Is That a Sea Serpent?

If you spotted a long, slimy, snake-like creature in the water you just might think you'd seen a sea serpent. It's more likely an American eel and you'd be lucky to see one because they're now an endangered species in Ontario. Their numbers have dropped by more than 90% over the last 40 years.

Have you ever heard the expression "slippery as an eel"? Eels are slippery: their bodies are covered with slimy mucus.

A Long Distance Swimmer!

In Canada, the American eel can be found in the St. Lawrence River, the Great Lakes and their tributaries. Mature females migrate a long way to spawn in an area of the Atlantic Ocean called the Sargasso Sea.

The Sargasso Sea is covered with huge mats of floating seaweed called sargassum. Eels come from all over the world to spawn in its warm, calm waters.

After laying millions of eggs, the female dies. When the young eels hatch they drift northward with the current. Eventually they start swimming northward. They keep swimming all the way up the east coast of North America to mature in freshwater. The trip can take years.

Strange but True

American eels don't become definitely male or female until they're 20 to 25 cm. (8 – 10 in) long. Their gender is in part determined by conditions such as crowding and food abundance.­­­ Almost all of the eels in the St. Lawrence system are female.

Photo: Erik Charlton

Threats to Eel Survival Many people think that eels are absolutely delicious, which is one of the reasons for their decline. In 2004 fishing for eels was banned in Ontario.

Can you believe it? Eel fritters!

Research shows that young eels have trouble getting past hydro electric dams as they swim up the St. Lawrence River towards their freshwater habitat.

Can a Fish Climb a Ladder? To help young eels climb over hydro dams, some power stations have constructed special "ladders". An eel ladder was built at The Moses-Saunders Power Station in Cornwall Ontario in the 1970's. Recent improvements have made it even more effective. Eels can now climb over the dam in approximately 2 hours. (The trip used to take 24 hours!) A built in counter can monitor the number of eels successfully crossing the dam.		Display of eel ladder design at the Moses- Saunders Power Station.

Another problem facing eels is that as they migrate downriver towards the Sargasso Sea, about 40% of the female adults are sucked into the turbines of power stations. To prevent eels getting caught in the turbines, Ontario Power Generation is experimenting with catching and transporting them downriver in trucks past all the dams.

Project Coordinator, Jane McCann, displays damaged eel below Chaudière Dam.

In the summer of 2009 a small field crew, sponsored by the Lanark Stewardship Council, surveyed the tail waters of selected dams along the Ottawa and Mississippi Rivers for eel remains. The study will provide more information about the timing of migration and mortality rates.

Spinning Eels? Eels' teeth are too small to tear off a chunk from a fish carcass. Instead, they break off a bite by clamping on to it and spinning their bodies at 6 to 14 spins per second! Olympic skaters can "only" spin 5 times per second!

Photo: Bill Ballantyne

The King of Fish

This fish is a very unusual, primitive looking fish. It is torpedo shaped and instead of scales it has bony plates that look like armour. Its skeleton is made of cartilage instead of bones. Hanging under its snout are four barbels which are whisker-like projections that it uses to feel the lake bottom where it likes to hunt for small fish, crayfish, and molluscs.

Photo: U.S. Environmental Protection Agency

In addition to being considered the King of Fish the sturgeon is considered a delicacy in fine restaurants. Its eggs are served as caviar and smoked sturgeon is considered a gourmet treat. Unfortunately, the eggs (roe) can't be harvested without killing the fish.

Like the American eel, the migration of sturgeons is upset by power dams. Power dams have also destroyed many rapids - the eel's favourite spawning grounds.

Sturgeon has been historically found all over Ontario and used to be abundant in the Great Lakes and their tributaries. In August 2009 the sturgeon was classified as "threatened" in most of Ontario.

For more information about species at risk in Ontario, please visit the Ministry of Natural Resources website.