Monday, December 19, 2011

Dr. Edith Widder: lady of light uses bioluminescence to find trace pollutants

In August of 2010, I wrote about bioluminescence and the amazing work of Dr. Edith Widder. Widder is the founder and chief scientist at ORCA (Ocean Research and Conservation Association). Her studies of the bio-illumination given off by marine animals has taken her and her equipment to the deeper depths of the ocean. It is in these regions, where sunlight does not penetrate, that animals use bioluminescence - organically-produced light - to hunt prey, camouflage from or deceive predators, and identify others of their own species.

Many of the pictures we have seen of examples of bioluminescence involve bizarre looking creatures from those cold deep depths, yet it is a feature more common than you might think. Indeed, as much as 90 percent of all creatures found in the open seas exhibit some degree of bioluminescence. Call it nature's night lights.

Dr. Widder's research has taken her into a new direction and one that can have a direct benefit on understanding the pervasive and subtle impact of pollution on oceans and waterways. In an excellent article in the New York Times, Erik Olsen writes about Dr. Widder's recent studies using bioluminescent bacteria and how it can be used to identify pollutants.

Olsen writes,
"Now, Dr. Widder has found a way to put bioluminescence to work to fight pollution in the Indian River Lagoon, a 156-mile estuary that scientists say is one of Florida’s most precious and threatened ecosystems.

Back in her laboratory here, she mixes the sediment samples with a bioluminescent bacterium called Vibrio fischeri. Using a photometer to measure the light given off by the bacteria, she can quickly determine the concentration of toxic chemicals in the sediment by seeing how much and how quickly the light dims as the chemicals kill the bacteria.

Measuring the level of pollutants in the sediment provides a better indication of the estuary’s health than measuring the level of chemicals in the water, Dr. Widder said. 'Pollution in water is transient,' she said, 'but in sediment it’s persistent.'

Her samples have revealed high concentrations of heavy metals and nutrients like phosphorus and nitrogen, which can cause runaway algae growth; those organisms consume oxygen and stifle life in the estuary. Dr. Widder has also designed sensors that are placed around the estuary and can beam real-time data like current and flow direction of the water. Pairing those data with the toxicity of the sediment, she can trace the source of pollution. The method is far cheaper and quicker than the more common practice of sending samples to a lab for analysis."

Click here to read the entire article. And here's a link to a great video about Dr. Widder's work. It's fascinating research from a true expert in the field. And with this new chapter in her body of work, Widder is bringing the a unique element of ocean science into the broader realm of conservation and ocean management.

As Widder, herself, says, “It’s my belief if we can make pollution visible, and let people know what small things they are doing are actually making an improvement in this incredible environment. I think it could make a huge difference. It can be a game-changer.”

Source: RTSeaBlog 08/06/2010
New York Times

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