Although not a native species of Lake Superior, for decades local area anglers have flocked to streams and creeks in the area for the annual Rainbow Smelt run every Spring around this time. The smelts are triggered to enter streams and creeks to spawn by the rise in water temperatures due to the Spring melt, making it easy to net these small fish in large quantities.
Rainbow Smelt are considered an invasive species after being intentionally introduced back in 1912 to a lake which drains into Lake Michigan. After quickly spreading into Lake Michigan and beyond, the smelt’s range now includes Lake Michigan, Lake Erie, Lake Huron, Lake Ontario, and Lake Superior.
This year however, the Ministry of Environment, Conservation and Parks issued an advisory not to consume any Smelts caught south of Batchewana Bay to the St. Mary’s River headwaters (the Goulais Bay area) due to a toxin which has recently been detected in them called Toxaphene. The MECP’s Guide to Eating Ontario Fish for 2021 is advising that ZERO Rainbow Smelt caught in the Goulais Bay area be consumed, including traditional catch streams throughout Harmony and Havilland Bay.
Toxaphene is an extremely persistent insecticide in the aquatic environment and is a mixture of over 670 different chemicals, produced by reacting chlorine gas with camphene. It was removed from general use in Canada in 1974, restricted in the United States in 1982 and banned globally by the 2001 Stockholm Convention on Persistent Organic Pollutants.
Toxaphene was a widely used pesticide on cotton, other crops, and in livestock and poultry. It has been shown to cause adverse health effects in humans with the main sources of exposure through food, drinking water, breathing contaminated air, and direct contact with contaminated soil. Exposure to high levels of toxaphene can cause damage to the lungs, nervous system, liver, kidneys, and in extreme cases, may even cause death. It is also thought to be a potential carcinogen in humans, though this has not yet been proven.
Lake Superior, North America’s largest fresh water lake, is known for its cold water which tends to attract toxaphene which can be transported around the world in the atmosphere and hang around in an environment for potentially up to 14 years. Once in the water, it takes a while to break down where it accumulates in sediment and fish tissues.
With the current COVID-19 emergency break pulled by the province which restricts in-restaurant dining, hopefully local area eateries will do their part to keep this popular dish off their menus as well, if sourced from the Goulais Bay area. In the meantime, this advisory doesn’t help any fish, birds or other wildlife which may consume these tasty fish regardless of the season.