OzCast

On this episode of OzCast, Dr Dominic Mcafee looks beneath the surface at Australia's lost shellfish reefs and our road to recover them back from the brink of extinction.

Dr McAfee is a marine ecologist at the University of Adelaide who has dedicated his career to the restoration of Australia's oyster reefs. After stumbling across the topic while at university, he has become one of the leading names spearheading the revival methods taking place throughout Australia and overseas.

His research encompasses ecological experiments on the seafloor and along shorelines, as well as within laboratory settings, all aimed at deciphering how oysters perceive their surroundings to select optimal habitats.

Throughout the episode, Dom dives into these techniques, explaining how they work, what he aims to achieve in doing them and, most importantly, what he has learnt across the past decade above and below the surface. Interestingly, Dom explains that one of the whackier techniques has been using underwater speakers and the effect these have had on the nearby baby oyster lavae that are looking for somewhere to begin their life on the seafloor.

With an unwavering commitment to achieving ecological and societal triumphs in marine restoration, he collaborates closely with communication experts, social scientists, anthropologists, economists, legal scholars and representatives from various industries and governmental bodies.

Throughout the conversation, Dom speaks to the trends he has seen in the world of habitat restoration and shares his observations on how the topic has increasingly become more "in vogue" in the past five years.

Researchers from countries all over the globe are sharing information which can help reverse the decline in shellfish Reefs.

His academic journey includes a notable PhD at Macquarie University in Sydney, during which he extensively examined the ways in which oyster habitats bolstered the resilience and productivity of coastal ecosystems spanning thousands of kilometres along Australia's eastern coastline.

His research extended to Hong Kong, where he demonstrated the role of oyster habitats in mitigating the adverse effects of climate change on coastal communities. His doctoral endeavours culminated in 2018, followed by his relocation to South Australia to lead pioneering efforts in Australia's inaugural large-scale oyster reef restoration project, Windara Reef.

It soon becomes apparent throughout this episode that Dom's understanding of shellfish is unparalleled, diving deep into the benefits these organisms have to the local fish populations. From their migration journey, recruitment strategies, lifecycle and benefits to the planet – Dom covers it all.

A testament to the significance of his research, Dom's collaborative work with peers on a national scale earned him the esteemed Eureka Prize for Applied Environmental Research. This groundbreaking research serves as the bedrock for what has evolved into Australia's most expansive marine restoration program. He holds a special passion for assisting local community groups invested in revitalising and monitoring their coastlines, showcasing his deep-rooted commitment to environmental stewardship.

In episode five of OzCast, we look below the surface with fisheries scientist Dr Craig Boys to address what he considers one of biggest threats to native fish across Australia - unscreened irrigation pumps. In this in-depth chat, Craig explains why 97 million fish are killed every year in NSW alone due to unscreened irrigation pumps. With the understanding that there are additional loses in other states, his research paints a very grim picture for native fish survival. Craig explains the use of fish screens in the United States has been a requirement for decades but not here in Australia. However, not all is lost. There is technology and infrastructure that Aussie irrigators have at their disposal through years of research that can prevent 100 per cent of these deaths - modern fish screens built for Aussie fish and Aussie rivers.

Craig Boys is a distinguished fisheries scientist from New South Wales and one of the leading figures of screening technology in the country. With expertise in fish ecology, he serves as a Principal Research Scientist for the NSW Department of Primary Industries (Fisheries) and holds the position of Adjunct Associate Professor of Research at Charles Sturt University.

Over the course of his impressive 20-year career, Craig has worked extensively across various regions, including Australia, South East Asia, Europe and America. He has dedicated his research efforts to collaborating with the primary industries sector, to enhancing environmental outcomes within these industries while supporting fish survival.

One of Craig's primary focus areas is in the design and operation of water infrastructure to facilitate safe fish passage and foster healthier fish populations. Throughout this episode, Craig sheds light on the different ways fish can be a victim to water infrastructure, such as weirs, regulators and hydropower plants, as well as the design of river diversions and pumps.

Over the past 200 years, Australia has increasingly diverted more and more water from our inland rivers to maintain the demand of irrigation and agriculture. Craig has visited and worked on a variety of these diversions and he explains that the old-school pump design and gravity-fed diversions result in large amounts of debris, including logs, leaves and unfortunately fish in that collateral damage. In some instances, mature Murray cod as well as golden and silver perch have been ripped through the pumps, along with other natives. The pumps don't recognise endangered species either.

In acknowledging this problem, Craig draws from his years of experience to explain how we can improve the way native fish navigate and live alongside man-made structures which will improve the health of rivers and our native freshwater fish.

Craig recounts some of the more significant days in his time working on fish screens, including collecting fish out of Burke irrigation dams in his university days, to travelling to the US and the UK to see how Australia can learn from other countries. Today, Craig is confident Australia is leading the world in fish passage and modern screening technology.

Craig believes one the important elements of this story is highlighting the mutual benefits of fish screens for irrigators and native fish. Craig explains that the past five years has seen a real shift as the benefits that screening provides to irrigators is a significant drawcard in growing the program across Australia. This is an episode for farmers, fishers and regional towns looking for solutions to support the health of their local rivers.

Prominent historian Anna Clark guides us through Australia's fishing history, delving into its pre-European settlement origins and highlighting the pivotal events and encounters that have shaped the present-day sport. With meticulous research dating back to the 1700s, Anna provides a vivid depiction of the past fishing landscape. She dispels the misconception that James Cook was the first foreign fisherman in Australia, revealing the annual pilgrimages of neighboring cultures from the north long before Cook arrived in Botany Bay aboard The Endeavour in 1770.

Anna Clark, a highly respected historian affiliated with the Australian Centre for Public History at the University of Technology Sydney, is renowned for her extensive research and written works on various aspects of Australian history. Her expertise extends to the recreational and commercial fishing industry, evident in her book "The Catch: The Story of Fishing in Australia," initially published in 2018 and set to be reissued by Penguin.

Within this book, Anna meticulously documents the earliest Indigenous fishing practices and the encounters between European settlers and Australia's bountiful waters. She explores the evolution of fishing techniques, the introduction of trout and fly-fishing, and the ongoing challenges in striking a balance between the needs of commercial and recreational fishers. Through captivating storytelling and illustrations, Anna effectively captures the enduring allure and cultural significance of fishing within the Australian context.

Throughout this episode, Anna takes us on a journey through significant events in the historical fishing timeline, illuminating their impact on modern Australia. She is also driven by a desire to debunk myths. Anna challenges the popular belief that Captain Cook was the first "fisherman" to explore Australian waters, shedding light on other indigenous cultures, such as Australia's First Nations fishers and Makassan trepang fishers, who ventured to the Great Southern Land in search of seafood.

Furthermore, Anna reveals the long-standing presence of the environmental movement in Australia, exemplified by a Royal Commission investigating overfishing's consequences in the late 1800s. She also dispels the notion that Australia had an inexhaustible fish supply when European colonists first arrived, emphasizing the delicate state of the fishing ecosystem due to the country's unique climate. Although large catches were occasionally made, Anna asserts that Australia's fishing resources have always been vulnerable.

The episode follows the early colony as they spend their initial months in Australia, encountering not only new fish species and habitats but also witnessing the diverse fishing techniques employed by the First Nations peoples.

Drawing from her personal passion for angling, Anna celebrates the significant role of women in fishing and highlights it as one of the notable changes in the evolution of fishing.

Anna provides a detailed account of the rapid decline of Australia's waterways since the early days of European settlement. Habitat degradation, over-harvesting, and a lack of education punctuate her narrative on the state of fishing in the country. However, she remains hopeful that by learning from past mistakes, it is not too late to prevent history from repeating itself.

This episode of OzCast is made possible with the support of BCF – Boating, Camping, Fishing, and the One Basin CRC.

Native fish in Australia have been fighting tooth and fin for survival and its time we paid attention. On this episode of OzCast Out of Sight Out of Mind, Australia's authority on endangered freshwater fish and invasive species Mark Lintermans takes us through the ins and outs of the history and problems facing some of our little-known freshwater fish that are struggling to survive. In particular, the trout cod Maccullochella macquariensis and stocky galaxias, Galaxias tantangara.

Mark Lintermans is considered a leading expert in Australian freshwater ecology and fish conservation in Australia and has received several awards for his contributions in the field. He is the author of more than 300 books and articles on the subject. This podcast takes listeners on a journey through the history of some of these unknown species, and their journey to discovery and now survival in Australia.

Surprisingly, Mark tells listeners that it wasn't until the late 1970s, that trout cod were known as a species. And we still only have a very limited understanding of small-bodied species like the stocky galaxias. Offering personal anecdotes about his role in the discovery of these species, Mark explains how long we have to go to completely understand the needs of freshwater fish in Australia.

Mark, known to many simply as 'Linto', first developed his passion for fish as a child through snorkelling and spearfishing with his dad around the rock platforms in Western Port Bay in Victoria. Since the early 1980s, he has specialised in the study of freshwater fish, specialising in the ecology and management of threatened fish; the impacts of introduced fish; and how to manage the major threats to freshwater habitats and their fauna. His career has centred around the fish of the Murray-Darling Basin, but he has also conducted research in the Wet Tropics, Edgbaston Springs, and the Tanami Desert (yes, there are fish in the Tanami).

Mark began his professional career in 1982 working for the ACT Parks and Conservation Service on a range of terrestrially-focused projects but soon worked his way to his love affair with native fish. That's when Mark embarked on a remarkable life journey dedicated to understanding and conserving Australia's freshwater ecosystems. After a long involvement with Murray-Darling Basin fishery, including work on native trout cod, Macquarie perch, Two-spined blackfish and introduced redfin perch, trout and oriental weatherloach, he branched out to become a part-time consultant to the Murray-Darling Basin Commission (MDBC, now MDBA).

Mark's expertise in the field quickly garnered recognition, and he soon became known for his ground-breaking research on the ecology and conservation of native fish species. His work primarily focused on understanding the factors affecting the decline of endangered and vulnerable species, which forms the focus of this OzCast.

In this episode, Mark discusses the plight of the trout cod - Maccullochella macquariensis within Australian river systems. He explains that while we can assume what happened after their discovery, the fact we thought they were a Murray cod until the 1970s meant that very little research was conducted on the species. Mark found that the trout cod abundance was undermined by the heavy exploitation of our rivers, the use of nets and traps and habitat destruction and pollution. By the early 20th century, trout cod populations had dramatically decreased and the species was on the brink of extinction.

Throughout his career, Mark has conducted extensive fieldwork, often venturing into remote and challenging environments to study and document the intricacies of freshwater ecosystems. Recently he has been researching the ecology of two of Australia newest threatened fish: the stocky galaxias and short-tail galaxias (both only formally described as species in 2014 and listed as threatened in 2022 and 2023 respectively). He has contributed to national reviews of conservation monitoring of threatened Australian fauna; coordinated and led the IUCN Red List assessment of all Australian freshwater fish; led the identification of the most imperilled Australian freshwater fish; and was part of the national team prioritising species for immediate conservation action following the 2019-20 fires in eastern Australia.

One of his focus areas has been the endangered stocky galaxias and the threat it faces from trout and wild horses. Mark, who spends most of his time in the field, explains in this episode that more attention needs to be given to these 'forgotten' fish. Throughout the hour interview, Mark outlines the importance of small-bodied fish to our ecosystems and runs us through a step-by-step progress to protecting them going forward.

Mark Lintermans' unwavering dedication to the conservation of aquatic ecosystems and his profound contributions to fisheries ecology makes this episode of OzCast one not to miss.

In this episode, we chat with Dr Martin Mallen-Cooper about the problems facing the Murray Darling Basin, in particular, the effect of weir pools on flow in the river and the knock-on effect this has on our native fish.

Martin takes us through a step-by-step summary of the demise of the Murray Darling Basin. He identifies five major practices that have incrementally killed fish and aquatic life in the last 100 years, which include; cold water pollution, fish barriers, weir pools, desnagging and the introduction of carp. Martin takes a particular interest in the effect of weir pools on flow and fish passage within the Murray Darling Basin and highlights that without flow, aquatic life simply cannot thrive.

This episode was recorded before the 2023 Menindee Fish Kills

Dr Martin Mallen-Cooper is an internationally respected fisheries scientist. He has advised on over 100 projects across the Murray-Darling Basin, and worked in advising governments of the Mekong River on fish ecology and fish migration. Martin is considered to be one of Australia's top experts in the management and conservation of freshwater resources.

Challenging accepted thinking has been a hallmark of his career. A good example is the accepted view that historically the Murray River dried to a series of pools in droughts. Contemporary scientists interpreted this as natural and therefore fish and other river animals are adapted to life in still pools, as well as a flowing river.

However, using archival data and research in old library files and books, Dr Mallen-Cooper and colleagues found that it was an exaggerated myth. In fact, early irrigation by numerous small pumps had caused the river to stop flowing historically. Moreover, it not only flowed but the Murray River had a big spring pulse of flow every year, even in droughts. Significantly, this meant a flowing river is the norm and that the fish are actually adapted to these conditions; this is now becoming a major theme (ecohydraulics) in environmental flow management. The finding also showed that weirs change a flowing river to pools, which has severely impacted fish and other aquatic animals. It also revealed a huge opportunity – that removing weirs can recreate the original flowing river and bring back native fish.

Along with fishways, Dr Mallen-Cooper did research on freshwater fish migration in the Murray-Darling Basin. In the 1990s he changed the predominant view that it was only adults of golden perch and silver perch migrating upstream to spawn; in fact, 95% of the migratory population were immature fish. This finding changed the primary objectives of fish passage to include these smaller fish.

With a career that has stretched over 50 years, Martin has had numerous breakthroughs that have been well-documented in academic literature. In this episode, Martin runs us through each of these achievements and the story behind how they were achieved. One of the highlights of the episode was Martin's take on how cultural science can be an invaluable tool for the recovery of the Murray Darling Basin. He provides anecdotes of working alongside first nations people, and sheds light on the knowledge they possess that could be the key to unlocking future management systems within Australian Rivers.

Throughout his career, Dr Mallen-Cooper has been a vocal advocate for the sustainable management of freshwater ecosystems. He has played a key role in the development of numerous policies and regulations aimed at protecting and sustaining these ecosystems. In recognition of his contribution to the field, Dr Mallen-Cooper received the prestigious 2018 International Career Achievement Award in Fish Passage. Dr Mallen-Cooper's work is widely recognized in the scientific community, and he has been invited to speak at numerous conferences and symposia on fish ecology and river rehabilitation

Join us, as we take a look below the surface.

This OzCast episode takes a look below the surface of our litter problem in Australia and chats to internationally recognised veterinary scientist Dr Matt Landos.

Contaminants, like plastic and other chemicals derived from human activities, enter waterways and impact ecosystems. The episode uncovers more to our litter problem than what meets the eye, as the conversation examines the lifecycle of these contaminants and how their properties affect behaviours and reproduction of both fish and humans.

Matt breaks down what effect different chemicals can have on living organisms and highlights the way they travel between waterways and across lands without us ever knowing. This is the episode every recreational fisher needs to listen to and it doesn't take long to find out why.

Matt is an expert in aquatic contaminants, and how they enter and impact aquatic ecosystems. Matt's veterinary career commenced in a mixed dairy cattle practice on the mid-north coast in 1995. He transitioned to a full-time focus on aquatic animals working for NSW Fisheries at Wollongbar Agriculture Institute undertaking field investigations, and research, reviewing laboratory submissions and providing biosecurity policy advice. In 2005, he became the founding director of Future Fisheries Veterinary Service Pty Ltd. His business has expanded to provide field, laboratory, research and technical aquatic animal health and production veterinary services to commercial aquaculture and wild fisheries throughout Australia and overseas.

Matt's work started initially with managing the health and productivity of many aquaculture species including a variety of fish, prawns, and shellfish in hatcheries and grow-out farms. He continues to work across tank-based systems through to earthen ponds and sea cages. This perspective offered him a terrific understanding of how aquatic animals function and reproduce. Today, he is working more and more in the wild fishery, bringing an understanding for how to restore the health and lost productivity of wild and native fisheries.

Matt has also completed projects for the International Pollutant Elimination Network (IPEN) on fisheries and pollution and worked with the National Toxics Network to seek rational regulatory reform of the Agvet chemical regulatory system.

Matt is an affiliate at Sydney University, Faculty of Veterinary Science, School of Farm Animal Health and Charles Sturt University, School of Animal and Veterinary Sciences where he has contributed to research and training undergraduate veterinarians. Future Fisheries Veterinary Service also contributes to research projects at Southern Cross University, Adelaide University, Queensland University and SARDI Aquatic Sciences. He is a former president of the Australian and New Zealand College of Veterinary Scientists, Aquatic Animal Health Chapter.

Join us, as we take a look below the surface.