JCU TropWATER researchers are investigating the challenges associated with developing water security in Northern Australia, particularly in regions celebrated for their ecological richness and diversity.

Under the Water Security for Northern Australia program, scientists from JCU TropWATER, Charles Darwin University and CQ University are examining targeted catchments from Western Australia to eastern Queensland, including the Gilbert River, Lower Fitzroy River, Daly River, and Ord River irrigation area.

JCU TropWATER Director Professor Damien Burrows said the amount of water needed for Australia’s agriculture will continue to grow along with the global population, and this has placed inevitable pressure on securing water from natural waterways.

“As we explore water security in Northern Australia, there’s a critical need to find a balance between meeting human needs and preserving the environment, while understanding the limitations to potential development,” he said.

“Science is critical in guiding these development decisions, particularly given the arid and challenging climate conditions of Northern Australia, coupled with few suitable catchments.

“Our challenge is to maximise these constrained opportunities through rigorous scientific measures, ensuring environmental preservation amid economic aspirations.”

Unravelling the impact of development on Northern Australia’s ecological values

With nearly half of Australia’s total land area and only 5% of the population, coupled with ample rainfall and abundant water resources, Northern Australia is a favourable region for water security for agricultural expansion.

Yet, while Northern Australia is recognised for its economic potential, it’s also ecologically important, renowned for vast, biodiverse aquatic ecosystems. Beyond this, the landscape also holds high cultural importance for Indigenous communities, who have maintained a deep connection with the land for generations.

TropWATER’s Dr Paula Cartwright said the region boasts countless wetlands with natural wet-dry seasonal cycles, housing a unique collection of fauna and flora that only exist under these conditions.

“The region features diverse ecosystems, where freshwater systems seamlessly connect to vital mangrove habitats and other marine ecosystems, allowing for biodiversity to thrive,” she said.

“The area’s natural wet-dry cycles also play a pivotal role in supporting the survival of distinctive species, such as the sawfish and global migratory birds.”

Dr Cartwright said that without environmental research, building infrastructure to secure water could disrupt water quality and the natural flow essential to ecosystems in both wet and dry seasons.

“Interfering with natural waterways can have far-reaching consequences, affecting migration patterns, sediment movement, nutrient cycling, and temperature. These disruptions, in turn, could have cascading effects on the diverse fauna and flora, including vulnerable species like the sawfish,” she said.

“Understanding the risks and implementing sustainable water management solutions means we can mitigate these disruptions and preserve the ecological integrity of water systems.”

A case study: a close look at the Queensland’s Gilbert River catchment

One region TropWATER scientists are investigating is Queensland’s Gilbert River catchment. It has been highlighted as containing critical habitats for aquatic species as well as seasonal watering holes for many terrestrial species.

Freshwater sawfish are a major focus for scientists in this area, with the species listed as endangered under state and federal legislation. Prawns and barramundi, both significant recreational and commercial industries, also rely on the water connectivity between salt and freshwater systems in this catchment.

Dr Cartwright said the team would survey across floodplains, rivers, and tributaries, to identify the diversity of aquatic and terrestrial species, using advanced technologies like eDNA sampling, sound bars, and in-water camera surveys.

“We’ll also use long-term satellite data to map waterhole fluctuations through wet and dry seasons and hydrology data to better understand groundwater/surface water interactions across the system,” she said.

“Together, an understanding of species distribution and their interaction through food webs, along with mapping of the interannual variability in waterholes, will allow us to pinpoint what is most sensitive to disruption of seasonal waterflows.”

“This helps identify areas at high ecological risk and those that can withstand certain levels of development without causing significant environmental harm.”

What next, in 2024?

In 2024, the Water Security for Northern Australia program builds upon the groundwork laid in 2023, conducting comprehensive desktop analyses and fieldwork in the Gilbert, Ord, Fitzroy, and Daly River catchments.

Post-wet season, researchers will address data gaps and explore the impact of varying wet season rainfall on species distribution and waterhole ecology.

The three-year program will continue to unravel the complexities of water security, ecology, and development to allow sustainable development.

As environmental challenges escalate, the need for cane farmers to help improve water quality continues to grow to build the resilience of ecosystems, like the Great Barrier Reef.

But how do you bring science to farmers in a way that matters, in a way that empowers collective action to meet the needs of the environment while also meeting the needs of farming?

Across the Great Barrier Reef catchment, scientists and cane farm extension officers are enhancing paddock-scale water quality monitoring projects to strengthen the crucial link between water quality science and sustainable agriculture.

The James Cook University TropWATER project unites ten water quality monitoring projects – spanning the Wet Tropics, the Burdekin, and Mackay Whitsunday regions – to collectively improve the data collection and communication of water quality science in farming communities.

This initiative harnesses the strong rapport between on-ground extension officers and farmers. It focuses on the potential impact that paddock-scale and sub-catchment scale water quality data has in directly empowering farmers in the transition to improved agricultural practices.

The TropWATER project, as well as the ten water quality monitoring projects, are funded by the partnership between the Australian Government’s Reef Trust and the Great Barrier Reef Foundation, under the Regional Water Quality Program (Regional Programs – Great Barrier Reef Foundation).

In this article, we explore the intricacies of balancing agriculture and good water quality, and the role this TropWATER project has in bolstering efforts of those on the ground working with farmers.

Why do sugarcane farms matter in the Great Barrier Reef catchment?

Australia’s agriculture industry, including sugarcane, plays a significant role in our economy and global food security. It supports the livelihoods of thousands of Australians and is at the heart of many small north Queensland communities.

About 90% of Australia’s sugarcane is produced in Queensland. Many of these cane farms stretch along the narrow coastal plains adjacent to the Great Barrier Reef, knitted among freshwater and inshore marine ecosystems. Given this close connection, managing the farming business and the protection of the environment is an essential balance in agriculture practices.

Cane extension organisations have supported farmers in adopting improved land management practices that has co-benefits for both farm production, profitability and preserving local ecosystems.

The connection between farmers and extension officers is proving vital in communicating robust water quality science directly to farmers – helping more farmers transition to environmentally sustainable and more efficient farming systems.

How does agricultural runoff impact freshwater and marine ecosystems, including the Great Barrier Reef?

Water quality issues impacting marine and freshwater ecosystems arise from a combination of factors, including urban development, climate change, and agriculture. Within this, intensive farming is recognised as a major contributor.

In the sugarcane industry, applying fertiliser (nitrogen, phosphorus, potassium and other micro-nutrients) is needed to enhance soil fertility, meet crop nutrient demands and promote healthy cane growth. Pesticides are also used to control and kill targeted pests, like the cane grub and grasses, vines and broadleaf weeds.

TropWATER Senior Researcher Dr Stephen Lewis said while these products were essential in modern farming systems, decades of research highlight the connection between farm runoff and its impact on water quality in both freshwater and inshore marine ecosystems.

“Heavy rainfall and intense irrigation can transport nitrogen and phosphorus fertilisers and pesticides off the paddock quickly and into drainage systems and waterways,” he said.

While inshore areas are commonly more turbid and nutrient-rich environments compared to offshore marine ecosystems, excess sediment and nutrients from runoff can reduce water clarity and exacerbate inshore nutrient levels. This causes phytoplankton blooms, persistent macroalgae outbreaks on inshore coral reefs and a loss of seagrass area and abundance.

“These elevated sediment and nutrient levels can drive water quality down, impacting the resilience of coral and seagrass communities to recover from major disturbances, like cyclones, floods and coral bleaching,” he said.

“The highest direct risk of poor water quality is to local waterways, freshwater wetlands, and inshore seagrass meadows and coral reefs close to the coastline.”

Every farm has its challenges in mitigating this runoff. Understanding those challenges is critical in making impactful changes to the farming system.

How can paddock-scale water quality monitoring drive improved farming practices?

Agricultural systems are complex. Each farm has a unique set of challenges that must be carefully managed under the variability of different target pests, soil type and rainfall.

Given each farm is unique, monitoring water quality allows farmers to compare different farming practices to better understand the amount of products lost from their farm and what strategies are most effective in mitigating this loss.

Dr Aaron Davis, TropWATER senior scientist and project lead on multiple water quality monitoring projects, said there were many farmers making great strides in improving their land management practices across the Great Barrier Reef catchment.

“Farmers care greatly about their local environments, but some farmers can be unsure about the role agriculture plays in declining water quality and how fertilisers or pesticides on their paddock can run into waterways,” he said.

“They also can be unsure if and what management practices can actually make a difference in improving water quality without decreasing the production of their farming business.”

Dr Davis says robust paddock-scale water quality data helps farmers confidently understand their irrigation, fertiliser, pesticide and sediment surface losses.

“Showing farmers paddock-scale data is empowering them to make decisions based on what is relevant to their farm – and farmers can see these direct results as they adjust their practices.”

Connecting monitoring efforts across the Great Barrier Reef

The GBRF and JCU TropWATER initiative connects multiple on-ground projects from different Great Barrier Reef catchments, aiming to help build farmers’ trust in water quality science to ultimately facilitate change in achieving a balanced farming system.

These on-ground projects focus on different strategies to improve farming practices and reduce runoff, including optimising irrigation efficiency, enhancing nutrient removal through water retention, refining fertiliser and mill mud application rates and strategies, and promoting responsible pesticide management.

TropWATER researcher Dr Zoe Bainbridge said the collaboration takes a distinctive approach that integrates scientific expertise from leading water quality researchers with strategies from science communication specialists.

“Our team has two decades of water quality science experience that span from the paddock to marine environments. We understand the water quality issues associated with multiple land uses, including the paddock-scale, and have applied water quality monitoring to show the benefits of various management practices,” she said.

“We’ve matched our scientific expertise with strategic communications, with a big focus on tackling communication barriers in water quality science. Our goal is to arm extension officers with tools and strategies to help overcome those challenges, including developing consistent messaging to address mixed messages and misinformation.”

In the last year, the project has hosted various workshops and training programs, provided critical resources to extension officers, developed legacy documents in technical guidance, and provided strategic communications support.

“TropWATER’s support has been a resounding success, with real legacy impact and a sustainable future for both farmers and the environment,” said Carolyn Trewin of the Great Barrier Reef Foundation.

“Projects have provided overwhelmingly positive feedback to the Foundation about their involvement, and we are confident that water quality monitoring activities are more robust, with effective engagement and communication strategies because of this initiative.”

It’s hoped the project can expand to continue to break down communication barriers in water quality science, ensure robust data are collected to drive a sustainable future for both farmers and the environment, and expand the collective efforts of extension staff and farmers in improving water quality across the Great Barrier Reef catchment.

This project is delivered in collaboration with specialists from the CSIRO, UQ’s Reef Catchments Science Partnership and AgriTech Solutions. Water quality projects are led by Farmacist, Sugar Research Australia, Burdekin Bowen Integrated Floodplain Management Advisory Committee (BBIFMAC), Catchment Solutions, LiquaForce, Herbert Cane Productivity Services, TropWATER and Terrain NRM.