Seagrass in Queensland ports

Queensland’s ports handle more than 347 million tonnes of trade each year, contributing over $30 billion to the state’s economy and supporting tens of thousands of jobs.

Many seagrass meadows lie close to or within port facilities. These high-value and vulnerable habitats – including those within the Great Barrier Reef World Heritage Area – provide essential food and shelter for turtles, dugongs, and fish.

Without careful management, activities such as dredging, shipping, and runoff can reduce water quality, alter flow, and limit light to impact the health of seagrass.

Our monitoring guides management of ports activities and provides early warning of ecosystem change, allowing for better management.

Longest seagrass programs across 10 ports

Our long-term monitoring at Queensland’s ports has created one of the world’s largest and most comprehensive seagrass datasets. These partnerships are advancing global science, guiding dredging and management decisions, and setting new benchmarks for how industry and seagrass ecosystems can be managed.

For over 30 years, our seagrass experts have partnered with port authorities to monitor the long-term health of seagrass meadows along the Great Barrier Reef coastline, Torres Strait, and northern Cape York Peninsula. We currently monitor over 166,000 hectares of seafloor across 10 Queensland ports, including:

• Abbot Point – since 2008, five meadows, over 5,500 hectares.

• Cairns Harbour and Trinity Inlet – since 2001, six meadows, over 1,000 hectares.

• Gladstone – since 2002, 14 meadows.

• Hay Point– 2005-2012 and yearly since 2014, five meadows, over 6,000 hectares.

• Karumba – since 1994, two meadows, over 800 hectares.

• Mourilyan – since 2000, five meadows, approximately 15 hectares.

• Thursday Island – biennially since 2002 and yearly since 2016, nine meadows, over 100 hectares.

• Townsville – since 2007, over 2,000 hectares.

• Weipa – since 2000, five meadows, over 4,500 hectares.

Our team has also conducted baseline seagrass surveys for ports at Bundaberg, Cape Flattery, Lucinda, Port Musgrave, and Skardon River.

How we monitor seagrass

Each year, we monitor the extent, species, and biomass of seagrass meadows, mapping habitats to track changes over time. This helps us understand how meadows respond to port activities and environmental disturbance and identify changes in these habitats, providing the evidence ports need to manage activities and potential impacts. These programs cover large sections of the Queensland coastline, including areas close to port activity and reference areas beyond ports waters.

We monitor seagrass through:

• Aerial and boat surveys: intertidal meadows are surveyed by helicopter and subtidal meadows by boat.

• Regular monitoring: key meadows near port infrastructure and reference sites are surveyed every year.

• Comprehensive mapping: all meadows within port limits are assessed every three years.

• Long-term datasets: we track seasonal patterns, weather impacts, and seagrass resilience and recovery.

Our consistent, robust approach ensures that we produce high quality data that can be compared between years and across sites – progressing ports practices to be as sustainable as possible.

How our data informs sustainable management

Our monitoring programs assist port authorities in designing and conducting ports operations, maintenance, and development in ways that minimise potential impacts to seagrass.

Results also feed directly into environmental health report cards for the Wet Tropics, NQ Dry Tropics, Mackay-Whitsunday-Isaac, and Gladstone regions as well as synthesis products for the Gulf of Carpentaria, Torres Strait, and the Great Barrier Reef.

These partnerships are the foundation for ongoing tropical seagrass research, including:

• Major seagrass restoration projects and trials of restoration methods.

• Identifying light management thresholds to protect seagrasses.

• Assessing blue carbon stocks.

• Evaluating seagrass recovery after disturbances such as flooding and storms.

• Identifying drivers of change in seagrass meadows.

To date, the team has published over 40 peer-reviewed research articles from this range of projects that build on the long-term monitoring programs.

These programs are enabling ecologically sustainable planning of ports operations, building our understanding of seagrass health and changing conditions in the region, and contributing innovative research into seagrass meadows across tropical Queensland.

Project details

This project is led by Michael Rasheed, Skye McKenna, Carissa Reason, Tim Smith, and Abbi Scott. Partnerships are funded by Gladstone Ports, North Queensland Bulk Ports, Ports North, and Port of Townsville.