Understanding oxygen dynamics and the importance for benthic recovery in Macquarie Harbour - Progress report

This report provides an ongoing update on the status of dissolved oxygen (DO) and benthic conditions in Macquarie Harbour. It follows on from the results previously outlined in the IMAS reports released throughout 2017 and 2018. These reports first described the deterioration of benthic and water column conditions in spring 2016, early signs of faunal recovery in the following autumn, when oxygen levels had improved, and the subsequent decline in benthic conditions when oxygen concentrations in middle and bottom waters returned to very low levels in spring 2017. In the most recent report we described a continuation of this cycle; an increase in faunal numbers in mid-2018 following improved oxygen concentrations in the middle and bottom waters through the summer of 2017/18. This report presents the results and preliminary interpretation of a repeat survey of benthic communities in January 2019 and DO monitoring data up until late May 2019.