Red imported fire ant. Photo by Wikimedia Commons, licensed under CCO 1.0
Three weeks have passed since the world’s leading ecologists, the 140-country IPBES (Intergovernmental Panel Science Policy Platform on Biodiversity and Ecosystem Services) warned of one of the costliest developments in the world—invasive species. Yet there has scarcely been a mention of the issue in the political campaigns in Aotearoa New Zealand.
While the report estimated that invasive species cost $400 billion per year, other estimates suggest it is costing the world over a trillion dollars each year. That is more than the cost of all natural disasters per year. The relentless spread of invasive species at an alarming rate are threatening nature, food security, our economies, and human health.
Although the report was global in nature, fragile ecosystems here in Aotearoa New Zealand are particularly vulnerable, as many of our native species have no defence developed against invaders. The recent unwelcome arrival of invasive Caulerpa seaweeds is one harbinger of our growing crisis. These seaweeds are forming dense mats, smothering native marine plants, reducing nursery habitat for fish, and blocking fish from finding their food. But there are others, and they are wreaking havoc.
Indeed, here, New Zealand is facing a mass extinction crisis. While some charismatic species, such as kiwi, have recovered from near extinction, many remain vulnerable particularly species receiving scant public attention, such as kākahi, a freshwater mussel, and toanui/flesh-footed shearwater. The government has acknowledged the dire state of ecosystems and biodiversity in its Environment Aotearoa reports, noting that almost 4,000 native species are either threatened or at risk of extinction (2019, 2022). These include 90 percent of seabirds, 80 percent of shorebirds, 26 percent of native marine mammals, and nine percent of sharks, rays, and chimaeras. Some, such as the Māui dolphin are in more dire condition with some fifty-five individuals over the age of one year remaining, while fifty-nine bird species, three frog, two reptiles, four insects and seven plant species have gone extinct, according to the Department of Conservation documents.
These losses are disastrous beyond mere numbers. Each species is part of a complex ecosystem, thriving together because of each other. Communities of plants, animals and other living things have evolved together in their habitats. Their interactions prop up entire ecosystems that sustain all of life. For example, many plants have specialist pollinators or seed dispersers, without which they cannot exist.
Not all the declines and extinctions are due to invasive species alone. Indeed, they arise from a combination of climate change, land use changes that alter, pollute, and destroy habitat, and inadequate policy, management, and oversight. In Canada, although wildfires are a natural part of their landscapes, climate change and poor forest management sent their forests ablaze, releasing massive carbon emissions into the air and threatening many of their other species. This year has seen earlier and more extensive wildfires surpassing all previous records.
In addition to mass extinction, invasive species compound the disasters from climate change. The recent fires in Hawaii that burned 3200 acres of land and killed at least 115 people (more than any wildfire in modern US history) resulted from a combination of non-native, highly flammable invasive grasses, and a climate change-driven drought.
Here, in New Zealand, exotic species, such as pines, are also highly flammable. While they offer economic resources, they blanket what was native forests. Should there be fires, native vegetation destroyed, while pine trees rapidly reestablish, those native species recover more slowly, creating a vicious circle. After repeated cycles of fires, those native vegetation communities become completely replaced by a monoculture of pine trees.
It is not all bad news, however. With sound resources, policies, practices, and management, we can restore our natural environment, protect our native species, and protect against some ravages of climate change. The island of Tiritiri Matangi, just off the Auckland coast, offers a small example of what is possible. What was once a sheep station and pastureland now feature spectacular numbers of native birds, including species like tīeke / saddleback, which are extinct on the mainland, apart from in fenced eco-sanctuaries. Beginning in the 80s and 90s, invasive species eradicated, and native bird species were reintroduced, and importantly, the community stepped in to replant the native vegetation.
This restoration can happen throughout our country, restoring New Zealand’s unique ecological treasures, helping stave off some effects of climate change and returning our rich native ecosystems. But it will require concerted efforts and cooperation across our politics, policy, research, and resources to get there. That also requires advancing it high into our political agenda. Now is the time to bring it into our political debates.
Maria Armoudian, Jacqueline Beggs, and David Noone are directors, University of Auckland’s Nga Are Whetū Centre for Climate, Biodiversity and Society