Paddlefish (Polyodon spathula) COSEWIC assessment and status report: chapter 11
Technical Summary
Polyodon spathula
Paddlefish – Spatulaire
Range of Occurrence in Canada:
Ontario
Extent and Area information
extent of occurrence (EO) (km²)
(Historic - Polygon Method) : >100,000 km²
Current : 0
specify trend (decline, stable, increasing, unknown) :
Unknown
are there extreme fluctuations in EO (> 1 order of magnitude)?
Unknown
area of occupancy (AO) (km²)
Historic : < 100,000 km²
Current : 0
specify trend (decline, stable, increasing, unknown) :
Not Applicable
are there extreme fluctuations in AO (> 1 order magnitude)?
Unknown
number of extant locations :
0
specify trend in # locations (decline, stable, increasing, unknown) :
Not Applicable
are there extreme fluctuations in # locations (>1 order of magnitude)?
Unknown
habitat trend: specify declining, stable, increasing or unknown trend in area, extent or quality of habitat :
Decline
Population information
generation time (average age of parents in the population) (indicate years, months, days, etc.)
- 16 for males
- 26 for females
number of mature individuals (capable of reproduction) in the Canadian population (or, specify a range of plausible values) :
0
total population trend: specify declining, stable, increasing or unknown trend in number of mature individuals :
Not Applicable
if decline, % decline over the last/next 10 years or 3 generations, whichever is greater (or specify if for shorter time period)
are there extreme fluctuations in number of mature individuals (> 1 order of magnitude)?
No
is the total population severely fragmented (most individuals found within small and relatively isolated (geographically or otherwise) populations between which there is little exchange, i.e., < 1 successful migrant / year)?
Yes
list each population and the number of mature individuals in each :
0
specify trend in number of populations (decline, stable, increasing, unknown) :
Not Applicable
are there extreme fluctuations in number of populations (>1 order of magnitude)?
No
Threats (actual or imminent threats to populations or habitats)
dams blocking access to spawning habitats, habitat degradation and overharvesting
Rescue Effect (immigration from an outside source)
Unlikely
does species exist elsewhere (in Canada or outside)?
Yes - US
status of the outside population(s)?
No longer found in the Great lakes basin, Extirpated from neighbouring states MI, PA, and NY, in decline in MN, IL, OH, and WI
is immigration known or possible?
Unlikely
would immigrants be adapted to survive here?
Unknown
is there sufficient habitat for immigrants here?
Unknown
Quantitative Analysis
Existing Status
- Nature Conservancy Ranks (NatureServe 2007)
- Global – G4
- National
- US – N4
- Canada – NX
- Regional
- US : AL (S3), AR (S2?), IL (S2S3), IN (S3), IO(S3), KS (S3), KY (S4), LA (S3), MI (SX), MN (S2), MO (S3), MS (S3), MT(S1S2), NE (S2), NY (SX), NC (SH), ND (SNR), OH (S2), OK(S1S2), PA (SX), SD (S4), TN (S3), TX (S3), VA (S1), WV (S1), WI (S2)
- Canada : ON – SX
- Wild Species 2005 (Canadian Endangered Species Council 2006)
- Canada – 1
- Ontario – 1
- Ontario – Extirpated (OMNR 2007)
- IUCN– VU (NatureServe 2007)
- CITES – Appendix II (NatureServe 2007)
- AFS – SC (NatureServe 2007)
- COSEWIC– Extirpated 1987, 2000, 2008
Status and Reasons for Designation
Status: Extirpated
Alpha-numeric code: Not Applicable
Reasons for Designation: This fish, once found in the Great Lakes, was apparently never common in the Canadian portion of its range. It has not been observed in Canadian waters since 1917 despite extensive sampling and the fact that such a distinctive fish would have been easily recognizable
Applicability of Criteria
- Criterion A (Declining Total Population): Not Applicable – no individuals seen since 1917.
- Criterion B (Small Distribution, and Decline or Fluctuation: Not applicable – no individuals seen since 1917.
- Criterion C (Small Total Population Size and Decline): Not applicable – no individuals seen since 1917.
- Criterion D (Very Small Population or Restricted Distribution): Not Applicable – no individuals seen since 1917.
- Criterion E (Quantitative Analysis): Not Applicable – no data.
Page details
- Date modified: