Didymo - 'Nuking' not an option - knowledge and awareness the key
In a perfect world there'd be no need for biosecurity - unwanted pests would respect national borders. There'd be no such thing as a problem, because there would always be readily available solutions, and people would always stick by measures that exist for everyone's benefit. But the world's not perfect, and Mother Nature throws curve balls like didymo.
So, like it or not, in October 2004 Biosecurity New Zealand (BNZ) was dealing with a microscopic invasive pest that had received little scientific scrutiny. Experts advised it could already be lurking undetected in other rivers, and that there were no available control tools. With such a starting point, didymo was always going to be a challenge.
Clearly BNZ had to do something. It immediately did two things: it began a research programme to learn more, and started a public awareness programme.
Initial research focused on the basic ecology and preferred habit and, in a world first, developed decontamination measures that were the backbone of the public awareness campaign.
The public awareness programme initially focused on Southland because a survey of Southland and Otago rivers found no further trace of didymo. The programme included signage, advertising, brochures, posters, river patrols, public meetings and media coverage.
Regional Councils, Department of Conservation (DOC) officers and Fish & Game staff around the country were told what to look for and it was this effort, after several false alarms, that lead to Fish & Game making other didymo finds in September 2005. At this point, the public awareness campaign broadened to other regions, and began to focus on changing behaviours to minimise further spread.
In taking the behaviour change approach, BNZ had to be mindful of several factors. The first was that BNZ cannot take any action that might cause a worse problem than it solves. This includes economic, environmental, social and cultural impacts. It was this logic that ruled out 'nuking' didymo-infested rivers. Another point is that didymo is microscopic. There were no guarantees it was confined, or that other rivers would remain unaffected. So which rivers should have been closed?
Another consideration was the massive logistics of closing rivers, the magnitude of enforcement, and the possibility of 'illegal' use regardless of any closure when keeping rivers open made 'self-policing' possible. Enacting controlled areas on just five affected rivers for a short period in September 2005 cost $2.2 million from a total budget of $5.9 million. Of that, $1.5 million was spent on research, and $1.9 million on public awareness. This year, the response budget is $6.5 million, with $1.7 for behaviour change, $2 million for research and $1 million for surveillance and monitoring. This amounts to some $7 million for research and public awareness so far.
The precedents for behaviour change campaigns are clear, especially when no 'cure' is available. Promoting preventative behaviours is the best weapon in the fight against HIV and sexually transmitted diseases, various forms of cancer, the common cold, poor food hygiene, drink-driving, and even drowning. While some of these issues have an enforcement element, it is human nature to still take risks. Enforcement or not, an element of personal responsibility will always apply. While behaviour change does have limitations and is unlikely to be accepted by 100 percent of the population, it is the most sustainable tool we've got to promote the message that all waterways could potentially be infected and that 'clean, check, dry' is a procedure required by everyone, everywhere, every time.
Since launching the behaviour change programme, BNZ has undertaken a diverse range of activities to encourage freshwater users to 'check, clean, dry'.
These activities have also been supported by efforts from DOC, regional councils, Fish & Game, Jet Boating New Zealand, the New Zealand Recreational Canoeing Association and many other organisations, to make freshwater users aware of how they can stop the spread of didymo. Nonetheless, it's a big job that needs a collective community response to be the most effective.
Time and time again we are shown instances where people have been giving a helping hand to help promote the 'check, clean, dry' message.
The Reefton holiday park, for example, put 'check, clean, dry' keyrings on their cabin keys to promote the message to visitors. And event organisers, such as Robin Judkins from the Speights Coast to Coast, have included cleaning requirements in events to ensure that people are aware of and undertaking behaviour to stop the spread of didymo.
In addition, many people have written to local papers to share their didymo experiences with others and help pass on the message to other river users.
While research may eventually deliver methods for controlling and containing the spread of didymo, it is the awareness and cooperation of all users of New Zealand's fresh waters that will be the most potent weapon against this invasive pest.
Back to Biosecurity Magazine - Issue 71
Page last updated: 24 June 2008