Prototype quillwort (Isoetes prototypus) COSEWIC assessment and status report: chapter 11
Technical Summary
Isoetes prototypus
Prototype Quillwort – Isoète prototype
Range of Occurrence in Canada:
Nova Scotia, New Brunswick
Extent and Area Information
Extent of occurrence (EO) (km²)
< 5000 km² (at this time there is no evidence to suggest that the range is continuous over the geographic area where the plants have been found).
General estimate of total area encompassed within polygons including extant localities and excluding major areas of non-suitable habitat (total area of lakes where the species occurs is only 959.4 ha)
Specify trend in EO
unknown, but suspect it may be stable
Are there extreme fluctuations in EO?
unknown
Area of occupancy (AO) (km²)
0.25 km². Combined area covered by I. prototypus populations
Specify trend in AO
unknown
Are there extreme fluctuations in AO?
unknown but likely fluctuates based on extensive drifts of uprooted plants noted in some years at some sites
Number of known or inferred current locations
12 in Canada, 1 in USA
Specify trend in #
unknown; still extant at the 4 lakes where it was collected about 50 years ago or more, 4 new sites found in 2003, 2 additional new sites found in 2004
Are there extreme fluctuations in number of locations?
unknown
Specify trend in area, extent or quality of habitat
possibly stable but cottage development and recreational activities have likely increased over the last 50 years and may have had some impact on habitat quality on some lakes
Population Information
Generation time (average age of parents in the population)
unknown
Number of mature individuals
perennial: >250,000 in Canada; 9,000 in USA
Total population trend:
unknown
% decline over the last/next 10 years or 3 generations.
Are there extreme fluctuations in number of mature individuals?
fluctuations of a potentially large magnitude may have occurred at some sites
Is the total population severely fragmented?
Yes. (The 12 Canadian populations are dispersed within 6-7 areas and none of the lakes in these areas where the species occurs are joined through intermediary connections.)
Specify trend in number of populations
unknown; likely stable
Are there extreme fluctuations in number of populations?
unknown
List Canadian populations with (estimated) number of mature individuals in each:
- Site 1 NS: 13,061
- Site 2 NS: 120+
- Site 3 NS: 202+
- Site 4 NS: 10,400+
- Site 5 NS: 20+
- Site 6 NS: 1,000+
- Site 7 NS: 100+
- Site 8 NS: 40
- Site 9 NS: 100+
- Site 10 NB: 32,210+
- Site 11 NB: 1,000+
- Site 12 NB: 192,600+
- Total: very conservative estimate >250,853
Threats (actual or imminent threats to populations or habitats)
The following threats are primarily potential in nature or of uncertain impact
- lake border encroached upon by roadways and causeways
- habitat modifications through cottage and shoreline development
- changes in water levels by damming or draining
- plants potentially damaged or uprooted by swimming, boating, fishing, the use of anchors, the installation of water intake pipes, or the activities of wildlife, road construction
- water pollution, eutrophication, siltation, changes in pH
- competition by invasive and/or exotic aquatic plant species
Actual impacts observed:
- Major uprooting likely due to natural disruption of the lake bottoms as evidenced by extensive drift lines along lakeshores
- Localized raking of swimming areas to remove plants
Rescue Effect (immigration from an outside source)
Status of outside population(s)?
USA: 1 population in Maine (site 13 which is discussed within this report)
Is immigration known or possible?
not likely – potential spread by waterfowl, mammals, botanists, boaters, fishermen
Would immigrants be adapted to survive in Canada?
likely
Is there sufficient habitat for immigrants in Canada?
likely
Is rescue from outside populations likely?
No, since all but one of the occurrences are in Canada, and the USA locality is considerably disjunct.
Quantitative Analysis (Table 4 from COSEWIC Assessment Process and Criteria)
unknown % probability of extirpation
Current Status
COSEWIC: Special Concern
Status and Reasons for Designation
Status: Special Concern
Alpha-numeric code: N/A
Reasons for Designation: A regional endemic with almost all of its global population in Canada. The species is an aquatic perennial with very specific habitat requirements limiting its occurrence in Canada to about 12 small, unconnected lakes in Nova Scotia and New Brunswick. The species is found in nutrient-poor, cold, spring-fed lakes. Although several sites have been shown to contain large numbers of plants, one half of the documented sites contain small populations. A wide range of potential limiting factors could impact the species, including changes in water quality, boating and shoreline development.
Applicability of Criteria
- Criterion A (Declining Total Population): No data available for decline.
- Criterion B (Small Distribution, and Decline or Fluctuation): Not met.
- Criterion C (Small Total Population Size and Decline): Not met
- Criterion D (Very Small Population or Restricted Distribution): Not met.
- Criterion E (Quantitative Analysis): Not applicable.
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