Environmental Engineering Reference
In-Depth Information
The islands were probably uninhabited before Europeans arrived. Aliens came too. The first black
rats hopped off warships in the seventeenth century and began eating the eggs of both endemic birds and
the giant tortoises. Goats, cats, and others soon mutinied from whalers visiting to stock up with tortoise
meat. The population of alien species exploded more recently as local fishers and others began to drop
anchor regularly, followed by a permanent population to service the two hundred thousand tourists that
visit every year. Now there are more than five hundred other introduced plant species—almost as many
as there are native plants—along with five hundred invertebrates and thirty-six vertebrates. Blackberry
bushes, originally from Asia, cover seventy-five thousand acres, taking over from the forests of Scalesia
trees in the uplands of Santa Cruz and other islands.
In 2000, a ten-year project, funded with $19 million from the World Bank's Global Environment Fa-
cility, set a goal of the “total control of invasive species” on Galapagos. Not eradication, control. Alto-
gether there were forty-three projects targeting thirty-five species of invasive plants, animals, and inver-
tebrates. But a decade later, just nine of the projects had achieved their targets. 25 Restoration of native
plant cover had been achieved on less than five hundred acres, said Gardener. And even those successes
were “not stable” and would “require continued high-level intervention” to keep the invaders from re-
turning. Efforts to uproot the alien guava and blackberry bushes had been worse than useless, he said.
The digging created more of the disturbed ground that invasive species so enjoy. Eradication of aliens,
Gardener concluded, “is not a viable tool.” The white flag was raised. 26
But all is not lost. “The Galapagos campaign that Gardener deems a failure is rife with success,”
insists Daniel Simberloff. 27 Around a quarter million goats have been eradicated from both Santiago
and Isabela Islands in campaigns involving hunting with dogs, shooting from helicopters, and the mass
release of hundreds of sterilized females to distract the males. 28 The recovery of vegetation following
goat eradication had brought the endangered Galapagos rail back from the brink of extinction on Pinta
Island.
Simberloff has a point. Despite the invasions, the Galapagos Islands have lost very few species. The
subspecies represented by Lonesome George was a high-profile exception. What Gardener wanted to
do was call off the “war” on aliens. Instead, he wanted to sue for a permanent peace, coming to an ac-
commodation with the aliens by working out how they might fit in while still protecting what is most
worthwhile about the old guard. In other words, he wanted to start work on engineering “novel ecosys-
tems” on islands more synonymous with conservation than any other on the planet. Simberloff argued
that this was good management, even if short of eradication. The difference was more rhetorical than
real. Finally, in the Galapagos, there seemed to be a meeting of minds. If this is the way forward for
Galapagos, then surely it is the future of conservation across the planet.
This is not a counsel of despair, even for those who want a revival of nature as near to what we had in
the past as possible. The story of the “pristine forests” is encouraging. Forests can regenerate in a few
centuries so that even experts cannot tell if they are pristine old growth or secondary regrowth. And
there is growing evidence that most other ecosystems can do the same. The idea that modern humans
are destroying nature forever is simply unsupported by the evidence. Even a few decades will see much
of it righted.
Holly Jones and Oswald Schmitz of Yale looked at 240 scientific studies of what happens to dam-
aged ecosystems if humans walk away. They found “startling evidence that most ecosystems globally
can, given human will, recover from very major perturbations.” More than a third showed full recovery,
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