This report assesses relationships between estuarine ecological health and sedimentation using a national dataset collated from 79 intertidal sites across 32 estuaries in Aotearoa New Zealand.
This report assesses relationships between estuarine ecological health and sedimentation using a national dataset collated from 79 intertidal sites across 32 estuaries in Aotearoa New Zealand.
The analysis found no strong or consistent relationships between sediment accretion rate (SAR) and macrofaunal indicators of ecological health. In contrast, sediment mud content showed much clearer and more consistent relationships with ecological health. Consequently, the authors recommend the continued use of the current sedimentation Default Guidelines Value as a contextual reference rather than a strict threshold and urge caution in interpreting SAR based thresholds without considering local site conditions and other measures of sedimentation stress. Further work could be done to try to tease apart the relationship between SAR and ecological health, and recommendations are provided in the report.