FerryMon keeps water, sea life safe

UNC professor Hans Paerl has helped ecosystems around the world through FerryMon, a successful model for water monitoring systems.

But he’s having to work extra hard to protect the Pamlico Sound.

In 2006, after Tropical Storm Ernesto plowed through eastern North Carolina, fishermen reported massive fish kills in the Neuse Estuary. Typically, when millions of fish turn up dead, it’s not an easy mystery to solve. But Hans Paerl and colleagues were prepared for their investigation long before Ernesto had even formed in the Atlantic.

Paerl, a William R. Kenan Professor of Marine Sciences, had installed special equipment on three ferries to monitor water quality in the Pamlico System, including the Neuse Estuary. The project, which he called FerryMon (short for Ferry Monitoring System), received funding from the N.C. General Assembly after 1999’s Hurricane Floyd.

From early 2000 through June 2011, three ferries carrying passengers across the Pamlico Sound also carried water-sampling instruments below deck. Paerl provided public access to his findings and helped the state manage the water quality of this large system.

Over the past decade FerryMon has become the model for monitoring systems across the nation, including on the Delaware Bay, Long Island Sound, Puget Sound and Nantucket Sound.

The instruments could alert Paerl when something fishy was happening to water composition.

After Ernesto, Paerl discovered high levels of chlorophyll in the sound. More chlorophyll meant more algae. And Paerl knew that too much algae could wreak havoc in sensitive ecosystems.

Sure enough, Pearl and colleagues found Karlodinium veneficum, an algae species that produces a deadly chemical called karlotoxin. If there’s enough karlotoxin in the water, fish would die en masse.

Murder solved. It was Ernesto with the karlotoxin in the Neuse.

But how exactly did Ernesto produce so much toxic algae and – fast forward five years – what happened after Hurricane Irene tore through the Pamlico Sound last summer?

That’s where the plot thickens. Paerl has some of the answers, but Irene, so far, has gotten off scot-free.

Read more from the Gazette article by Mark Derewicz, from the Division of Research.

Published April 9, 2012.