06-JUL-2010

Lake Sampling Starts with Lake Siso, Global Lake Sampling (GLS)

Chris and Carles in Lake Siso

May 8th 2010

Early on Saturday May 8th Chris and I headed to the University of Girona, which is located about 69 kilometers (42 miles) from Blanes, to setup our sampling gear in a aboratory on campus. We were a bit exhausted from the long drive the day before and lack of sleep due to lots of German teenage tourist running up and down the hall all night long!

Route from Blanes to Lake Banyoles
Route from Blanes to Lake Banyoles
Filter setup in lab
Filter setup in lab

After the gear was setup we drove to our first site, Lake Siso or Ciso depending on who you ask. Lake Siso is a small (very small) holomictic lake with a maximum depth of 6.5 meters (21 feet). Long term extensive limnological and microbiological studies of the lake have shown seasonal characteristics, including an anoxic winter mixing which leads to an almost exclusively prokaryotic population. One of the key driving forces of the lake is the level of dissolved sulfate in the water which is converted to sulfide by the microbes in the lake.

Lake Siso
Lake Siso

Chris and Carles rowed a small inflatable dinghy to the deepest part of the lake and took a profile of the water column. From the profile two sample sites were chosen and water was pumped ashore into 50 liter carboys.

Lake Siso water profile
Lake Siso water profile

Two samples were collected, one above the anoxic zone (1.75 m) and one in the anoxic zone (4.5m).

Water on left is from above anoxic zone, while water on right is from the anoxic zone
Water on left is from above anoxic zone, while water on right is from the anoxic zone

We loaded up the carboys and drove back to the laboratory at the University of Girona, where we processed the samples.

clogged 3.0um filter from anoxic zone
clogged 3.0um filter from anoxic zone
Sample team from left to right: Frederic, Chris, Carles, Emilio, Maria and Marc
Sample team from left to right: Frederic, Chris, Carles, Emilio, Maria and Marc