This week we welcome Cassandra Cummings to share her adventures in New York State in the gorgeous Adirondacks.
Some of the best hiking on the Canadian Shield can be found in the Adirondacks, NY, and I was lucky enough to do 3 summers of field work there. The Adirondacks are an old mountain range that makes up 20% of New York state, and contains more than 3,000 freshwater lakes. They were hit hard in the 80’s and 90’s by acid rain, and have remained an interesting study site ever since.
Since the Adirondacks are somewhat isolated, there is an absence of long-term monitoring data. This is where my field of study, paleolimnology, comes in handy. Paleolimnology uses the physical, chemical, and biological characteristics in lake sediment cores to infer their environmental histories. For my fieldwork, I collected sediment cores from 30 lakes throughout the Adirondacks. Collecting a sediment core is similar to putting a straw in a cup of water and putting your thumb on the top; when you pull it out, you take the water with you.
In my cores, I examined microscopic algal remains called diatoms. These algal remains are abundant and can survive in the sediments for millennia. They are also incredibly specious and can survive in a wide range of conditions. Their diversity is part of what makes them such a useful indicator species: by determining which species used to exist in a lake, you can infer what the conditions of the lake were like.
We may not have been after forest creatures, but they did manage to keep things interesting! We got to see loons attempting to fly (it takes an entire lake’s distance just for them to make it out of the water!), a snake catch a frog, and a just-out-of-sight bear. Twice, our hiking paths were flooded by beavers. The first time, we were hiking and came across a surprise pond. At first we thought it was our study site, but it was way too shallow. Then we assumed we lost the path and spent half an hour looking for it, before we saw the next marker across the pond. We tried to go around it, but decided the easiest way would be to cross it. We blew up our inflatable dingy, and two of us crossed the pond with half our stuff. We thought we were well on our way to defeating those rascally beavers, until I was dropped across the pond with the packs and my field mate turned back to pick up our third hiker. Turns out it’s hard to cross a pond with one person using one oar in an inflatable dinghy. It moves less in a straight line, and rotates more side to side. She eventually made it back, but it moved like a drunken bathtub in the meantime!
Fortunately, the second time beavers flooded the path we were warned in advance. We brought a canoe, and could all make it in one go!
Injuries on our field trips were kept to a minimum. But when we did have one, it was almost always mine! Our first day out the second summer, on a wide, flat path, I managed to twist my ankle and end up out of commission for a week. I also found out the hard way that I’m allergic to deer fly bites. Good thing I’m right handed…
When field work ended, we got back to the lab to begin the long, tedious process of diatom identification. After enumerating the diatoms at the top and bottom of the core, we were able to infer how some aspects of the lakes had changed from the 1850’s to present. Lakes are warming up faster than they used to each year, leading to changes in the way a lake stratifies (a warmer, less dense layer on top of a colder, denser layer below). Ice is melting earlier in the spring, and forming later in autumn. These changes caused corresponding changes in which diatom species were most successful in a lake, with diatoms that sink slowly becoming more abundant.
My project gave insight into the extent of ecological change in algal communities that could be attributed to a ‘climate’ effect. By understanding how climate change affects lakes, we can begin to understand and interpret changes from lakes that are recovering from multiple stressors.
Cassandra Cummings is a 2nd year masters student at UBC, doing a masters in Environmental Planning. In 2014, she completed her masters in biology at Queen’s University. She has hiked in the Muskokas, Rocky Mountains, and Central America, but the Adirondacks are still some of her favourite! She is passionate about the environment, enjoys being outdoors and loves to dance.