-PROVFLUX ARTIST-
Oxygen Mapping in Narragansett Bay
by Emily Saarman
For centuries, Narragansett Bay has been an important part of the Rhode Island way of life, providing valuable fisheries, recreation opportunities, tourism, and a shipping port. Never-the-less, most Rhode Islanders know very little about the bay they love or how the surrounding urban environment impacts its health.
In recent years the urbanized environment surrounding Narragansett Bay has been taking an enormous toll on the health of the estuary. Huge regions of the bay are permanently closed to swimming and shellfish harvesting due to frequent discharges of inadequately treated sewage. While old timers remember when the waters of the bay were clear, today you can expect nothing more alluring during the summer months than murky green water with slimy rafts of algae floating on the surface. As if the murky water and stink of algae rotting on the beach were not enough, the excess of algae can cause massive fish kills. Last summer roughly 1 million small fish washed up dead on the west shore of the bay to rot. The stink was unbearable and many Rhode Island residents began to ask WHY?
The simple answer is nutrient pollution. Nutrient inputs to the bay cause excessive growth of mostly microscopic water plants (algae). When these plants die, as all things must, they fall to the bottom of the bay where they rot. The process of decay consumes oxygen dissolved in the water, the same oxygen that fish and shellfish “breathe” through their gills. If the oxygen is not replenished from the surface, the bottom water rapidly becomes so low in oxygen that it can suffocate even the most hardy inhabitants of the bay.
For the last 5 years, a number of scientists from both Rhode Island and Massachusetts have been volunteering their time to measure the oxygen levels in the bay during the summer months. From this data, I have used geographic information systems (GIS) software to generate maps of the oxygen in Narragansett Bay that are both informative and aesthetically pleasing. For the Provflux I will compile a number of these maps along with some information about the causes and effects of oxygen depletion in the most valuable and underappreciated urban environment in Rhode Island.
Emily Saarman was born in San Francisco, CA. She received
her Sc. B. in Aquatic Biology from Brown University in 2002. During her senior
year of college she began studying water quality and dissolved oxygen in Narragansett
Bay for her senior thesis. She currently lives in Providence, Rhode Island
and works at Brown as a research assistant for the Geological and Environmental
Science departments. Most of her work is focused on the environment and water
quality of Narragansett Bay.
