Puerto Ayora, Galapagos

Stepping into town at Puerto Araya is an experience to which I’ve become unaccustomed after the past few weeks. Hammers clang metallic from a nearby construction site, a scooter wooshes past, kicking up a cloud of dust, the sharp rhythms of reggaeton echo from a nearby bar. It’s noisy, chaotic, and, in a way, it feels like home.

I’m back in my usual habitat, the town. I head to a bar, order a café con leche, sit on a metal table outside and watch life go by. Pigeons coo, sirens blare, and soon, I have a companion - the bar’s resident dog. His breed is completely indeterminate, but he has a good, long snout, small-ish floppy ears and a charismatic black and white pelt. He leans against me for a pat, I oblige, because he’s very cute, but unfortunately, his species is causing considerable damage to the Galapagos.

Dogs, alongside a score of human-introduced species on the Galapagos, are what is known as ‘invasive species’. Invasive species are non-native species introduced to an environment that end up outcompeting indigenous organisms, preying on them, introducing diseases and disrupting the natural habitat. Dogs who have escaped, been abandoned or simply allowed to roam free have become the island’s top predators, threatening endangered species such as marine iguanas and sea turtles which have no evolved defences against predation. Of course, the problem here is not with the dogs themselves, but with irresponsible pet ownership and increasing feral dog populations, which is damaging for both wildlife and the dogs themselves.

Pigs introduced by ambitious human ranchers also cause untold destruction. Pigs eat the hatchlings and eggs of most of the land-based animals on the islands, and through their rooting, trampling and digging, destroy local vegetation and disrupt the delicate local soils.

Non-native plant species are also destroying local habitats. One of the greatest offenders is the Hill raspberry. Introduced during the 1960s, this plant grows incredibly fast in the island’s volcanic soil, creating thick banks over 7ft (2m) tall, which choke and smother the endemic daisy tree forests. The plant is hard to control due to its fast growth and large seed bank, but the loss of the daisy forests would be a catastrophe, impacting thousands of other species that rely on this unique ecosystem to survive.

It’s not just sad to see native numbers depleted by invasive species; it’s dangerous. Invasive species are one of the top 5 causes of biodiversity loss in the world, and a less biodiverse environment is a less secure one, as extinctions in one part of the ecosystem have ripple effects on others. The result is a drastically changed and poorer natural environment, dominated by a few non-native species. Unfortunately, island environments, with their closed boundaries and small landmasses, are especially vulnerable to invasive species and biodiversity loss.

But the Galapagos are fighting back. A successful sterilisation campaign has halted the over-reproduction of dogs, and projects to reduce the feral pig population are well underway. Softer campaigns, such as encouraging responsible dog ownership and discouraging the practice of allowing dogs free rein of the island, strict rules on the importation of live organisms to the island, and the encouragement of softer-impact ecotourism options have also helped mitigate the worst effects of invasive populations. 

Additionally, to clear the Hill raspberry thickets, conservationists are experimenting with methods of biocontrol, or using natural organisms to control this weed’s populations. One potential avenue is the use of rust fungus, which could destroy Hill raspberry populations whilst leaving local vegetation intact. At present, this is just an idea, but it has the potential to save the irreplaceable natural wonder of the Galapagos daisy forests.