Sampling Methods 1

Sampling Methods 1

Quadrat and Mark-Recapture

Sampling is done for scientific research

• To determine population size

• To study the behaviour of mobile organisms

• To study growth and spread of non-mobile organisms

• To understand organisms to be able to help in preserving species

Multiple Choice

Quadrat sampling is best used for non-mobile and very slow organisms

• True

• False

Multiple Choice

Capture-mark-recapture or Mark-Recapture is best suited for....

• Organisms that are hibernating and easy to count

• Organisms that are mobile and and hard to count

• Only animals that live in the ocean

• Animals that are hard to count non-mobile and mobile

Extrapolation

• The information calculated from quadrants can be extrapolated to get an estimated population size for an area.

• This is calculated based on frequency of species or number.

Multiple Choice

When extrapolating quadrant values, the best approach for an accurate estimation will be to....

• Do more random sampling to gather more data

• Take values from a very few quadrants and then extrapolate

• Extrapolate the values based on what you see even if it is not in the quadrat

• Disregard empty space

Mark-Recapture

• This is used when it is near impossible to estimate populations or study them due to their mobile nature.

• Can be done for tiny organisms such as ants and bees and giant beasts such as leatherback turtles.

Multiple Choice

Do scientists think this method to be an accurate one?

• Yes

• No

Multiple Choice

What is a disadvantage of the mark-recapture method?

• Accuracy depend on a few organisms

• Accuracy depend on capturing a large proportion of the population

• They take into account organisms that fall prey to others

• There are no disadvantages

Multiple Choice

I want to study the types of grasses that grow in my school's compound to determine the type of plants that may be best suited for a school garden. What is the best suited approach?

• Aerial photography

• Quadrat sampling

• Mark-recapture

• Photography

Multiple Choice

Between these methods, which will give a better population estimation for ocelots (endangered), in Trinidad?

• Quadrat sampling

• Mark-recapture

• Aerial photography

• Counting

Review

• Quadrats are most suitable in areas that are controlled

• Mark-recapture are most suitable when the environment and the organism cannot be controlled

• Both are effective ways of sampling

Poll

I understood the purpose and use of quadrat sampling.

• Yes

• No

Poll

I understood the use and purpose of the mark-recapture method.

• Yes

• No

Open Ended

Can any of the content covered today influence your decisions in your daily practices?

THE END ...TILL THE NEXT SESSION