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cRam Session is a VCU News feature that highlights the breadth of offerings in the VCU Bulletin course catalog and the wide-ranging expertise of the instructors. Professor Paul Bukaveckas, Ph.D., is a river ecologist in the Center for Environmental Studies and the Rice Rivers Center, which are part of VCU Life Sciences. He shares quick insights from his course Water.

Give us an insightful connection between past and present on this subject.

Humans have been collecting data from the water environment for a long time – not just decades, not just centuries, but thousands of years.

One of the first standardized measurements was developed by the Egyptians to gauge the peak flood height at locations along the Nile River. And this knowledge had more than practical value: Because flooding was considered at the whim of the gods, it was viewed as a referendum on whether they were pleased with the current state of society.

On a less spiritual level, this was crucial information for the Egyptians to manage food stores and anticipate tax revenue. That’s because flood height determined the amount of land inundated, which in turn determined the amount of land that could be cultivated and the size of the resulting harvest.

I teach how aquatic ecosystems work, and today, we measure many variables to assess their health – some by the traditional way of taking instruments out into the field, some by deploying automated sensors, and some that can be inferred from satellite images. My class focuses on huge volumes of data collected from streams, lakes, rivers, estuaries and oceans – and the computational skills to process and interpret it.

At VCU’s Rice Rivers Center, we have deployed a network of sensors in the James Estuary that record every 15 minutes throughout the day. Each year, we capture over a quarter-million data points.

How does an element of this subject intersect intriguingly with a different field?

When we consider major cities of the world – New York, Boston, Washington, London, Paris, etc. – what do they have in common? They are all built on rivers.

Rivers provide a source of fresh water to meet the needs of industry and domestic consumption. They provide an outlet for wastewater by taking away the large amount of pollutants we generate by congregating in cities. Rivers are also a means of navigation, bringing goods to and from a global market.

Right here in Virginia, the James is considered our nation’s founding river, as it was the site of the first permanent European settlement. The James continues to serve us as a source of drinking water, a means to take away wastewater, a route to transport goods and a place for recreation and relaxation.

In this way, waterways are intimately connected to the history of colonization and societal development. The challenge lies in managing these systems to preserve the vital services they provide to our society.

What is a significant development or trend related to your course’s subject?

The most obvious effect of climate change is rising air temperatures, but that causes rising water temperatures, too.

In lakes and rivers, water temperatures are rising faster than air temperatures, but rates are quite variable, even among lakes in the same region. It has been reported that lake surface temperatures are rising, whereas bottom temperatures are falling – the “hot tops, cold bottom” effect.

My recent work has shown that among Virginia reservoirs, bottom temperatures are rising faster than surface temperatures. This may be due to rising temperatures in river inflows. The effect is that the normal layering (stratification) of warm water at the surface and cold water at the bottom is being disrupted. Students in my class learn about the implications of this phenomenon for lake ecosystems.