Concern at flood of ecological immigrants

The arrival of the zebra mussel in the Shannon has highlighted the problem of alien species disrupting indigenous life forms, …

The arrival of the zebra mussel in the Shannon has highlighted the problem of alien species disrupting indigenous life forms, reports Phil O'Connell

Research scientists at University College Cork are leading an international investigation to examine the environmental effects of foreign species that arrive here daily on ships and aircraft. The arrival of these alien life forms can lead to potentially catastrophic changes in the plant and animal ecosystem.

"We have already seen the introduction of the freshwater zebra mussel into the Shannon," says Prof John Davenport, the director of the Environmental Institute at UCC.

"This creature has had a devastating effect on the great lakes in North America. It has out-competed the local species and spread at great speed through the entire Great Lake system."

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A heavy concentration of this foreign species has led to blockages in the cooling systems of power stations and factories around the Great Lakes. These mussels also consume most of the plankton in the water, which dramatically reduces the biodiversity.

The UCC researchers are looking closely at the zebra mussel to see what impact it will have on the ecosystem of the Shannon. This harmful species probably arrived in the ballast tanks of ships, but today there is more concern about human transport of species from one place to another and how the built environment can influence the natural environment.

"Ireland has one of the densest volumes of traffic on the roads today. The new roads that have been laid down fragment and destroy the natural habitats of plants and animals," says Davenport.

Man has for centuries been transferring organisms from their natural environments and introducing them to new ones all over the world. This can have major consequences, sometimes fatal, for the other species in the changed habitats.

Irish roadbuilding has contributed to this.

"The effects of building these roads are that it creates an isolated ecosystem. An isolated ecosystem can degrade over time. You only have to look at the Amazon rainforests where isolated ecosystems have been created through the cutting down of sections of trees," says Davenport. Many species have disappeared as a result.

Davenport is co-ordinating the three-year research project that will see a number of internationally renowned scientists working together to examine the history of species migration and its implications for the future.

One part of the project will examine the transmission of the foot-and-mouth outbreak throughout Britain and Northern Ireland and eventually into the Republic. The research work will trace the outbreak's origins and its movements in order to design a system of preventative measures against a future outbreak.

"At the moment there is no unification in this research. We are hoping to bring the knowledge and experiences from other countries here," says Davenport.

"There is a scientist in Israel investigating the eastern Mediterranean transport of species from the Red Sea into the Suez Canal. Peter Woodman, an archaeologist here, has been investigating the introduction of foreign mammals in Ireland. We are trying to get as many people involved from these diverse backgrounds as possible."

RECENT research has shown that the number of toxic algal blooms in rivers has increased. Some of this is as a result of high levels of fertiliser spread on the land, which in turn promotes the growth of toxic algae.

"We are going to be looking at the possibility that certain levels of these coastal nutrients are the result of foreign invasion," says Davenport.

The project title is "the ecological impact of the human transport systems" and the team plans to publish its results in book form. The work is EU-funded under the Science of Environmental Risk programme.

The research starts in September with a number of international workshops to be organised by Davenport at the department of zoology and animal ecology at UCC.