Featured Research

from universities, journals, and other organizations

While The Cat's Away: How Removing An Invasive Species Devastated A World Heritage Island

Date:
January 13, 2009
Source:
British Ecological Society (BES)
Summary:
Removing an invasive species from sub-Antarctic Macquarie Island, a World Heritage Site, has caused environmental devastation that will cost more than A$24 million to remedy, ecologists have revealed. Writing in the new issue of the British Ecological Society's Journal of Applied Ecology, they warn that conservation agencies worldwide must learn important lessons from what happened on Macquarie Island.

Removing an invasive species from sub-Antarctic Macquarie Island, a World Heritage Site, has caused environmental devastation that will cost more than A$24 million to remedy, ecologists have revealed. Writing in the new issue of the British Ecological Society's Journal of Applied Ecology, they warn that conservation agencies worldwide must learn important lessons from what happened on Macquarie Island.

Using population data, plot-scale vegetation analyses and satellite imagery, the ecologists from from the Australian Antarctic Division (AAD), the University of Tasmania, Blatant Fabrications Pty Ltd and Stellenbosch University found that after cats were eradicated from Macquarie in 2000, the island's rabbit population increased so much that its vegetation has been devastated.

According to the study's lead author, Dr Dana Bergstrom of the Australian Antarctic Division: “Satellite images show substantial island-wide rabbit-induced vegetation change. By 2007, impacts on some protected valleys and slopes had become acute. We estimate that nearly 40% of the whole island area had changed, with almost 20% having moderate to severe change.”

Rabbits were introduced to Macquarie Island in 1878 by sealing gangs. After reaching large numbers, the rabbits became the main prey of cats, which had been introduced 60 years earlier. Because the rabbits were causing catastrophic damage to the island's vegetation, Myxomatosis and the European rabbit flea (which spreads the Myxoma virus) were introduced in 1968. As a result, rabbit numbers fell from a peak of 130,000 in 1978 to less than 20,000 in the 1980s and vegetation recovered. However, with fewer rabbits as food, the cats began to eat the island's native burrowing birds, so a cat eradication programme began in 1985. Since the last cat was killed in 2000, Myxomatosis failed to keep rabbit numbers in check; their numbers bounced back and in little over six years rabbits substantially altered large areas of the island.

According to Bergstrom: “Increased rabbit herbivory has caused substantial damage at both local and landscape scales including changes from complex vegetation communities, to short, grazed lawns or bare ground.”

Invasive species can cause large-scale changes to ecosystems, including species extinctions and – in extreme cases – ecosystem “meltdown”. As a result, control or eradication of invasive alien species is widely undertaken. However, important lessons must be learned from events on Macquarie Island, say the authors.

“Our study shows that between 2000 and 2007 there has been widespread ecosystem devastation and decades of conservation effort compromised. The lessons for conservation agencies globally is that interventions should be comprehensive, and include risk assessments to explicitly consider and plan for indirect effects, or face substantial subsequent costs. On Macquarie Island, this cost will be around A$24 million,” says Bergstrom.

The changes documented in this study are a rare example of so-called “trophic cascades” - the knock-on effects of changes in one species' abundance across several links in the food web. “This study is one of only a handful which demonstrate that theoretically plausible trophic cascades associated with invasive species removal not only do take place, but can also result in rapid and detrimental changes to ecosystems, so negating the direct benefits of the removal of the target species,” Bergstrom says.

Macquarie Island (34 km long x 5 km wide) is an oceanic island in the Southern Ocean, 1,500 km south-east of Tasmania and approximately halfway between Australia and the Antarctic continent. Low-lying, with a cool, maritime climate, it is covered with tundra-like vegetation. It was inscribed as a World Heritage Site in 1997 because of its geological significance – it is the only place on Earth where rocks from the Earth’s mantle (6 km below the ocean floor) are being actively exposed above sea-level.


Story Source:

The above story is based on materials provided by British Ecological Society (BES). Note: Materials may be edited for content and length.


Journal Reference:

  1. Dana M Bergstrom et al. Indirect effects of invasive species removal devastate World Heritage Island. Journal of Applied Ecology, 2009; DOI: 10.1111/j.1365-2664.2008.01601.x

Cite This Page:

British Ecological Society (BES). "While The Cat's Away: How Removing An Invasive Species Devastated A World Heritage Island." ScienceDaily. ScienceDaily, 13 January 2009. <www.sciencedaily.com/releases/2009/01/090112093523.htm>.
British Ecological Society (BES). (2009, January 13). While The Cat's Away: How Removing An Invasive Species Devastated A World Heritage Island. ScienceDaily. Retrieved July 30, 2014 from www.sciencedaily.com/releases/2009/01/090112093523.htm
British Ecological Society (BES). "While The Cat's Away: How Removing An Invasive Species Devastated A World Heritage Island." ScienceDaily. www.sciencedaily.com/releases/2009/01/090112093523.htm (accessed July 30, 2014).

Share This




More Earth & Climate News

Wednesday, July 30, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
In Virginia, the Rise of a New Space Coast

In Virginia, the Rise of a New Space Coast

AP (July 30, 2014) Every summer, tourists make the pilgrimage to Chincoteague Island, Va. to see wild ponies cross the Assateague Channel. But, it's the rockets sending to supplies to the International Space Station that are making this a year-round destination. (July 30) Video provided by AP
Powered by NewsLook.com
Climate Change Could Cost Billions, According To White House

Climate Change Could Cost Billions, According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Climate Change Could Cost Billions According To White House

Climate Change Could Cost Billions According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins