Areas of research

Pāuatahanui Inlet and the surrounding area have attracted both ecological and archaeological interest. The Inlet is the largest estuarine system in the lower North Island and has extensive intertidal sand and mud flats and a large salt marsh. Although apparently not a site for major settlement in prehistoric times, the area nevertheless attracted early moa-hunter Maori for the birds of its forests and the abundant shellfish to be found in the Inlet. While the forest has largely disappeared, many species of birds continue to live in or visit the Inlet and there is an impressive variety of fish. High numbers of cockles, crabs, snails and other small animals inhabit the sand flats and seagrass beds. The Inlet is recognised nationally as a site of significant ecological and wildlife conservation value. It remains relatively unpolluted but is threatened by human activity around its margins. These features, and its closeness to a major population base, have made it a favoured site for research.



The most wide-ranging scientific research programme to date was done in the late 1970s by the New Zealand Department of Scientific and Industrial Research (DSIR) in response to local concerns about the effects of silt run off from urban development. This study (Healy1980) documented the current state of the physical and biological components of the Inlet and gave a baseline against which future research could measure change.


Since this time the Greater Wellington Council and Porirua City Councils have commissioned a great deal of research as they make progress towards implementing the integrated management programme for the Inlet and its catchment outlined in the Porirua Harbour Strategy and Action Plan and Detailed Action Plan. GOPI will continue to assist through our triennial cockle survey.


The Inlet is an important nursery area for commercial fish species such as snapper, rig and flounder, with ongoing investigations being carried out by the Ministry for Primary Industries and the National Institute of Water and Atmospheric Research (NIWA).


Various organisations are researching more basic scientific topics. Graduate students and staff at Victoria, Auckland and Massey Universities, GNS Science and NIWA have been studying aspects of pollution of the Inlet and the harbour and other aspects of marine biology. Research on birds, whitebait and the biology of catchment streams has also been carried out.



The archaeological research that has been done to date has centred on the investigation of middens from the fifteenth and sixteenth century. A study was carried out in 2000 which, amongst other discoveries, showed that cockles in the middens were, on average, far bigger than the modern Inlet cockle. The authors hypothesised that either human predation was sufficiently heavy and sustained to take out enough large cockles to permanently reduce average size, or that there has been significant environmental change at some stage since the archaeological site was occupied. Increased sedimentation, decreased salinity and/or decreased water temperature are all prime suspects, but deciding which, if any, was the culprit is difficult with present knowledge. The authors suggest two areas of further research: an analysis of oxygen isotope ratios in cockle shells to provide data on ambient temperature at the time, and a survey of nineteenth century midden cockle shells to give a better than two-point time line to judge when the decline in size might have occurred.


Davidson and Leach are currently using collections from Te Papa Tongarewa, the Museum of New Zealand, to carry out new investigations into cockles.



A comprehensive history of the Pāuatahanui area has been published called 'Pāuatahanui - A Local History'. Written by Hellen Reilly, with the help of a research team set up for the purpose of documenting the story of the area, this book covers the history of Pāuatahanui from a time before the arrival of Europeans to the modern day.

Various smaller publications deal with specific aspects of local history. 



Healy, W.B. (1980) Pāuatahanui Inlet — an environmental study. DSIR Information Series 141. NZ Department of Scientific and Industrial Research.

(This book is out of print but is available at public libraries).






Last Updated: 14/05/2016 6:51pm