Waimea Inlet

The primary purpose of the 2020 survey was to describe and map the dominant substrate and vegetation features present including seagrass, salt marsh and macroalgae based on the framework outlined in New Zealand’s National Estuary Monitoring Protocol (NEMP). Results are summarised in the following table and compared to previous NEMP surveys (1999, 2006, 2014) and, for some indicators (e.g. salt marsh extent), with earlier data from 1946, 1985 and 1990. 

Overall, despite extensive historical habitat modification, significantly reduced habitat diversity, and large areas of mud-dominated sediments, Waimea Inlet retains many areas of very significant ecological value. However, the large areas of mud-dominated substrate, the persistence of localised dense macroalgal beds and HEC’s, and pressures on salt marsh near the estuary margin from drainage and reclamation are key stressors that threaten these values. We are likely to see further salt marsh loss in the future in response to sea level rise due to the current limited capacity for landward migration. Reductions in sediment loads, and targeted management of localised nutrient inputs, will be required to improve estuary condition.