Ahoy! My name is James Hoehner, and this summer I will take you through the research happening at the Cornell Biological Field Station on Oneida Lake and beyond. This week I got a chance to cruise Lake Erie aboard the R/V Lake Guardian, the Great Lakes’ largest research vessel. Take a look at all the different projects that happened on the voyage.
One of my team’s main tasks was to collect zooplankton samples at each of the 30 stations on the lake. Zooplankton are tiny animals that serve as food for many small fish, making them an important member of the food web. Lake Erie is the shallowest Great Lake, so we had to make sure to keep our net at least two meters away from the sediment at the bottom to avoid catching mud. Once the zooplankton were caught, we preserved them on the ship to be processed on land. After processing, data such as biomass (how many zooplankton) and diversity (what types of zooplankton) is sent to the EPA for them to monitor the health of the lake.
Look closely to see the zooplankton. They are the wiggling white spots
In addition to netting zooplankton, we also collected larval fish samples using the “tucker trawl” method. This involved towing a large net at the surface behind the boat for five minutes.
This claw is called a ponar grab and is used to collect samples from the bottom of the lake. Look at all the mussels we caught! Zebra Mussels and Quagga Mussels are invasive to the Great Lakes and have had severe impacts on the environment, such as causing harmful algae blooms.
The rosette measures water temperature, dissolved oxygen, pH, and more at different depths. These variables can affect life throughout the food web, so it is important to track changes over time. We met with a group from Cornell’s main campus who used the rosette to sample bacteria in the water at different depths.
Rosette lowering into the water
What a busy week! The data and samples we collected will be used to better understand the state of the Great Lakes and can also give insight into other lakes within their watershed, like Oneida Lake. Speaking of which, I’ll be writing from the Cornell Biological Field Station on Oneida Lake next week, so stay tuned for more freshwater fun.
