Sand dunes are critically endangered ecosystems, supporting a wide variety of specialist native flora and fauna (Jamieson, 2010). They have declined significantly in the past century, due to coastal development, exotic invasions, and stabilization using marram grass (Ammophilia arenaria). The Maketu spit is 3.5km long and covers an area of 45 hectares, it is the most intact coastal dune ecosystem in the Tauranga Ecological District.
The dominant vegetation on the fore dunes are the native grasses spinifex (Spinifex sericeus), pingao (Ficinia spiralis) and sand tussock (Austrofestuca littoralis). These fore dune plants are well adapted to the dynamic environment, tolerating high temperatures, low moisture conditions, salt spray and burial by sand (Esler, 1970). These species are in good condition on the spit but are threatened by invasive pest plant species and rabbits. The back dune is dominated by Pohuehue (Muhlenbeckia complexa) and Wiwi (Juncus pallidus).
This native flora provides high-value breeding habitat for native birds, specifically the Northern New Zealand dotterel (Charidrius obscurus), variable oystercatcher (Haemantopus unicolor), red-billed gull (Larus scopulinus) and white-fronted tern (Sterna striata). Breeding success of birds (including New Zealand dotterel) has improved recently, which has been attributed to increased pest control on the spit by Maketū Ongatoro Wetland Society (MOWS) volunteers.
A wide variety of native and migrant birds also use the spit and associated mudflats for feeding and roosting, especially during the winter, including: bar-tailed godwits (Limosa lapponica), royal spoonbills (Platalea regia), wrybill (Anarhynchus frontalis) and the extremely rare and threatened fairy tern (Sterna nereis).
The dune system also has a high incidence of native invertebrates, well over 150 species have been recorded, including five new or un-described species notably a new spider and a new beetle. Shore skinks (Oligosoma smithii) occur all along the spit, MOWS are currently conducting a survey to estimate the population size and distribution.
References: Esler, A. E. (1970). Manawatu sand dune vegetation. Proceedings of the New Zealand Ecological Society, 17: 41-46.
BirdLife International (2012). Charadrius obscurus. In: IUCN 2012. IUCN Red List of Threatened Species. Version 2012.1. . Downloaded on 03 August 2012.
Jamieson, S. L. (2010). Sand dune restoration in New Zealand: Methods, Motives, and Monitoring. Unpublished MSc Thesis. Victoria Universityof Wellington, Wellington, New Zealand. 158p.