A Week on the R/V Lake Guardian
By Ron Pilatowski
and John Taylor-Lehman
As teachers, we try to present opportunities for our students to use data and analyze it. We probably donít give a great deal of thought to how that data was obtained. If we donít give it much thought as teachers, our students likewise donít really appreciate how the data was collected.
This past summer, both of us were presented with the opportunity to experience first-hand how a variety of limnological data were collected on one of our Great Lakes, Lake Huron. We arrived at the dock in downtown Detroit early on the morning of Saturday, July 25th. We joined about a dozen other teachers from states bordering the Great Lakes and awaited the arrival of the R/V Lake Guardian. The skies were overcast with a light drizzle as we introduced ourselves to one another. The main topic that dominated our discussions revolved around potential seasickness and wondering what the trip had in store for us. The ship slowly made its way upriver and docked alongside Cobo Arena. It was time to get onboard!
We stowed our gear, got a quick tour of the ship and then assembled on the top deck for survival training. We nervously laughed and hoped that we would never have to try to get into our survival suits in a hurry as they were cumbersome and made us all look like a group at the National Gumby Convention, but we knew that in the event of an emergency, they would keep us safe. At high noon, we departed and sailed up the Detroit River and into Lake St. Clair and into the St. Clair River. It was readily apparent that the Great Lakes provided an important transportation artery, as well as providing a source of water for all types of manufacturing processes. We docked in Port Huron for the first night of our trip.
We cast off into the early morning sun on Sunday, and sailed under the Blue Water Bridge connecting Port Huron and Sarnia, Ontario. The wide-open waters of Lake Huron soon replaced the industrialized banks of the river as we made our way to the first of our sampling stations. The Lake Guardian was equipped with thrusters that allowed it to remain on station so that we could assist the team of scientists on board in collecting a variety of data. We determined water turbidity by using a Secchi disk, took samples of bottom sediments with either a PONAR Dredge or box corer, depending upon the lake floor conditions. Water samples were taken at varying depths using a Rosette Sampler. This device was lowered over the side of the ship and was programmed to collect water samples at pre-determined depths, while probes attached to it measured water temperature, dissolved oxygen levels, pH, and chlorophyll levels, a proxy for photosynthetic activity. The teachers were involved in all phases of sampling, donning slickers, boots and hard hats at all hours of the day and night to assist in this important work, as the ship operated 24/7.
We slowly made our way up Lake Huron, stopping at a variety of sampling locations, both near shore and farther out on the lake. We met a number of Great Lakes scientists who shared their research results, ranging from how the Great Lakes fishery continues to change, to recent evidence of the migration of native peoples from Michigan to Ontario across an ancient land bridge now submerged on bottom of Lake Huron. We sailed across an area dotted by a number of shipwrecks, testimony to the powers of the lakes. What did it feel like to be on board one of those ships when it was all but certain that you were doomed to going down? We voyaged in the comfort and safety of the modern 180í long Lake Guardian, but you had to be impressed with the courage and fortitude that people had to set sail on the Great Lakes in the 1800ís on board wooden sailing ships or primitive steamships with little or nothing in the way of navigational equipment. Wow!
The days melted into one another as we continued our trek up Lake Huron. We sampled by the light of the sun during the day and by the light of the moon at night. Thereís nothing quite like being on the rear deck of the Lake Guardian at 3 am collecting samples with the dark waters of Lake Huron all around you and the bright moon high overhead!
There was also ample time to spend topside during the day and night, too. Time to work on your journals, time to reflect about the vastness of the expansive freshwater resources we call our Great Lakes, time to think about how insignificant one feels out in the middle of the lake, time to think about how humans have taken these bodies of water for granted and misused them. Time to take in the great vistas of water and sky, time to be out on deck gliding beneath the Mackinac Bridge at 4 in the morning, time to look up at the stars without having to contend with the lights of the cities and suburbs. It all made for a great experience!
The teachers on board divided into several teams, based upon the grade levels they taught. John and I teamed up with another teacher from Pennsylvania to work on our project. We decided that we wanted to take some of the data that we gathered and develop an activity around it based upon looking at some of the data collected from two different sampling stations, one nearshore and one offshore. John took the lead in taking data gathered by the probes on the rosette sampler and whittling down thousands of data points into a more manageable set that students could work with. The data included depth, water temperature, dissolved oxygen, and fluorescence, an indicator of photosynthetic activity. As our team consisted of all high school teachers, we wanted our students to be able to graph data using both a primary and secondary x-axis and look at trends in the data and develop tentative explanations for the patterns. Science is all about looking at data, finding patterns, and providing possible explanations. We felt that our experience on the Lake Guardian offered an ideal opportunity to develop a great activity for our students with the added bonus of being able to actually relate to our students how the data was actually gathered.
On our last evening on board, on our down-bound leg across Lake Michigan heading to the Lake Guardianís home port of Milwaukee, everyone gathered on the main deck to share team presentations. Presentations ranged from activities and songs designed to raise awareness about the Great Lakes for elementary students to activities that involved data analysis. One thing was quite clear, however. The experiences that we shared on the Lake Guardian were both inspiring and amazing and they would change the way we taught and how we looked at the Great Lakes. (And we never did have to worry about seasickness! The entire voyage was smooth as silk!)