Siders Pond ancient DNA

Analysis of ancient DNA, that is, leftover DNA from long-dead organisms, is a new and exciting area of research. It can give key insights to the history of human, animal, or plant migrations, the diets of ancient organisms, changing microbial diversity, and more. The method is frought with difficulties, mostly related to procurring and analyzing samples free of contamination. Because DNA breaks down over time, the amount of aDNA is relatively small, especially relative to all the potential sources of DNA contamination (for example from your hands, airborn dust and microbes, microbes living next to your environmental sample, etc.)

This spring the Brown University-Marine Biological Laboratory IGERT class set out to analyze aDNA in a sediment core from lovely Siders Pond, Falmouth, MA. This is a pond I have sampled multiple times during my time working at MBL and for the Semester of Environmental Science. It is a meromictic pond, somewhat brackish at the surface and quite salty in the hypolimnion (it receives Atlantic Ocean water during high tides and storms). The pond is in downtown Falmouth and is thought to have undergone significant changes during the course of Falmouth’s growth. The IGERT class wanted to test this using aDNA. The plan is to take a sediment core, generate an age model chronology for the sediment, and assess what types of organism turnover and diversity changes have occurred through time.

Here are pictures from our coring day. Data is so far unavailable.

Here we are on the lawn of a science-friendly Falmouth resident, assembling our coring platform.

Our coring platform consists of two pontoon floats, metal crossbars, and 2×6’s. It is very stable and plenty big for 4 workers.

Anne and Longo ferry the anchors about 30 m from the raft to help secure our position. Four HEAVY anchors usually does the trick.

We have a barrel full of Siders Pond water, getting ready to push into the mud.

Our first core!! This 1 m of sediment represents appxorimately 500 years.

Morgan and Dr. Rand remove the core head from core IGERT15-1A-1.

Morgan loves sediment coring. But who doesn’t.

The goal of this coring endeavor is to use ancient DNA, preserved in a sediment core, to learn about how this pond has been impacted by residential development since the pilgrims arrived at Cape Cod. Here Longo, Morgan, and Steve, the three IGERT students, work to sample the sediment for DNA. The need to be verrrry clean and not sneeze on anything.