Walking across NH lakes

As a first year master’s student at the Center for the Environment, I began this February, with my advisor, Dr. Lisa Doner, the field work for my master’s project. My project involves temperature and water quality monitoring with sediment analyses in two local lakes: Ossipee Lake (Ossipee, NH) and Squam Lake (Holderness, NH). Our goals for field work were to establish a mooring, with temperature monitors and sediment taps, and collect water samples in each lake. The temperature monitors are placed every meter on the rope, recording temperature every 15 minutes, so we will get a full profile of the thermal state of the lake and be able to observe stratification and turnover events. Since lakes in central New Hampshire develop a thick layer of ice, usually in January, it was easiest to set-up our mooring in the winter time because we could work from a flat, solid surface rather than on a rocking boat. So we waited until mid-February when the ice conditions were deemed safe enough to make a trek across the ice to the deepest point in each lake.

Our first field trip was to Squam Lake on a rather cold day right before a large snow storm moved in. The deep spot in Squam is not far off shore from the Rockywold Deephaven Camps (RDC) in Holderness. The people at RDC were very nice and allowed us to use their camp as an access point to our site. Since we didn’t have exact coordinates for the deepest point in the lake, we first had to explore the water depths in the area by drilling holes in the ice and sending down a measuring tape with an anchor attached. After five attempts we settled for a site that was approximately 90 feet deep. Rushing to beat the snow storm, Lisa, Rachelle (from the Center for Rural Partnerships), and myself took some measurements of temperature and dissolved oxygen and collected water samples before deploying our mooring.

Just a week later, we went back out, but this time to Ossipee Lake. The deepest point in Ossipee Lake is closer to the center of the lake, so we had to walk almost a mile each way with snowshoes in slushy snow to get there. Luckily this time, we had a lovely sunny day in the low forties. Working with the Green Mountain Conservation Group, we had coordinates for the deepest spot and were able to fairly quickly get our water samples and set-up our mooring. However, the walk to our site took over an hour each way.

We’ve been back to Squam twice since setting up our mooring to take a sediment core and more water samples, but the ice has not been safe on Ossipee to return. The ice on both lakes has begun to melt, but it will still be a few more weeks before the lakes are boat navigable. Once ice-out has occurred, I will be heading back to each lake to take more water samples and to take more sediment cores. Our goal is to take weekly water samples during the summer and monthly samples throughout the rest of the year. Ultimately, I hope to use our sampling and sediment analyses to understand both past and current relationships between climate conditions and water quality, comparing trends between both lakes.