Lessons from old fenced plots: eco-cultural Impacts of feral ungulates and potential decline in sea-level rise resilience of coastal floodplains in northern Australia

Management of feral animals can be complicated by conflicting economic, social, cultural and political values of stakeholders. To visually demonstrate the ecological impacts of feral ungulates, natural resource managers often construct exclusion fences; however, lessons are not often widely shared in the scientific literature and Indigenous insights are rarely recorded. Here, we report on long-term (7–11 years) feral buffalo and pig exclusion fences that were constructed by the Yirralka Rangers in ephemeral coastal wetlands of the Laynhapuy Indigenous Protected Area, northern Australia. Elevation transects across fence boundaries suggested that feral ungulates may be eroding floodplains and therefore reducing elevation. Comparisons of intermittent photos and contemporary inside–outside fence floristic assessments suggested that feral ungulates have an obvious and significant effect on vegetation cover and composition which may also inhibit natural soil accretion. Interviews with senior Indigenous knowledge holders revealed that feral ungulate culling was broadly supported due to impacts on cultural and spiritual values. Synthesis of the results suggested that feral ungulates are having substantial impacts on the cultural use, flora and soil stabilisation of coastal wetlands. Further research on soil erosion and accretion in places with and without ungulates will elucidate the effects of ungulates on potential sea-level rise resilience of coastal wetlands. This paper highlights the benefits of cross-cultural and collaborative multi-disciplinary research such as producing holistic outcomes relevant to stakeholders that can inform management decisions.