Featured Lesson

Lesson 1:6 – From Frozen to Fascinating

by Michelle Kelly

November 2009

frozen lake landscapeThe frozen world is fascinating!

Chapter 1 of the MinnAqua Leader’s Guide - Fishing: Get in the Habitat! focuses on Minnesota aquatic habitats and houses six of our 39 lessons. Lesson 1:6 – From Frozen to Fascinating is the last lesson in Chapter 1. November winds are blowing and winter will soon envelop our lakes, rivers, and streams. The seasonal changes are dramatic in Minnesota and stark winter landscapes can appear nearly empty of all the living things that inhabited these places just a few months before.

What happens to all of the aquatic organisms in the winter? Do they sleep for the winter under the sheets of ice and blankets of snow? How do aquatic organisms weather the cold winter conditions and reawake in spring?

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Lesson Summary

In this activity, students investigate how spring-like conditions trigger plankton and algae from bottom sediments to emerge and resume activity after winter dormancy. Students add scoops of bottom sediment (liquid or frozen, collected after frost) from an icy-cold lake, pond, or wetland to large containers of water to make “mini-ponds.”

Working in groups, students design their own experiments and place their mini-ponds in various environments within the classroom to encourage dormant organisms to emerge. Groups make predictions, decide where-and in which conditions-in the room to place their mini-ponds, record observations over a four-week period, and draw conclusions. They also use identification keys and pond field guides to identify and sketch organisms in the developing mini-pond. Each group prepares a final presentation that communicates their results to the class.

Tips & Tricks

  • This lesson is season-specific. You will want to plan to do this lesson mid-winter, when lakes and wetlands are frozen, and covered with ice.
  • To add to the “drama”, take the kids outside and let them experience first-hand the frozen conditions where the aquatic organisms are overwintering in the “muck” and bottom sediments.
  • Bring students along with you to the collection site and have the students collect the bottom samples through the ice and snow capping the water. Note: Be certain ice conditions are safe, before bringing students out on the ice.
aquatic invasive species signBe careful not to spread invasive species.
  • Avoid collecting sediments and samples from waters that have been posted “Infested Waters” by the Minnesota DNR. It is illegal to transport water from waters infested with invasive species. A list of infested waters is posted on the MN DNR website. Wetlands are not usually posted for invasive species. But if you know that an area contains purple loosestrife, or another invasive species, don’t collect sediment there – it’s illegal to transport purple loosestrife seeds or plant parts.
  • Sediment and frozen muck samples can be stored in the freezer. To thaw- remove samples from the freezer the day before the experiment.

MinnAqua Lesson Connections

Teaching about adaptations exhibited by aquatic organisms for surviving Minnesota winters with Lesson 1:6 - From Frozen to Fascinating connects well with Lesson 2:8 – Fish In Winter in which students learn about the limitations imposed on fish survival by Minnesota winters. Lesson 2:8 provides an opportunity for students to role-play being fish in winter.

Completion of these two lessons provides a good foundation for a winter unit that includes an ice-fishing trip that will surely create lasting memories for your students. Prepare kids for going ice-fishing with Lesson 5:7 – Making Ice Fishing Jiggle Sticks. Get comprehensive information on what you will need to bundle up in layers and safely take kids outside with their new jiggle-sticks to go ice fishing with Lesson 6:2- Ice Fishing and Winter Safety.

Ice fishing is both easy and exciting. It’s fun to hike across the ice to your fishing holes imagining hungry sunnies or walleyes lurking below!

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