For the past two years, a consortium of stakeholders in the salmon fishery has proposed to poison Miramichi Lake and 15 km of the Southwest Miramichi River to eradicate the invasive smallmouth bass population.
The consortium includes the Atlantic Salmon Federation, the Miramichi Salmon Conservation Centre, the New Brunswick Salmon Council, Anqotum Resource Management, the Miramichi Water Management Committee, the NB Wildlife Management Committee and the Northshore Micmac District Council. The consortium contends that the smallmouth bass population poses a threat to the Atlantic salmon population that spawns in the headwaters of the Miramichi Watershed.
Intensive studies of the smallmouth bass threat have been ongoing by the Department of Fisheries and Oceans (DFO) since 2009. In 2019, the consortium decided that the financial cost of suppressing the bass population was becoming overly burdensome and thus proposed to implement a program of lake poisoning with a piscicide that includes the chemical Rotenone and other fish toxicants.
Many Indigenous people and settlers opposed the proposal and in August 2021, Wolastoqey Mothers and Grandmothers stopped the poisoning of the lake by maintaining a presence at the lake. Given that the poisoning could not proceed while the lake was occupied, the issue landed in court where it was determined that the consortium had not adequately consulted affected First Nations. Terry Ann Sappier has given a moving account of the Wabanaki Mothers and Grandmothers’ struggle against the lake poisoning.
With another year of information meetings having transpired, the issue promises once again to rear its ugly head in August 2022. While there exists significant and heated debate about the efficacy and wisdom of resorting to lake poisoning to eradicate an invasive species, some basic issues tend to get lost in the uproar. With the upcoming annual “Season of Poison” approaching, and renewed confrontation looking inevitable, it is interesting to examine who actually will be in violation of the law when the proponents of the poisoning clash with protesters.
Project to poison the lake without a Comprehensive Environmental Impact Assessment
Given that the smallmouth bass constitute 0.4 per cent of the total fish population in Miramichi Lake, it is puzzling that no comprehensive Environmental Impact Assessment (EIA) was ever required of the poisoning proposal. Given this slide through the EIA process, non-governmental organizations were not given the opportunity to express an expert opinion on the ecological risks of the project. Even DFO, upon whom the New Brunswick Department of the Environment relied for tacit EIA approval of the Rotenone application, took issue with the consortium’s application stating:
There is no literature on the population level consequences of Smallmouth Bass presence on Atlantic Salmon productivity and abundance. The history of Smallmouth Bass establishment in many watersheds with Atlantic Salmon, and the few studies, do not support the statements in the application of consequences to Atlantic Salmon associated with the establishment of Smallmouth Bass in riverine habitat as devastating.
Without a comprehensive EIA, the project was also allowed to forego compliance with existing provincial water regulations. Most poignantly, the project was allowed to proceed without addressing the issue of the legality/illegality of applying a contaminant to a lake that has been classified as the high quality Class AL under the still existing Water Classification Regulation 2002-13 of the New Brunswick Clean Water Act 2002-56.
The Classification Regulation was not mentioned in the application for Environmental Impact Assessment (EIA1549) that briefly considered and approved the proposal to apply Rotenone along with many additional contaminant compounds to Miramichi Lake. This oversight, deliberate or otherwise, constitutes a failure on the part of the New Brunswick government and the proponent to follow “due process.” Under the regulation, “The water of all lakes, ponds and impoundments in the Province was placed into the AL Class automatically on passage of the Regulation.” Under the regulation, prohibited activities include: “Direct discharge of a contaminant that is not being released, or any increase in the volume or concentration of a contaminant that is being directly discharged, on the commencement of the Regulation to which this Schedule is attached; creation of a new mixing zone.”
As no exemption to the regulation has been requested or granted by the Minister of Environment, the application of Rotenone and the other contaminants to Miramichi Lake is in violation of the Classification Regulation. In 2014, the provincial Ombud chastised successive governments for their failure to clarify the classification regulation despite repeated government claims that the law was defective. Eight years later, the regulation remains in effect, just as it was when implemented in 2002.
It remains to be seen who will have the law behind them when the gendarmes start confronting and handcuffing the opposing sides in August.
Questionable interpretation of scientific data to justify poisoning the lake
Beyond this direct violation of existing law, there are also scientific issues that have not been adequately addressed by the government and the consortium. The consortium claims 87 per cent effectiveness of Rotenone application in eradicating smallmouth bass when a study by researchers at Carleton University found an equal split of successful and unsuccessful eradications in the Canadian context. Overall, the Carleton study found a less conservative finding of 75 per cent effectiveness of Rotenone compared to 58 per cent effectiveness of electrofishing and other forms of passive removal.
In any case, it is foreseeable that repeated applications of the Rotenone mixture will be required over a number of years. This possibility is overly downplayed in the proponents’ report. Such repeated applications of the Rotenone mixture would be far more ecologically damaging than repeated applications of electrofishing and other passive methods.
It is also troubling that the Carleton study was used to fortify the argument for the proposed use of Rotenone when the Carleton study itself stated: “Overall, inadequate data quality and completeness severely limited our ability to make strong conclusions about the relationships between non-native fish abundance and different methods of eradication and population control and the factors influencing the overall success rate of each method.”
If anything, the Carleton study indicated that more research is required before valid comparisons between chemical and non-chemical treatments can be made.
Poisoning will likely render the lake ecologically impaired over many years
In a 2017 DFO study by Biron, the author reported on the effectiveness of non-chemical control methods:
There is evidence of depletion of Smallmouth Bass in Miramichi Lake since 2010 but the extent of the reduction is unknown. The lower catch of Smallmouth Bass, lower catch per unit-effort from electrofishing boat, gillnets and beach seining, as well as the reduced distribution of Smallmouth Bass in the lake all supports this conclusion (Biron et al. 2014). However, the number of Smallmouth Bass that survived to older ages and have been captured since 2009 indicates a stable cumulative adult recruitment level of < 20 fish per year class, a level lower than from the 2006 to 2008 year classes in Miramichi Lake. There has been a small increase in catches of all age groups since 2015 and 2016.
The consortium claims, “Studies show affected insects and invertebrates will recover over a period of a few weeks to a few years” without defining “few years.” The consortium provides no evidence that baseline data on insects and invertebrates have been compiled against which recovery can be assessed. Benthic macro invertebrates are used as key indicators of water quality in the State of Maine, and in lieu of an updated water classification system in New Brunswick, they remain the only scientifically recognized indicator of water quality in the province.
Given that repeated applications of Rotenone are highly indicated, it is likely that Miramichi Lake will be in an ongoing ecologically impaired state if the Rotenone option is adopted. From the data on man-hours involved, it appears that the Rotenone chemical alternative is motivated more by potential cost saving rather than biological effectiveness. Could it be that a social license for a pesticide solution to unwanted aquatic species will be used to claim a social license for Glyphosate application to unwanted vegetative species?
Biron also indicated that spatial distribution of bass in the lake is highly non-random, with smallmouth bass catches spatially concentrated in 2 of 16 lake sectors. These results suggest that a more spatially sophisticated approach to non-chemical methods would result in more cost effective smallmouth bass control, while simultaneously avoiding the massive ecological impacts to other flora and non-bass fauna that result from Rotenone application. The Biron results seem to suggest that efforts toward more targeted non-chemical control should be attempted.
Applying other poisons in the lake further violates provincial regulations
The proponents further skirt around the issue of the many additional contaminants in the Rotenone cocktail, including benzyl alcohol, propylene glycol, solvent naphtha, naphthalene and other unnamed ingredients. Unlike Rotenone, some of these compounds do not biodegrade over time and will progressively accumulate with repeated applications. The claim by the proponent that some or all of these compounds are “organic” is misleading and disingenuous.
As stated above, the application of these contaminants is in violation of the Classification Regulation. The proponent does not report the likely environmental impacts of the one-time or repeated application of these contaminants. Since eradication is not 100 per cent effective under any scenario of Rotenone application, the evidence presented indicates that repeated application will be required before many zooplankton and benthic macro-invertebrates have had a chance to recover. Given that projections of lake recovery can range beyond three years, according to McGann and Strecker (2022), adoption of the Rotenone option will in all likelihood result in the long-term ecological impairment or death of Miramichi Lake.
Given that EIA 1549 was a flawed process from the beginning, and given the illegality of the contaminant application to a Class AL lake, and given the scientific results to date, the evidence suggests that the application of Rotenone to Miramichi Lake should be rejected in favour of more targeted non-chemical approaches to invasive species control.
Lawrence Wuest is an ecologist living in the Upper Nashwaak on unceded territory of the Wəlastəkwiyik, Mi’kmaq, and Peskotomuhkati.
