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Period: Jan 1, 1200 to
Population is small and groups of people are isolated enough that nature can recover from most pollution
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Period: Jan 1, 1200 to
Pollution is largely excrement
Some dyes from factories polluted water supply, but the majority of water pollution came from excrement until after industrialization, when industrial runoff containing chemicals, and air pollution from factories became a problem. Pesticides and herbicides also contain stronger, more harmful chemicals now than they did in the past. -
Jan 1, 1300
Native Americans build towns in and around the Chesapeake Bay
The Native Americans clear land around the Chesapeake Bay to grow crops such as corn, squash, beans and tobacco. They create small, permanent villages near their agriculture. -
Apr 21, 1400
Europeans land in the area for the first time
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Apr 21, 1500
The Native American population is around 24,000
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The Jamestown colony is formed in Virginia
It is made up of Europeans who arrived from England. -
There is a very large demand for tobacco
Tobacco requires a lot of nutrients from the soil. The soil gets worn out very quickly and can't be used again. The worn out land does not purify groundwater as well as it did before. -
St. Mary's city is founded in Maryland
It is the first official city in the colony called Maryland. -
Colonists start cutting down large amounts of forest
The wood is used to make boats, and more houses for the growing population. These forests purified runoff before it flowed into the Chesapeake Bay, absorbed excess nutrients, removed sediments and prevented erosion. -
The Native American population is now only around 2,400
Many have died from the sudden increase in water-borne diseases, due to concentrated waste from the cities and towns near water sources, and the lack of trees upstream that absorb runoff. -
Settlers build dams in fast-flowing streams for energy
The energy is used to run their new mills. -
English settlers begin to harvest oysters
An oyster can purify up to 1.3 gallons of water per hour. Oysters take in water to feed, and detain most toxins, microorganisms and polluted particles. Then, they release the water, which is now purified. In the 1600s there is still an abundant supply of wildlife in the area. -
Period: to
More cities are being formed
1681: The colony of Pennsylvania is established.
1695: The city of Annapolis, Maryland is established.
1699: The city of Williamsburg, Virginia is established. -
Period: to
More and more immigrants are arriving
New immigrants chop down acres and acres of dense forest around the Chesapeake Bay to use for building purposes. Roads are leveled and packed down with dirt to make transportation easier. These roads do not absorb water, creating excess runoff, and a shortage of groundwater. -
Colonists notice that the water is getting murkier
Port towns in Maryland are experiencing trouble because of the lack of forests to remove sediment upstream. The sediment is filling the waters, making transportation difficult. -
Population is around 380,000
Almost the entire Chesapeake Bay region has been filled with farms, towns, raods, cities, and small industries. -
Population reaches 700,000
Almost 30% of all coastal forest land has been cut down or burned by colonists. Populations of native plants and animals begin to decline due to habitat destruction. -
Washington, D.C. is established
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Population reaches 1 million
People in the area start using dredging to harvest oysters. Dredging completely destroys oyster beds. -
Economy shifts from tobacco production to livestock, wheat, and corn
Much of the livestock is kept along the coasts of the Chesapeake Bay. Much of their manure runs off into the Bay, polluting it and causing bacteria growth. Also, wheat and corn are known as some of the most water-intensive crops, meaning they use very large amounts of water. -
Virginia bans dredging
It is too destructive to oysterbeds, and VIrginia feels that oysters are being overharvested. It is known that they play an important role in purifying water. -
Population reaches 1.3 million
Large-scale deforestation is taking place. Entire forests are being cleared to produce charcoal. It takes 20-30 thousand acres of forest to produce enough charcoal to melt 1,000 tons of iron. -
Cholera epidemic kills tens of thousands of people
Cholera spreads throughout the country. Large-scale outbreaks of malaria and yellow fever occur. Crowded urban slums become breeding grounds for tuberculosis. -
The Washington Aqueduct is completed
The Washington Aqueduct was constructed to carry water from a dam built above the Potomac River to reservoirs in Georgetown and Washington, D.C. -
Fish-hatcheries open to spawn and grow threatened fish
All of the dams that are being built and all of the commercial fishing that is happening are making the numbers of fish decline. -
The skies and waterways are suffering from intense pollution
Factory smoke is making the sky black. Sediment and sewage is flowing into the water. Industrial waste and human and animal waste is a huge problem. -
Coal mining pollutes rivers & pollution threatens underwater grasses
There is a lot of coal production going on in mines in the upper Potomac and Susquehanna River basins. Waste from these coal mines flows into the streams and rivers and makes the water toxic.
Sport fishermen and scientists begin publishing reports that talk about how the underwater grasses are being threatened by invasive species and pollution. -
Baltimore is first to create wastewater treatment plants
This is an effort to try to save the oysters in the surrounding waters. -
The region’s population exceeds 4.5 million
The government begins setting aside wilderness lands and historical sites for animal refuges, parks, and national forests and monuments.
The blue crab population is experiencing a decline. Crabbers are only landing half the amount of blue crabs as they were in previous years. -
Sewage and industrial waste being dumped into the Bay
The water quality is really bad. People start noticing phytoplankton (algae) growing in the water. This causes a big problem for the underwater grasses and oysters. -
Use of chemicals to fertilize crops becomes a widespread practice
Pesticides and herbicides also became widespread practices.
Fertilizer runoff contains Nitrates and Nitrites. These chemicals, when imbibed can cause serious illnesses and blue-baby syndrome.
Pesticide and herbicide runoff often contains Diquat, Dioxin, and Glyphosate. Diquat is known to cause cataracts, Dioxin can cause birth defects, and Glyphosate is known to cause kidney problems and reproductive difficulties. -
The regional population climbs to 7 million
The population boom puts a serious strain on the water quality. -
Many wetlands drained to build suburbs
This increases the levels of nutrients, sediment, and toxins in the Bay. The water quality of the Bay significantly decreases. -
New oyster disease hits the Virginia portion of the Chesapeake Bay
It is called MSX, and it devastates the oyster populations there. -
The Federal Water Pollution Control Act is passed
This law says that every state has to have the same water quality standards. It places limits on the kinds of things that can be dumped into rivers, and it requires new sewage lines and water treatment plants to be built. -
Kepone is found in the James River in Virginia
Kepone is a toxic chemical. It seriously threatens fish, wildlife, and human health. -
The Chesapeake Bay Agreement is signed
The agreement , among the states of the bay watershed, aims to restore and protect underwater grasses, reduce erosion and sedimentation, restore wetlands and other habitats, manage fisheries, restore wildlife stocks, and many other things. It is a very important agreement for the health of the Bay. -
Local governments ban phosphate detergent
Phosphorus is found to cause extensive algae blooms. Algae blooms block sunlight, killing underwater grasses and destroying animal habitats. Red algae contains a neurotoxin which kills fish, manatees, and other marine creatures. If neurotoxins are ingested by humans the results can be fatal. -
Oil spill in the Chesapeake Bay kills waterbirds
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Chesapeake Bay's dead zone area doubles since the 80s
A “dead zone” is an area of water in which there is almost no oxygen. Any creatures that can’t swim away usually end up dying, because they can’t breathe. Dead zones are caused by high levels of nutrients (nitrogen and phosphorus) in the water. -
Population in the region reaches 16.6 million
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Housing boom increases rate of deforestation and fertilizer runoff
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Chemical contaminants persist in the Chesapeake Bay
PCBs and mercury are among the most widespread toxins, and other carcinogenic chemicals (chemicals known to cause cancer) are increasing in the Bay. Most of these chemicals come from factories, and waste that people dump into the Bay. -
The Chesapeake Bay is still losing its underwater grasses
The Chesapeake Bay and its rivers have lost 44 percent of their underwater grasses over the past three years, -
Some conditions in the Bay are improving
According to the Chesapeake Bay Program, there is more oxygen available to fish and crabs, and there is less nitrogen and phosphorus in the water compared with previous years. However people still pollute the bay, and there are certainly more carcinogenic chemicals today than there were in the past. Industry and our population continues to grow.
