Thursday, February 16, 2012
Wednesday, February 15, 2012
Work Cited
Pollution - Chesapeake Bay Program." A Watershed Partnership - Chesapeake Bay Program. Chesapeake Bay Program. Web. 16 Feb. 2012. <http://www.chesapeakebay.net/issues/issue/air_pollution>.
"Air Pollution and Water Quality | Total Maximum Daily Loads (303d) | US EPA." Home | Water | US EPA. Enviornmental Protection Agency. Web. 16 Feb. 2012. <http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/airdeposition_index.cfm>.
"Blue Crab." NOAA Chesapeake Bay Office. National Oceanic and Atmospheric Administration, Jan. 2012. Web. 15 Feb. 2012. <http://chesapeakebay.noaa.gov/fish-facts/blue-crab>.
"Chesapeake Bay." Wikipedia, the Free Encyclopedia. Wiki. Web. 16 Feb. 2012. <http://en.wikipedia.org/wiki/Chesapeake_Bay>.
"Oysters - Chesapeake Bay Program." A Watershed Partnership - Chesapeake Bay Program. Chesapeake Bay Program, Dec. 2011. Web. 16 Feb. 2012. <http://www.chesapeakebay.net/issues/issue/oysters>.
"Striped Bass - Fish Facts - Chesapeakebay.noaa.gov." Environmental Education - Wetlands- Fisheries - NOAA Chesapeake Bay. National Oceanic and Atmospheric Administration, Jan. 2012. Web. 16 Feb. 2012. <http://chesapeakebay.noaa.gov/fish-facts/striped-bass>.
"WATER QUALITY ISSUES: Air Pollution." Chesapeake Bay Foundation. Chesapeake Bay Foundation. Web. 16 Feb. 2012. <http://www.cbf.org/Page.aspx?pid=519>.
"Chesapeake Bay National Estuarine Research Reserve, Maryland." Encyclopedia of Earth. N.p., n.d. Web. 15 Feb. 2012.
"Follow the Smith Trail - Southern Maryland - This is Living Magazine." Southern Maryland - This is Living Magazine. N.p., n.d. Web. 15 Feb. 2012.
"The Chesapeake Bay | The Pippa Hunnechurch Mysteries." The Pippa Hunnechurch Mysteries | America's Favorite Brit Headhunter. N.p., n.d. Web. 15 Feb. 2012. .
"Chesapeake Bay National Estuarine Research Reserve, Maryland." Encyclopedia of Earth. N.p., n.d. Web. 15 Feb. 2012.
Ground and Soil Conditions
The ground conditions of the Chesapeake Bay estuary really range depending on what part of the estuary you are talking about. Closer to land there are marshy areas where the soil is classified as tidal marsh. The soil materials can range from sand to clay and in some areas can be very mucky. As you go further away from land, the bottom becomes more sandy like the bottom of the ocean. The Chesapeake Bay estuary is quite large so the ground conditions vary quite a bit.
Anthropogenic Enviornmental Threats
Up to one-third of the
nitrogen that pollutes the Bay and its rivers comes from the air. Sources of
air pollution include vehicles, industries, power plants, gas-powered lawn
tools, and farm operations. Nitrogen from vehicle
exhaust washes into the Bay and contributes to algae blooms. These blooms cloud
the water and absorb the oxygen, creating dead zones in the Bay that cannot
support underwater grasses, crabs, fish, and other marine life. In addition, roads,
parking lots, and other paved surfaces—make erosion and sediment pollution
worse in the Bay. Air pollution, primarily from power plants, is also the main
source of the mercury that contaminates fish in the Bay watershed. As a result,
anglers are warned to limit their consumption of certain fish species due to
potentially harmful levels of this toxic chemical. EPA recently proposed
regulations to limit air pollution from the nation’s coal-fired power plants,
however the damage has already been done. Surface run-off is also a source of
damage to the ecosystem. When it rains, water accumulates on man-made surfaces
such as roads, roofs and parking lots. These hard (impervious) surfaces prevent
the rain from soaking in. As more houses, roads, and shopping centers are
built, more water runs off the surfaces and enters our streams and other
waterways, either directly or through urban storm drain systems, in the
estuary. Storm water carries a host of contaminants from the land into the
water: sediment, phosphorus, nitrogen, toxic metals, herbicides and pesticides,
organic material, oil compounds, and bacteria. Roadways, for example, release
oil and grease, tailpipe emissions, and other toxics from motor vehicles. Lawns
contribute fertilizer and animal waste. Construction sites release quantities
of mud. Sediment keeps sunlight from reaching underwater grasses. As these
plants die, the animals that rely on them are imperiled. Storm water pollution
is responsible for about 19 percent of the nitrogen and phosphorus pollution in
the Bay, if the contribution of nitrogen from air pollution is
included. It is one of the major reasons that the Bay remains on the EPA's
"dirty waters" list. Those aren't the only things that storm drains
bring in to the estuary. Toxic chemicals are
constantly entering the Chesapeake Bay and its tributaries via wastewater,
agriculture, storm water and air pollution. While chemicals such as DDT and
PCBs have been banned from production for years, many chemical contaminants are
still widely used or persist in the environment. There are many groups and
projects (many state run) that are dedicated to cleaning and restoring the
Chesapeake Bay Estuary.
The Striped Bass
The Striped Bass, also known as the rockfish, were once
overfished, but then the state started to manage them, and implement laws to
return their populations to a sustainable level. The state was successful in
doing so, because now the Striped Bass Populations are the highest they've been
in decades. Striped bass larvae and postlarvae drift downstream toward
nursery areas located in river deltas and the inland portions of the coastal
sounds and estuaries. Juveniles typically remain in estuaries for two to four
years and then migrate out to the Atlantic Ocean. Striped bass spend the
majority of their adult life in coastal estuaries or the ocean, which is why so
many are found in the Chesapeake area. During different stages in their life
cycle, striped bass feed on zooplankton, fish larvae, insects, worms,
amphipods, Bay anchovy, spot, menhaden, herring, shad, white perch, and yellow
perch. This shows how important they are in the food web. They are a main
predator, and do not have very many predators
Because they are an important predator, and abundant in the Chesapeake Bay estuary they are a
keystone species.
Oysters!
Oysters are keystone animals in the Chesapeake Bay Estuary,
because they filter algae and
provide habitat and shelter for other animals and underwater plants. Therefore,
without them, the ecosystem would use an important part of its ecosystem, and
has been. While the bay's
salinity is ideal for oysters and the oyster fishery was at one time the bay's
most commercially viable, the same is not true for today. The Chesapeake used to be filled
with oysters, but due to overharvesting, and the introduction of Diseases such
as Dermo and MSX, and sediment pollution, their populations have become
dangerously low. Reef building, establishing protected sanctuaries, and
breeding for disease resistance may all be key to fostering a comeback of the
Bay’s native oysters.
Blue Claw Crabs
Blue Claw Crabs thrive in shallow warm water, which is why
the Chesapeake Bay is an ideal climate for them. Blue crab distribution varies with age, sex, and season:
Blue crabs tend to be abundant in shallow-water areas during warm weather; in
winter they are plentiful in the Bay's deeper portions. Males range farther up
into the fresher waters of the Bay and its rivers than females, who congregate
in saltier waters. Blue crabs are bottom-dwellers that use beds of submerged
aquatic grasses as sources of food, nursery habitat for young, and shelter
during mating, and molting. Blue crabs occupy a wide variety of habitats
throughout their life history. Offshore, high-salinity waters are used during
early larval stages. Larvae move into the estuary and use intertidal
marshes, sea grass beds, and soft-sediment shorelines as they grow. Crabs are
highly tolerant of temperature and salinity variations and can live in just
about any region of the Bay. Habitat loss and increased nutrient loading
present the greatest threats to the population. Red drum (not too many in the
Chesapeake area), croaker (amount varies from year to year), striped bass, and
other blue crabs prey upon blue crabs. The blue claw crab is a major part of
the Chesapeake Bay Ecosystem. Due to the economic and iconic value of the blue
crab, it is considered a keystone species influencing many aspects of the Bay's
ecosystem.
Friday, February 10, 2012
Osprey Eating Bass
Want to learn more?
Check out these short and interesting videos about the bay and the organisms that live there!
http://www.chesapeakebay.net/discover/bay101
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