biodiversity test

Why is the river in trouble? 3 Reasons

1. Excessive nitrate fertilizers are polluting the river. 2. Acids from factories and industries are polluting the river. 3. Pesticides are polluting the river.

The number of different species in an area is called species diversity or

biodiversity

In what year was the biodiversity of species living near the Peril River the highest?

1950

How many algae and bacteria are in this sample?

2 algae and 2 bacteria

What dissolved oxygen range is optimal, or best, for aquatic organisms?

7-11 mg/L

What is the average dissolved oxygen for Test Site 1? Test Site 6?

9, 3

About how many algae and bacteria are in this sample?

About 30 of each

What are acids?

Acids are substances that add hydrogen ions into a solution, lowering the pH

Describe the process of biomagnification.

Biomagnification is what occurs when toxins become magnified, or built up, as organisms move through the food chain. It builds up through trophic levels from primary producers to top predators. Biomagnification magnifies or increases as it moves up the food chain.

Describe the average dissolved oxygen concentrations in both samples.

Both are a healthy 9 ppm

Describe the two samples of water in the microscope.

Both are clear with low levels of algae and bacteria.

Chemical analysis identified the pesticide as what banned chemical?

DDT

As DDT moves up the food chain, it becomes more concentrated. Why?

DDT is absorbed in the fat of animals. Since fish eat lots of insects, DDT moves into their tissues. Since a pelican eats a lot of fish, more DDT builds up in its tissues and is trapped in its body.

What can you conclude about the dissolved oxygen levels in the Peril River watershed system?

Dissolved oxygen levels are highest is water that has less algae and bacteria.

Describe how DDT moves through the food chain, eventually harming bald eagles

Farmers sprayed DDT to kill insects. Some insects were contaminated, but did not die. Small fish ate those insects and accumulated DDT in their tissues. Larger fish ate the smaller fish and acquired the DDT molecules in their tissues. Eventually, bald eagles ate the larger fish with the DDT and DDT built up even more in the eagle's body tissues. This caused the eagle's egg shells to become soft and easily breakable, limiting their reproductive capacity.

What groups of animals decreased in number since 1950?

Fish, Crabs, Pelicans, and Insects

Compared to the original condition of the river, how has monitoring nitrate run-off and eliminating DDT affected the water quality of the Peril River ecosystem?

Increased dissolved oxygen levels, less algae and bacteria levels, increased biodiversity and the water is no longer green and yucky.

Where is the green sample of water from?

It is from the mouth of the river, leading into the ocean.

Where is the clear blue water sample of water from?

It is from the upper reaches of the river, where the river starts.

How does dissolved oxygen affect living organisms in the river?

Low levels of dissolved oxygen make it difficult for fish and other aquatic animals to survive.

What are nitrates and where are they found?

Nitrates are nutrients that plants need that are found in natural and artificial fertilizers in the soil.

What is dissolved oxygen?

Oxygen found dissolved in the water and it is very important to organisms

What animals have increased in abundance since the reduction of DDT in the environment?

Pelicans, fish, crabs, and insects have all increased in abundance

What are pesticides?

Pesticides are chemicals that used to kill insects and other pests. They are used to protect crops from damage.

What are two negative effects of pesticides?

Sometimes they will harm other species than the species they were aimed to kill. They also can change the balance of organisms in an ecosystem.

What can you conclude about species diversity and abundance in the Peril River watershed system?

Species Abundance and Biodiversity have both decreased.

What happens to pelicans when they have a high level of DDT in their bodies?

The pelican's eggs break very easily, and they are unable to reproduce.

Why can excessive nitrates be a problem?

They cause algae to bloom, causing bacteria to decompose the algae, and low dissolved oxygen levels in the river.

What is the crime committed by the organic farm?

Use of DDT, an illegal pesticide

What are the photosynthetic plant-like organisms that are making the water green?

algae

What are the microorganisms that act as decomposers in an ecosystem?

bacteria

Has biodiversity in the Peril River increased or decreased over time?

decreased

Is there any acid pollution entering the River?

no

What animal has the highest level of DDT in its tissues?

pelican

Has biodiversity in the oceans surrounding Peril River increased because of your plan?

yes