• A fascination for environmental science and coastal systems has yielded research insights into a lower Mid North Coast estuarine mangrove forest
• The researcher is the first Charles Sturt University environmental science Honours student at Port Macquarie and she is employed in her chosen field before she graduates
• The research examined the historical ecology records and multiple lines of evidence for the Macleay River estuary of the Dunghutti traditional owners, the fourth largest coastal river system in NSW

The first-ever environmental science Honours graduate at Charles Sturt University in Port Macquarie is already employed in the region and continues the work that inspired her research.

Ms Chloe Baker (pictured top, and below) conducted her Honours research in the Charles Sturt School of Agricultural, Environmental and Veterinary Sciences in 2021, submitted her thesis in February 2022 and recently presented the results of her Honours thesis at the Australian Mangrove and Saltmarsh Network Annual Conference in Ballina in early October.

Her research presentation is titled ‘Understanding the history and current condition of mangrove forests using a mixed method approach: A case study of the Macleay River estuary’ and was well received by the more than 90 delegates at the conference.

Ms Baker graduates at the Charles Sturt graduation ceremony in Port Macquarie on Monday 19 December and is already employed as a Marine and Estuary Support Officer with the NSW Local Land Services (Hunter) in Taree, NSW.

Ms Baker’s research examined historical ecological records to identify changes to the Macleay River estuary shape and mangroves forests. This included the use of multiple lines of historical evidence such as historical maps, charts, photographs, government reports and documents, newspaper articles, and interviews.

“I found that when the historical data (such as images and reports documenting flooding events) and mangrove condition data (i.e. size, age and density and tidal flooding patterns) are linked it provided a more contextual understanding of a site for natural resource practitioners to manage mangroves more effectively,” Ms Baker said.

“Natural resource practitioners are extremely interested in conserving mangrove systems for their ability to effectively sequester blue carbon.”

“Mangroves are impacted by events that are remote in time and space; for example, both past and present flooding have influenced the sediments beds of the Macleay River estuary and the extent and condition of mangroves. Established mangroves also play an important role in stabilising sediments and reducing the impact of floods on human settlement and are extremely important.”

She said mangroves are found globally within estuaries and are part of the intertidal vegetation zone.

Ms Baker’s study area, the Macleay River estuary of the Dunghutti People traditional owners, is the fourth largest coastal river system in NSW with a catchment of approximately 740 square kilometres.

It has a tidal limit reaching 54 kilometres upstream at Belgrave Falls and makes up approximately five per cent of the total mangrove vegetation in NSW, with the upper limit of mangrove extending approximately 22 kilometres upstream from the entrance.

The estuary has experienced extensive modification over time, resulting in a change to the extent and condition of mangroves throughout the estuary.

“Mangroves have unique adaptations to tolerate the inundation of the tide and are sensitive to hydrology and sediment pathways,” Ms Baker said.

“They are important because they provide coastal protection and stabilization of sediment, wildlife habitat, fish nursery and production values, and carbon sequestration.”

Ms Baker said the major threats to mangrove estuaries include anthropogenic development and modification, deforestation, disruption of ecological processes (such as hydrology and sediment delivery), climate change, and rising sea levels.

As a result of these disturbances, mangroves globally have experienced changes in extent, mortality, and changes to the condition of the mangrove system.

Ms Baker said the key findings of her research are:

• Historical analysis has a key role in understanding current estuary and mangrove condition.
• Mangrove condition within the Macleay River estuary was variable, highlighting the need to understand local-scale variation in addition to regional-scale extent.
• Multiple lines of evidence provide a richer understanding of the historical changes to the estuary and current condition of mangroves.

Ms Baker’s research was co-supervised by Lecturer in Environmental Management Dr Alexandra Knight (principal supervisor) and Professor of Environmental Sciences Robyn Watts both in the Charles Sturt School of Agricultural, Environmental and Veterinary Sciences, and Mr Patrick Dwyer, Senior Manager - Coastal Systems (Biodiversity Offset), Aboriginal Fishing, and Marine and Coastal Environments, NSW Department of Primary Industries – Fisheries.

Dr Knight, who is based at Charles Sturt in Port Macquarie, said, “Chloe was a great student to supervise during her Honours year, very dedicated and hard-working, with great communication skills and a positive attitude.

“As a result of the skills she built through her thesis research Chloe has gained employment in her chosen field of work with the Hunter Local Land Services as a marine and estuary officer.”

Dr Knight noted that there are opportunities for other students interested in Honours programs focused on coastal management at the University’s coastal campus in Port Macquarie.