Sub-Antarctic Marion Island, which lies about 2800 km SE of Cape Town, is one of the world’s most pristine environments. It also belongs
to South Africa, which has had a continuous scientific presence on the island since 1947, undertaking weather observations and scientific research.
As is the case with all isolated islands, Marion Island has not been colonized by many kinds of animals because the distance and intervening
ocean have simply proven too much for them to survive. It has a relatively simple system dominated by some kinds of invertebrates and plants, but missing many
others. However, with human activity has come an increased chance of the introduction of species from continents. Hitching a ride on a ship is just as easy a
way for all kinds of organisms to cross the ocean as it is for people. So, mice, slugs and a variety of other ‘alien’ animals and some alien plants have
established on Marion Island, and are causing substantial trouble for local species and ecosystems.
One of the most recent human-assisted arrivals on the island is a wood louse (the isopod Porcellio scaber), a small grey invertebrate
of the kind typically found below moist flower pots or in damp vegetation. It is a European species that is a very good traveller globally. It was first discovered
around the scientific station buildings in 2001, and seems to have arrived with a shipment of building supplies.
Since then, scientists from Stellenbosch University’s Centre for Invasion Biology and conservation staff have been removing individuals by hand during
monthly eradications. While this has kept the species from spreading it has not led to its eradication, the ultimate aim of the Prince Edward Islands Management Plan,
implemented by the national Department of Environmental Affairs.
Now, the situation is set to change. As part of a national gearing up of the invasive species eradication campaign on Marion Island, Bayer has stepped
in to assist. Bayer has recommended the most appropriate product for very localized use (the isopod is still found just around the station buildings area in the island’s
heavy use Zone 1). Bayer has also supplied the product, appropriate spraying gear, and training to Centre for Invasion Biology staff. In April 2012, during the annual
relief voyage to the island, the first phase of the eradication campaign will begin, with appropriate follow-up thereafter. An assessment will then be made in 2013.
The campaign to remove isopods from Marion Island, which cause much change to island ecosystems elsewhere, has been given a much-needed boost by
Bayer. It forms part of a larger eradication programme for alien species at the island which is a partnership between several national government agencies, the Centre
for Invasion Biology, and now Bayer.