Little Quarry Lake Limnetic Threespine Stickleback
Scientific Name: Gasterosteus aculeatus
Taxonomy Group: Fishes
COSEWIC Range: British Columbia
COSEWIC Assessment Date and Status Change: November 2015
COSEWIC Status: Threatened
COSEWIC Status Criteria: D2
COSEWIC Reason for Designation: This small, slender-bodied freshwater fish is a unique Canadian endemic that is restricted to one small lake in coastal British Columbia. The wildlife species is highly susceptible to extinction from aquatic invasive species that have been observed to cause rapid extinction of similar species in at least two other lakes. Many invasive aquatic species already occur in southwestern British Columbia, and any range expansion or introduction of new invasive species to Little Quarry Lake would likely lead to the extinction of this species.
COSEWIC History of Status Designation: Designated Threatened in November 2015.
SARA Status: No schedule, No Status
Date of Listing (yyyy-mm-dd):
Please note that this information is provided for general information purposes only. For the most up to date and accurate list of species listed under the Species at Risk Act, please see the Justice Laws Website.
Little Quarry Lake Benthic and Limnetic Threespine Sticklebacks are one of three extant species pairs of Threespine Stickleback that live in sympatry. In each pair, Benthics eat mainly benthic invertebrates in the littoral zone while Limnetics primarily feed on plankton in open water. Each has traits adapted to their feeding lifestyle; for example, Benthics have a greater overall body depth, shorter dorsal and anal fins, a smaller eye, and a shorter jaw that is more downward-oriented. Most Little Quarry Lake Benthics also lack a pelvic girdle. Molecular genetic evidence strongly supports the independent evolution of each pair in different lakes, despite their similar appearances. Thus, a stickleback species pair from one watershed is genetically and evolutionarily distinct from pairs in other watersheds. Little Quarry Lake Benthics and Limnetics are genetically distinct from one another, and hybridization between them occurs naturally in the wild at a low level. They have high scientific value and are only found in Canada. The Threespine Stickleback Benthic and Limnetic species pairs are among the most extensively studied examples of ecological speciation in nature, giving insight into the processes that give rise to Canada’s biodiversity. (Updated 2017/01/24)
Distribution and Population
The geographic distribution of Little Quarry Lake Benthic and Limnetic Threespine Sticklebacks is highly restricted; they are found in one lake, Little Quarry Lake, on Nelson Island, southwestern British Columbia. (Updated 2017/01/24)
In general, Benthic and Limnetic Threespine Sticklebacks habitat needs include vegetated littoral habitat and pelagic areas of lakes with gently sloping sediment (e.g., silt, sand, gravel) beaches for spawning. The species pairs do not appear to have a specific suite of abiotic factors or habitat structure that sets them apart from solitary Threespine Sticklebacks inhabiting other lakes. The habitat requirements for the Little Quarry Lake Benthic and Limnetic Threespine Stickleback species pair include features of the environment that prevent hybridization, such as littoral zone vegetation and adequate light penetration for nest building and mate selection, respectively. That is, Benthic and Limnetic species pairs require habitat features needed to maintain mate recognition and reproductive barriers between the two species, in addition to those needed to maintain a viable population of either species. (Updated 2017/01/24)
There has been almost no direct study of the biology of Little Quarry Lake Benthic and Limnetic Threespine Sticklebacks. They are assumed to be ecologically and behaviourally similar to the other Benthic-Limnetic species pairs that have been studied extensively. Their reproductive biology is assumed to be similar to that of other freshwater Threespine Stickleback, with some spatial and temporal segregation between Benthics and Limnetics: Benthics build their nests under cover of macrophytes or other structures while Limnetics tend to spawn in more open habitat; Benthics begin reproducing earlier in the year than Limnetics, although there is considerable overlap in spawning times. There is also strong assortative mating between them. Combined, these factors result in low levels of hybridization. A simple fish community appears to be a major ecological determinant of where Benthic and Limnetic Threespine Stickleback species pairs are found; relatively low to absent interspecific competition and predation is likely key to their diversification into species pairs and their persistence. (Updated 2017/01/24)
The relatively small littoral zone and small amounts of macrophyte coverage in Little Quarry Lake are likely limiting factors to Benthics and Limnetics. Productivity may also be a limiting factor in this lake. The primary threat to Little Quarry Lake Benthic and Limnetic Threespine Sticklebacks comes from the introduction of non-native species that could prey on them and/or disrupt the habitat requirements of the species pair. The imminence of this threat is uncertain, but the consequences would probably be disastrous. Little Quarry Lake’s relatively remote location likely offers some protection, although remoteness did not prevent the introduction of the exotic Brown Bullhead (and subsequent extinction of a Benthic-Limnetic species pair) in a lake of comparable accessibility, Hadley Lake. Habitat threats from water extraction by local oceanside residents for domestic use, and land-based development e.g., forest harvesting, appear to have been limited to date. Excessive scientific collecting activities also constitute a potential threat. (Updated 2017/01/24)
Provincial and Territorial Protection
PLEASE NOTE: Not all COSEWIC reports are currently available on the SARA Public Registry. Most of the reports not yet available are status reports for species assessed by COSEWIC prior to May 2002. Other COSEWIC reports not yet available may include those species assessed as Extinct, Data Deficient or Not at Risk. In the meantime, they are available on request from the COSEWIC Secretariat.
5 record(s) found.
- COSEWIC Status Reports (1 record(s) found.)
- Response Statements (1 record(s) found.)
- COSEWIC Annual Reports (1 record(s) found.)
- Permits and Related Agreements (1 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2015-2016 (2016-10-13)Over the past year COSEWIC re-examined the status of 25 wildlife species; of these, the majority (68%) were re-assessed at the same or lower level of risk. Of a total of 45 species assessed, seven were assigned a status of Not at Risk (two re-assessments and five new assessments). To date, and with the submission of this report, COSEWIC’s assessments now include 724 wildlife species in various risk categories, including 320 Endangered, 172 Threatened, 209 Special Concern, and 23 Extirpated (i.e., no longer found in the wild in Canada). In addition, 15 wildlife species have been assessed as Extinct, 54 wildlife species have been designated as Data Deficient, and 177 have been assessed and assigned Not at Risk status.