Chapter 8
Biological Invasions in South Africa’s
Offshore Sub-Antarctic Territories
Michelle Greve , Charles Eric Otto von der Meden ,
and Charlene Janion-Scheepers
Abstract The sub-Antarctic Prince Edward Islands (PEIs) constitute South Africa’s
most remote territory. Despite this, they have not been spared from biological
invasions. Here, we review what is known about invasions to the PEIs for terrestrial
taxa (vertebrates, invertebrates, plants and microbes), freshwater taxa and marine
taxa. Currently, Marion Island is home to 46 alien species, of which 29 are known to
be invasive (i.e. they are alien species that have established and spread on the island).
Prince Edward Island, which has no permanent human settlement and is visited only
infrequently, has significantly fewer alien species: only eight alien species are known
from Prince Edward Island, of which seven are known to be invasive. The House
Mouse (Mus musculus), which occurs on Marion Island, can be considered the most
detrimental invader to the islands; it impacts on plants, insects and seabirds, which
result in changes to ecosystem functioning. The impacts of other terrestrial invaders
are less well understood. At present, no invasive freshwater or marine taxa are
known from the PEIs. We conclude by discussing how invasion threats to the
PEIs are changing and how the amelioration of the climate of the islands may
increase invasion threats to both terrestrial and marine habitats.
8.1 Introduction
South Africa’s southernmost territory, the Prince Edward Islands (PEIs), consists of
two islands: the larger Marion (~270 km
2 ), and the smaller Prince Edward (~45 km
2 )
Islands (Fig. 8.1a). The islands lie approximately 2000 km south-east of Cape Town,
M. Greve (*)
Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
e-mail: michelle.greve@up.ac.za
C. E. O. von der Meden
South African Environmental Observation Network, Cape Town, South Africa
C. Janion-Scheepers
Centre for Invasion Biology, Iziko Museums of South Africa, Cape Town, South Africa
© The Author(s) 2020
B. W. van Wilgen et al. (eds.), Biological Invasions in South Africa, Invading
Nature - Springer Series in Invasion Ecology 14,
https://doi.org/10.1007/978-3-030-32394-3_8
207
Biological Invasions in South Africa’s
Offshore Sub-Antarctic Territories
Michelle Greve , Charles Eric Otto von der Meden ,
and Charlene Janion-Scheepers
Abstract The sub-Antarctic Prince Edward Islands (PEIs) constitute South Africa’s
most remote territory. Despite this, they have not been spared from biological
invasions. Here, we review what is known about invasions to the PEIs for terrestrial
taxa (vertebrates, invertebrates, plants and microbes), freshwater taxa and marine
taxa. Currently, Marion Island is home to 46 alien species, of which 29 are known to
be invasive (i.e. they are alien species that have established and spread on the island).
Prince Edward Island, which has no permanent human settlement and is visited only
infrequently, has significantly fewer alien species: only eight alien species are known
from Prince Edward Island, of which seven are known to be invasive. The House
Mouse (Mus musculus), which occurs on Marion Island, can be considered the most
detrimental invader to the islands; it impacts on plants, insects and seabirds, which
result in changes to ecosystem functioning. The impacts of other terrestrial invaders
are less well understood. At present, no invasive freshwater or marine taxa are
known from the PEIs. We conclude by discussing how invasion threats to the
PEIs are changing and how the amelioration of the climate of the islands may
increase invasion threats to both terrestrial and marine habitats.
8.1 Introduction
South Africa’s southernmost territory, the Prince Edward Islands (PEIs), consists of
two islands: the larger Marion (~270 km
2 ), and the smaller Prince Edward (~45 km
2 )
Islands (Fig. 8.1a). The islands lie approximately 2000 km south-east of Cape Town,
M. Greve (*)
Department of Plant and Soil Sciences, University of Pretoria, Pretoria, South Africa
e-mail: michelle.greve@up.ac.za
C. E. O. von der Meden
South African Environmental Observation Network, Cape Town, South Africa
C. Janion-Scheepers
Centre for Invasion Biology, Iziko Museums of South Africa, Cape Town, South Africa
© The Author(s) 2020
B. W. van Wilgen et al. (eds.), Biological Invasions in South Africa, Invading
Nature - Springer Series in Invasion Ecology 14,
https://doi.org/10.1007/978-3-030-32394-3_8
207