Studying the Lake George food web

Though sensors were out over the winter collecting data around Lake George, the Jefferson Project (named for the third president’s famous quote on the lake) is really kicking into high gear. Believe it or not, they’re already halfway through the three year project. We have an update on what they’ll be doing this summer in Tuesday’s paper.

One of the most visible of the four sensors collecting data that you’ll probably notice around the lake are the vertical profilers. There are two of them anchored in the lake. They look like yellow floating buoys, sort of like little pontoon boats, equipped with solar panels around the lake.

They contain a weather station and winch inside that continuously lowers and raises a large blue cylindrical device with sensor prongs to measure pH levels, algae, dissolved oxygen, temperature and other characteristics at every depth of the lake.

They were out last fall before the freeze, but this year they’re equipped with more sophisticated technology.

“They have solar-powered controlled computers inside. They also can remotely talk to them trough wireless communication and can adjust what they do and what depths of water they’re (measuring). They have some ability to think on their own and we also communicate with them remotely. We don’t have to go out there to adjust something, often we can do that from a laptop or through wireless,” said Project Director Rick Relyea.

“We can actually send signals to it and tell it what to do. We can do that now remotely, but the idea is that the platform will do this by itself. We will add more analytical code to do different things” said IBM Research Distinguished Engineer Harry Kolar, associate director of the project.

Another interesting aspect of this project is the interdisciplinary nature of it. I met scientists with varied backgrounds from computer science to biology working on this. Kolar said IBM Research has people working on this in various labs, including in Ireland and Brazil.

Relyea said the vertical profilers were built to be “robust” and natural conditions shouldn’t harm them. He said they also have “confidence that people in the area will be looking out for them and letting us know if there is anything that needs to be looked after.”

Food web

I didn’t have room to get into it for this story, but Relyea also said a large part of work this summer will be monitoring the food web from algae, and tiny zooplankton to fish.

Here is Relyea, an aquatic ecologist, on the food web:

“One of the things that drives the whole lake food web is how much algae you produce. Everything depends on that. Things eat the algae, things like zooplankton eat algae and and other animals like fish eat zooplankton so algae are the key.

Most lakes are limited in how much algae they can grow by how much phosphorous comes into the lake. The more phosphorous the more fertile it becomes and the more algae you can grow. At some point, if you have too much algae, because you have too much phosphorous, you have problems. The water clarity declines and you have what we call algal blooms. In some cases in some lakes around the world those blooms can be species of algae that are toxic. Drinking water can be shut down like it was Toledo. Those are real problems if the lake was to become overfertilized with phosphorous. Lake George is not close to that point yet. As far as we know, it’s a low fertility lake, but every lake has concerns about more phosphorous coming in because it will make more algae and the water will be less transparent.”

He said it’s not necessarily just measuring the amount of algae, but the kind.

“If you have a bit more algae, you can have more things eating the algae, and that can provide more food for the fish, but it’s just never, ever that simple. Sometimes a little more algae can be good and even more algae might be harmful. What we need to know is what kind of algae we’re talking about,” he said. “Just saying there is more algae is really only part of the story.

Understanding the food web in a 32-mile lake is a massive undertaking.

“This is our first step in understanding the food web of Lake George from the algae to the big fish. We have lots and lots of species we need to look at,” he said, including where the invasive species such as Asian clams or zebra mussels factor in. “We need to figure out where things live and where they’re abundant.”

“Perhaps the more important thing is to understand what they do. What are the consequences of having them here? That is really an experimental question we can ask. What role do the different invasive species play in Lake George? Do they have negative effects? Do they have positive effects? Or are they neutral in their effect?” he said.


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