SAVE THE
SILVER
The Silver Lamprey
The Silver Lamprey is an eel-like fish with sucking disc mouth. They have no jaws or paired fins and generally grow to about 12 inches long. The silver lamprey is parasitic species that attach onto the flesh of other fish and feed on their blood. They are important to our ecosystems as they are both predator and prey to many species. They also act as ecosystem engineers and filter feeders.
Where is it found?
The silver lamprey is native to Canada, having been found primarily in the Great Lakes and tributaries, the St. Lawrence river, Lake Nipissing, Lake-of-the-Woods and tributaries, and the Ottawa River.
The silver lamprey requires different kinds of habitats due to for distinct stages of their Life cycle. Unrestricted migratory routes are necessary for them to spawn in rivers and live out their adult lives in lakes. They also require clear and clean water for juveniles and to detect suitable prey.
Image: ontariofishes.ca
Figure1. Distribution of the Silver Lamprey in Canada
Life Cycle
The silver lamprey migrates throughout its lifecycle. They start in rivers and streams as larvae, transitioning to lakes to live out their lives as adult parasites. These fish then migrate back to rivers and streams to spawn and die.
Image: Borowiec et al. 2021
FUN FACT
Silver lampreys belong to the most ancestral lineage of vertebrates. We can learn a lot from them because of this, such as insights into the evolution of jaws.
Ver·te·brate
An animal that contains a backbone
What threatens it?
HUMAN ACTIVITY
-
Dam implementation, used to control the flow of water in rivers and lakes, restricts movement of the silver lamprey between rivers and lakes. This limits their ability to find a fitting habitat throughout their life cycle
-
300+ dams are owned by the Ontario Ministry of Natural Resources and many of them may directly obstruct movement of the silver lamprey
-
-
Pollution can have detrimental impacts on water quality and fish abundance. This obstructs vision of the silver lamprey and reduces available food source
-
pollutants such as atrazine and sediments have substantial impacts on lamprey populations
-
INVASIVE SPECIES
The sea lamprey (Petromyzon marinus)
The sea lamprey is an invasive species to Canada, known to be native to ranges of the Atlantic coast of Europe. Sea lamprey's are believed to have invaded the Great Lakes at the beginning of the 20th century, adapting to a freshwater lifestyle.
-
Upon the mid twentieth century, the sea lamprey had a substantial impact on fisheries in Canada and the United States. To mitigate the effects, measures were developed to effectively target this species at different life stages, including use of chemicals to kill larvae and implementation of barriers to trap and demobilize adult lamprey (Ontario Ministry of Natural Resources and Forestry, 2018).
-
Unfortunately, species of lamprey are very difficult to distinguish. Larvae often appear uniform across species and adults are specifically identified through fins and arrangement of teeth. This leaves native species of lamprey vulnerable to mitigation efforts.
Image: Michigan Sea Grant
Image: https://wchstv.com/
From 1958-1986, lampricide treatments were introduced in the great lakes in an effort to control the invasive sea lamprey. Unfortunately, this mitigation it could not be specifically targeted toward the invasive sea lamprey. While the effort was successful, reducing the presence of lampreys by 80-99%, this reduction also included native populations.
The problem
-
Assessment of the silver lamprey as a species of "special concern" means it is not protected by the Species at Risk Act prohibitions
-
These prohibitions typically protect at-risk species from being captured, harmed, killed, traded and more
-
-
Instead, Fisheries and Oceans Canada is responsible for developing a management plan that keeps this species from reaching endangered status
-
Unfortunately, little effort has been put towards a management plan for this species, and little research accurately represents population dynamics and effects of threats on this species
-
Additionally, reports from the Government of Ontario in 2018 reveal that population sustainability and decline trends are of "insufficient information" for this species