This learning sequence incorporates three dimensional learning from the K-12 Framework for Science Education with connections to Common Core, and the Maryland Environmental Literacy Standards.
The sequence was originally conceptualized by a team of educators from the Chesapeake Bay region: Eric Greenlee (Anne Arundel Public Schools), Patricia Benner, Merrilee Perko, and Pamela South (Somerset County Public Schools), and Katie Seman (Wicomico County Public Schools).
The sequence is comprised of seven lessons, each building on the knowledge and skills of the previous one incorporating the three dimensions of learning. These dimensions are included in each lesson and the learning sequence builds toward deeper understandings and issue investigation skills. (http://www.nextgenscience.org/three-dimensions)
The lesson sequence will engage students in a local environmental issue by showing them the historical context of how the Eastern oyster populations and the Chesapeake Bay watershed have changed since the time of Captain John Smith. Students learn about water quality parameters and have opportunities to investigate the effect of land use on water quality and ultimately the oyster populations and the reef ecosystems. Finally, students are asked to learn about the effect of management practices on water quality and asked to suggest ways that these can be used to increase the health of the Chesapeake Bay ecosystem and its water supply through healthy oyster reef systems. The sequence of seven activities is divided into 2 modules building toward skills and knowledge to tackle more in-depth issue analysis in the high school sequence.
There are two modules in the unit with these Essential Questions:
In Lesson 1: Then and Now, students will explore the historical changes in the ecological conditions and water quality of the Chesapeake Bay. Students will confirm or refute their predictions after reading excerpts from John Smith’s journal and viewing reports from the Chesapeake Bay Foundation or other sites. This activity will set the stage for students to investigate waterways near them and to look at the role of oysters in the Chesapeake Bay ecosystem.
Captain John Smith was an English explorer who played a pivotal role in the European settlement of America. His contact with Native Americans and his Chesapeake voyages was documented in maps and journals helped early English colonists to learn about the region. Smith led two voyages on the Bay. His journal entries give us a clue about the ecological conditions of the Bay at the time.
One of the most visible changes is the amount and diversity of animals that live in and around the Bay. In Smith’s days, oysters “lay as thick as stones,” and the Bay contained more sturgeon “than could be devoured by dog or man.” During Smith’s time, the land surrounding the Bay was home to bears, wolves, cougars, falcons, partridges, waterfowl, and had cypress trees that were 18 feet around the base and up to 80 feet tall. The water then was substantially clearer as well.
Students will be able to:
Module 1, Lesson 2: Where Am I? explores geospatial systems so that students can create waypoints and record latitude and longitude of places in a watershed as a first step in monitoring a local waterway. These skills are basic to understanding how locations are found on earth with the use of maps, coordinates, and technology.
Humans have looked to the skies to find their way since ancient times. Ancient sailors used the constellations in the night sky to figure out where they were and where they were going. Today, all we need is a simple hand-held GPS (short for Global Positioning System) receiver to figure out exactly where we are anywhere in the world. However, we still need instruments high in the sky to figure out where we are and how we get to other places.
Instead of stars, we use Global Positioning System (GPS) satellites, to help determine a location on the planet. The concepts behind GPS positioning are very simple, but the application and implementation require amazing precision. Over 30 navigation satellites are zipping around high above Earth. These satellites can tell us exactly where we are. GPS is a system. It’s made up of three parts: satellites, ground stations, and receivers. (http://spaceplace.nasa.gov/gps/en/)
Students will be able to:
Students will measure water quality and its relevance to stream health by understanding water quality parameters. They will use standard water testing equipment to test and record precise measurements of water quality and learn about the indicators of a healthy waterway and the role oysters provide in a healthy Bay ecosystem.
Water quality is a measure of how suitable water is for a particular use based on certain physical, chemical, and biological characteristics. Scientists measure water temperatures, turbidity (clearness of the water), and other “indicators” to monitor the health of the Chesapeake Bay. Students will assess the water quality of a local stream or river, and compare their findings to published data of tributaries in the Chesapeake Bay. Ideally, water quality testing will continue throughout the school year, so the students can observe and try to explain trends in the data and begin to think about the consequences of human actions.
Students will be able to:
This activity investigates local watersheds and what land use factors influence water quality of the rivers and the Bay. Students then look at data from a local monitoring station to find the health of their stream. Using maps of land use areas in parts of the Bay, students will look at land use and compare that with local stream health. They will learn about point and non-point source pollutants and determine possible local sources; then they will consider ways that these can be managed or reduced to enhance water quality, just one step in restoring oyster populations.
The simplest definition of a watershed is the area of land that catches precipitation and channels this water into a marsh, stream, river, lake, or underground reservoir (groundwater). These water bodies can be contaminated by runoff that carries pollution from land surfaces anywhere within the watershed. Pollution is the presence of substances in the air, land, or water that can degrade human health and environmental quality. These substances may come from many sources, but some of the most serious pollution problems are the result of unwanted by-products—commonly called wastes—from human activities.
Students will be able to:
This activity explores the physical characteristics that make oysters efficient filter feeders through an investigation into oyster external and internal anatomy. They will design a water filter and test its function with dirty water, then investigate the ecosystem services that oyster reefs provide to organisms that depend on oyster reefs.
Oysters have remained relatively unchanged for 190 million years. This mollusk is found throughout much of the Bay in water depths up to 100 feet, although today they are rarely found below 30 feet. The adaptive nature of the oyster in a changing estuarine environment has allowed it to become extremely successful. This success is also due to its simple anatomy and it ecological niche.
Aquatic reefs are complex, diverse communities made of densely packed oysters. Healthy reefs form when oyster larvae attach to adult oysters, and layers of oysters grow upward and outward. Hundreds of aquatic animals find food and shelter in oyster reefs.
Students will be able to:
This activity explores the historical and technological changes in the harvest of oysters through the years. It encourages students to think about how humans have affected the Bay and the Eastern oyster. During the game, dried beans represent oysters, and students test out four different types of oyster harvesting tools; nippers, hand tongs, skipjack dredges, and power dredges. After each round of “harvest”, students observe and discuss how the structure of the reef has changed, and how the physical changes affect oysters and future populations.
At one time, oysters were so abundant in the Chesapeake Bay that their reefs defined the major river channels. The reefs extended to near the water surface; to stray out of the center channel often posed a navigational hazard to ships sailing up the Bay. The oyster population in the Bay is less than 1% of what it once was. This activity will investigate one factor in the oyster population decline in the last 130 years, harvesting methods.
Students will be able to:
Oysters are a valuable part of estuary ecosystems. They help purify the water, control erosion, and provide habitat for numerous other species. In this activity, students will investigate a hypothetical scenario in a town on the Chesapeake Bay, and devise a management plan to “Save the Oyster Reef”.
Since colonial times, the Chesapeake (meaning "great shellfish Bay" in Algonquin) has lost more than 98 percent of its oysters. Gone are the days when oyster reefs posed navigational hazards to Chesapeake Bay explorers. Their reefs defined the major river channels. The reefs extended to near the water surface and often posed a navigational hazard to ships sailing up the Bay. Now, after decades of damage to reefs from harvest, increased disease, falling salinity due to the increased runoff that accompanies increased impervious surface, and increased sedimentation from runoff, a significant amount of hard bottom habitat has been lost. The oyster population in the Bay is less than 1% of what it once was. The native Eastern oyster—Crassostrea virginica—plays an important role in the Bay's ecosystem, as both a habitat for a variety of sessile plants and animals and free-swimming fish and shellfish, and as filter feeders because they feed upon phytoplankton (algae).
Students will be able to: