Please note our Whitianga office will be closed to the public on Tuesday, 16 September and Wednesday, 17 September 2025. You can still contact our staff on freephone 0800 800 401 or via an online form.
Because sediment-dwelling organisms respond predictably to many kinds of natural and human-made stresses or disturbances they have been widely used as indicators of estuary health in environmental monitoring programmes worldwide. Changes in the types and abundance of animals present within an estuary may indicate the effects of localised disturbances (e.g. channel dredging) or regional-scale pressures or activities (e.g. terrigenous sediment, nutrient enrichment).