Monday, April 19, 2010

Mark Grismer (UC Davis) and Robert Collison (UC Davis) were unable to stay until the end of the expedition, so the watershed group has changed its focus a bit. With the addition of Marion Wittmann (UC Davis), this group has begun a near-shore survey. Marion, Eliska, and students are boating around the perimeter of the lake to sample invertebrates, algae, water, sediments, and plants. This is expected to take three days to complete.

Photo: plant samples from near shore survey are identified, labeled, and packed safely for transport (Marion at right)

The large boat continued sampling for water chemistry, phytoplankton, and invertebrates in different parts of the lake. The afternoon winds came very early today, which made sampling a challenge.

Annie Caires, University of Nevada, Reno

The past few days have been a bit surreal, as we went out on the boat at night to help with a nutrient addition experiment as well as primary productivity measurements. Many of the students and researchers here had been up for around 30 hours by yesterday afternoon. Despite that, everyone appeared to be in good spirits, and all of the lab work (filtering) was completed after naps around the 40th hour. Very impressive; some great data should be obtained! The night on the boat was something that I will probably never forget. Working at night allowed for mostly calm waters. The night sky was beautiful and the lights from the villages around the lake sparkled on the shore. When the boat captains awoke from their naps, the party got started around 3 or 4 am, as they cranked up the music on a huge speaker on the top of the boat. Just after 5 am, the sun came up; also a memorable moment. Laughter fueled us for the rest of the morning.

The morning before we went out on the boat, I attended a meeting with teachers from the area at a school in Solola. It was great to be able to see the school and to meet with local teachers. Nancy gave a great talk on Lake Atitlan and basic limnological concepts. Afterwards, we broke up into groups to talk with the teachers. Although each group was supposed to discuss a specific limnological concept, it seemed as if all of the groups tended towards one theme: what was going on with the lake and how to decrease lake contamination. I was impressed with the passion that many of the teachers seemed to feel for cleaning up the lake and their desire to pass this information along to their students.

Photo: Annie (at left) in small group discussion with teachers

Although I feel that changing people’s habits around the lake and trying to come up with sewage treatment methods is a daunting task here, I came away from the teacher’s meeting feeling positive and realizing that public awareness of lake contamination sources is certainly increasing.

There has been a great deal of work accomplished to this point; however, it seems we could spend another month here and still not accomplish everything we would like to. And only another 3 working days left! Venga, con prisa!

Clint Davis, University of Nevada Reno and Desert Research Institute

Spent the day catching up on rest after a marathon Friday night/Saturday AM sampling event. Previously I had spent Friday AM sampling on the beach near the Hotel San Buena Ventura, basically attempting a pilot experiment, so to speak, to attain metabolic rates of attached algae in the eulittoral area. Looked to be mostly Cladophora spp. (green filamentous), which appears to be quite common around the lake. Unfortunately I have not had time to work up/process the data collected from that experiment, as I joined the nighttime sampling in the middle of the lake. We had several objectives that included: 1) test newly-acquired rope/weight system that would immediately be deployed for the next 2 objectives; 2) primary productivity measurements at 13-15 depths spanning the epi-, meta-, and hypolimnion for the daylight period of Saturday; 3) nutrient bioassays to test for nutrient limitation (N, P, N+P, trace elements); 4) any additional plankton tows that we could fit in.

These assays required approximately 300 meters of rope to be deployed, which takes some finesse. We did not have buoys, so were using improvised hard plastic containers instead. Due to the high ‘traffic’ across the lake, it was decided to sink these a bit to avoid vandalism. Hydroacoustic tags were attached to both ropes to help with relocation at a later time. I would expect it is definitely a little dicey attempting to pull off an experiment like this in a large, deep lake. Overall, things went well. Spirits were high all around, despite slow progress. By mid-AM Saturday (2ish am), laughter filled the boat, as sleep-deprivation set in. Managed to fit in a birthday celebration for one of the students, Monika, amongst the many other tasks. I’d say my favorite moment was right at dawn. Everything seemed to quiet down for that transition period, and I took a moment to take in the surrounding landscape. . . volcanoes, twinkling city lights, and of course, the mirror-like waters of Lago Atitlan.