Her system’s ability to do real-time monitoring are singular
Edith Widder presented a handful of greenish muck that had been pulled from the shallows of the Indian River Lagoon and cupped it in her palm.
“See that?” she asked. “That’s a lot of decayed organic matter. It’s just a great holding area for pollutants.”
Collecting mud is a new calling for Dr. Widder, a marine biologist who is known around the world for her work in much larger bodies of water.
Over a career spanning almost 30 years, Dr. Widder has made hundreds of dives in deep-sea submersibles to study the remarkable number and diversity of animals that make light. This ability, called bioluminescence, is strikingly common, shared by as many as 90 percent of the creatures in the open ocean.
“Animals use light to help them survive, to help them find food, to attract mates and to defend against predators,” she said. For example, in the ocean — “where there are no trees or bushes to hide behind” — a bioluminescent creature can use light to attract larger predators to its own enemies.
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.
“The potential benefits of Edie’s efforts are huge,” said George Jones, executive director of Indian Riverkeeper, a local conservation organization.
Other organizations monitor the waters here, but Dr. Widder’s use of bioluminescent bacteria as a pollution marker and her system’s ability to do real-time monitoring are singular.
“One of the remarkable things about Edie is that, for a biologist, she is the most technologically savvy scientist I’ve ever come across,” said Bruce Robison, a senior scientist at the Monterey Bay Aquarium Research Institute in California.
Another homegrown project of Dr. Widder’s design is opening a new perspective on deep-sea life.
She long wondered what kind of animals lurked beyond the bubbles and lights of big and noisy manned submersibles. So she developed Eye-in-the-Sea, an ocean-floor camera that uses a type of red light that sea creatures cannot see.
She drew animals to the camera with a spinning dial of LED lights resembling the distress call of a species of bioluminescent jellyfish, Atolla wyvillei, that appears to use light as a kind of burglar alarm, luring predators to go after whatever is attacking it.
Less than a minute and a half after the jellyfish lights were activated in the Eye-in-the-Sea’s first test, in the Gulf of Mexico in June 2004, a six-foot squid lurched out of the darkness toward the camera. It was a species never seen before by scientists.
“I couldn’t have asked for a better proof of concept,” Dr. Widder said.
In December 2009, another Eye-in-the-Sea camera was placed in 3,000 feet of water in the Monterey Canyon, off the coast of California, where it remained for a year. The resulting videos, spanning about 5,300 hours, are being studied by researchers and graduate students at the Monterey Bay Aquarium, who have discovered numerous new behaviors of deep-sea animals.
In March, Dr. Widder plans to deploy her system in Bahamian waters to study the behavior of deep-sea sharks that she hopes will be attracted to the spinning LED lights of her fake jellyfish.
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