White shark (Carcharodon carcharias) COSEWIC assessment and status report: chapter 11

Technical Summary - Atlantic Population

Carcharodon carcharias

White shark – Atlantic population: Grand requin blanc

Range of Occurrence in Canada:
Atlantic Ocean

Extent and Area Information

Extent of occurrence (EO) (km²)
Insufficient data for a calculation Unknown
Specify trend in EO:
Unknown
Are there extreme fluctuations in EO?
Unlikely
Area of occupancy (AO) (km²) [explain source of information and calculation]:
Unknown
Specify trend in AO:
Unknown
Are there extreme fluctuations in AO?
Unlikely, possibly seasonal
Number of known or inferred current locations:
Unknown (rare in Canadian waters, no records found north of Newfoundland)
Specify trend in #:
Unknown
Are there extreme fluctuations in number of locations?
Unlikely
Specify trend in area, extent or quality of habitat:
Unknown

Population Information

Generation time (average age of parents in the population):
23 yrs (est.)
Number of mature individuals:
Unknown
Total population trend:
Declining
 % decline over the last 14 years (~0.6 generations):
Unknown (Canada) 79% (North America)
1
Are there extreme fluctuations in number of mature individuals?
Unlikely
Is the total population severely fragmented?
Unknown
Specify trend in number of populations:
Unknown
Are there extreme fluctuations in number of populations?
Unlikely
List populations with number of mature individuals in each:
No data available

Threats (actual or imminent threats to populations or habitats)

Commercial fishery bycatch worldwide, but only 13 recorded gear interactions from Atlantic Canada in 130 years; market for jaws, teeth, and fins; sport angling (not in Canada); coastal habitat modification, pollution.

Rescue Effect (immigration from an outside source)

Status of outside population(s)?
USA: Unknown
Is immigration known or possible?
Possible
Would immigrants be adapted to survive in Canada?
Yes
Is there sufficient habitat for immigrants in Canada?
Yes
Is rescue from outside populations likely?
Possible

Quantitative Analysis

Not done

Current Status

  • COSEWIC: Endangered (April 2006);
  • CITES Appendix II (October 2004);
  • IUCN - Vulnerable

Status and Reasons for Designation

Status :  Endangered

Alpha-numeric code: A2b

Reasons for Designation: The species is globally distributed in sub-tropical and temperate waters, but absent from cold polar waters; hence Atlantic and Pacific populations in Canada are isolated from each other and are considered separate designatable units. This very large apex predator is rare in most parts of its range, but particularly so in Canadian waters, which represent the northern fringe of its distribution. There are only 32 records over 132 years for Atlantic Canada. No abundance trend information is available for Atlantic Canada. Numbers have been estimated to have declined by about 80% over 14 years (less than one generation) in areas of the Northwest Atlantic Ocean outside of Canadian waters. The species is highly mobile, and individuals in Atlantic Canada are likely seasonal migrants belonging to a widespread Northwest Atlantic population; hence the status of the Atlantic Canadian population is considered to be the same as that of the broader population. Additional considerations include the long generation time (~23 years) and low reproductive rates (estimated gestation is 14 months and average fecundity is 7 live-born young) of this species, which limit its ability to withstand losses from increases in mortality rates. Bycatch in the pelagic long line fishery is considered to be the primary cause of increased mortality.

Applicability of Criteria

Criterion A: (Declining Total Population): Meets Endangered, A2b (population declines > 50% over the past 3 generations, using an index of abundance appropriate for the taxon, where the reduction or its causes may not have ceased or may not be understood).

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 available. 

1 The abundance trend estimate for the Northwest Atlantic (Baum et al. 2003) has been disputed (Burgess et al. 2005); however, the Marine Fishes Species Specialist Subcommittee considered the Burgess et al. (2005) critique to have been convincingly rebutted by Baum et al. (2005)

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: