Chapter 11

One major problem associated with the Chesapeake Bay due to increased human pressure is:

an increase in nutrients resulting in more frequent kills of bottom-dwelling or benthic animals.

Estuaries

Any coastal body of water in which river water mixes with and dilutes seawater. Estuaries are protected from the dynamic ocean and thus provide good natural harbors. They are highly productive areas and serve as important nursery grounds for fish and other marine organisms.

Importance of Marshes: •They help us understand sea-level rise because we can sample and date the peat (which forms at or very near sea level). •Geochemical cycles (C, N, S). •Important in terms of productivity, storm buffer, sediment stabilization, filtration, beauty, and wildlife.

*Helps control the chemistry of coastal waters by filtering excess nutrients. This helps to prevent major algal blooms which can cause hypoxic waters and fish kills. •Net primary productivity is among the highest in any of the world's ecosystems (but low diversity). •Nursery grounds for fish and shrimp. •Major link in the food web of coastal ecosystems.

Estuaries (3 main types): Influences and other environmental issues: -The input of freshwater which stratifies the water column creating a halocline. -Thermal properties and stratification. -Tidal flow which provides energy to mix the fresh and salt water. -Wind energy/wind tides.

*Salt-wedge estuary - small tidal range, large river discharge; have a well-developed halocline. Ex) seaward zone of Mississippi River *Partially-mixed estuary - medium tidal range, medium river discharge Ex) Chesapeake Bay *Well-mixed estuary - large tidal range relative to freshwater discharge; e.g. Delaware Bay

Types of Marsh Plants:

*Spartina *Juncus

What is an "exclusive economic zone"?

- a marine area where countries have the right to explore and extract resources -An exclusive economic zone (or EEZ) is defined by the United Nations, and can extend up to 200 miles beyond a country's coastline.

Of the following statements about the physical characteristics of coastal oceans, which is/are true?

-In middle-latitude coastal oceans where evaporation is high, a halocline can develop. -In low-latitude areas where there is no mixing, surface water temperatures can be very high. -Because of onshore wind and coastal runoff, geostrophic currents along western North America flow northward. -In high-latitude areas, the coastal ocean is isothermal (has a uniformly low temperature from surface to deeper waters).

How is positive feedback affecting the arctic?

-It is causing arctic temperatures to rise faster than areas of lower latitude. -Open ocean is less reflective than sea ice. If sea ice melts, the arctic energy balance changes and more heat is absorbed, causing temperatures to rise faster.

What could be considered by some a positive outcome of the changing climate conditions in the arctic?

-an increase in coal mining profits on the islands near the arctic. -Warming conditions lead to a decrease in the amount of ice, increasing access to reserves and extending the shipping season for coal miners.

The percentage of the original area of wetlands currently left in the United States is approximately:

50%

Approximately how much of the world's oil and natural gas reserves are believed to be in the arctic?

About 25 percent of the world's oil and natural gas reserves are believed to be in the arctic, but are currently inaccessible due to the covering of ice.

The _____ refers to the portions of Earth's surface where water exists in solid form.

Cryosphere About 15 percent of Earth's surface is covered with snow and ice.

The Pamlico Sound, a body of water between coastal North Carolina and the barrier islands of Cape Hatteras and Ocracoke Island, is an example of a

Bar-built estuary *Form when a spit forms across an embayment. -Ex. Martha's Vineyard Barrier Coast; -Pamlico Sound (combination of bar-built and drowned river valley)

Which of the following solutions would best address the threat posed to arctic wildlife as a result of drilling for oil?

Create a comprehensive arctic treaty that oil companies must obey

form from flooding of broad dissolution features in limestone terrain. Ex) Tampa Bay, Sarasota Bay, & St. John's River

Dissolution Valley Estuaries

Who were the first people to profit from arctic waters?

Early whalers in the arctic hunted some species, like the Greenland Right Whale, almost to extinction.

An estuary formed at high latitudes & have their origins in the creation of steep valleys carved by glacial advance.

Fjords

The time it takes to exchange all of the water in an estuary with the ocean:

Flushing Time

What is one result of the changing conditions in the arctic?

Large ice floes are melting, so polar bears must swim longer distances between them to find food and many of them drown.

•Coastal ecosystems with communities of nonwoody, salt tolerant plants (halophytes) occupying intertidal zones. •Exist at the interface of land and marine waters where wave energy is sufficiently low to allow their development.

Marshes! *Regions of low relief and high tidal range are likely to have extensive salt marshes.

*rapid circulation, low estuary volume. *wastes are removed quickly

Rapid flushing (short-residence time)

What is known as the average length of time a particle of water stays in the estuary?

Residence Time: T=m3/m3s-1 *"T" for Albemarle-Pamlico Estuarine System (APES) is 11 months. *important because it determines how toxins may be concentrated within the estuary

Why are countries like Russia, Canada, and the United States interested in securing legal rights to the arctic?

Scientists think a large amount of oil and natural gas exists in the arctic that was previously inaccessible due to ice.

*Slow circulation, high estuary volume. *Ex) Albemarle, Pamlico Sounds *risk of accumulating wastes (land-derived pollutants: nutrients, pesticides, herbicides, & heavy metals: Pb, Zn, Cr, Cd, Cu, Hg, etc.)

Slow flushing (long-residence time)

An estuary produced by faulting or folding of rocks that creates a dropped-down section into which a river flows

Tectonic Estuary Ex) San Francisco Bay

Salt marshes serve as nurseries for over half of the commercially important fish in the southeastern United States.

True

The toxicity of marine pollutants is evaluated through bioassays by:

calculating the concentration at which 50% of the test organisms die.

Minamata disease is associated with:

ingestion of methyl mercury-contaminated fish and shellfish

According to the World Health Organization definition of marine pollutants, __________ is NOT a pollutant.

oil from offshore seeps