Ecosystem impacts of feral rabbits on World Heritage sub-Antarctic Macquarie Island: a palaeoecological perspective

• Published in: Anthropocene
• Main Authors: Saunders, KM, Harrison, JJ, Hodgson, DA, de Jong, R, Mauchle, F, McMinn, A
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier Ltd 2014
• Subjects: Environmental Sciences; Environmental Science and Management; Environmental Monitoring; Antarctic; Antarc*; Macquarie Island
• Online Access: https://doi.org/10.1016/j.ancene.2014.01.001; http://ecite.utas.edu.au/90852

The introduction and establishment of non-indigenous species through human activities often poses amajor threat to natural biodiversity. In many parts of the world management efforts are thereforefocused on their eradication. The environment of World Heritage sub-Antarctic Macquarie Island hasbeen severely damaged by non-indigenous species including rabbits, rats and mice, introduced from thelate AD 1800s. An extensive eradication programme is now underway which aims to remove all rabbitsand rodents. To provide a long-term context for assessing the Islands pre-invasion state, invasionimpacts, and to provide a baseline for monitoring its recovery, we undertook a palaeoecological studyusing proxies in a lake sediment core. Sedimentological and diatom analyses revealed an unproductivecatchment and lake environment persisted for ca. 7100 years prior to the introduction of the invasivespecies. After ca. AD 1898, unprecedented and statistically significant environmental changes occurred.Lake sediment accumulation rates increased >100 times due to enhanced catchment inputs and within-lake production. Total carbon and total nitrogen contents of the sediments increased by a factor of four.The diatom flora became dominated by two previously rare species. The results strongly suggest a causallink between the anthropogenic introduction of rabbits and the changes identified in the lake sediments.This study provides an example of how palaeoecology may be used to determine baseline conditionsprior to the introduction of non-indigenous species, quantify the timing and extent of changes, and helpmonitor the recovery of the ecosystem and natural biodiversity following successful non-indigenousspecies eradication programmes.