Following the discovery of zebra mussels in Lake Independence, a Three Rivers Park District official was quoted as saying1, “the district is looking to boost funding for inspections next year since it’s often cheaper than responding afterward.” But is that true?
In the lake management profession, we often visit the easy advice that prevention is cheaper than the cure for all lake woes. Where aquatic invasive species (AIS) are concerned, I don’t think this is true.
Let’s look at this from several angles.
With zebra mussels and all other AIS, there have been noble attempts, but there are no cures. There are others costs, as economists can argue. There are societal, environmental or opportunity costs to AIS infestations, and these arguments are credible. Unfortunately, most policy makers neither understand nor weigh these costs. As a result, investments in prevention actions are usually inadequate.
What about prevention? We don’t know what the true costs of AIS prevention are because we do not yet have a good model of what prevention actions are effective.
Recent zebra mussel infestations in major lakes (Christmas, Green, Independence and White Bear) demonstrate that whatever prevention programs we have been relying upon do not work. There are no objective studies that guide AIS prevention programs. We do not know that for X level of effort, we reduce the risk of infestation by Y. We are guessing. Some say we can buy time to find cures. This is disingenuous because a) we have no good way of knowing how much time we are buying and b) we have not made significant investments in AIS research.
The Minnesota Legislature authorized the expenditure of $10 million per year for Minnesota counties to implement AIS prevention programs. Will spending this money do more of the same – inspections, education, decontamination – result in a different outcome? No. How could it? The available evidence shows we can expect AIS infestation to continue.
The current thinking on the prevention-cure-management equation clearly does not work for AIS.
What then, should we do?
We need more AIS research (see my September 2014 blog on the topic). Lacking research, we are managing in the dark and will always be behind the curve. An investment in research will require discipline and prioritization. Research is expense and requires a long-term commitment. We should make that investment for the long-term rather than doing what is politically or economically acceptable now while shrugging our shoulders at the poor results.
Until we have effective and reliable prevention programs, we must consider quarantine as a necessary stopgap prevention measure. In light of our ignorance regarding AIS risks, this step is consistent with epidemiological models and it’s inexpensive to implement. It is controversial – but what else do we have?