The report card uses an easy to understand grading system of ‘A’ through ‘F’ for five zones within the estuary. The grades represent the overall health of the Tamar River estuary from 16 monitoring sites using data collected over 12 months.
Ecosystem Health Report Card Grades (‘A’ to ‘F’) are generated for five (5) functional zones in the Tamar River estuary. Parameters are assessed against local water quality targets for the Tamar River estuary resulting in the determination of a single grade for each zone. The Ecosystem Health Index (EHI) is a numerical representation of how often the indicators meet the water quality targets.
It is important to monitor and understand the health of the Tamar River estuary so that natural resource managers can better evaluate the condition of our waterways and target investment and on-ground works to improve waterway health. The Ecosystem Health Assessment Program (EHAP) will also enable managers to better evaluate the effectiveness of future activities undertaken to improve waterway health such as sewage treatment plant upgrades, stormwater controls, and catchment activities.
WHAT IS ECOSYSTEM HEALTH?
Ecosystem health is determined by the response of the environment to natural and human inputs and is defined as the degree to which the actual state of an ecosystem diverges from an ideal state as defined in management objectives. A healthy estuarine and marine ecosystem will have the following characteristics: key processes operating to maintain stable and sustainable ecosystems, zones of human impacts that do not expand or deteriorate and aquatic ecosystems (critical habitats) which remain intact. As these characteristics are complex and difficult to measure, there are more easily measured parameters that are used to infer ecological health which have been used in the EHAP. These parameters include water quality and biological indicators.