Phosphorus as Estuary Topic: Unlikely, Rewarding

Posted on Friday, September 29th, 2017 | Posted in iWR,News

Phosphorus was the draw for 120 estuary researchers, administrators, and students usually concerned with nitrogen’s impact on the environment.

Conference speakers

Presenter Paul Stacey fields a question at the Estuary Research Workshop. Also in the photo, left to right: Chris Kincaid, Zhanfei Liu.

The participants in NEIWPCC’s second estuary research workshop came to hear Hans Paerl from the University of North Carolina, Robert Howarth of Cornell University, and other leading nutrient and coastal researchers.

The daylong conference was held at the Coastal Institute at the University of Rhode Island, in Narragansett. The Institute cosponsored the event.

Participants filled Corless Auditorium to hear about how, where, and under what conditions phosphorus pollution threatens estuaries.

Phosphorus is the critical nutrient pollutant in most freshwater ecosystems. However, in marine and estuarine environments researchers usually attribute to nitrogen the chief role in feeding algae and plankton blooms.

Nonetheless, conference participants were eager to explore the role that phosphorus, from runoff and other sources, plays in ecosystems where fresh and salt water mix.

Phosphorus Also Matters

The critical nutrient of concern is called limiting, because the level of that nutrient limits the growth of algae and plankton.

Paerl told the gathering that in some estuaries where nitrogen is limiting, phosphorus is nevertheless linked to greater biomass of blooms. He cited evidence that reductions of both nutrients are needed to control blooms.

Howarth told participants to pay attention to inputs of nitrogen and phosphorus from coastal oceans to estuaries. “These ocean inputs are a key factor in making estuaries different from lakes,” he noted in the abstract for his presentation.

James Ammerman, the science coordinator for the Long Island Sound Study, noted that under some conditions parts of the Baltic Sea, the Chesapeake Bay, and some other environments are phosphorus limited.

Zhanfei Liu, of the University of Texas, described research suggesting that phosphorus plays a role in the decomposition of organic matter in estuaries and bays. Decomposition depletes dissolved oxygen.

“Pick something to measure, and measure it regularly.” Veronica Berounsky, another conference presenter, recalled getting that guidance from the late Scott Nixon.

Berounsky’s work measuring nitrogen and phosphorus in the Pettaquamscutt estuary in Rhode Island spans 25 years. Other presenters remembered Nixon, who died in 2012, as a mentor and pioneer in estuary research.

Presentation materials, and exhibits from the poster session, are online on NEIWPCC’s website.

poster session

Kevin Rosa, a URI graduate student, presents his work during the poster session at the Estuary Research Workshop.

Further Information