In August 2003, over one million fish were killed in Greenwich Bay. Rhode Islanders were shocked, but what was the cause? State scientists knew—life in the bay was being deprived of oxygen because of dangerously high nitrogen levels from land sources like stormwater run-off and wastewater treatment facilities.

Reducing these levels in Narragansett Bay has since been a priority for Rhode Island decision-makers.

Now, through grant funding from the Rhode Island Consortium for Coastal Ecology Assessment, Innovation and Modeling (RI C-AIM) and Rhode Island Sea Grant, researchers are establishing a sampling station at the Castle Hill Lighthouse in Newport to better understand the bay’s ‘nitrogen budget,’ explains Dr. Christopher Kincaid, professor of Oceanography at the University of Rhode Island’s Graduate School of Oceanography.

“We have for years been trying to understand the circulation of the bay and its impact on the surrounding ecosystem,” says C-AIM researcher Kincaid. “While the focus has been understanding nutrients coming from the land side of the Narragansett Bay system, and seeing if modifications to wastewater treatment facilities can improve the delicate balance between too little and too much nitrogen, we are now focused on what enters from the ocean.”

“It is the science equivalent of Paul Revere’s famous warning, ‘one if by land and two if by sea’.”

Nutrients such as nitrogen at low levels drive Narragansett Bay’s engine, serving as valuable food sources for species living in the bay. Oxygen arrives in the bay when marine plants decay. Events such as the 2003 fish kill, however, occur when organisms such as algae grow rapidly in nitrogen-rich waters and thus block sunlight, reducing those oxygen levels.  Large algal blooms can severely harm plant and animal life.

“Our hypothesis is that large water intrusions from offshore can carry nitrogen all the way to the growth areas of middle Narragansett Bay, and are becoming a bigger part of the bay’s nitrogen budget as watershed sources are reduced,” asserts Kincaid. “This pump station at Castle Hill Lighthouse will provide us with the first measurements of water flowing from the ocean into the bay, as well as the organisms and chemicals arriving with it.”

Data collected by Kincaid and others, thanks to previous funding from Sea Grant, suggest that the water intruding from Rhode Island Sound into the East Passage during the summer dwarfs that coming from rivers and WWTFs. Scientists cannot yet be sure, says Kincaid, if such water flows definitively impact the bay’s nitrogen budget.

“The pioneering work by the late URI professor Scott Nixon and colleagues showed that Rhode Island Sound has very high nitrogen levels in summer,” adds the C-AIM researcher. “But can these nutrients make it far into Narragansett Bay and exert a control over its biological productivity?  Stay tuned.”

Although Rhode Island researchers have been at the forefront for data collection related to coastal management, a new challenge has arisen in recent years: the cost of ocean-sensing equipment.

“The new generation computer models being developed for simulating and managing such resources requires data from multiple places and at very frequent time intervals,” explains Kincaid. “Instruments, however, are expensive and coastal waters can be hostile, leading to unacceptable data.”

The solution? Scientists will study water samples from the bay within the protected confines of the Castle Hill Lighthouse, which is owned and operated by the U.S. Coast Guard. Instruments can easily be calibrated and changed out to ensure high data quality, notes Kincaid, and will measure nutrient levels and salinity, among other water characteristics.

“We are trying to get a raw water sample that is undisturbed rather than pushed through a pump, whipping around at 1800 RPMs,” explains Stephen Granger, a marine research associate at the GSO. “We can thus house sample larva and plankton accurately without losing them in the process.”

Water samples taking the ‘pump station ride,’ says Kincaid, will also pass though cameras which capture various phytoplankton and zooplankton species.

“The pump station is the perfect mix of science and outreach,” says the professor of Oceanography with a smile. “We now will have the ability to remotely monitor when a massive water flow begins and then turn on our ‘data jukebox robot’ to begin capturing water samples, any time of the day or night.  Rhode Island classrooms will also be partners in this hunt for new knowledge, being able to monitor when these events begin and how they play out online.”

For RI C-AIM researcher Kevin Rosa, figuring out which nutrients are entering Narragansett Bay from Rhode Island Sound and beyond will help scientists understand changes in other aspects of the bay’s ecosystem, from fish migrations to wind patterns.

“One of the cool things about having the pump station is it can be permanent,” says Rosa, who is also a graduate student at the GSO. “We have all these different signals on top of each other in the bay, such as changes in a water treatment facility or climate signals from warming. Understanding nutrients like nitrogen coming into the bay from the ocean is a big piece which could be one of those dominant signals.”

If coastal scientists can collect better samples and generate more accurate data on the nutrients arriving in Narragansett Bay, modeling the various and complex ecosystems at work can become much easier.

“We have dynamic changes occurring in the bay and there are many pieces moving all at once,” says Granger. “If we can nail one down like offshore nutrients, we at least have something steady while measuring the other ones that are changing.”

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Funded by a $19 million grant from the National Science Foundation, RI C‑AIM is a collaboration of engineers, scientists, and students from eight higher education institutions across the state developing a new research infrastructure to assess, predict and respond to the effects of climate variability on coastal ecosystems. Working together with businesses and area communities, RI C-AIM seeks to position Rhode Island as a ‘center of excellence’ for researchers on Narragansett Bay and beyond.