Toxic Metal Cadmium Can Enter Great Lakes Food Chain Through Algae

Apr 29, 2008

Some algae from the Great Lakes can use cadmium for nutritional requirements. A recent study published in the Journal of Great Lakes Research reports that algae collected from lakes Erie and Ontario can use cadmium, a known toxic metal, as a nutrient replacement for zinc, an essential trace metal.

"This observation makes pollution of our lakes even more of a concern since low levels of pollutants, such as cadmium, in vast offshore areas will be actively sought by microbes like algae and gain entry into the food chain where it can ultimately increase to toxic levels," states lead investigator Michael R. Twiss, a Clarkson University biology professor.

Despite visibly polluted coastal areas in the Great Lakes, offshore areas out of sight of the shore can have concentrations of trace metals during summer as low as expected in mid-ocean regions. This means that algae can have their growth limited by inadequate nutrition of essential metals. One such metal is zinc, an essential metal for algae and humans alike.

In this study, algae were collected from central regions of Lake Erie and in Lake Ontario from onboard both Canadian Coast Guard and U.S. Environmental Protection Agency ships during summer. Once the algae were purified in the laboratory, experiments were conducted under stringent controls needed to assess responses to low levels of these potentially toxic metals.

By carefully removing zinc from the growth media of the algae researchers were able to starve algae of zinc and the growth of these microbes slowed. By then offering low amounts of cadmium, a metal with similar chemical properties to zinc, the algae were able to resume their growth. A similar observation was made by providing the zinc-starved algae with cobalt, another trace metal that is chemically closely related to zinc.

Results of this study, "Nutritive Substitution of Zinc by Cadmium and Cobalt in Phytoplankton Isolated from the Lower Great Lakes," are reported by Asha Intwala, Tara D. Patey, Damien M. Polet and Michael R. Twiss in the latest issue (Volume 34, No. 1, pp. 1-11) of the Journal of Great Lakes Research, published by the International Association for Great Lakes Research (IAGLR), 2008.

Source: Clarkson University

Explore further: Magnitude-7.2 earthquake shakes Mexican capital

add to favorites email to friend print save as pdf

Related Stories

Phosphorus: Essential to life—Are we running out?

Apr 02, 2013

Phosphorus, the 11th most common element on earth, is fundamental to all living things. It is essential for the creation of DNA, cell membranes, and for bone and teeth formation in humans. It is vital for ...

Scientists Find Unusual Use of Metals in the Ocean

May 19, 2005

Cadmium, commonly considered a toxic metal and often used in combination with nickel in batteries, has been found to have a biological use as a nutrient in the ocean, the first known biological use of cadmium ...

Recommended for you

Magnitude-7.2 earthquake shakes Mexican capital

Apr 18, 2014

A powerful magnitude-7.2 earthquake shook central and southern Mexico on Friday, sending panicked people into the streets. Some walls cracked and fell, but there were no reports of major damage or casualties.

User comments : 0

More news stories

China says massive area of its soil polluted

A huge area of China's soil covering more than twice the size of Spain is estimated to be polluted, the government said Thursday, announcing findings of a survey previously kept secret.

UN weather agency warns of 'El Nino' this year

The UN weather agency Tuesday warned there was a good chance of an "El Nino" climate phenomenon in the Pacific Ocean this year, bringing droughts and heavy rainfall to the rest of the world.

Poll: Big Bang a big question for most Americans

Few Americans question that smoking causes cancer. But they have more skepticism than confidence in global warming, the age of the Earth and evolution and have the most trouble believing a Big Bang created the universe 13.8 ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.