Understand how ocean currents affect the weather over the continents.
There are two types of aquatic systems: freshwater and saltwater.
There is a mixture of fresh and salt water.
Mountain streams have clear water that flows over waterfalls.
As streams merge, a river forms and gets wider and deeper.
Wetlands and estuaries can be found at the mouth of the river, where it divides into many channels.
There is a high oxygen content in the water.
The trout are a major predator.
There is little oxygen and a lot of silt in the water.
Blue crabs are found in the water.
The salts are left behind when the sun's rays cause the water to evaporate.
In Chapter 45 fresh water rises into the atmosphere, cools and falls as rain.
When there is rain, some of the water sinks into the ground and saturates it.
The water table is the layer of water in the ground.
All fresh water is returned to the sea when land is above sea level.
It is contained in lakes and ponds along the way to the sea.
There are underground rivers called aquifers.
Water will rise to the level of the water table when the Earth has basins or channels.
Wetlands hold some amount of water during the year.
Wetlands are classified by their vegetation.
Wetlands that are frequently flooded by water are called marshes.
They are characterized by the presence of rushes, reeds, and other grasses, which provide excellent habitat for ducks and small mammals.
One of the most productive ecosystems is the marshes.
The swamp trees include cypress, red maple, and tupelo.
The American alligator is a top predator.
The wetlands are characterized by acidic waters.
Most of their water comes from precipitation.
Orchids, cranberries, Venus flytraps, and pitcher plants are some of the plants that thrive in the bogs.
Humans have historically diverted rivers and filled wetlands with the idea that "useless land" was being improved.
These activities can cause flooding and degrade the habitats for fish and other wildlife.
Wetlands break down toxic waste and excess nutrients to purify waters.
Wetlands absorb storm waters.
They protect farms, cities, and towns from floods.
Wetlands have been protected by federal and local laws.
Lakes are bodies of fresh water.
The lakes are characterized by a small amount of organic matter and low productivity.
Eutrophic lakes are characterized by plentiful organic matter and high productivity.
These lakes are usually located in regions with high levels of nitrogen and other minerals.
Eutrophic lakes have large populations of plants that use up oxygen and leave little for fish to eat.
In the winter and summer, deep lakes have different vertical zones.
There are three layers of water in the lakes in the summer.
The more dense water of the thermocline floats on top of the less dense water of the epilimnion.
During the spring and fall, the deep waters receive oxygen from the surface waters.
Phytoplankton use up a lot of different vitamins and minerals as they photosynthesize.
This layer has a ready supply of oxygen.
Oxygen is used up as decomposing occurs at the bottom of the lake.
Decomposition releases vitamins and minerals.
As the season goes on, the epilimnion becomes weak and the hypolimnion depletes of oxygen.
The epilimnion cools in the fall and warms in the spring.
The upper epilimnion waters become cooler in the fall.
The temperature is uniform throughout the lake until the layers are mixed.
The circulation of water is aided by the wind at this point.
Oxygen and nutrients are distributed evenly.
Further cooling of the water below can be prevented by ice.
This allows organisms to live in the water during the winter.
The cooler water on top sinks below the warmer water on the bottom in the spring.
The temperature is uniform throughout the lake until the layers are mixed.
The surface waters absorb solar radiation.
In the summer, coldwater fish move to the deeper water while in the winter they stay in the upper water.
In the fall and spring, there is a lot of growth at the surface.
When a green scum or red tide appears on the water, they become more noticeable.
Life zones can be divided into lakes and ponds.
Plants and organisms live in the littoral zone.
The fishes are in the sunlit limnetic zone.
The profundal and littoral zones are where the curafishes and molluscs are found.
The pike are prized by fishermen.
Largemouth bass are a type of ambush predator that waits among vegetation around the margins of lakes and pounces on passing prey.
The birds are feeding in the littoral zone.
The water strider can walk on water and live at the water-air interface.
Small fishes, such as minnows and killifish, serve as food for larger fish in the limnetic zone.
In the profundal zone, zooplankton, invertebrates, and fishes such as catfish and whitefish feed on debris that falls from higher zones.
The benthic zone is composed of silt, sand, and dead organic material.
Decomposers, such asbacteria, are found in the benthic zone and break down waste and dead organisms into food for the producers.
A portion of the ocean is where fresh water and salt water mix.
Mangrove swamps are found in tropical and subtropical zones.
The bays, fjords, and lagoons are classified as estuaries.
The term estuary has a broad definition.
Migrant birds frequent mudflats.
The coastlines of many tropical and subtropical lands are skirted by mangrove swamps.
Some organisms live on the rocky coast.
Organisms adapted to the estuarine environment benefit from the abundance of vitamins and minerals.
Estuaries are productive and diverse.
There is an abundance of food and habitat for animals in the estuaries.
The estuarine environment is home to nearly two-thirds of marine fishes and shellfish, making it the nursery of the sea.
There is an abundance of fish and shellfish.
As the tides roll in and out, the sea bombards the sandy shores.
The calcareous outer plates of barnacles remain in place even after the animal dies in the upper portion of the intertidal zone.
In the middle of the intertidal zone, rockweed may overlie the barnacles.
Below the intertidal zone, seaweeds anchor themselves to the rocks with holdfasts.
The ocean is home to many organisms.
Organisms can't attach themselves to shifting sands on a sandy beach, so most of the permanent residents are underground.
Either they burrow during the day or stay within their burrows and tubes at night.
Ghost crabs and sandhoppers burrow above the high tide mark and feed at night.
Sandworms and ghost shrimp remain in their burrows in the intertidal zone and feed on whatever they can find.
clams, cockles, and sand dollars are found.
shorebirds visit the beaches and feed on fish.
There is food for zooplankton and small fishes here.
These attract a lot of fish.
As the water gets deeper, seaweed can be found growing on outcroppings.
Sea stars, lobsters, crabs, and brittle stars prey on clams, worms, and sea urchins.
Coral reefs are found in shallow, warm, tropical waters.
Their main components are stony corals, animals with a calcium carbonate (limestone) exoskeleton, and calcareous red and green algae.
The corals feed at night while the algae grow during the day.
Coral reefs are usually developed in shallow, sunlit waters.
There is a lot of life on the reef.
The large number of crevices and caves give shelter to filter feeders and scavengers.
The barracuda, moray eel, and shark are some of the top predators in coral reefs.
There are many types of small, beautifully colored fishes here.
These become food for larger fishes.
The majority of the ocean's volume is within the pelagic zones.
There are a lot of whales in this zone.
Baleen whales eat small crustaceans from the water, while toothed sperm whales feed on squid.
The benthic division's epipelagic, mesopelagic, and bathypelagic zones are home to unique organisms.
Shrimps, squids, and fishes, including lantern and hatchet fishes, are some of the organisms that are translucent, red colored, or even luminescent.
Animals and fishes migrate from the mesopelagic zone to the surface at night.
There are animals in this zone.
There are strange-looking fishes with distensible mouths and abdomens.
Many animals survive there by feeding on debris floating in the water.
Sea lilies rise above the seafloor, sea cucumbers and sea urchins crawl around on the sea bottom, and tube worms burrow in the mud.
The flat plain is interrupted by mountain chains.
Sulfate reacts with water and forms hydrogen sulfide along the axes of the ridges.
There are organisms at the vents that live mutualistically with Chemo autotrophicbacteria that obtain energy from oxidizing hydrogen sulfide.
They are the beginning of a food chain that includes huge tube worms, clams, crustaceans, and fishes.
Light doesn't need light energy to exist in this environment.
We talked about food webs and energy flow in the section.
The biomagnification of Mercury is discussed in the Biological Systems.
Mercury emissions into the environment can cause serious health effects for humans.
Mercury emissions negatively impact fish and wildlife.
Humans are at risk if they come into contact with fish and wildlife.
Recent fish studies show that mercury is present in streams, wetlands, and lakes in the majority of the United States.
Mercury becomes a serious environmental risk when it is bioaccumulated.
A bioaccumulation occurs when an organisms accumulates a contaminant faster than it can eliminate it.
Most organisms can eliminate half the mercury in their bodies every 70 days if they don't eat any more during this time.
Problems arise when organisms can't eliminate mercury.
The base of the food chain is where Mercury tends to enter and increase in concentration.
The most vulnerable to high levels of mercury in their body tissues are top-level predator and organisms that have been around for a long time.
Humans are exposed to mercury due to eating contaminated fish or breathing mercury fumes.
Birth defects in infants and damage to the central nervous system can be caused by the form of mercury called methylmercury.
Every state in the United States has developed fish advisories for certain bodies of water.
45 states warn pregnant women to limit their fish consumption.
Mercury poisoning is not limited to aquatic species.
In the northeastern United States and Canada there was research that showed the presence of mercury in a variety of birds.
The consumption of contaminated fish can lead to high levels of mercury in the birds.
The presence of mercury in the songbirds raised serious concerns among ecologists.
Some theorize that songbirds in the northeast are consuming mercury when they feed on insects that have picked up the toxin from eating smaller insects.
Concerns about mercury's ability to enter food webs and bioaccumulate in previously unknown ways have been raised.
Humans are to blame for mercury pollution.
There are no limits to where mercury can be found.
With coalburning power plants being the largest source of mercury emissions, it will be up to us to find a solution.
High levels of mercury can be found in tuna due to biomagnification.
Fetal development can be affected by high levels of mercury in fish.
Climate is driven by the sun, but the oceans contribute to heat in the biosphere.
The distribution of the sun's rays causes water to be warm at the equator and cooler at the poles.
Warm air moves from the equator to the poles as air takes on the temperature of the water below.
The ocean makes the winds blow.
The oceans hold heat longer and remain cooler during periods of changing temperature than do the landmasses.
When wind blows across a large expanse of ocean for a long time, it causes the water to get wet.
The ocean currents are counterclockwise in the Southern Hemisphere and counterclockwise in the Northern Hemisphere.
Warm water is taken from the equator to the poles.
The Gulf Stream brings tropical Caribbean water to the east coast of North America and the higher latitudes of western Europe.
Without the Gulf Stream, Great Britain would be as cold as Greenland.
The eastern coast of South America is warm by another major ocean current.
The locations and directions of the major ocean currents are indicated by the arrows on the map.
Carrying warm water to cool latitudes and cool water to warm latitudes has a major effect on the world's climates.
There is a current in the Southern Hemisphere that goes toward the equator.
Along the west coast of South America, the Humboldt Current carries cold water.
The abundance of marine life in South America is due to the enriched waters.
Birds deposit their droppings on the land where they are mined for a commercial source of phosphorus.
The phenomenon is called an El Nio-Southern Oscillation.
The position of a region on the Earth and the amount of solar radiation play a role in determining the region's weather patterns.
Warm air rises near the equator and then descends at 30 degrees north and south to the poles.
The great deserts of the world are formed at 30 degrees latitudes when the air descends.
The winds blow in opposite directions above and below the equator because of the Earth's rotation.
On the windward side, air rises over coastal ranges.
The pattern of the world's biomes is influenced by temperature and rain.
When traveling up a mountain, the effect of temperature causes the same sequence of biomes.
Most of the water in the soil is frozen in the winter.
These are the most productive of all the biomes.
Some desert plants, such as cacti, are Succulents with thick stems and leaves, and others are shrubs that are deciduous during dry periods.
The freshwater and saltwater systems are divided.
There are three life zones in lakes and ponds.
plankton and fishes live in the sunlit limnetic zone, while bottomdwelling organisms such as crayfishes and molluscs live in the profundal zone.
The oceans and coastal ecosystems are different.
Estuaries are near the mouth of a river and are considered the nurseries of the sea.
The ocean is divided into two parts.
The most life can be found in the epipelagic zone.
The zone has organisms adapted to minimal or no light.
The bathypelagic zone is dark.
The continental shelf, continental slope, and the abyssal plain are on the ocean floor.
The base of these communities are the Chemoautotrophicbacteria.
The ocean currents are moving in a circular pattern.
Pick the best answer for the question.
The seasons are explained by the distribution of temperature and rain.
The northern and southern hemispheres are between 30 and 60 degrees.
The rotation of the Earth causes this.
The winds blow from the ocean.
The tundra is only described by low-lying vegetation.
A tropical rain forest has a multilevel canopy.
The westerlies explain the mild climate of Great Britain.
The ocean current is prevented from upwelling.
The tropical rain forests are being bioprospected.
These companies are looking for naturally occurring compounds in plants and animals that can be used as drugs.
Ski resorts, golf courses, and homeowners all contribute to water pollution.
Some farmers are using irrigation methods that deliver water directly to plant roots, no-till agriculture that reduces the loss of topsoil, and integrated pest management, which relies heavily on good bugs to kill bad bugs.
In some cases, encouraged by state and federal agents, dairy farmers have built sheds, concrete containments, and underground liquid storage tanks.
The manure is trucked to the fields.
In Minnesota, builders are required to control soil erosion with filter fences, to steer rain away from exposed soil, and to plant protective buffers.
Homeowners need to have a 25-foot and 50-foot setbacks from wetlands and lakes.
They are encouraged to have their systems pumped out every 2 years.