Investigating an ecological niche

AS 3.14 Credits

Biozone book pages 14 - 52

Choosing an Organism

Location: Kina Peninsula

Possible organisms:- Mud crab- Tube worms- Flat worms- Sea Anemones- Catseyes- Whelks

Monday 19th of March

Trip one to Kina:You will only have about an hour to check

out the site. A hand out will be given for you to fill out.Try to identify as many rocky shore

organisms as possible.Think about variables you could

manipulate to investigate an ecological niche of an organism.

Background Research – Needed for your INTRODUCTION

Research possible rocky shore organisms before Monday 19th of March, from the list in slide 2, or any ones that might interest you. BE PRACTICAL THOUGH!

Research:Habitat, ecological niche of organism,

adaptive features of organism, advantages, disadvantages, feeding, protection ….

Aim

A formal statement of the purpose of the investigation.

Example:

To investigate Periwinkle activity in different

salinity concentrations.

HypothesisA testable statement of the expected

outcome of the investigation.Null hypothesis – not necessary (A statement of the expected outcome if

the variable has no effect on the organism)

Example:

Periwinkles will become less active in decreasing

Salinity concentrations.

This is because the tidal zone is exposed to rain

which can decease the salinity concentration.

An accurate description of the materials andexperimental procedure used in theinvestigation.

Written in third person.

Method must be detailed enough so that anindependent person could carry out theinvestigation with out your help.

Method

Periwinkle MethodExample

1. Collect sufficient number of similar sized periwinkles (minimum 150)

2. Collect 1 litre of sea water from flowing sea3. Need 1 litre of tap water4. Make up 5 different concentrations of sea water (100mls each)5. Make sure periwinkles are out of water for at least 30mins prior to

the investigation6. Place 10 periwinkles in each of the Petri dishes, add to each Petri

dish 5ml of each of the different concentrations of seawater.7. Leave for a set time (10 seconds), then count how many

periwinkles in each Petri dish are active, record.8. Repeat the process 1 – 7 three times.9. Control – light (carry out in shade), temperature (water room

temperature), amount of seawater (5ml) and number of periwinkles (10/petri dish) so that it is the same for all trials.

Periwinkle method cont….

Salinity concentrations:20% - 20mls seawater + 80mls tap water40% - 40mls seawater + 60mls tap water60% - 60mls seawater + 40mls tap water80% - 80mls seawater + 20mls tap water100% - normal seawater (nothing done to it)

How the controls might effect my investigation:If light and temperature are not controlled then the periwinkles may notbe exposed to the same conditions. Therefore what they mayberesponding to is not salinity concentration but light or temperature.

ActiveThe periwinkle is visible. Front part of theanimal is out of the shell (feeding apparatus).

Thursday 22nd March

Must get to me before trip with equipmentrequirements. If you see me on Thursday P3 Imay not be able to help you!

Carry out your investigation. If you find youneed to modify your method, make a note ofThat in your log book.

Record data - YAY

Recording data

Example only

Seawater concentrations

20% 40% 60% 80% 100%

Trial 1 0 0 3 9 8

Trial 2 0 0 2 10 8

Trial 3 0 0 0 10 8

Average 0 0 2.5 9.7 8

Results

This should be a summary of your findings.Have tables and graphs accompanied byexplanations.

You can carry out statistical analyses,however this does not have to be done butcould be a good way to show validity ofresults!

Conclusion & Discussion

• A statement of the conclusion(s) from your findings, it should relate back to your aim and hypothesis.

• Follow the conclusion with an in-depth discussion of the biological significance of your results and how they relate to the organisms ecological niche.

• If your results do not show this you need to discuss this discrepancy.

Evaluation

This is where you get to discuss your

Limitations (problems with your investigation):

• Problems encountered and how they may have effected your investigation

• How the effects of bias were reduced (Random selection, control of variables)

• Sources of error and how they were eliminated• The validity of the conclusion (if you use stats)

References

APA – American Psychological Associationformat.

NO REFERENCE NO PASS!!!!

Use this website to help you:http://www.waikato.ac.nz/library/learning/g_apaguide.shtml

Otherwise look up books in library or go see Miss Gass

5th Aprils (Thursday)

3.1 is DUE and its Holidays, so YAYHappy Easter

Hand in to Miss Gass by 3:30pm. If you can’t find Miss Gass take if to office and get them to put the time on it and the office can put it in my pigeon hole.

You must hand in your log book