Islands of hope
A pioneer in offshore conservation work shows how ecological decline can be reversed.
AHUAHU: A conservation journey in Aotearoa New Zealand, by David Towns (University of Canterbury Press, $79.99)
Islands have always been an enduringly enticing presence in our lives, with their promise of escape, potential sanctuary and new horizons. For leading New Zealand conservation biologist Dr David Towns, the role of the island as a protector has taken on a new dimension. In his new book, he suggests New Zealand’s offshore islands can provide the key to ensuring the survival of unique but threatened natural worlds. It’s a challenging prospect, but a scattering of seven islands off the north-eastern coast of the Coromandel Peninsula might be a practical object lesson in ecological conservation.
The natural history of the Mercury Islands also provides a valuable lesson in the wider story of the impact of human settlement on New Zealand’s biodiversity. As fragments of the Earth’s largely submerged eighth continent, Zealandia / Te Riu-a-Maui – the New Zealand land mass is currently the largest exposed portion – the natural environment of the Mercury Islands existed for millions of years before being settled by the first Polynesians. The arrival of the Māori was followed during the ensuing centuries by waves of human immigrants. These were frequently accompanied, through accident or design, by other newcomers in the form of rats, mice, feral cats and dogs. Even introduced plants threatened a previously undisturbed, delicately balanced environment. A rich diversity of unique birds, insects, plant life and invertebrates confronted a slow but apparently inevitable destruction.
In 1971, when Towns first arrived on Ahuahu (Great Mercury), the largest and only inhabited island in the group, the situation was parlous. But five decades later, what happened on these islands provides an invaluable lesson in how to reverse an environmental tragedy. It has been a slow, often frustrating process involving the progressive eradication of rodents and other threats, but as Towns sets out to prove, it can succeed through a viable working partnership between local communities, scientists, government agencies and individuals.
The book’s greatest strength is Towns’ ability to communicate not only the science behind this major conservation programme, but also his own infectious enthusiasm for the place and its natural environment. Even the ecological intricacies are accessible to the layperson. It’s this that transforms the book from being a detached academic discourse into an energetic and engaging account. Abundant illustrations also play their part in making it absorbing and informative reading.
Towns also widens the book’s scope to include the experiences of other islands, places that he sees as ideal sanctuaries and classrooms in what hopefully will be ongoing conservation programmes. He describes a diverse collection ranging from the volatile volcanic environment of Raoul Island to the wind-lashed Antipodes and Campbell islands in the far south and the familiar whaleback shape of Kapiti
A rich diversity of unique birds, insects, plant life and invertebrates faced apparently inevitable destruction.
Island, north of Wellington. Each one, he believes, holds different lessons for the long-term protection of very different but equally significant environments.
Towns’ book provides an insight into what can be achieved. It is a tribute to the many people who have contributed to ensuring the survival of the Mercury Islands environment and the rich catalogue of flora and fauna they shelter. But as Towns observes, this and other programmes can face uncertainty, unpredictability and criticism that they are simply “gardening” on a grand scale.
The challenges obviously remain in this unfinished story. As he writes, “we will need not only the lessons of the past but the energy and inspirations of the future”. ▮