A Burbot Tale
BY JENNIFER L. JOHNSON, ALPENA FWCO – WATERFORD, MI SUBSTATION
caught near an artificial reef in the St. Clair River. Credit: Jennifer L Johnson,
Burbot (Lota lota) are a species of fish that are truly unique in North America. A member of the Lotidae family, Burbot are essentially a freshwater cod and are the only species of their kind. Distinguished by a single barbel on the chin, these winter spawners are typically associated with cold, deep water of lakes and large rivers. Not much is known regarding the population status of Burbot across their range, particularly in the Detroit and St. Clair rivers.
The Detroit and St. Clair rivers historically supported an abundant fishery; however like many river systems, these rivers have been greatly altered. The creation of navigation channels and other anthropogenic disturbances have resulted in the decline of native fish populations and loss of habitat. Like many other native fish species, pollution, invasive species, and habitat degradation may have contributed to declining numbers of Burbot. In order to restore these impairments, artificial reefs have been constructed in the Detroit and St. Clair rivers. While Burbot were not a target species when considering reef construction, they are a species which may be benefiting.
Burbot captured during fall gill net surveys
on the St. Clair River. Credit: USFWS
Each year the Alpena Fish and Wildlife Conservation Office (FWCO) - Waterford Substation conducts several surveys on the St. Clair-Detroit River System (SCDRS) using multiple gear types. Prior to the beginning of reef construction, no Burbot were recorded in any surveys. In 2015, all that changed. A total of five Burbot were caught in SCDRS that year. Three occurred in the St. Clair River while two were caught in the Detroit River. Even more Burbot were caught during the last field season with a total of eight in 2016. This time five were caught in the Detroit River and three in the St. Clair River. This means a total 13 Burbot have been caught in the last two years. Thirteen may not seem like a lot of fish, but when compared to zero in the previous 10 plus years, thirteen is a good number! Both the time of the year and gear type used in the survey does not seem to have an effect on whether or not Burbot were captured. Fish were caught in setlines, gill nets, and minnow traps in months ranging from April through December.
How does this relate to the artificial reefs? One of factors the Burbot catches had in common was the reefs. All of the Burbot captured in the Detroit River have been caught during surveys near the artificial reefs which have been constructed since 2008. Only two of the Burbot caught over the last two years in the St. Clair River were not caught on or near the reefs.
While it cannot be said conclusively that the artificial reefs in the SCDRS are benefiting Burbot populations, Alpena FWCO –Waterford Substation have documented Burbot utilizing this area. While various populations may be declining, the future for Burbot in the St. Clair – Detroit River System may be bright.