Victorin's water-hemlock (Cicuta maculata) COSEWIC assessment and status report: chapter 11

Cicuta maculata var. victorinii
Victorin’s water-hemlock Cicutaire de Victorin
Range of Occurrence in Canada: Quebec

 

Extent and Area Information  

Extent of occurrence (EO)(km²)

(Based on GIS calculation of a polygon in which all points at outer limits of range are included)

~ 171 km²
·         Specify trend in EO Increasing due to more intense search effort
·         Are there extreme fluctuations in EO? No

·         Area of occupancy (AO) (km²)

(determined as an approximation of shoreline areas at the sites documented)

perhaps 2 km2
·         Specify trend in AO Unknown
·         Are there extreme fluctuations in AO? No
·         Number of known or inferred current locations 33
·         Specify trend in # Unknown (increased number known due to greater search effort)
·         Are there extreme fluctuations in number of locations? No
·         Specify trend in area, extent or quality of habitat Decline in habitat quality based on various impacts

 

Population Information  
  ·         Generation time (average age of parents in the population) Unknown (perennial, perhaps several years )
  ·         Number of mature individuals Estimated between about 1,800 and 6,300
  ·         Total population trend: Stable
  ·         % decline over the last/next 10 years or 3 generations. Not Applicable
  ·         Are there extreme fluctuations in number of mature individuals? No
  ·         Is the total population severely fragmented? No
  ·         Specify trend in number of populations Likely stable (increasing number known due to increased search effort)
  ·         Are there extreme fluctuations in number of populations? No

·        List populations with number of mature individuals in each:

Beaupré: 11-50

Berthier-sur-Mer, Anse de Berthier: 115-1060

Berthier-sur-Mer, Trou de Berthier: 2-10

Cap-Rouge, Anse du Cap-Rouge: 100-1000

Grondines: 11-50

Grosse-Île: 50-100

Île aux Grues, La Grande Rivière: 100-250

Île aux Grues, wharf: 11-50

Lévis, Pointe Martinière: 250

L'Islet, Rocher Panet: 200-500

L'Islet-sur-Mer, cove to the east of the wharf: 1

Neuville: 30-50

Pointe-aux-Trembles-Ouest, pointe à Alain: 2-10

Saint-Augustin-de-Desmaures: 15-60

Sainte-Anne-de-la-Pérade: 3-10

Sainte-Croix, Pointe au Platon: 3

Saint-Étienne-de-Beaumont, Anse de Vincennes: 11-50

Saint-François: 1

Saint-Jean, Pointe Dauphine: 155-310

Saint-Jean, Rivière Lafleur: 2-10

Saint-Jean-de-Boischatel: 1

Saint-Jean-Port-Joli, Anse de Trois-Saumons: 100-1000

Saint-Jean-Port-Joli: 30-120

Saint-Laurent, Village-des-Anglais: 2-10

Saint-Laurent-d'Orléans, Anse aux Frères: 200-500

Threats (actual or imminent threats to populations or habitats)

Actual threats:

- human trampling/ATV use

- mowing of grass beds

- ice scouring (questionably a threat since it is a natural occurrence; causes some changes in population sizes)

- water quality and level (likely of limited impact)

Potential threats

- suitable habitat becoming limited due to filling 

- Agricultural Abuses Act(control of widespread Cicuta maculata var.maculata with which var. victorinii can be confused)

- oil spills

 

Rescue Effect (immigration from an outside source) None
 

·         Status of outside population(s)?

USA: none; this is a Canadian endemic

  ·         Is immigration known or possible? Not Applicable
  ·         Would immigrants be adapted to survive in Canada? Not Applicable
  ·         Is there sufficient habitat for immigrants in Canada? Not Applicable
  ·         Is rescue from outside populations likely? Not Applicable
Quantitative Analysis Not Applicable

Other Status

COSEWIC: Special Concern (1987)

Quebec: Menacée

Status and Reasons for Designation
Status:  Special Concern

Alpha-numeric code:  Not applicable

 

Reasons for Designation:

A geographically highly restricted perennial that is endemic to the freshwater or slightly brackish shoreline areas of the St. Lawrence River estuary in Quebec. It is present at about 33 localities but in very small localized habitats where it is at risk from a wide range of impacts. These impacts include: actual destruction of plants due to ATV traffic and human trampling, and mowing of shoreline vegetation; losses of suitable potential shoreline habitat also occurs through shoreline in-filling and development and potential loss of plants may occur due to confusion with the common variant of the species that is considered a noxious weed. Oil spills may also pose a potential risk.

 

Applicability of Criteria

Criterion A (Declining Total Population): Not Applicable: No overall declines documented but a significant increase in number of localities (30 new sites) due to increased search effort.

Criterion B (Small Distribution, and Decline or Fluctuation): Not Applicable: Extent of occurrence and area of occupancy are small but the taxon is not fragmented, populations do not fluctuate and the taxon occurs at 33 sites.

Criterion C (Small Total Population Size and Decline): Not Applicable: Total population estimate is  <10,000 and possibly even less than 2500 but significant future decline of population size cannot reasonably be inferred in spite of various existing threats; some populations may contain >1000 plants; no population contains at least 95% of mature individuals and no extreme fluctuations are known.

Criterion D (Very Small Population or Restricted Distribution): Does not meet the criterion because this endemic variety consisting of about 33 extant populations with an AO of < 20 km2, likely will not become highly endangered over a very short period of time and new populations may still be found.

 

Criterion E (Quantitative Analysis): Not Applicable

 

 

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