Where have all the lake eels gone? Queen's prof asks

December 14, 2007

A Queen’s University environmental scientist will head a new international study to determine whether American eels – the slimy, snake-like fish considered worldwide to be a food delicacy – are dying from chemical pollution in Lake Ontario.

Biology professor Peter Hodson and his team of toxicologists and chemists have received $536,450 from the Natural Sciences and Engineering Research Council (NSERC) to solve the mystery of Lake Ontario’s disappearing eel population.

Declared a “species of concern” under Canada’s new Species at Risk Act, American eels have until recently supported a multi-million-dollar historic fishery in Ontario and an even larger industry in Quebec. But with rapidly decreasing numbers of eels, the Ontario fishery has been closed and the Quebec fishery is in serious decline.

“A prime suspect in the case of the missing fish is the accumulation of toxic chemicals by the parent eels as they feed, grow, and mature in polluted freshwater lakes and streams,” says Dr. Hodson. “Our task will be to determine whether female eels transfer sufficient chemicals to their offspring to cause their death before reaching Lake Ontario.”

The team hopes to learn whether chemicals have played a role in the decline of the eel, whether some lakes and rivers are better than others for re-stocking with juvenile eels, which chemicals are the “bad actors” and whether eels pose a hazard to human consumers.

American eels begin their lives as eggs hatching in the Sargasso Sea near Bermuda. They take years to reach freshwater streams where they mature to a length of up to a metre before returning to their birth waters to spawn and die. However, since the mid 1980s there has been a spectacular drop in the numbers of juvenile eels migrating to Lake Ontario from the Sargasso Sea, and a corresponding decline in the numbers of adults.

“The loss of eels is significant from an economic, cultural, and ecological perspective,” says Dr. Hodson, adding that the impact on other fish species in Lake Ontario of removing a top predator has yet to be recognized.

Most of the harvest of American eels is exported to a global market, particularly to Western Europe and Asia where they are smoked, jellied, marinated, and even served raw as sushi. They are so highly prized that prices are rising as supplies dwindle.

The Queen’s-led research team will study eels from both clean and polluted habitats, as well as those stored frozen since the 1980s. They will compare the concentrations and toxicity of chemicals in the tissues of eel among different habitats and provide a perspective on past contamination.

Source: Queen's University

Explore further: Research ties megavolcanoes to pre-dinosaur mass extinction, says sudden climate shift could have analog today

Related Stories

Land-ocean connections

February 27, 2012

Scientists from the School of Ocean and Earth Science and Technology (SOEST) at the University of Hawaii – Manoa (UHM) and colleagues recently discovered that land-based plant material and coastal macroalgae indirectly ...

Scents latest weapons in fight against sea lamprey

January 2, 2011

(AP) -- In the never-ending battle to prevent blood-sucking sea lamprey from wiping out some of the most popular fish species in the Great Lakes, biologists are developing new weapons that exploit three certainties in the ...

Team to study eels' disappearance

January 1, 2008

An environmental scientist at Queen's University in Canada will lead a study of whether chemical pollution is killing American eels in Lake Ontario.

Study finds way to cut sea lamprey numbers

October 3, 2005

Minnesota scientists say they've found a way to reduce sea lamprey populations in the Great Lakes by attracting them to areas where they can be sterilized.

Recommended for you

New Horizons team selects potential Kuiper Belt flyby target

August 29, 2015

NASA has selected the potential next destination for the New Horizons mission to visit after its historic July 14 flyby of the Pluto system. The destination is a small Kuiper Belt object (KBO) known as 2014 MU69 that orbits ...

Seeing quantum motion

August 28, 2015

Consider the pendulum of a grandfather clock. If you forget to wind it, you will eventually find the pendulum at rest, unmoving. However, this simple observation is only valid at the level of classical physics—the laws ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.