Saturday, 19 August 2023 15:25

Biosecurity challenges for New Zealand's future: Gazing into the Crystal Ball

Written by  Sophie Badland
Te Motu Te Motu

Biosecurity stakeholders are becoming increasingly concerned about how well our biosecurity system will stand up to challenges such as climate change, future trade patterns, changing population dynamics and agrichemical availability.

A recent study by a group of New Zealand researchers in the Better Border Biosecurity (B3) collaboration examined a suite of ‘global megatrends’ and how these might impact on New Zealand’s biosecurity system in the future. Here we highlight just some of the megatrends identified as likely to impact on plant sector biosecurity in New Zealand.

Agrichemical availability

Globally, demand for pesticides for food production continues to increase. At the same time, there is pressure to remove broad-spectrum pesticides from use and replace them with greener, more targeted chemistry. Loss of agrichemical controls and scarcity of product may allow pest populations to increase overseas, and arrive in greater numbers at New Zealand’s border. New Zealand itself is a small market for agrichemical suppliers, and it can be difficult to get new products registered for use here; therefore there is a risk that existing chemicals are withdrawn from use without suitable replacements, limiting our ability to deal with pest outbreaks onshore.

Climate warning

According to the Ministry for the Environment, as local climates change in response to rising CO2 levels, New Zealand is expected to get warmer, with the east becoming drier while the west becomes wetter. As a result of global climate change, pest distributions will shift overseas. Within New Zealand it is predicted that pest species already present will increase in population and cause more damage. New invasive pest species will also find the warmer conditions more suitable and become more likely to establish and spread. Combined with this, land-use change (as some crops become more difficult to farm and climate becomes more suitable for others) may contribute to the arrival of new invasive species as new crop types and new varieties of existing crops are sought from overseas.

Global trade patterns

Global trade has been increasing for decades, with data showing it has more than doubled every 20 years since the mid-1900s. As the effects of climate change are felt regionally and impact supply and demand, it is expected that trade patterns, commodities and routes will all shift. This in turn will expose New Zealand to new biological threats. As trade continues to increase, biological invasions are expected to occur more frequently, meaning more resource will need to be allocated to biosecurity response and management.

Population mobility

Similar to trade patterns, data shows the number of international travellers coming into New Zealand has been increasing over a long period of time. Prior to the Covid-19 pandemic, almost 4 million tourists were arriving annually via air travel or cruise ships. Increasing numbers of travellers bring increased risk of hitchhiker pests arriving in New Zealand. Hitchhiker pests generally are not associated with any particular commodity and are therefore notoriously difficult to predict and manage. The brown marmorated stink bug (BMSB) is a hitchhiking pest and is at the top of the Most Unwanted list for the New Zealand wine industry.

Sea and air currents

Recent oceanographic studies show there has been a substantial acceleration of global mean ocean circulation since the early 1990s, increasing the speed of ocean currents in several areas. In New Zealand, NIWA predicts stronger westerly winds will occur across the Tasman sea throughout winter, particularly affecting the lower North and South Islands. Wind and water natural dispersal pathways for pest incursions are particularly hard to manage, with models struggling to account for the number of factors that can influence where pests might eventually come to rest, and surveillance needing to occur over large areas to provide early warning of an incursion. Wind events can also result in simultaneous incursions in multiple regions. In 2022, the fall armyworm, predominantly a pest of maize crops, arrived in New Zealand and has since spread to several regions. It is thought it arrived via a wind event, likely blown over from Australia.


Globally the number of people living in urban centres (as opposed to rurally) has been steadily increasing, with the United Nations predicting more than two thirds of the world’s population will be urban by 2050. In New Zealand this is already higher, with 86% of people living in urban areas (though many work rurally). Urban populations tend to be less aware of biosecurity risks than their rural counterparts, and often do not experience firsthand the consequences of biosecurity incursions. This makes maintaining social licence to respond to new incursions in urban areas more difficult.

Where to from here?

The B3 report highlights a raft of challenges facing New Zealand’s biosecurity system as we look to the future, most of them related in some way to climate change and population growth. The report suggests four priority areas for future research, to help us better understand and navigate these challenges – future pests and threats, changing pest pressure on the border, vulnerablity of host plants and ecosystems, and evolving biosecurity management tools. There is a real need for biosecurity research specific to the New Zealand context, as our experience of climate change and other future trends will undoubtedly differ from that of other countries.

Read the full B3 report – Global Change and New Zealand Biosecurity – at

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