Archive for November, 2011

A road less travelled

November 22, 2011

Note: Skidaway Institute volunteer Nancy Tennenbaum wrote this account of her recent trip to Lake George, NY with Skidaway Institute professor Marc Frischer.

Two roads diverged in a yellow wood,

And sorry I could not travel both

And be one traveler, l stood

And looked down one as far as I could

To where it bent in the undergrowth;

Seasons descend.  New friends are made.  Life as I know it

becomes a new path not well previously traveled.

Rensselaer Institute, home to the Darrin Fresh Water Institute (DFWI), rests peacefully on a wooded hill top overlooking, the cold, sparkling waters of Lake George.  Fall has worked its secret magic here on the aging leaves dwelling in a silent woods. 

Intense yellows and reds paint the landscape.

A nature concert, a continual sound of bubbling water, rushes past.  Footsteps to the main lodge on an inclined leaf scattered path measure time well spent.

I breathe in slowly so poetry of the moment can seep in by osmosis. The importance of why I have traveled here is

clear and uncluttered. This is the road less taken.  

I am just its fortunate visitor.

Sandra Nierzwicki-Bauer, the director of DFWI, is an individual pulled in a thousand different directions.  She is in fact the embodiment of this institution. 

Who she is can be summed up by the motto, I will not take no for an answer.  And of course she would be naked without her three adorable pugs who follow her around as if she were their super hero.

Paradise is at her doorstep, yet there is with not enough time in the day to enjoy it.

A shadow hangs ominously over her life. Her treasured friend, Sharon, who is battling cancer, has consumed the existence of Sandra. There are endless phone calls to her doctors and relatives. Sharon’s horses must now be watered and fed twice a day. The incomprehensible fact is that there is nothing fair about life.

Five undergraduate students are doing a semester here. As most 20 something’s, they are fun and crazy, filling the lodge with a fresh perspective on life.

Marc Frischer, is here to collaborate with Sandra on papers needing to be published.

Steve Resler and Dan Marelli are scientific SCUBA divers here studying Asian Clams that recently invaded the Lake and threaten its fragile ecology.

Yet, despite the time stress, Sandra carves out time for me every day as if nothing could be important than poring over the phytoplankton photos from an August 2009 mesocosm study that we are analyzing.

You might wonder what we have accomplished here and what we leave behind.

At the beginning of the week I spent the days gathering information on the phytoplankton of Lake George that SKIO did not have. The library was searched for reference books and manuscripts. The brains of many patient staff people here were cross-examined in an attempt to uncover additional reference material.

The most important source of expertise is Sharon who is receiving chemotherapy and was unavailable.

On Wednesday, I was drafted quite by surprise to participate in the DFWI Asian Clam eradication project. I found myself in a kayak on Lake George collecting water samples from SCUBA divers, Steve (aka Captain Seaweed) and Dan (aka Diver Dan).

The best part of the day was dinner when Marc was the chief cook.  As the lodge has an enormous industrial kitchen having several assistants was the norm.  Being a rather picky eater I am happy to say that everything Marc made was delicious. 

Saturday, as I sat in the library, writing this blog, I had to remind myself that were leaving that afternoon.  It is easy to fall in love with this place, therefore I leave reluctantly. 

Two roads diverged in a wood, and I

took the one less traveled by,

And that has made all the difference.

Skidaway Institute scientists study Intracoastal Waterway erosion

November 17, 2011

The banks of the Atlantic Intracoastal Waterway (AIWW), an artificial channel running through Georgia’s marshes behind the barrier islands, are steadily eroding, and there are several possible causes, including wakes from recreational boats. That is the conclusion of a year-long study by scientists at the Skidaway Institute of Oceanography.

 “Our goal was to quantify the impact that waves are having on the Georgia segment of the AIWW,” said Skidaway Institute professor Clark Alexander. “We also wanted to see if the salt marshes that line much of the waterway were expanding or retreating.”

Georgia contains more than one third of the salt marsh on the eastern coast of the United States and more than 90 percent of its AIWW shoreline is salt marsh. These marshes are essential habitat for fish and crustaceans because they play an important role in the life cycle of most local commercial and recreational species. The AIWW was designed to support both recreational and commercial vessel traffic.

“The major environmental impact of boats on the estuarine environment is the erosion of the channel margins from wakes,” said Alexander. “In Georgia, this diminishes the extent of the salt marsh habitat and causes the channels to widen – in some cases, at rates of up to half meter a year, which is pretty significant.”

Wakes undercut the marsh, causing to them to fail and collapse, particularly at low and mid-tides. Frequently, intertidal oyster bars are buried by eroded sediment, and oyster larvae are hindered from settling because shell material is not available upon which to settle.

Erosion is a natural process in salt marshes. However, in a natural setting, when one side of a tidal creek erodes, the other side usually accretes. Along the AIWW this was typically not the case. Alexander found extensive stretches where the shoreline was eroding on both sides of the channel.

Alexander and his team used historic and recent charts and aerial photography to track the erosion and accretion along the entire 91 mile length of the waterway between South Carolina to Florida. They also used a combination of high-definition video camera connected to a Global Positioning System (GPS) receiver to document both sides of the waterway along its length.

The research team examined shoreline change over two time periods, the first from 1933 to 1976 and the second from 1976 to 2004. The team limited their study to the eight relatively narrow main sections and six alternative sections of the waterway, avoiding the sounds where wind and storm waves might have a significant impact on shoreline change.

“Erosion has become increasingly significant and widespread in the 1976  -2002 time period,” Alexander said. “That isn’t to say that every section is eroding, but most of them are.”

Comparing the earlier time period to the later, the study found a strong trend towards more erosion in the more recent time period. Boat traffic and their wakes provide a mechanism for bank erosion.

“We don’t see commercial boating as being significant because the number of ships and tonnage in the AIWW has gone down by about 80 per cent in the past 18 years,” said Alexander. “But recreational boat registrations in coastal counties (currently about 29,000) have continued to increase.”

Alexander also has another explanation that cannot be ruled out with current information. Except for two short segments, the Corps of Engineers is no longer dredging the AIWW to maintain its target depth and sea level is rising at about 1 foot per century.  The channel could be widening because it is becoming shallower but must still transport and contain the same amount of water.  “Boating is most likely the immediate primary erosion force, but rearrangement of the channel cross section may contribute as well,” he said. “We just don’t know absolutely at this time.”

Marc Frischer talks about climate change on WSAV

November 14, 2011

Dr. Marc Frischer was on WSAV’s Coastal Sunrise program this morning to talk about his upcoming talk on climate change. If you missed it, you can see the replay here.