Ecosystem impacts of feral rabbits on World Heritage sub-Antarctic Macquarie Island: a palaeoecological perspective
Saunders, KM and Harrison, JJ and Hodgson, DA and de Jong, R and Mauchle, F and McMinn, A, Ecosystem impacts of feral rabbits on World Heritage sub-Antarctic Macquarie Island: a palaeoecological perspective, Anthropocene, 3 pp. 1-8. ISSN 2213-3054 (2014) [Refereed Article]
The introduction and establishment of non-indigenous species through human activities often poses a
major threat to natural biodiversity. In many parts of the world management efforts are therefore
focused on their eradication. The environment of World Heritage sub-Antarctic Macquarie Island has
been severely damaged by non-indigenous species including rabbits, rats and mice, introduced from the
late AD 1800s. An extensive eradication programme is now underway which aims to remove all rabbits
and rodents. To provide a long-term context for assessing the Island’s pre-invasion state, invasion
impacts, and to provide a baseline for monitoring its recovery, we undertook a palaeoecological study
using proxies in a lake sediment core. Sedimentological and diatom analyses revealed an unproductive
catchment and lake environment persisted for ca. 7100 years prior to the introduction of the invasive
species. 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 causal
link 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 conditions
prior to the introduction of non-indigenous species, quantify the timing and extent of changes, and help
monitor the recovery of the ecosystem and natural biodiversity following successful non-indigenous
species eradication programmes.
diatoms, invasive species, lake sediments, management, palaeoecology, pest eradication, rabbit, Macquarie Island