Grade 8 Science - Unit E - Section 3 and 4

diversity

Description of the variety of different species in an ecosystem; may also be used to describe variety in a population or species

adaption

a physical characteristic or behaviour of a species.

What is one indicator of a healthy aquatic environment?

lots of plants, diversity and animals.

Describe the diversity you would find in a pond by SAB?

ducks, geese, birds, frogs and worms

What is an ecosystem? Why is the diversity of living things in salt water greater than in freshwater?

different animals, plants and organisms work together. because the ocean has more variety of environments.

What are some adaptations that aquatic species must have?

gills so they can remove oxygen from the water.

There are a number of environmental factors that lead organisms to develop certain adaptations

Temperature- Which temperature fish can survive in.

light- How much they thrive in light.

pressure- The weight of the water.

salinity- How much salt content.

Water movement- How fast/slow the water moves

Describe the four different ecosystems that can form in oceans.

Intertidal zone- Different ecosystems include rocky, sandy or muddy. Species here have specially adapted to live in this zone.

estuary- Marshes often grow around here. Many different plants, animals ancestry tolerate the brackish water. Rich in bird life because of food and shelter available.

Continental shelf- Canada's largest continental shelf is on the east coast. The water is warmer and light penetrates almost all to the bottom. Very rich area for plants and animals.

Oceanic zone- Many animals and plants, like the blue whale. Upper Parts of the ocean live on phytoplankton, while others deeper live off each other and waste that drops from above. In between surfaces are jellyfish, shellfish, squid, octopus, shrimp, etc.

Describe the type of organisms that live in the upper, middle, and lowest zones of a lake.

Middle zone- Phytoplankton is what the fish eat here. Those fish can also move to the darker and middle zone.

Upper zone- Bulrushes, water lilies, small fish, clams, insects, frogs, worms, snails and leeches.

Lowest zone- Fish down here eat the waste from plants and other fish above.

population

group of organisms of the same species living in the same area

The body of water that supports the greatest diversity of ecosystems is most likely

the oceans

The continental shelf is a 'shelf' of land that extends out from the edge of a continent below the ocean's surface. The water in this zone of the ocean is

relatively warm, light, and rich in nutrients

The zone in the ocean ecosystem that contains brackish water is the

estuary zone

What might a change in a population indicate? Why does a population change?

more or less organisms, plants, animals, etc. It could change because of disasters, sickness, environment change etc.

The shoreline area that may form different ecosystems in an ocean is known as the

intertidal zone

Which of the following is an example of a physical adaptation?

A chameleon changes colour to hide from its enemies.

What is a "dead" lake?

a lake that looks clean and pure, but was affected by acid rain and no fish or organisms can survive in it.

What causes an algal bloom? How does it contribute to a decrease in fish population?

when the amount of dissolved nutrients increases greatly. Because the water isn't pure and clean.

There are three major types of changes to populations. In the table below, describe each of them.

Seasonal change- A change in the weather that happens every season.

Long term change- A change that happens over a long period of time.

Short term change- A change that happens in a short period of time.

The zebra mussel population in the Great Lake has exploded. Do you think that this population growth will continue in the same way?

depends on the changes that happen in the future.

What is a population?

A group of organisms of the same species that live in a particular area.

What types of population changes can occur naturally but do not take place every year

Short-term

Purple loosestrife is a wetland plant native to Europe and Asia that was brought to North America in the early 1800s. Since it was brought to North America, purple loosestrife has become a serious invader of wetlands and roadsides. Without a natural predator, it spread all across Canada, crowding out native plants and reducing diversity. What type of change is this

long-term

. In 1979, 378 000 cod were caught off Canada's east coast. In 1988, 400 000 cod were caught off Canada's east coast. By 1993, this number had dropped to 50 000. The decrease in the cod population is mainly due to ________________

over-fishing

whats an example of seasonal change

Bears hibernating

Often, when too many chemicals are added into an environment, pollution occurs. This is evident when fertilizer runoff from farmer's fields increases the growth of green slime in a body of water nearby. This green slime is called a(n)

algal bloom

A lake that may look clean and pure, but does not contain any organisms is known as a(n

dead lake

Which of the following environments would have the greatest diversity?

sea

Brine shrimp are microscopic organisms that live in salt lakes and brine ponds. Few other organisms can live in these environments because it is so

salty

Which of the following statements about algal growth is incorrect

Excess algal growth produces more oxygen in aquatic environments, which supports underwater organisms.

benefits of: agriculture

Helps crops and provide for people who live their

Agricultural products can be sold to other countries

Provides jobs in agriculture

benefits of: industry

Industry provides jobs, products, and services therefore governments do not regulate water usage.

diluting pollutants when releasing them into the environment.

benefits of: domestic

Purified before enters house (canada)

percentage of: domestic

5%

percentage of: industry

22%

percentage of: agriculture

73%

costs of: agriculture

over-irrigation of soil can dissolve salts in the soil and cause salts to deposit on the soil's surface

Can deplete groundwater supplies

costs of: industry

Governments do not regulate water usage.

costs of: domestic

In many developing countries, people do not have clean water piped into their homes. This may be because no distribution system exists or because they cannot afford to pay for pipes to bring water to their house.

Some have to walk far to get water

powerstations

Sometimes discharge warm water into lakes and rivers that can kill some animals and encourage excessive plant growth

factories

Might add dangerous chemicals to the water and thermal pollution killing plants and animals. Some effects form the chemicals are tumours, birth defects, not able to breed,

runoff (farmland)

Can cause excessive plant growth, can contain herbicides or pesticides that can kill animals and plants.

runoff (cities)

Large amounts of oil, chemicals and salts. Affect plants and animals.

habitat destruction

Takes away the places animals can live and plants can grow.

sewage

Lots of oxygen which means lots of microorganisms. If micro-organisms use oxygen then fish will suffocate. Phosphorus promotes plant growth that can change the whole ecosystem.

oil spills

Ships cna harm animals in, on or near the water.

The major agricultural use of water is for

irrigating

Of all the water that is used by people in the world, what portion is used by agriculture

73%

Which of the following is a benefit of how humans use water

It provides jobs and products

Rivers and lakes are impacted by many human activities. The primary source of thermal pollution is

powerstations

Which of the following statements about human activities and water systems is correct

Habitat destruction takes away the places that animals can live and plants can grow.

How do we help guard against health problems caused by a sudden increase in the population of harmful micro-organisms in our water supply?

monitoring

A small micro-organism parasite, that lives in local water supplies, called Giardia, causes 'giardiasis', which makes people sick. This illness is also referred to as

beaver fever

To maintain high standards of water quality, cities and towns hire _____________________ to measure chemicals and organisms in the water.

water technicians

Science and technology are two ways to solve many of the environmental problems society faces, but authentic problem solving requires

a strong commitment form people

Dumping toxic waste into a major river over many years can make a 'dead' river that is a hazard to people's health. Which river was once so polluted that the smell of it could make you sick, but is now so clean and clear that fish have reappeared?

The Thames River in London

Why is monitoring the water supply an important technique in environmental protection?

it helps identify what sort of pollution there is in the water, and where it comes from.

How can we help guard against problems with water quality?

volunteer to clean the water, dispose of waste properly, set up signs for others to understand what's wrong and what's right, etc.

monitor

To watch closely and frequently; to observe and make note

Why can't science and technology alone solve all our environmental problems?

our environment needs humanity and resources humans can supply and technology can't.