The Mingan thistle aka the meadow thistle was discovered in 1924 by Brother Marie-Victorin in the Mingan Archipelago. According to the
Act Respecting Threatened or Vulnerable Species, the Mingan thistle is an endangered species in Quebec. In Canada, it can only be found in the Mingan Archipelago National Park Reserve and in a limited area on the southern edge of Alberta and British-Columbia.
The species has been monitored in the park reserve since 1995 and population projections confirm its precariousness. A re-establishment program was launched in 2001 to increase the number of plants in the most vulnerable colonies and public outreach efforts have been made to raise public awareness.
Protecting a species requires team effort. The collaboration of all park users is essential for the success of this project.
The Mingan thistle (Cirsium scariosum) aka meadow thistle is a rare plant from the Aster family (Asteracea).
It is hard to distinguish from other species until it flowers because for most of its lifespan, it is made up of basal leaves only. It grows generally from one summer to the next until basal leaves reach a diameter between 0.7 and 111 cm. Then, between the ages of 4 and 19 years old, the Mingan thistle flowers only once around mid-July and dies. At this stage, it has a stem (between 2.6 and 99.5 cm) ending with pale purple to pink capitulums.
Each “flower” is actually a capitulum made of many tiny flowers.
At maturity, the seeds are topped by aigrettes or feathery crowns and fall near the plant. Seeds are their only mean of spreading.
The most likely hypothesis to explain the Mingan thistle’s geographic distribution is that it could be a remnant of Western flora that established itself in the area following the last ice age.
In Quebec, the Mingan thistle is only found in the Mingan Archipelago National Park Reserve where it grows mainly along the coast of four of the islands of the park reserve. Elsewhere in Canada, the species can be found in a small area south of Alberta and British-Columbia; it can especially be found in Waterton Lakes National Park. The two distribution areas are 3,500 km apart.
In 1924, Brother Marie-Victorin identified the species for the first time: “The most spectacular discovery of our Anticosti-Minganie exploration is without a doubt that of the Mingan thistle.”
The Mingan thistle is an endangered species in Quebec (as defined by the Act Respecting Threathened or Vulnerable Species). The most recent demographic projections confirm the Mingan thistle’s precarious status in the Mingan Archipelago National Park Reserve. The species has been monitored there on annual basis since 1995.
The Mingan thistle is in danger because as little as 2 to 23 individual flower yearly, therefore limiting the arrival of new plants. In 2011, the census survey carried out in the Mingan Archipelago identified about 1,700 plants divided in 8 colonies; four of these colonies were too small to survive.
Moreover, many disturbances factors like stormy tides, drought, forest progression on the coast, little snow cover, grazing by hare, anthills and trampling are affecting the Mingan thistle.
In addition to being physically isolated from each other - because they are on four different islands - the eight colonies of the Mingan thistle are 3,500 km away from their "closest relatives" living in Western Canada!!!
It is important to protect the Mingan thistle because even if the total number of Mingan thistle has been rising over the years, the 2012 data showed that four out of eight colonies were considered too small to survive in the long term.
The Mingan thistle has the advantage of having preserved a distinct genetic make-up compared to those found in Western Canada. The latest were hybridized over the years with other species of thistles.
This native species has a cultural and historical value for the region and has interested many botanists.
Monitoring of populations
From 1995 to 2005, very precise monitoring was put in place to assess and predict demographic trends of the Mingan thistle in the Mingan Archipelago National Park Reserve. Important information on the biology of the species and population dynamics were collected then. In 2006, the Mingan thistle has been integrated to the rare plant monitoring of the park reserve under the Ecological Integrity Monitoring Program. Therefore, the individuals of each colony continue to be counted.
Thanks to ESRF, a re-establishment program was launched in 2001 to increase the number of plants in the most vulnerable colonies. After pollination, nets are set up around the flower to collect the seeds. The seeds are then counted and sown in their native colony. A total of 7,837 seeds were sown between 2001 and 2012 with a germination rate of 44%. Amongst the plants grown from these seeds, 147 were still present in 2012. Two of these plants flowered in 2008. The project is working well but the lack of flowering plants in some colonies has delayed attainment of the main objectives.
Steps have been taken to inform people and raise awareness about the Mingan thistle. Here are the most important steps taken to this day:
In the specific area known as La Minganie:
- Conference to the population
- Conference to the horticultural society Les Flores-Alliés de la Minganie
- Conference to students from grade 3 to grade 6
- Press releases to the community television station
- Information leaflet in the mail
- Summary of work published in the park newsletter
- Meeting with tourism stakeholders
- Involving local residents in field work
- Sowing seeds in an experimental garden and monitoring of rosette formation
For the general public:
- Producing an educational leaflet, a bookmark and a postal card
- Installing markers and panels around some colonies
- Establishing a colony at the marina with an interpretation panel
- Report on the television show « La semaine verte » (French only)
- Publishing various articles in magazines and newspapers
- Producing a poster
- Producing an educational traveling roll-up
These initiatives helped develop local residents’ interest and to obtain their collaboration.
It is important that re-establishment, conservation and awareness-raising efforts be pursued to protect this rare and threatened species. As rosettes are very difficult to spot, you can help protect the thistle by taking a few precautions:
- Walk on the coast and in area devoid of vegetation
- Avoid areas that are marked out
- Avoid searching out for colonies; to observe the thistle, go to the Havre-Saint-Pierre marina
Your cooperation is necessary for the survival of this unique resource!