On Midway Atoll, Christy Finlayson and her team have employed
a multipronged approach to removing invasive golden crownbeard and
restoring the island's native vegetation in a way that is both
effective and ecologically sound — pulling up plants, carefully
using herbicides, replanting native species and educating the
Photo courtesy of Christy Finlayson
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For the Birds
Perched amid the turquoise waves of the central Pacific, a
1,500-acre knob of sand and coral offered World War II airmen a
much-needed dose of dry land to break up the monotony of the open sea.
Midway Atoll, once a regular stop for transpacific military flights,
welcomed fliers of the nonhuman variety long before work began on the
U.S. Naval Air Base in the 1940s. Its isolated location and nearly
predator-free terrain made it the perfect spot to raise the new year's
brood, and, even today, its shores are a nursery for more than 2 million
Human habitation of the island, especially regular visits from abroad,
has opened up its once pristine shores to a variety of invading
opportunists, however. Brought to the island inadvertently in crates and boxes and bags of soil, or released on purpose with the best of
intentions, invasive plants and animals have wreaked havoc with the
island's delicate ecosystem, threatening native plants and seabirds that
depend on the island's relative safety for survival.
Enter Christy Finlayson. A one-time tourist to Midway, the University of
Maine Ph.D. candidate now leads the charge to protect the ecology of the
tiny island from the ravages of unwanted guests — especially a cheerful
yellow aster known as golden crownbeard (Verbesina encelioides).
"It's really a pretty little plant," says Finlayson, "but as it has
spread and pushed out the native plants, it has also caused problems by
forming dense stands that interfere with seabird nesting. It is also
very, very hard to get rid of."
Finlayson's project combines research, educational outreach, and good
old-fashioned muscle to combat the tenacious plants, and has proven
effective so far. The project began as an assignment for a
graduate-level course on biological invasives taught by Finlayson's
adviser, UMaine biological sciences professor Andrei Alyokhin.
"I wrote a mock grant proposal for the course, and decided to focus on a
real issue that was of interest to me. I contacted the Friends of Midway
Atoll National Wildlife Refuge and worked with them to secure a grant
from the National Fish and Wildlife Foundation's Pulling Together
Initiative grant program. We were awarded the grant in May of 2006,
which funded two crews of volunteers to work on the island."
While the project has been a success, the battle to remove the island's
well-entrenched crownbeard population is far from over. On Midway, the
plant can uncharacteristically grow 8 feet tall. Drought tolerant and
highly adaptable, crownbeard can withstand a wide range of temperature
and moisture conditions. It produces copious amounts of seed and can
self-pollinate, giving a single plant the potential to become the source
of a full-blown invasion.
In addition to outcompeting native plants, dense golden crownbeard
stands can prevent seabirds from nesting. Worse yet, the rapidly growing
stems can effectively trap growing chicks, preventing them from reaching
the water when they are ready to fledge. Crownbeard's thick vegetation
can make it difficult for adults to find their chicks at feeding time,
and can often host populations of ants that may feed on vulnerable young
Finlayson and her team have employed a multipronged approach to
eliminating golden crownbeard, utilizing a combination of techniques to
remove the invasive and restore the island's native vegetation in a way
that is both effective and ecologically sound.
"The volunteers pulled a lot of plants; we made huge piles along the
side of the road. Long-term management is the goal, however, and
crownbeard does very well in disturbed soils, so simply pulling up the
plants just makes room for others to take their place," says Finlayson.
"With a combination of pulling, careful use of herbicides, and an active
program to re-establish native species that can competitively exclude
golden crownbeard, we hope to remove the crownbeard and restore the
island's natural habitat."
Finlayson recently received additional funding from the National
Geographic Conservation Trust for a project that will continue the fight
against invasive species on Midway by establishing a comprehensive
management strategy and conducting research aimed at identifying how
invasive plants such as golden crownbeard may indirectly affect the
health of native ecosystems. By harboring pest insects and serving as a
vector for viruses and other pathogens, invasives may be harming native
populations to a much greater degree than previously thought. Finlayson
hopes to use the isolated island location to quantify these secondary
As with many invasive species control projects, education is the key.
Experienced in a variety of outreach and education methods, Finlayson is
always searching for new ways to educate the public about the dangers of invasives. When the invader is a hardy flower with dainty, daisy-like
blooms, the lesson can be a hard sell.
"Golden crownbeard is a serious threat to native ecosystems, but you can
still purchase it in wildflower seed mixes in the U.S. where it may not
be native and ship it to locations where we know it is not native.
Teaching people about the dangers of invasives can be just as important
as the research itself," says Finlayson.