Science for Policy Research findings in brief Project 2.1 Big trouble for little fish: Identifying Australian freshwater fishes at imminent risk of extinction In brief In Australia, many freshwater fish described in the past decade, and (The Environment Protection and species have declined sharply since seven are awaiting description. Biodiversity Conservation Act 1999 the 1950s. Preventing extinctions Twenty-one of the species identified (EPBC Act)). Listing of the other will require identifying the species are small-bodied, with the majority 19 species would provide essential most at risk. occurring in southern Australia, a protection and recognition for the remaining individuals of these We used structured expert elicitation region where introduced predatory species and their critical habitat. and other available published and trout species have taken a heavy unpublished data to identify the toll, especially on native galaxiids. The fate of all 22 species will depend freshwater fishes at greatest risk Although the majority of these species upon individual targeted action, of extinction, and to estimate were once far more widespread, all 22 investment and collaboration among the likelihood of extinction within fishes now have small distributions with governments and non-government ~20 years if there is no change areas of occupancy ranging between organisations to mitigate threats to current management. 4 – 44 km2; this greatly increases the and support recovery. We identified 22 species at high risk of risk that single catastrophic events, such The assessments were undertaken extinction (from ~315 species known as a large bushfire, could cause species prior to the 2019–20 Black Summer to occur in Australia), 20 of which had extinctions. Climate change is another bushfires, which impacted many of at least a 50% probability of becoming threat to all of the identified species. the species that were identified as extinct within ~20 years under current Only three of the species identified highly imperilled in our assessment. management. Twelve of the species are currently listed nationally as Some species may now be on the identified have only been formally threatened under Australian legislation brink of imminent extinction. Further Information Mark Lintermans – [email protected] Hayley Geyle – [email protected] The main threat to the Daintree rainbowfish is loss of stream flow due to drought, climate change and water extraction. Image: M. Hammer, MAGNT The stocky galaxias is one of 14 species of galaxias identified as at high risk of extinction. Predation by introduced trout is a major threat to these small-bodied native species. Image: Tarmo Raadik Background Research aims The Australian Government has For Australian freshwater fishes we 4. Identify what policy, resourcing, committed to averting extinctions, aimed to: management and prioritisation are and this first requires identification required to prevent extinctions. 1. Identify the species at most of the species at most immediate immediate risk of extinction; The findings of this research will be of risk. This can forewarn governments, greatest importance to policy-makers conservation managers and the 2. Estimate the probability of extinction in state and federal government community so that they can (in the wild) in the next ~20 years agencies and funding bodies, as well implement emergency care for each of the species identified; as conservation land managers and and recovery actions to prevent 3. Identify key threats to these species researchers looking to prioritise and extinctions before it is too late. and our progress towards lessening apply research and management Freshwater fishes (and their habitats) their impacts; and actions for threatened freshwater fishes. are declining at alarming rates in many parts of the world, including in Australia, where the populations What we did of many species have fallen sharply Our assessment of extinction risk a workshop in early 2018, where we since the 1950s. The declines of Australian freshwater fishes used used structured expert elicitation to have been attributed to habitat available published and unpublished estimate the extinction probabilities for loss, introduced species, alteration evidence, and was undertaken using a the final list of 22 species considered to natural flow regimes, habitat structured expert elicitation approach. to be at high risk of extinction. We fragmentation, water pollution performed statistical modelling of An initial list of 90 freshwater fishes at and overexploitation. the expert estimates to predict the high risk of extinction within ~20 years probability of extinction for each Despite evidence of catastrophic was produced by the ASFB Threatened species, finding that there was a high declines, freshwater fishes have Fishes Committee based on expert level of agreement among the experts typically been neglected in review by committee members and in their assessments of extinction risk conservation planning. Compared external experts. Further assessment for most species. We also assessed the to other vertebrate groups, there are reduced this to a shortlist of 37 timing (continuing, near future, distant currently few species listed under species. Included in this assessment future), extent (proportion of the range national environmental legislation were: 1) species that were assessed likely to be impacted) and severity (EPBC Act). Application of IUCN by the ASFB as meeting IUCN criteria (the proportion of the population likely criteria by the Australian Society for listing in a threatened category to be impacted) of threats, assessed for Fish Biology (ASFB) indicates (Critically Endangered, Endangered the level of current understanding that many more freshwater fish or Vulnerable); and 2) additional on how to manage each threat, species qualify for statutory listing. species that have only recently been and the effectiveness of current Without listing, at-risk species are recognised and currently undescribed, management actions. not afforded basic protection. but likely to meet threatened criteria. A final list of 22 species were Further, recent taxonomic work This waterfall in New South Wales is all that has shown that there are many considered to be at risk of extinction protects the upstream population of stocky undescribed species that are likely within ~20 years. For each of these galaxias from the invasive trout below. to meet criteria for listing as species, the ASFB identified the major Image: Mark Lintermans threatened, and in many cases in threats; historical, recent and predicted higher categories, e.g., Critically population trajectories; initial estimates Endangered. Only one fish species, of extinction risk; biology; habitat the Pedder galaxias, is officially requirements; population parameters; recorded as extinct in the wild and geographic range. in Australia (with another now Our research team included 15 considered extinct before it was researchers and freshwater fish described), although we have almost biologists from 10 Australian certainly lost other species before universities, state-based research we even knew about their existence. institutions (such as the Arthur Rylah Institute), and Bush Heritage Australia. Each of these experts participated in The little pygmy perch in the far south-west corner of Western Australia is one of only three of the imperilled species that is formally protected under the EPBC Act. Image: Stephen Beatty, Harry Butler Institute, Murdoch University Table 1. The 22 Australian freshwater fish species at greatest risk of extinction; their likelihood of extinction within ~20 years; if they have been formally described; and their conservation listings under the EPBC Act (as at August 2019) and the Australian Society for Fish Biology (as assessed using IUCN criteria). Species Region Area of Likelihood of Year described EPBC Status ASFB Status occupation extinction (%) (km2) Shaw galaxias Critically Vic 4 ≥70 2014 Not Listed Galaxias gunaikurnai Endangered West Gippsland galaxias Critically Vic 12–16 ≥70 2014 Not Listed Galaxias longifundus Endangered Tapered galaxias Critically Vic 16 ≥70 2014 Not Listed Galaxias lanceolatus Endangered Dargo galaxias Critically Vic 16 ≥70 2016 Not Listed Galaxias mungadhan Endangered Morwell galaxias Vic 20 ≥70 Undescribed Not Listed Not Assessed Galaxias sp. McDowall’s galaxias Critically Vic 8–28 ≥70 2014 Not Listed Galaxias mcdowalli Endangered Malanda rainbowfish Critically Qld 28 ≥70 Undescribed Not Listed Melanotaenia sp. Endangered Stocky galaxias Critically NSW 4 50–69 2014 Not Listed Galaxias tantangara Endangered Red-fin blue-eye Critically Scaturiginichthys Qld 4 50–69 1991 Endangered Endangered vermeilipinnis Kosciuszko galaxias Critically NSW 8 50–69 2014 Not Listed Galaxias supremus Endangered Yalmy galaxias Vic 36 50–69 Undescribed Not Listed Not Assessed Galaxias sp. East Gippsland galaxias Critically Vic 12 50–69 2014 Not Listed Galaxias aequipinnis Endangered Hunter galaxias NSW 44 50–69 Undescribed Not Listed Not Assessed Galaxias sp. Moroka galaxias Vic 4 50–69 Undescribed Not Listed Not Assessed Galaxias sp. Barrow cave gudgeon WA 8 50–69 2013 Not Listed Not Assessed Milyeringa justitia Swan galaxias Critically Tas 15 50–69 1978 Endangered Galaxias fontanus Endangered Short-tail galaxias Critically NSW 16 50–69 2014 Not Listed Galaxias brevissimus Endangered Running River rainbowfish Critically Qld 16 50–69 Undescribed Not Listed Melanotaenia sp. Endangered SW Victoria