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Invasive exotic species

Invasive exotic species, whether plants or animals, are a significant threat to biodiversity: they can cause a decline in indigenous species and irreversibly upset the natural balance that existed before their introduction.

Projects 2021-2026

Raising awareness of aquatic invasive species

While some aquatic invasive species have been accidentally introduced into the aquatic ecosystems of the St. Lawrence, others have been deliberately introduced and have had negative consequences. In this context, education and awareness are the best strategies to avoid new introductions and limit the spread.

The previous phase of this project brought together the awareness and information efforts of the provincial and federal departments and resulted in a concerted message to the public. The ultimate goal of this message is to bring about a change in the habits of the targeted clientele. However, assessing and quantifying these changes in habit is a major challenge. This project therefore aims to identify barriers, agree on ways to overcome them and promote the desired new behaviours. Good prevention practices are essential to safeguarding St. Lawrence ecosystems, especially in the context of climate change, which may promote the dispersal of aquatic invasive species.

Improve detection and monitoring of aquatic invasive species

This project is a continuation of the activities that led to the establishment of sampling and environmental DNA (eDNA) analysis protocolsExternal link for the detection of aquatic invasive species in the St. Lawrence. This first phase also allowed the development of genetic tools for the identification of priority animal species.

The 2021-2026 phase of SLAP will continue the integration of eDNA into existing detection activities. This project will test and develop simple detection methods for inclusion in a voluntary aquatic invasive species detection network open to partners. It will increase the detection capacity of these species in Quebec by encouraging the participation of ZIPs, watershed organizations, municipalities and associations, as well as the general public. It will also propose to test various technologies as part of a pilot project carried out in collaboration with a partner and to choose those technologies that can be integrated into the network. In short, the voluntary aquatic invasive species detection network will improve early detection and monitoring capacity, increase spatial and temporal coverage, and serve as a public awareness tool for this environmental issue.

Implement response plans to address aquatic invasive species

The introduction of aquatic invasive species threatens the biodiversity of the St. Lawrence. The risk of introduction of these species and its effects may be influenced by climate change. Early detection can lead to rapid intervention to control or even eradicate species in order to limit their spread. To coordinate this type of response, a response plan is a valuable decision-making tool. It allows us to evaluate whether an intervention is possible or desirable and to choose the best intervention strategy according to the situation, in addition to facilitating the implementation of the intervention.

This SLAP project will develop response plans for priority species that will be implemented when aquatic invasive species are detected in Quebec.

Projects 2016-2021

Raise public awareness about aquatic invasive species

Aquatic invasive species, such as the zebra mussel, common water reed and green crab, are a danger to Quebec biodiversity. They multiply faster than local species and compete with them for the same resources. Citizens need to be aware of these species, so they can help detect them early and limit their spread.

The goal of this project is to produce information sheets that communities, river users (fishers, recreational boaters, municipalities) and citizens can consult at any time.

Improve the detection and monitoring of aquatic invasive species

In the first phase of this project, our experts established new methods for sampling aquatic invasive species (AIS). The objective was to develop monitoring tools that would allow for the early detection of AIS when they are in the pre-colonization phase, i.e., in low numbers in a given aquatic ecosystem, or that would track the progress of a species already established.

Environmental DNA (eDNA) analysis is a method of detecting DNA of targeted species in a water sample. Without putting aside the so-called classical methods, notably sampling specimens by net, eDNA analysis allows the detection of a species even when it occurs in very low numbers. The DNA of a species can be found in water from a variety of sources, including body fluids (gametes, blood, mucus, etc.), organic waste, and even fragments of skin, scales, and decaying structures (leaves, stems, carcasses, etc.). 

In the second phase of the project, our experts aim to develop and improve methods for monitoring aquatic invasive species. In addition to designing ways to detect a larger number of AIS, some of which are on the verge of moving into Quebec, they are expanding the monitoring areas in the St. Lawrence and its tributaries, focusing on areas deemed to be of greater concern and increasing the annual sampling frequency. Improved sampling protocols are also being established.

Establish a response plan to address aquatic invasive species

Aquatic invasive species pose a risk to ecosystem health. When they are detected in a new sector of the St. Lawrence, rapid and effective action is required. Various measures adapted to the identified species can be implemented. It is possible to eliminate the individuals or limit their spread by capturing them or installing barriers to prevent their invasion. In all cases, the goal is to control the presence and spread of these species as best as possible.

The initial phase of this SLAP project led to the creation of a framework for the development of response plans to address aquatic invasive species. A response plan is a decision support tool. It is used to identify stakeholders and to support decisions based on the best information, costs and available resources. The second phase of the project aims to develop a first response plan for a priority species. These steps allow to guide the interventions in the field in an efficient way and to ensure effective communications between the concerned actors.

Study invasive alien fish species and their impact on freshwater mussels

The freshwater mussels that live in the St. Lawrence River have an unusual method of spreading their progeny: their larvae cling to fish gills and fins. Once metamorphosis takes place, the juvenile mussels drop off and continue their development. However, since the late 1990s, a new invasive fish species has made its way into the river: the round goby.

In the first phase of the SLAP, our specialists showed in the laboratory that freshwater mussel larvae, which are commonly found in the St. Lawrence River, fail to develop normally in the gills of this alien fish species, which releases them before their metamorphosis can be completed.

Scientists used genetic sequencing tools to identify freshwater mussel larvae attached to the gills of round gobies and other invasive fish species in the St. Lawrence. After analysis, not only the goby is a frequent host of freshwater mussel larvae but it is also a host for at least four freshwater mussel species, including two specialists. These results suggest that the reproduction and dispersion of certain species of specialist mussels in the St. Lawrence could be affected by the round goby, particularly in environments where this exotic species is very abundant.

Detect the spread and assess the impacts of alien parasites

In 2012, researchers discovered an exotic parasite in Lake St. Louis, Schyzocotyle acheilognathi. This intestinal worm was introduced to North America by Asian carp and can infect a wide range of fish families, including cyprinids. It causes fish to become thin and potentially die, especially when they are young. In the Great Lakes, this pathogen has been shown to be spread through parasitized baitfish sold live for sport fishing. In order to limit the spread of aquatic invasive species and disease-causing organisms, Quebec has recently imposed stricter regulations on the use of baitfish.

For this project, our experts are studying three important aspects related to this exotic parasite: the spread and establishment of the parasite in the river as well as its dispersal, the effectiveness of Quebec’s baitfish legislation and the health status of native fish affected by this parasite.

Analyses conducted to date confirm the establishment of S. acheilognathi in Lake St. Louis. Fish infected with this exotic cestode were also found further downstream in the Montreal area between 2013 and 2015, suggesting that it is spreading in the St. Lawrence. The infected fish are species that were often used as bait for sport fishing before the adoption of the new legislation. However, the frequency and intensity of infection remains low, suggesting little effect on the health of fish carrying the parasite to date.

Projects 2011-2016

Evaluate the effects of invasive exotic fish on freshwater mussels indigenous to the St. Lawrence

Several species of freshwater mussels in the St. Lawrence are at risk: six are on the list of species likely to be designated as threatened or vulnerable under Quebec legislation, and another is considered to be endangered by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). The purpose of this research project is to evaluate the hypothesis that the round goby would act as an “imposter” host for the larvae of certain species of indigenous mussels and would damage their recruitment and spread. The situation could also be the opposite: the goby could be a compatible host for mussel larvae, which would thus be favoured.

Read the backgrounder for this project.

Coordinate initiatives relating to aquatic invasive species and priority vectors of introduction

Fisheries and Oceans Canada has conducted risk assessments concerning the introduction of aquatic invasive species and of related vectors of introduction. The selection of species and vectors for these assessments has so far been based on consultations carried out by Fisheries and Oceans Canada and the National Aquatic Invasive Species Committee (NAISC). Incorporating stakeholders affected by this issue into the process will help to build further consensus and harmonize intervention priorities.

Read the backgrounder for this project.

Develop shared information and awareness tools about invasive exotic species

Although some invasive exotic species have been introduced into the St. Lawrence ecosystem inadvertently, others have been added voluntarily with similar undesirable effects. As a result, education is the most effective approach for limiting their spread. The pooling of various initiatives and information and awareness raising tools about invasive exotic species can help to harmonize approaches and the messages conveyed. This exercise will also assist in planning and developing new tools and documents that are more general in nature for wider distribution.

Read the backgrounder for this project.

Harmonize detection and monitoring programs and activities relating to aquatic invasive species and identify problems

A number of participants and collaborators in the St. Lawrence Action Plan 2011-2026 are carrying out activities to detect and monitor the spread of aquatic invasive species. The harmonization of these programs and activities will support the identification of any gaps in terms of geographic sectors, species or habitats and assist in the development of complementary programs and activities to address these gaps.

Read the backgrounder for this project.

Develop joint action and response plans in the event of detection of aquatic invasive species

In addition to their capacity to survive in a range of different habitats and climates, aquatic invasive species typically have few or no predators and are less vulnerable to disease. These two factors help them to spread quickly, thereby disrupting the equilibrium of their adopted environment, often irreversibly. In this context, response plans will be developed to set out priority actions and identify the organizations designated to respond in the event new aquatic invasive species are discovered. Simulation exercises will also be conducted to prepare stakeholders for taking effective, coordinated action to limit the spread of these species.

Read the backgrounder for this project.

Harmonize databases on aquatic invasive species

Several participants and collaborators have compiled databases on aquatic invasive species. Harmonizing the information held in these databases will make it easier to compile a general picture of the situation.

Read the backgrounder for this project.

Develop an aquatic invasive species component at the St. Lawrence Global Observatory

A number of participants and collaborators in the St. Lawrence Action Plan 2011-2026 have been producing and disseminating a broad variety of data and information concerning aquatic invasive species. Developing a component on these species at the St. Lawrence Global Observatory will help to increase access to this information both to the public and the organizations that produced it.

Read the backgrounder for this project.