Out of sight, out of mind – why endangered fish have an uphill battle to survive with Mark Lintermans

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.