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The Chesapeake Bay (w/narration)
Transcript of The Chesapeake Bay (w/narration)
So now we know too much fertilizer is bad...but just how does it cause an algae bloom (eutrophication) to occur?
Why is too much fertilizer especially harmful to aquatic ecosystems?
Here's what real eutrophication (aka algae blooms or dead zones) look like...
A quick timeline of the Chesapeake Bay...
Read the following articles and answer questions 9-10 on your worksheet.
Today, over 16 million people live in the Chesapeake Bay watershed. Humans used the land for many different purposes - agriculture, residential, industrial, commercial, recreational, and more. All of that human presence has taken a toll on the bay.
At the same time, people love their shellfish and seafood! Over harvesting (overfishing), combined with pollution and disease, started to drastically reduce conditions in the bay. From the 1960s-1980s, conditions in the bay had hit rock bottom. Most of the aquatic plants in the bay had disappeared. Bird populations started to die off or permanently migrated elsewhere. Some populations - such as the bald eagle - were reduced by as much as 90%. The blue crab population had decreased by 70%.
Things started to change in
the 1600s... What do you
Understanding the Food Chain
Now we know that over harvesting and pollution both caused great harm to the Bay -- but what is the science behind this? Read the following article, then answer questions 7-8 on your worksheet.
Leading up to the 1600s, virtually all of the land which makes up the Chesapeake Bay watershed was covered with dense, old growth forests. The canopies of these tress protected the soil from the impact of heavy rains, while the massive root systems kept erosion under control. As a result, fresh water entering the Bay was exceptionally clean and crystal clear. The water clarity allowed rooted plants to thrive on the bottom of the Bay, providing ideal habitat for fish, crabs, and other organisms. Early explorers of the Chesapeake were amazed by the amount of marine life that they witnessed in this incredibly productive environment.
- Excerpt from Sultana Projects, Inc.
Everything began to change with the arrival of English settlers in the early 1600s. Though Native Americans had been in the area for centuries, John Smith & early explorers realized the resources in the bay and its tributaries provided an ideal habitat for human settlements. Not only did the bay itself provide plenty of food, but its tributaries – which included the James, York, Rappahannock, Potomac, and Susquehanna rivers – provided a steady supply of freshwater and therefore were ideal to establish new settlements. Over the next 400 years, humans would establish many heavily populated areas, including Jamestown, Richmond, Washington, D.C., Norfolk, Baltimore, Annapolis, Harrisburg, and more. Originally, the land was primarily used for farming, but eventually the industrial revolution began, and the Bay was suddenly on the receiving end of waste from a heavily populated 64,000 square mile area.
With the help of scientists and educating people on the importance of the Bay, the past 20 years has finally started to slow some of the declining populations of plants and animals and restore of the Bay's condition to a healthy status.
Laws have helped manage over-harvesting, new technology has helped us manage waste, and people living in the Bay's watershed have become more educated about what they can do to help. Non-profit organizations dedicated to restoring the bay have created jobs and funded research to find ways to continue helping.
Sometimes this involves complicated scientific research, and sometimes this simply involves planting vegetation or raising wildlife to then release in the bay. Either way, there are always things to be done for those willing to help.
What's being done
Watch the following video and answer questions 1-3 on your worksheet. Click the arrow when you're ready.
Use the following data chart to answer question #11 on your worksheet
As you work through the timeline, answer questions 4-6 on your worksheet
As the human population and number of cities continued to grow, so did the impact on the bay. Many forests and wetlands have been cleared to make room for farms, roads, and neighborhoods. With all the concrete and residential development taking place, pollution and runoff both increased, adding harmful chemicals to the bay and causing disease among many animal populations.
However, it's not all doom and gloom. The good news is that because of the work of scientists, and the help of people around the Bay, the last 20 years has seen significant improvements to many of the Bay's problems. But there's still a long way to go.
Continue to see a few examples of animals that used to flourish in the Chesapeake
300,000 years ago, the Bay wasn't even a bay - it was a river. It wasn't until around 10,000 years ago, at the end of the last ice age, that ice started to melt and the bay started to form.