Rainbow Smelt Lake Utopia large-bodied population
Scientific Name: Osmerus mordax
Taxonomy Group: Fishes
COSEWIC Range: New Brunswick
COSEWIC Assessment Date and Status Change: November 2018
COSEWIC Status: Endangered
COSEWIC Status Criteria: B1ab(iii)+2ab(iii)
COSEWIC Reason for Designation: This population of smelt is the larger of a divergent species-pair endemic to a lake in southwestern New Brunswick. Its persistence is dependent on the ecological conditions that gave rise to the divergence of the species-pair from a single ancestor. Changing predator and prey environment through recent and potential invasive species, and hybridization with the smaller member of this species-pair threaten the long-term viability of the species-pair.
COSEWIC History of Status Designation: Designated Threatened in November 2008. Status re-examined and designated Endangered in November 2018.
SARA Status: Schedule 1, Endangered
Date of Listing (yyyy-mm-dd): 2019-08-08
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.
Named for the lake in southwestern New Brunswick in which they live, the large-bodied population of Lake Utopia rainbow smelt (Osmerus mordax) are freshwater fish that belong to the smelt family (Osmeridae). Lake Utopia is also home to a small-bodied population of rainbow smelt. The large- and small-bodied populations exist together as a species pair. These populations have different physical features, use different spawning streams, spawn at slightly different times and are genetically different. They are recognized as a rare example of 2 populations of the same species that live together, but have evolved differently (sympatric). Although the large- and small-bodied populations are genetically different, some hybridization (breeding between populations) is known to occur. The large-bodied population has the following features: slender, streamlined, slightly laterally compressed body (flattened from side to side); elongated head and pointed snout; back is pale green to dark blue; sides are silver with blue, purple and pink iridescence (a shimmer of glittering and changeable colours); belly is silvery white; tail fin is deeply forked; small adipose fin (soft fleshy fin found on the back and located between dorsal fin and tail fin); typically greater than 170 mm fork length (the length of a fish measured from the tip of the snout to the end of the middle tail fin rays); and prior to spawning, males develop tubercles (small, rounded bumps) on the head, body and fins. The large-bodied population’s features differ from those of the small-bodied population in the following ways. The large-bodied population has: a longer body length at maturity (small-bodied length is typically less than 170 mm fork length and large-bodied length is greater or equal to 170 mm fork length); relatively smaller eyes; a relatively larger upper jaw; and fewer gill rakers (internal projections off the gill arch, involved in filter feeding).
Distribution and Population
The large-bodied population of Lake Utopia rainbow smelt occurs in a single lake in the Magaguadavic River system in southwestern New Brunswick, Lake Utopia and 3 of its streams: Mill Lake Stream, Trout Lake Stream, and Spear Brook. The main tributary stream that the large-bodied population uses for spawning, Mill Lake Stream, is located on the northeastern side of the lake. Other potential spawning streams include Trout Lake Stream and Spear Brook, also located on the northeastern side of the lake. Mill Lake Stream averages 4 m wide and less than 1 m deep. Smelt passage to Mill Lake is prevented by a dam. Trout Lake Stream averages 10 m wide and has slow-moving water and deep pools. Spear Brook is about 4 m wide with a low gradient and an extensively braided outlet into Trout Lake as a result of beaver damming activities.
Lake Utopia is a 14 km² cold-water and oligotrophic (low nutrient) lake that is typically frozen from early December until early April. Little is known about how the various life stages of large-bodied smelt use habitats within Lake Utopia. In other lakes, resident rainbow smelt populations tend to occupy cooler, deeper waters of the lake, except during the spring spawning season when adult spawners migrate to spawning streams.
In Lake Utopia, large-bodied smelt spawn between late March and mid-April. Spawning lasts for 5 to 10 days. During the spawning season, they begin to move into the streams around dusk and continue to migrate upstream throughout the night. Peak migration typically occurs after midnight. Most smelt move back into the lake just before dawn; however, some males may remain. Smelt eggs are sticky and cling to silt and gravel, rocks and underwater vegetation, which aids in preventing them from being swept away by the water current. At the completion of the spawning season, fish migrate back into deeper areas of the lake. Eggs develop in the streams for 20 to 26 days depending on water temperature. After hatching, the tiny fish (fry) drift downstream into Lake Utopia. During their early development, the large-bodied population feeds mainly on zooplankton and later feed on small fish. The generation time for both large- and small-bodied smelt is approximately 3 years and their lifespan is approximately 6 years. Predators of Lake Utopia rainbow smelt include landlocked Atlantic salmon, brook trout and aquatic invasive species, like chain pickerel and smallmouth bass.
Threats to the large-bodied population of Lake Utopia rainbow smelt resulting from human activities fall under 4 main categories: direct mortality, changing water levels, loss of quality habitat and poor water quality. All of these threats have the potential to negatively impact Lake Utopia rainbow smelt production by directly impacting individuals, impacting their lake or spawning stream habitat or limiting access to their spawning streams. Given their limited spawning habitat, they are particularly vulnerable to activities that impact, or limit access to, their spawning streams. Threats of greatest concern are predation by aquatic invasive species, water level fluctuations in Lake Utopia impeding access to their spawning streams, flooding of the spawning streams and forestry and other land-altering activities near spawning habitat (e.g., road construction). Other threats of concern include effluent (liquid waste) discharge or other nutrient and chemical inputs and all-terrain vehicles and foot traffic impacting the spawning streams.
The Rainbow Smelt, Lake Utopia large-bodied population, is protected under the federal Species at Risk Act (SARA). More information about SARA, including how it protects individual species, is available in the Species at Risk Act: A Guide.
The large-bodied population of Lake Utopia rainbow smelt was listed as threatened under the federal Species at Risk Act (SARA) on August 16, 2019. The small-bodied population was listed as threatened under SARA on June 6, 2003 and both populations are also protected under the Fisheries Act. The large- and small-bodied populations of Lake Utopia rainbow smelt were assessed by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) as threatened in 2008. Both populations were re-assessed by COSEWIC in 2018 as endangered. A status change from threatened to endangered is currently being considered under SARA.
Provincial and Territorial Protection
Recovery Progress and Activities
The recreational dip-net fishery for both populations of Lake Utopia rainbow smelt was closed in 2011 and recreational angling for Lake Utopia rainbow smelt was closed in 2013. Given the co-dependence of the large- and small-bodied populations, a recovery strategy has been developed for both populations with a broad recovery goal of maintaining the existing distribution and abundance of both populations and the genetic diversity of this Lake Utopia rainbow smelt sympatric species pair. An action plan is being developed to support implementation of the recovery strategy. There is a proposed version of the action plan posted on the Species at Risk Public Registry. Now that the large-bodied Lake Utopia rainbow smelt has been listed under SARA, the recovery strategy and the action plan will be amended to be compliant under the Species at Risk Act for the large-bodied population. Various recovery actions including research, monitoring and outreach have been undertaken to date by DFO, Indigenous groups, academic partners, provincial departments, and industry partners. For example, new information has been generated about population abundance, spawning and rearing habitat use, the genetic structure of the large- and small-bodied populations, and invasive species interactions. Also, signs have been posted near the spawning streams to raise awareness about the Lake Utopia rainbow smelt and its habitat.
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.
14 record(s) found.
- COSEWIC Status Reports (2 record(s) found.)
- Response Statements (2 record(s) found.)
- Orders (2 record(s) found.)
- COSEWIC Annual Reports (2 record(s) found.)
- Permits and Related Agreements (5 record(s) found.)
- Consultation Documents (1 record(s) found.)
COSEWIC Status Reports
COSEWIC Annual Reports
COSEWIC Annual Report - 2009 (2009-08-28)2009 Annual Report to the The Minister of the Environment and the Canadian Endangered Species Conservation Council (CESCC) from the Committee on the Status of Endangered Wildlife in Canada.
COSEWIC Annual Report 2018 to 2019 (2019-10-09)Over the past year COSEWIC assessed a total of 56 wildlife species, 2 of which were assigned a status of not at risk. Of these 56, COSEWIC re-examined the status of 25 wildlife species; of these, the majority (80%) were reassessed at the same or lower level of risk. To date and with the submission of this report, COSEWIC’s assessments now include 799 wildlife species in various risk categories including 356 endangered, 189 threatened, 232 special concern, and 22 extirpated (that is, no longer found in the wild in Canada). In addition, 18 wildlife species have been assessed as extinct, 59 wildlife species have been designated as data deficient, and 199 have been assessed as not at risk.