CHESAPEAKE BAY

Chesapeake as an Estuary An estuary is a semi-enclosed body of water that has a free connection with the sea An estuary is a semi-enclosed body of water that has a free connection with the sea.

Chesapeake as an Estuary Estuaries have more food for organisms, but the organisms usually have to deal with large temperature and salinity changes, high silt content and pollution. Estuaries have more food for organisms, but the organisms usually have to deal with large temperature and salinity changes, high silt content and pollution.

The Susquehanna River, the nation’s 16th largest watercourse at 444 miles in length, is the largest tributary of the Chesapeake Bay, providing 90 percent of the freshwater flow to the upper bay and half of its total flow.

Facts About The Chesapeake Bay

The Chesapeake Bay is the largest estuary in the United States.

The bay is shallow. Can you guess its average depth? 106 ft. 106 ft. 56 ft 56 ft 32 ft. 32 ft. 21 ft. 21 ft. 14ft. 14ft. 9ft. 9ft.

THE ANSWER! 21 feet is the correct answer. The deepest spot in the bay is 174 feet near Annapolis Md. 21 feet is the correct answer. The deepest spot in the bay is 174 feet near Annapolis Md.

A watershed is the drainage area for the bay. Can you name the 6 states that make up the watershed of the Chesapeake Bay? Can you name the 6 states that make up the watershed of the Chesapeake Bay?

Virginia Virginia Maryland Maryland West Virginia West Virginia Delaware Delaware New York New York Pennsylvania Pennsylvania

Can you name the 5 major rivers that flow into the bay? From South to North From South to North James James York York Rappahannock Rappahannock Potomac Potomac Susquehanna Susquehanna

Which of those 5 rivers contributes the most fresh water to the bay? The Susquehanna River provides about 50% of the fresh water coming into the Bay. The Susquehanna River provides about 50% of the fresh water coming into the Bay. The river empties an average of 19 million gallons of water per minute. The river empties an average of 19 million gallons of water per minute.

Can you name a mammal that is named after the Bay? Think you know? Think you know? The Chesapeake Bay Retriever The Chesapeake Bay Retriever

The Bay area is home to over 15,000,000 people! About 50,000 commercial vessels enter the Bay each year. About 50,000 commercial vessels enter the Bay each year.

The Bay area is home to over 15,000,000 people! All these people and activities put a strain on the Bay ecology. All these people and activities put a strain on the Bay ecology.

Bay Organisms The Bay is home to over 3600 living organisms!

Marsh Dwellers Marsh dwellers are located in and around marshes. They include small fish, birds, and marsh grasses. Marsh dwellers are located in and around marshes. They include small fish, birds, and marsh grasses.

SAV Communities Submerged Aquatic Vegetation Communities are important for many reasons. They include ducks, crabs, and eelgrass. Submerged Aquatic Vegetation Communities are important for many reasons. They include ducks, crabs, and eelgrass.

Plankton Community The plankton community includes the drifters of the Bay. The plankton community includes the drifters of the Bay.

Plankton Community It includes phytoplankton, bacteria, and zooplankton. It includes phytoplankton, bacteria, and zooplankton.

Benthic Communities Benthic refers to the bottom of the Bay. Benthic organisms include oysters, clams, barnacles, and mud crabs. Benthic refers to the bottom of the Bay. Benthic organisms include oysters, clams, barnacles, and mud crabs.

Nekton Communities Nekton refers to the swimmers of the Bay. Nekton refers to the swimmers of the Bay.

Nekton Communities Croaker, Spot, and menhaden use shallow water in the Bay as a nursery Croaker, Spot, and menhaden use shallow water in the Bay as a nursery

Problems we have…

Refined Designated Uses for Chesapeake Bay and Tidal Tributary Waters A. Cross Section of Chesapeake Bay or Tidal Tributary B. Oblique View of the “Chesapeake Bay” and its Tidal Tributaries Shallow Water Open Water Deep Water Deep Channel Open Water Habitat Shallow Water Habitat Deep Water Deep Channel Migratory Finfish Spawning and Nursery Habitat

Important Habitat Requirements

Draft Bay Dissolved Oxygen Criteria Minimum Amount of Oxygen (mg/L) Needed to Survive by Species Hard Clams: 5 Striped Bass: 5-6 Worms: 1 Migratory Spawning & Nursery Areas Shallow and Open Water Areas Deep Water Deep Channel Crabs: 3 Spot: 2 White Perch: 5 American Shad: 5 Yellow Perch: 5 Alewife: 3.6 Bay Anchovy: 3

Draft Bay Water Clarity Criteria Good Water Clarity Poor Water Clarity Algae in the water Sediment and other particles in the water Algae on the leaves Percent of sunlight reaching leaves: 9% in low salinity waters 15% in high salinity waters + + equals Very low percentage of sunlight reaching leaves – Bay grasses grow poorly or die.

Why do you think high silt (solid stuff, like mud) would be a problem for marine organisms? Hint How does this organism get its food? Hint How does this organism get its food?

Many marine organisms are filter feeders so silt can be a major problem.

Many of these filter feeders are important as food to humans.

Colonization of Estuaries

Estuaries are regions of transition and sharp gradients. Estuaries are regions of transition and sharp gradients. Estuaries support fauna recruited mostly from the sea Estuaries support fauna recruited mostly from the sea

The number of different species in an estuary is greatly reduced, but the number of individuals is large. The number of different species in an estuary is greatly reduced, but the number of individuals is large. What does that mean? Can you explain that last statement? What does that mean? Can you explain that last statement?

The Answer For those organisms that can survive the problems of the estuary, there is a great deal of food. For those organisms that can survive the problems of the estuary, there is a great deal of food.

The Answer These organisms tend to be in large numbers. These organisms tend to be in large numbers.

Estuary Types The Chesapeake Bay is a drowned river valley. This is the most common type of estuary. It was formed during the last ice age some 12,000 – 18,000 years ago. T There are other types of estuaries. Can you name any of them?

Bar-Built Estuaries These are found where sand bars and barrier islands form. These are found where sand bars and barrier islands form.

Bar-Built Estuaries The shallow water behind these barrier islands forms low salinity estuaries. The shallow water behind these barrier islands forms low salinity estuaries.

Tectonic Estuaries These estuaries form where land sank or subsided. These estuaries form where land sank or subsided.

Tectonic Estuaries A good example of this type of estuary is San Francisco Bay. A good example of this type of estuary is San Francisco Bay.

Do you know the name of the last type of estuary? Think Ice!

Fjords! Fjords were created when retreating glaciers cut deep in the earth. Fjords were created when retreating glaciers cut deep in the earth.

Fjords! Where in the United States might we find fjords? Where in the United States might we find fjords?