Inshore seagrass and habitat condition: ²⁰

• In the 2019–20 monitoring period, the Burnett–Mary region seagrass condition index remained largely unchanged and rated as a poor grade. The index remains well below the 2015–2016 level (which was the second highest on record) due to trends in all of the indicators.
• Over the long term, seagrass abundance regionally has fluctuated greatly (e.g. periods of loss and subsequent recovery). Increases between 2012 and 2016 were largely due to large increases at Urangan, which have since declined, while abundances at other locations have steadily increased. The long-term trend suggests that where losses have been observed, they are not part of a declining trend.
• Reproductive effort remained low and rated as very poor in 2019–20. Reproductive effort is generally low in the region, but occasional large increases have occurred in 2008–9 and 2015–16.

Seagrass abundance, composition and extent: ²⁰

• Seagrass abundances (per cent cover) across the Burnett–Mary region in 2019–20 were greater in coastal than estuarine habitats (15.2 ±0.6 per cent and 5.8 ±1.5 per cent, respectively), however estuarine abundances were higher in the late dry than the late wet season (10.2 ±2.0 per cent and 1.4 ±0.3 per cent, respectively). Half of the monitoring sites decreased in abundance in 2019–20 relative to the previous period, while only a third increased. Only one of the estuarine meadows in Rodds Bay remained stable in 2019–20.
• Since monitoring was established, the estuarine meadows have come and gone on an irregular basis. The only site to significantly decline over the long-term, was in the north of the region in the Rodds Bay estuary (RD2), however this decline was due to changes in the intertidal bank topography which rendered the site no longer suitable for ongoing monitoring, and the site has been discontinued. In the south, despite recent declines, both an estuary and a coastal site have significantly increased over the long-term, while no trend is apparent at the remaining monitoring sites.
• The estuarine and coastal seagrass habitats have remained dominated by Zostera muelleri with varying components of Halophila ovalis. In 2019–20, the proportion of colonising species increased at estuarine meadows compared to the previous monitoring year, but conversely continued to decline well below the Reef long-term average in coastal meadows. An increase in the proportion of colonising species in the meadows suggests some level of physical disturbance which may reduce ability to tolerate/resist major disturbances in future.
• Over the last 12 months, meadow spatial extent has remained stable at coastal meadows relative to the previous year. Estuarine meadows, however, continued to decline slightly in extent. This decline was restricted to meadows in the south (Urangan) which have fluctuated greatly with periods of decline, absence and recovery over the life of the MMP.

Seagrass reproductive status: ²⁰

• Seagrass reproductive effort in the dry season increased for the first time this year at coastal habitats since assessments commenced, but were not as high at estuarine sites compared to the previous monitoring period.
• A seed bank persists at all meadows monitored across the region, which was slightly greater at estuary sites in 2019–20 than the previous period. This may indicate the meadows have a greater capacity to recover from the declining abundances, provided conditions are favourable.
• The apparent disconnect between reproductive effort and seed densities may be an artefact of the sampling frequency and the somewhat stochastic triggers and possibly short flowering period.

Epiphytes and macroalgae: ²⁰

• Epiphyte cover on seagrass leaf blades in 2019–20 remained higher than the long-term average for the sixth consecutive year at estuarine habitats.
• Alternatively, at coastal habitats, the epiphyte abundance has remained below the long-term average for the fourth consecutive year).
• % cover of macroalgae has remained low and below the long-term average at across the habitats monitored), with the exception of a slight increase in estuarine habitats in the late wet of 2019.