Nooksack Dace

Rhinichthys cataractae ssp.

SARA Status
No Status
NS
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

SARA Status

  • No Status NS
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX
COSEWIC Status
Not at Risk
NR
Special Concern
SC
Threatened
TH
Endangered
EN
Extirpated
EX

COSEWIC Status

  • Not at Risk NR
  • Special Concern SC
  • Threatened TH
  • Endangered EN
  • Extirpated EX

Description

The Nooksack Dace is a small freshwater minnow that grows to less than 15 centimeters long. The species is one of several closely related dace that are found in the Pacific Northwest. It is part of the Chehalis fauna, a unique group of fish species that originated during the Pleistocene glaciation.

The Nooksack Dace has a rounded back, flat underside, and long snout that overhangs its mouth. The species is greyish-green and has a dull brassy stripe over its lateral line. Its colouring gradually changes to silvery-white from below the lateral line to the belly. Sometimes Nooksack Dace have a black stripe in front of their eyes. The species has distinct pale marks near its dorsal fin that are visible when viewed from above. Young Nooksack Dace have a black lateral stripe and dark spot at the base of the tail. This species is difficult to distinguish from the Longnose Dace (Rhinichthys cataractae), a closely related species.

Habitat

The Nooksack Dace is only found in Washington State and four creeks in the Fraser Valley in British Columbia, Canada. The four Canadian populations of Nooksack Dace are found in: Bertrand Creek, Fishtrap Creek, Pepin Brook, and the Brunette River. The species exists as one designatable unit in Canada. Declines in the species probably occurred over the past half-century.

Adult Nooksack Dace are riffle specialists. This means they prefer shallow and moderately turbulent water. The species is typically found in fast-flowing streams with loose gravel, cobble, or boulder bottoms. Nooksack Dace spawn at the upstream end of riffles in coarse substrate and the young-of-the-year often stay in shallow, calm pools and glide downstream of riffles.

Threats

Nooksack Dace populations appear to be the most vulnerable to sediment deposition and seasonal lack of water. Physical destruction of habitat including channelization, dredging and infilling, and habitat fragmentation also threaten the species. All of these activities can directly destroy, degrade and fragment stream habitat. The Nooksack Dace is a riffle habitat specialist and its distribution is limited by riffle habitat quality and availability. Riffle habitats are often targeted for modification in drainage projects. Many such modifications occur every year to streams in the Fraser Valley.

The Nooksack Dace can also be negatively impacted by beaver ponds or human-made impoundments, deleterious substances and hypoxia caused by nutrient overload.

Further Information

The Nooksack Dace was listed under the Species at Risk Act as Endangered in 2003.  In 2008, the Recovery Strategy for Nooksack Dace (Rhinichthys cataractae) in Canada was posted to the Species at Risk Public Registry. This document outlined goals and objectives to protect and recover the species. After the Recovery Strategy was published, several projects aimed to recover the Nooksack Dace were initiated. This included monitoring, restoring and enhancing the species' critical habitat. The Habitat Stewardship Program funded several of these projects. For example, volunteer groups planted native plants in riparian zones. Public outreach lectures, presentations, and workshops have also been held.  An Action Plan for the species was published in 2017.

This species is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available on the Species at Risk Public Registry. Additionally, fisheries protection and pollution prevention provisions of the Fisheries Act provide protection to this species. Critical habitat of Nooksack Dace became legally protected in 2016 by a Species at Risk Act Critical Habitat Order.

To find out if this species is protected by provincial or territorial laws, consult the provinces' and territories' website.