Coastal Restoration Trust of New Zealand

Coastal Dune Ecosystem Reference Database

Broad scale habitat mapping of sandy beaches and river estuaries – Wellington Harbour and South Coast. Technical Report

Author
Stevens, L., Robertson, B. and Robertson, B.
Year
2004
Journal / Source
Report for Greater Wellington the Regional Council. Cawthron Report No.
Publisher / Organisation
Cawthron Institute, Nelson, New Zealand.
Volume
913
Keywords
Beaches, soft substrate, estuaries, vegetation, intertidal, effect of grooming, contaminants, estuarine, ecological survey
Summary
Greater Wellington Regional Council (GWRC) recently contracted the Cawthron Institute to map the substrate and vegetation of 13 sandy beaches and 3 river estuaries within Wellington Harbour and the adjoining South Coast. The approach used field-verified broad scale mapping of habitat zones, supported by fine scale sampling undertaken at specific locations (Petone, Lowry Bay, Fitzroy Bay, Hutt River Estuary) to provide a systematic classification of different areas. This report presents the results of the 2004 sampling programme (grain size, nutrient and organic enrichment, toxic contaminants, sediment biota, environmental pressures). Overall, all of the sites were found to be in a healthy condition. Clearly, some localised impacts are present, but across the majority of the habitat at all of the sites, the intertidal sediment quality of the sites was high. At the fine scale sites, selected to provide a picture of the areas most likely to be affected, sediment analyses found no signs of adverse nutrient enrichment or chemical contamination. All sites supported a biological community typical of other NZ beaches and estuaries in good condition.