Biosecurity in Hawke’s BayWhakamarumarutanga koiora ki Te Matau-a-Māui

What is biosecurity?

The NZ Biosecurity Institute defines biosecurity as “the protection of an environment from biological threats. In New Zealand action is taken to prevent unwanted organisms from damaging the economy, natural biodiversity, or the health of the New Zealand public.”

Why is biosecurity important?

Biosecurity is essential for managing our regions natural resources, stopping biodiversity decline, and protecting cultural values like recreations, ancestral lands, waters, wāhi tapu, and taonga. It’s also important for economic activity relating to primary industries.

How we prioritise pest management

Regional councils have a mandate under Part 2 of the Biosecurity Act 1993 (the Act) to provide regional leadership in activities that prevent, reduce, or eliminate adverse effects from harmful organisms that are present in their region. We deliver this through the Regional Pest Management Plan (RPMP), which targets pests that can’t be effectively controlled through public action alone. This means that landowners will have responsibilities for pest control that will vary by species, and those requirements are detailed in the RPMP.

While the Ministry for Primary Industries (MPI) works at the border to keep many non-native species out, many invasive organisms are already established in NZ. Although there are many ‘undesirable’ or ‘nuisance’ organisms in Hawke’s Bay, only 63 currently have management plans in the RPMP. Many factors must be considered when determining which invasive organisms to allocate our limited resources. Regional councils need to carefully consider the following points:

1. The harm this species can cause if left unchecked – through competition, predation, etc.
2. Its potential for reaching our region (if not here already) – transportation pathways, national occurrence, etc.
3. Its potential for spreading within our region - habitat availability, food sources, etc.
4. The difficulties we might have in managing the species - speed of reproduction, efficiency of control methods, assistance through collaborations, etc.
5. The value this species may have to humans (if any) - game species, timber, public perception, etc.

We address these points using predictive tools and/or status assessments, helping us understand the spread and impact of each pest species in our region. These results can then be compared to balance priorities, justify control programmes, and maximise actions through a regionally coordinated approach.

Having weighed the costs and benefits of various strategies for protecting our regional values, the RPMP then uses tools like ‘The Invasion Curve’ below to determine either exclusion, eradication, progressive containment, or long-term control programmes for each of the region’s prioritised pests. The management programme for each pest will depend on how well established a species is on The Invasion Curve.

Our pest management programmes

‘Exclusion Programmes’ aim to act before a pest arrives in the region to prevent it from establishing. With the best cost:benefit ratio (around 1:100), prevention is always the most economic strategy. The faster we can identify an incursion, the more economical our response efforts are likely to be.

An ‘Eradication Programme’ attempts to reduce a pest incursion to zero over a short period of time. To be successful, the rate of removal must exceed the rate of increase of the pest. Reinvasion from other areas must also be prevented, and all potentially reproductive pests must be targeted. Eradication programmes require robust design, effective implementation, enough money, and trained field staff. For these reasons, eradication tends to be far more expensive than an exclusion programme.

For well-established pests whose harmful effects and spread can still be reduced, ‘Progressive Containment Programme’ provides the most cost-effective approach. As complete eradication may be very hard at this stage, the goal is to keep the pest population as low as possible and restrict it to a specific area while reducing numbers over time. Containment programmes typically focus on invasive species in high-value habitats that need protection and restoration.

‘Sustained Control’ is our last chance to hold well-established pests at an acceptable maximum. However, the costs of management and control grow in-step with the size of the invasive population. Because economic returns can fall to 1:5 or less, most of this work is focused on species in sites of high ecological value.

There are many organisms in New Zealand we consider ‘undesirable’ or ‘a nuisance’, but the Biosecurity Act 1993 contains strict criteria to justify council intervention. This means many unwanted organisms can’t be assigned a control programme. Our RPMP only addresses pests where voluntary action by the public would not be enough. These decisions are based on the species involved and the likely costs and benefits of acting or not acting.

In our RPMP you’ll also find 28 ‘Organisms of interest’, many of which are common in Hawke’s Bay. These species are monitored because they can harm biodiversity, primary production, or cultural values. Other invasive species may not be listed in the RPMP, either because their overall impact is low or because they are so widespread that controlling them would require unrealistic resources.

Some of Hawke’s Bay’s most disliked and widespread pests are too difficult for any single organisation to manage. Our advice is always based on success of community control efforts, biocontrols, and other biosecurity initiatives

Hawke's Bay Biosecurity issues

Keeping the farm gate closed is not practical, so constant work is needed across the whole community. Hawke’s Bay Regional Council focuses on the particular biosecurity demands of the region and we manage animal pest programmes in rural and urban areas, and target specific plant pests for control or eradication.  These are detailed in the Pest Management Plan.

Farmers are helping by managing possum control on their land, controlling noxious weeds and ensuring good land management practices to ensure unwanted pests don’t reinfest their land.

In urban areas, councils control weeds and animal pests on reserve land, while residents  help by controlling pests on their properties and ensuring that these don’t spread to neighbouring areas.

One of our greatest successes in Hawke's Bay has been in working with property owners - both in the country and in our towns - to significantly reduce the possum population. Possum control remains the responsibility of landowners until the Possum Control Programme (PCA) transitions to being delivered by professional possum contractors.

Note that the Regional Council does not provide services for controlling wasps, bees, flies etc. You can find more about bee swarms here, or please contact a local pest controller service.

Who else do we work with?

As well as other regional councils throughout New Zealand, we work with other organisations involved in biosecurity:

• Ministry of Primary Industries – protecting people, environment and primary sectors is a priority for MPI. They have a leading role in watching for harmful pests and diseases entering New Zealand and managing their control or eradication if they do get in.
• Department of Conservation - DOC manages 8 million hectares of land, about 30% of New Zealand's land area, and is responsible for preserving and protecting these areas, including managing threats from invasive pests and diseases. 
• New Zealand Biosecurity Institute – this organisation has open membership for anyone interested in biosecurity issues, and works to raise awareness of biosecurity issues, encourages the development and application of best practice in biosecurity and connects people and organisations to share knowledge.