everything else in-between. It is a must read. Predator Free NZ produces a series of excellent guides on the main predator species which can be viewed via this series of links. Ferret , Weasel , Stoat , Ship Rat , Norway Rat and Possum . Below are listed three of the best guides to mammalian pest control. All slightly different - follow the basics but adapt to your own personal situation as required. Foxton Beach Predator Trapping Results With funding and assistance from Horizons Regional Council and Predator Free NZ, Wildlife Foxton Trust with the help of numerous enthusiastic volunteers administer the trapping program in the Foxton Beach area covering the estuary, woodland, farmland and around the township. Results of all this effort is beginning to show as can be seen from the graph below produced by the Traps NZ site, where all our catch details are entered. Various traps are available, on loan, from Wildlife Foxton Trust. Sections below, in time, will not only cover many of the dominant and well known species but some of the lesser known types which prey on some of Aotearoa New Zealand's other unique wildlife. possum MUSTELIDS Three species make up this most lethal suite of introduced predators that Aotearoa New Zealand has. Weasel, Stoat and Ferret are capable killers being able to decimate entire populations of native species from areas that are not protected with an eradication program. Traps and boxes can be purchased as a complete unit or separately. Boxes for these traps have a design which must be followed. The DoC 250 for stoats and ferrets and DoC 200 for weasels are the industry standard and design details can be found in this handy guide. More information is available in the three guides listed above. The video opposite was taken by Cleland Wallace for which we acknowledge his permission to use. This photograph is of a ferret and was taken on the recent Bittern Muster (survey) at Lake Omanu. Being the domesticated form of the Polecat, they tend to be more confiding than the other two species. Efforts are underway to start a trapping program in the area, an important habitat for many species of birds. Brush-tailed Possum Trichosurus vulpecula This serious pest of forests and gardens was introduced to Aotearoa New Zealand with a view to creating a fur trade. The first, in 1837 was unsuccessful but it was the 1858 attempt which started the colonisation of this destructive pest. While some possum fur is still used, usually combined with wool to give extra strength, it is the side effect that is being felt now. Possums are now trapped extensively to try to eradicate them. Wildlife Foxton Trust has a trap library and loan out possum specific traps, with instructions for use in the Foxton Beach area. Enquiries via their website wildlifefoxton.org BLACK AND YELLOW STRIPEY STINGY THINGS Wasps are in the same order as bees and ants and while most live solitary lives, it is the social wasps that are a real pest, both to native wildlife and to humans and their activities. German wasps are nuisance at certain times of the year especially when outdoor eating is involved. In terms of their pest status the least troublesome to humans but to native invertebrates they are a real problem are the paper wasps, especially the Asian Polistes chinensis which is particularly abundant in this area, building their nests in a variety of locations including guttering, bushes and in log piles. They are not aggressive and their stings are reputed to be not that painful. They take a heavy toll on native insects and their nests should be destroyed as soon as they are found. Normally only small structures they can sometimes be large. First spray with a commercial fly spray and when there is no sign of wasps in the vicinity, destroy nests which will kill any remaining pupae. If Monarch Butterflies breed in your garden there will be a nest close-by and would be worth checking as these can take a heavy toll. Perhaps the most familiar of the wasps are the two species of Vespula , those annoying species of the summer months. Depending on several factors both the German V. germanica and Common V. vulgaris can be quite abundant some years. Unlike the paper wasps, both these species build nests where the egg chambers are enclosed with an outer covering with one or more entrance hole. They can be situated underground, in wall cavities or in buildings. Being stung by an individual can not only be very painful but dangerous if allergic, often warenting a visit to hospital Nests if discovered should not be approached as they are very aggressive creatures. Destruction should only be done by a professional pest control person, but there are traps and baits available for use away from nests to attract them. Details of of one of the most effective is given below for control of Hornets A recent addition to the list of invasive species is the Yellow-legged Hornet Vespa velutina. This is potentially a very destructive species and has caused havoc with bee populations in an increasing number of countries as it is a very aggressive predator, attacking bee hives. Populations are spreading worldwide with the first record for Aotearoa New Zealand in 2025. Immediately, MPI/Biosecurity developed a strategy to control this pest and help contain and ultimately eliminate the threat. Since the initial sighting, a total of 77 queens and 132 have been destroyed as of early April 2026. There is a wealth of information on the MPI/Biosecurity website which covers all aspects associated with what is being done to help eradicate Yellow-legged Hornets, including what to look out for and where to report possible sightings. An information leaflet is available to download at MPI documents CONTROL German and Common Wasps and Yellow-legged Hornets, besides being a threat to native species are potentially a threat to humans because of their sting. Nests of all species need to be reported to the appropriate authority for elimination and not to be attempted by untrained individuals. However, measures can be taken by individuals to protect personal space by using different types of bait containers and lures with several different types are available. The main consideration is bycatch, species for which bait and equipment is not intended. Sweet sugary liquids in homemade dispensers is not ideal. Best to use a specific wasp attractant which is of low risk to bees and which is placed in a suitable which does not allow easy access to the bait. One of the best is the dome-shaped container which holds the bait. Trials have been held over a few years by the Department of Conservation with a new bait, developed by Merchento called Vespex . It has proved very effective in controlling both wasps and hornets which take it back to the nest resulting in the killing of the whole colony. Check out the link above for more details. Lester, P. 2018. The Vulgar Wasp: The Story of a Ruthless Invader and Ingenious Predator. Victoria University Press. Lester, P. 2022. The Management of Invasive Species, Pests and Diseases in New Zealand. Te Herenga Waka University Press.

Päpaka/Tunnelling Mud Crab Austrohelice crassa Endemic. Not assessed. A frequently seen animal on the mudflats around the estuary which is easily observed from the viewing platform on Dawick Street. As their name suggests they are enthusiastic tunnellers and can have a very complex burrow system which they diligently clean out at low tide. Scavengers by nature, they will eat not only carrion, worms and algae (seaweed) but also rummage through mud for morsels to eat. As far as mud crabs go, they are a small species with a carapace (shell) growing to a maximum of 40mm. Eyes are on stalks, and these are reputed to see movement up to 40 metres distance but even so, they are a favourite prey of kōtare/kingfishers around the estuary which hunt them from perched on tree debris or other structures that provide them with some elevation. iNaturalist-T unneling Mud Crab titan acorn barn Titan Acorn Barnacle Megabalanus coccopama What is believed to be the first record for this large and colourful barnacle found naturally in Aotearoa New Zealand was in November 2020 at Foxton Beach. There are several other records however of them being attached to ships. Their natural distribution is the Pacific coasts of South and Central America but is now being reported from other parts of the world, plus heading northward towards North America. It has been reported several times from Australia. As the individual found locally was attached to a cuttlefish bone it is thought to have originated from Australia where the nearest population of these familiar beach oddities are found. Like numerous other species it is thought to be expanding its range as sea temperatures gradually warm. Wikipedia-Titan Acorn Barnacle Smithsonian Institute-Invasive data

Retoreto/Red Azolla Azolla rubra Native. Not assessed. This is perhaps Aotearoa New Zealand's most unusual species of fern is as much as it is entirely aquatic, being found on ponds, slow-flowing streams and ditches. It is found throughout both Islands but has predominantly been replaced in Northland by an introduced Australian species. Also, found throughout the Pacific reaching as far as India. As can be seen from the photograph it can form dense patches which can cover entire areas. Usually brick red or glaucous green it produces spores which are dispersed either by wind, water or by attaching themselves to anything that move through their environment. NZPCN-Azolla rubra iNaturalist-Red Azolla azolla Rauarahu/Austral Bracken Pteridium esculentum Native. Not threatened Thought by many to be the bracken of the Northern Hemisphere it is in fact native to parts of Southeast Asia, the Islands, Australia and New Zealand and is easily distinguished from its northern cousin by its more delicate foliage. It is a fairly robust plant which grows from underground rhizomes and spreads quickly in disturbed ground to the extent that it can quickly become a serious pest. As can be seen in the photograph the frond are upright and are triangular when fully open. It is said that this species is less toxic to stock than other species but can still prove detrimental if eaten over long periods. Rhizomes are reputed to be edible. NZPCN-Pteridium esculentum bracken spleenwort Petako/Sickle Spleenwort Asplenium polyodon Native. Not threatened. This is a species of fern that prefers either full or partial shade and is frequently found in woodland. In the region plants can be found in the pine plantations that border the Estuary with the odd plant being located further into the dunes that have a covering of vegetation, usually non-native. Occurring throughout most areas of Aotearoa New Zealand but mostly in western areas of the South Island. Although not threatened nationally, it has a regional classification of naturally uncommon for Otago. It is also to be found in Australia, Pacific Islands, Indo-Malaysia and Madagascar. Spores which are bourn on the underside of the leaves are dispersed by wind. NZPCN-Sickle Spleenwort