Invasive species also threaten neighboring ecosystems
Published: Thursday, Apr 4th 2024, 09:50
Updated At: Friday, Apr 5th 2024, 01:59
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The impact of invasive species is more far-reaching than assumed. As researchers from the aquatic research institute Eawag have shown in a study, the negative consequences of invasive species extend up to 100 kilometers beyond the ecosystems they have invaded.
These findings are of great importance for the management of ecosystems, Eawag announced on Thursday.
As an example, the researchers cited the Himalayan balsam, originally native to the Himalayas. This plant is a widespread invasive species in Switzerland. According to the new study, certain substances from this plant, known as secondary plant compounds, are leached into neighboring bodies of water. There they impair the growth and reproduction rates of aquatic organisms. Balsam therefore not only affects the ecosystem in which it grows, but also nearby bodies of water.
Rats threaten fish
Another example cited in the Eawag press release was rats that were introduced to islands in the Chagos archipelago in the Indian Ocean. The animals have significantly reduced bird populations there. Fewer birds means less bird droppings, which disrupted the flow of nitrogen from the islands to the coral reefs. This in turn had an impact on the fish in the reefs, whose biomass decreased by up to 50 percent. As a result, important ecosystem functions of the fish, such as grazing, were severely impaired.
"The strong impacts that invasive species can have across ecosystem boundaries call for a paradigm shift in the study and management of invasive species around the world," wrote Eawag researchers Tania Peller and Florian Altermatt in the study published in the journal "Nature Ecology & Evolution". The study shows that alien species should not only be considered within classic ecosystem compartments such as sea, land or freshwater, but that their management requires a more holistic perspective.
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