BC Conservation Data Centre: Conservation Status Report
Catostomus sp. 4
Salish Sucker
| Scientific Name: | Catostomus sp. 4 |
|---|---|
| English Name: | Salish Sucker |
| Provincial Status Summary | |
| Status: | S2 |
| Date Status Assigned: | May 15, 2019 |
| Date Last Reviewed: | May 15, 2019 |
| Reasons: | Salish Sucker has a small, restricted range in the lower Fraser River Valley in southwest BC. This fish faces significant threats including severe hypoxia and habitat degradation. |
| Range | |
| Range Extent: | D = 1,000-5,000 square km |
| Range Extent Estimate (km2): | 1709 |
| Range Extent Comments: | The Salish Sucker is found in southwest BC from the lower Fraser River Valley (COSEWIC 2012m). |
| Area of Occupancy (km2): | E = 26-125 |
| Area of Occupancy Estimate (km2): | 65 |
| Area of Occupancy Comments: | Locations of Salish Sucker are in the lower Fraser and Nooksack drainages, including the Salmon River and other creek systems and their tributaries (COSEWIC 2002f). Since the 2002 COSEWIC report was published, four new populations have been discovered in Kent (Mountain Slough and Agassiz Slough) and in Chilliwack (Elk Creek/Hope Slough and Hopedale Slough). A population that was thought to be extirpated (Little Campbell River) was rediscovered in 2011 (COSEWIC 2012m). |
| Occurrences & Population | |
| Number of Occurrences: | B = 6 - 20 |
| Comments: | As of 2018, the BC Conservation Data Centre has 13 occurrences mapped, based on a 10km separation distance. |
| Number of Occurrences with Good Viability / Ecological Integrity: | Rank Factor not assessed |
| Number of Occurrences Appropriately Protected & Managed: | Rank Factor not assessed |
| Population Size: | F = 10,000 - 100,000 individuals |
| Comments: |
2018: Pearson (2004a in COSEWIC 2012m) reports the total number of mature individuals to be greater than 9,648 (note that populations at five of the 11 locations are unknown). 2010: Conservative estimates give 500 to a maximum of 5000 in various creeks, Peden (2002) estimates 7000 to 10000 total not including young of the year. |
| Threats (to population, occurrences, or area affected) | |
| Degree of Threat: | AB = Very high - high |
| Comments: |
2018: Very high - high: "Salish Sucker populations appear to be most vulnerable to acute hypoxia and to habitat loss. These conditions are common throughout the range and result primarily from overapplication of fertilizers and manure, drainage, channelization, dredging and infilling activities associated with agriculture and residential land development. Hypoxia is difficult to address in the current regulatory and policy context and is likely the single largest threat. Although it is poorly known, predation by introduced species is currently considered only a moderate threat, as these species appear to have coexisted with Salish Sucker for a decade in some parts of their range. However, the ubiquity of introduced predators and their documented impacts on other species justifies the ranking of this threat as moderate. Habitat fragmentation is currently a moderate threat to Salish Sucker, but its impacts are poorly understood. Sediment deposition and toxicity (in the form of contaminated sediments) appear to be major threats in some, but not all, watersheds" (Fisheries and Oceans Canada 2016c). 2010: Very high - high: Rapid urban expansion and agricultural pollution, riffle habitat is disappearing through ponding, siltation and dredging. Summer flows are decreasing with increases in drainage for agriculture and urbanization increases (Pearson 2000). |
| Trend (in population, range, area occupied, and/or condition of occurrences) | |
| Short-Term Trend: | F = Decline of 10-30% |
| Comments: |
2018. From COSEWIC (2012m): sufficient data is not available to quantify watershed trends or fluctuations. However, trends are known from Pepin Creek between 1999 and 2003. From 1999-2002, there were high densities of Salish Sucker in a main stem beaver pond, but in 2003 the habitat became nearly anoxic and appeared devoid of fish during the summer. Since then (2004, 2005 and 2011) the reach remains hypoxic and there are very few fish. A second reach in Pepin Creek (Gordon's Brook restoration site), has been monitored since 2002. Catch per unit effort increased from 2002-2004 but declined to near zero in 2007 with the onset of severe hypoxia. Since then, reed canary grass has been removed, and manure spreading in a field has stopped; oxygen and fish abundance has shown signs of rebound. (COSEWIC 2012m). 2010: Decline of 10-30%. Probably extirpated from one stream, declining in others. There has been zero or sporadic recruitment in many years (McPhail pers. comm. in Pearson 2000). |
| Long-Term Trend: | U = Unknown |
| Other Factors | |
| Intrinsic Vulnerability: | C=Not intrinsically vulnerable |
| Comments: | large numbers of eggs, protracted spawning period |
| Environmental Specificity: | B=Narrow. Specialist or community with key requirements common. |
| Comments: | They are most often found in slow currents over sand and silt substrate with in-stream vegetation and over-stream cover. Spawning occurs in riffle areas over fine gravel. Habitat characteristics summarized in Pearson (2000). |
| Other Rank Considerations: | |
| Information Gaps | |
| Research Needs: | |
| Inventory Needs: | More detailed knowledge is needed of spawning, rearing and over-wintering areas. |
| Stewardship | |
| Protection: | Creekside habitat needs to be secured. This includes riparian vegetation that provides the cover seemingly preferred by juveniles. |
| Management: | |
| Version | |
| Author: | Cannings, S.G. L.R. Ramsay and L. Gelling |
| Date: | June 21, 2018 |
| References | |
|
COSEWIC. 2012m. COSEWIC assessment and status report on the Salish Sucker Catostomus sp. cf. catostomus in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xi + 36 pp.
|
|
|
Fisheries and Oceans Canada. 2016c. Recovery Strategy for the Salish Sucker (Catostomus sp. cf. catostomus ssp.) in Canada. Species at Risk Act Recovery Strategy Series, Fisheries and Oceans Canada, Vancouver. ix + 64 pp.
|
|
|
Pearson, M. 2000. The Biology and Management of the Salish Sucker and Nooksack Dace. Pp. 619-624 in L.M. Darling, ed. 2000. Proc. Conf. on the Biology and Manage. Species and Habitats at Risk, Kamloops, B.C., 15-19 Feb., 1999. Vol. 2; B.C. Minist. Environ., Lands and Parks, Victoria, BC, and Univ. College of the Cariboo, Kamloops, BC. 520pp.
|
|
|
Pearson, M.P. 2004. The ecology, status and recovery prospects of Nooksack dace (Rhinichthys cataractae ssp.) and Salish sucker (Catostomus sp.) in Canada. PhD Thesis, Univ. of British Columbia, Vancouver. 236pp
|
|
|
Peden, A.E. 2002. COSEWIC status report for Salish Sucker CATOSTOMUS SP. Report prepared for the Committee on the Status of Endangered Wildlife in Canada. 44pp.
|
|
Please visit the website Conservation Status Ranks for information on how the CDC determines conservation status ranks. For global conservation status reports and ranks, please visit the NatureServe website http://www.natureserve.org/.
Suggested Citation:
B.C. Conservation Data Centre. 2018. Conservation Status Report: Catostomus sp. 4. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jan 24, 2025).