Rust tide caused by Cochlodinium in the Peconic Estuary, 2012 (photo courtesy of Bill Portlock)
SOUTHAMPTON, NY, August 19, 2013 – Southampton, NY, August 19th 2013 – A ‘rust tide’ has emerged across several eastern Long Island estuaries including the Peconic and Shinnecock Bay. Monitoring by The Gobler Laboratory of Stony Brook University’s School of Marine and Atmospheric Sciences has recorded the rust tide algae at densities exceeding 10,000 cells per milliliter in the western extreme of the Peconic Estuary.
Densities exceeding 1,000 cells per milliliter were present in Shinnecock Bay as well as Flanders Bay and its tributaries such as Meetinghouse Creek. Densities above 500 cells per milliliter can be lethal to marine life. The rust tide alga, Cochlodinium, has been notorious on Long Island since it first appeared in 2004 having been responsible for the deaths of both finfish and shellfish. This marks the tenth consecutive year these destructive blooms have occurred in Shinnecock Bay and the Peconic Estuary. While rust tides have also occurred in Great South Bay as recently as 2011, the presence of a new ocean inlet in eastern Great South Bay that formed during Hurricane Sandy may be assisting in keeping the blooms away in 2013.
Rust tide caused by Cochlodinium in the Peconic Estuary, 2010 (photo courtesy of Newsday)
Professor Gobler indicated that his lab is beginning to understand why these blooms have become annual events.
“In the last year, we have published two important, new discoveries that help explain the chronic recurrence of these events,” said Gobler. “First, we have discovered the organism makes cysts or seeds which wait at the bottom of the bay and emerge each summer to start a new bloom. At the end of the bloom, they turn back into cysts and settle back to the bay bottom. This allows for the blooms to return every year. Second, we have found that nitrogen loading makes these blooms more intense and more toxic. As nitrogen loading has increased into our bays, these events have intensified.”
Experiments conducted in the Gobler Lab have demonstrated that this alga can kill fish in hours and shellfish in days. Last fall, bay scallop densities in the Peconic Estuary declined tenfold in some regions during the rust tide, causing great disappointment among baymen and lovers of this delicacy. The impacts of this year’s bloom will likely depend on its duration.
“The rust tide is expected to spread in the coming days and weeks and typically extends into the fall or until water temperatures drop below 60 degrees,” said Gobler.