Marine Sciences research
In an era of climate change, ensuring the protection and sustainability of the world’s precious marine environments is one of humankind’s greatest challenges. It is one that Southern Cross University accepts as a privilege.
SCU is fortunate to have our campuses situated in close proximity to the ocean, rivers, coastal wetlands and other aquatic environments that serve as a living laboratory for our brilliant researchers. Their work extends from our backyard to the world.
Importantly, we also acknowledge the support of our many industry, government, business, education and other partners without whose belief and generosity this work would be impossible.
While projects may differ, goals are shared: to provide relevant, real and innovative solutions for our marine environments and the extraordinary biodiversity they contain.
An educational harvest
Pacific Island communities are being enhanced through University projects and partnerships.
One example – supported by the Australian Centre for International Agricultural Research (ACIAR) – involves the export of dried sea cucumber, known as bêche-de-mer. A major source of income for some Pacific Island nations, the Chinese market alone is worth up to $50 million a year.
“Harvesting and processing sea cucumbers has long been achieved by artisanal methods,” says Associate Professor Steven Purcell, from Southern Cross University’s National Marine Science Centre.
“However, while wild harvests provide a source of income to more than 300,000 small-scale fishers in the western Pacific, returns are often less than optimal largely because fishers have poor knowledge of proper post-harvesting handling and processing methods.
“While this contributed to a need to fish large quantities of sea cucumbers, it undermined the value of these resources for national economies.”
Working with national fishery organisations in Kiribati, Tonga and Fiji, Southern Cross University has implemented village-based workshops and a training program that features user-friendly manuals and training videos in local languages.
In collaboration with James Cook University and the University of Wollongong, researchers soon found that almost 80 per cent of fishers who attended the workshops changed their post-harvest processing methods. They also reported saving time in their catch processing.
In another plus, across 22 species of sea cucumbers sold in Fiji, the reported selling prices of processed bêche-de-mer by fishers trained through the project averaged 45 per cent higher than the same species sold by untrained fishers.
One even set up a small kiosk in his village with the extra income he was making.
The Fijian research has involved collaboration with the Wildlife Conservation Society and Partners in Community Development Fiji.
The bêche-de-mer market is worth up to $50 million a year in China alone.
Aquaculture offering alternatives
While the adorable Dory was a co-star in the film Finding Nemo, marine research led by Southern Cross University’s Professor Symon Dworjanyn has the beautiful blue tang fish at the top of the bill.
“Demand from the international aquarium market for species like the blue tang means pressure on wild populations is only increasing,” he says.
“In turn, this is affecting Indo-Pacific communities whose livelihoods depend on fish collection.”
Hence Professor Dworjanyn’s project to breed Dory in the laboratory, then share that technology and contribute to aquaculture-based employment alternatives for the Indo-Pacific.
For Professor Dworjanyn and National Marine Science Centre colleague Dr Benjamin Mos, the task of developing viable commercial alternatives to wild harvesting is top of mind.
This also extends to seaweed farming in Indonesia and commercial sea urchin culture in Australia and Japan.
Industry partners range from multinationals to Australian start-ups.
“Regional fisheries in the Indo-Pacific are not as bountiful as they once were, so there is incentive to boost stocks in a way that provides an alternative to wild harvesting. Blue tangs and sea urchins are great examples of this,” says Professor Dworjanyn.
“The popularity of sea urchin roe for sushi and pasta dishes in Japan and parts of Asia is another issue.
This depletion of wild fish stock creates issues for environmental sustainability, regional livelihoods and even the price you pay in your favourite restaurant.”
Technology developed by Professor Dworjanyn and colleagues at Southern Cross University has now been licensed, allowing the breeding and farming of sea urchins without resorting to the wild or negatively impacting livelihoods.
“We’ve also helped develop a way to grow a particular seaweed in the ocean and now we have a thousand families working to grow this industry in Indonesia.”
There is incentive to boost stocks in a way that provides an alternative to wild harvesting.
Getting to the root of multi-faceted mangroves
Depending on who you talk to, mangroves are a blessing or a curse.
On one hand, they store a lot of carbon, hold sediment in place, defend staunchly against storms and can provide a habitat for many species of fish and shellfish.
On the other hand, they are criticised as environmental eyesores. Add the place of mangroves in some Indigenous cultures and you have a multi-faceted issue.
For Southern Cross University coastal scientist Dr Debra Stokes, this clash of ecology, culture and clearing has taken her research to New Zealand’s North Island.
In studying how estuary systems change after mangroves are removed, Dr Stokes has worked with the University of Waikato, the Waikato Regional Council and the National Institute of Water and Atmosphere.
“There was extensive land clearing in this part of New Zealand back in the early 1900s and it occurred in areas of small catchments, steep terrain, high rainfall and ensuing major sediment flow,” she says.
“Then when New Zealand banned activities such as cattle grazing in these coastal areas, mangroves soon took advantage and spread. It changed the area substantially in terms of environmental processes and public access to waterways and shorelines.”
By adopting a catchment approach that limits sediment influx after mangroves are cleared, communities and councils hope to bring people back to these areas.
“It’s not enough simply to remove the mangroves,” says Dr Stokes. “That’s why we’re looking at tidal movements, water flow, sediment release and root material decomposition, all of which contribute to environmental recovery.”
Understanding the oceanic carbon cycle
In reconstructing environmental history to help sustain the environmental future, Associate Professor Christian Sanders studies coastal wetlands around the globe.
Based at Southern Cross University’s National Marine Science Centre (NMSC), this Florida-born and internationally renowned scientist is leading research into the importance of mangrove and saltmarsh in the oceanic carbon cycle, including their role in mitigating climate change.
State-of-the-art technology is essential, exemplified by the NMSC’s radioisotope laboratory. The laboratory enables researchers to measure a range of natural and artificial radioactive chemicals, and is a major contributor to work on carbon sequestration in mangrove forests and marine systems.
“We can date soil sediments back 150 years, to the time when many environmental issues driving debate today actually began,” says Associate Professor Sanders.
“As well as pinpointing how and where such influences began, we are identifying the source of pollutants entering the ocean today. Mercury, arsenic and pesticides are particularly damaging. We can also see and show how much carbon is being sequestered in soils on a yearly basis, both in coastal areas and in vegetated areas.
“Coastal wetlands lock up vast quantities of carbon in pace with sea level rise, so it makes sense to preserve them rather than to drain and then build on top of them.”
Associate Professor Sanders is buoyed by community support and industry partnerships with groups such as the Coffs Harbour City Council and the NSW Environment Protection Authority.
“By monitoring pollutants, agricultural and urban sediments, and other materials that are flowing into the ocean, the data we gather presents the epitome of a flow-on effect.”
When it comes to seafood in Australia, prawns and oysters are favourites on the menu.
Southern Cross University marine scientist Professor Kirsten Benkendorff wants to keep it that way, applying her expertise to the quality and sustainability of prawn and oyster stocks.
Professor Benkendorff is studying the impact of entrenched and emerging pesticides. Of particular interest is the effect of neonicotinoids, which are banned in some countries, though not Australia.
“Pesticides have such wide-ranging uses today and they wash easily into rivers. They also flow downstream into estuaries, often in quantities above what is considered safe,” she says.
“Estuaries are hotbeds of seafood production and if we continue to pollute them, we will only cause more damage and potentially lose species.
“In the case of prawns and oysters, pesticides can absorb into their flesh. While this dissipates after about four days, that still presents a window of risk to consumer health and seafood organisms.”
Research has found prawns to be more vulnerable, but oysters are also challenged: “Even at lower concentrations of pesticide exposure, there is a change in their fatty acids from polyunsaturated to saturated. That’s detrimental to the oyster’s energy, cell tissue and seafood quality.”
Collaborations with groups such as Ozfish, Ridley and the Department of Primary Industries are bringing scientific data to bear on resource protection, restoration and sustainability.
At Southern Cross University, Associate Professor Dirk Erler’s research on coastal systems is helping to ensure that water quality, species diversity and habitat health are maintained.
“Estuaries and reefs support diverse communities that are reliant on nutrient supply,” says Associate Professor Erler, who is a specialist in nutrient cycles in aquatic environments.
“Problems occur when nutrients are produced in excess, for example through excessive fertiliser discharge or the influx of wastewater.
“Habitats can change as a result of this overfertilisation, much to the detriment of the coral, fish, other species and, in worst cases, entire ecosystems.”
The good news is in projects enabling positive change, as demonstrated recently in the Cook Islands.
“Increased nutrient inputs were affecting the idyllic Muri Lagoon, which has undergone development as a tourist hotspot,” says Associate Professor Erler.
“We worked with local government and community groups to test and install improved treatment systems that benefit both the natural environment and the local economy.”
The Great Barrier Reef is another important site for Associate Professor Erler as he addresses challenges posed by agricultural, industrial and urban activity. He also stresses that estuarine and reef issues extend beyond tropical environments.
“Sub-tropical and temperate regions make up the bulk of the Australian coastline. Our practices on the land exert a huge influence along our entire coastal system.”
The research has been supported by industry partnerships with groups including AusAid (through the Department of Foreign Affairs & Trade), the Australian Research Council and Australian Pacific Science Foundation.
Many of the world’s coral reefs could start to erode within 30 years, according to research led by Southern Cross University’s Professor Bradley Eyre.
Professor Eyre and US colleagues have found the sands that provide material for the building and maintenance of coral reefs will begin to dissolve due to increasing ocean acidity.
In fact, they show the rate at which coral reef sediments dissolve is ten times more sensitive to ocean acidification than the rate at which corals grow.
“Coral reef sediments will trend towards dissolving when seawater reaches a tipping point in acidity – likely to occur well before the end of this century,” says Professor Eyre, from the University’s Centre for Coastal Biogeochemistry.
“This will potentially impact coral reef ecosystems – not to mention tourism, fisheries and the many other human activities that occur around reefs. It is vital that we put pressure on governments globally to act in concert to lower CO2 emissions as this is the only way we can stop the oceans acidifying and dissolving our reefs.”
Researchers placed benthic chambers at four reef locations in the Pacific and Atlantic oceans to measure the impact of future seawater acidity. The research was published in the prestigious journal, Science.
While more research is needed, there is hope: “It may be possible to reduce the impact of ocean acidification on the dissolution of reef sediments by managing the input of organic matter at local and regional scales,” says Professor Eyre.
Finding Nemo isn’t an issue for Southern Cross University marine biologist Dr Anna Scott.
Dr Scott is based at the National Marine Science Centre (NMSC) in Coffs Harbour. The marine park outside her office has the world’s highest density of sea anemones and anemonefish, like Nemo.
As she examines their response to changing environmental conditions, Dr Scott’s data is informing broader strategies around ecosystem health, species abundance and sustainable aquaculture for regional economies in the Indo-Pacific.
“Of a thousand species of sea anemone, only 10 provide a habitat for anemonefish like Nemo and his cousins,” says Dr Scott.
“These iconic animals tend to be rare on reefs, however here at the NMSC I can study a unique population on my doorstep.
“As research uncovers the secrets of our reefs, we learn more about how species behave and survive individually. We also see how heavily reliant they are on each other.
“This raises questions around issues such as climate change, ocean warming/acidification and temperature tolerance.
“There is also an economic imperative to support the regional people whose livelihoods depend on farming the sea.”
Captive breeding is one strategy working to mitigate the pressures caused by large numbers of anemone and anemonefish being taken from the wild for the aquarium trade.
Techniques are helping to ease those pressures while still meeting market demand, all without causing further stress to marine species and their environment.