Species at risk

Species-at-risk

Various threespine stickleback populations in British Columbia are threatened or endangered. The limnetic-benthic species pair in Hadley Lake, Lasqueti Island, is now extinct. The limnetic-benthic species pair in Enos Lake, Vancouver Island, has collapsed to a hybrid swarm (photo of Enos benthic male above, courtesy of Ernie Cooper). Both extinctions were associated with invasive species. Remaining species pairs appear to be healthy but require protection and regular monitoring. A new species pair was discovered in 2007 in Little Quarry Lake, Nelson Island and is becoming listed at SARA.

Status under SARA

Enos Lake species pair: Endangered
Hadley Lake species pair: Extinct
Little Quarry Lake species pair: pending
Paxton Lake species pair: Endangered
Vananda Creek species pair: Endangered

The latest information on status can be found on the stickleback page at the SARA Registry

SARA documents

Population size estimates

Schluter, D., M. Roesti & T. Veen. 2017. Mark-recapture estimates of stickleback population sizes in Paxton and Priest Lakes in 2016. v5.1. Unpublished document.
Preprint | *Supplement
*Includes recalculation of 2005 population estimates in Paxton Lake by M. Nomura.

COSEWIC Assessments 2000 - 2023

Enos Lake Benthic Threespine Stickleback: Extinct

Enos Lake Limnetic Threespine Stickleback: Extinct

Hadley Lake Benthic Threespine Stickleback: Extinct

Hadley Lake Limnetic Threespine Stickleback: Extinct

Little Quarry Benthic Threespine Stickleback: Threatened

Little Quarry Limnetic Threespine Stickleback: Threatened

Paxton Lake Benthic Threespine Stickleback: Endangered

Paxton Lake Limnetic Threespine Stickleback: Endangered

Vananda Creek Benthic Threespine Stickleback (Spectacle, Priest and Emily Lakes): Endangered

Vananda Creek Limnetic Threespine Stickleback (Spectacle, Priest and Emily Lakes): Endangered

COSEWIC Threespine Stickleback species bundle: COSEWIC assessment and status report 2023

COSEWIC Reasons for status

Extracted from the 2023 COSEWIC report on the Threespine Stickleback species bundle.

Enos Lake species pair

The two species collapsed into a hybrid swarm resulting in the loss of the original two species. The revised status reflects the inability to find genetically non-hybridized individuals of this distinctive Canadian species despite repeated surveys. There is sufficient information to document that no individuals of the species remain

Hadley Lake species pair

This Canadian endemic fish was known only from Hadley Lake, Lasqueti Island, British Columbia. It was lost as a result of nest predation by the introduced brown bullhead.

Paxton Lake species pair

The species are unique Canadian endemics restricted to a single small lake in coastal British Columbia (BC). The main threat to these species is introduction of invasive species, which have caused the rapid extinction of similar species pairs in two other lakes in coastal BC, either through predation or hybridization resulting from habitat modification. Invasive species continue to spread in the region. Water extraction could also result in loss of habitat and increase the risk of hybridization. If these threats are not mitigated, they could lead to the extinction of this distinctive Canadian species.

Vananda Creek species pair

This pair of small freshwater fish are unique Canadian endemics restricted to three small, interconnected lakes in coastal British Columbia (BC). The main threat to these species is introduction of invasive species, which have caused the rapid extinction of similar species pairs in two other lakes in coastal BC, either through predation or hybridization resulting from habitat modification. Invasive species continue to spread in the region. Water extraction could also result in loss of habitat and increase the risk of hybridization. If these threats are not mitigated, they could lead to the extinction of this distinctive Canadian species.

Little Quarry Lake species pair

This pair of small freshwater fish are unique Canadian endemics restricted to one small lake in coastal British Columbia. The main threat to these species is introduction of invasive species, which have caused the rapid extinction of similar species pairs in two other lakes in coastal BC, either through predation or hybridization resulting from habitat modification. Invasive species continue to spread in the region. Water extraction could also result in loss of habitat and increase the risk of hybridization. If these threats are not mitigated, they could lead to the extinction of this distinctive Canadian species.