Week 9: IB Biology

1. Week 9: IB Biology Monday: G.4.: Conservation of Biodiversity ‘Explain the use of biotic indices and indicator species in monitoring environmental change’ Tuesday: Measurement Techniques: • Quadrat measurement • Transect Sampling • Catch and release methods • Biotic Indices • Simpson’s Diversity Index • Biomass Wednesday: Practical session with Quadrat Sampling and Transect Sampling Friday: Review Sections G.1, G.3, G.4.1 Monday 5.11.12: TEST ON SECTIONS G.1., G.3., G.4.1

2. G.4.1: Biological monitoring and indicator species What is an indicator species? • Any biological species that defines a trait or characteristic of the environment: • May indicate a particular ecosystem • May indicate a disease outbreak • May indicate pollution • May indicate species competition • May indicate climate change

3. Indicator Species – Marine health • Oysters and mussels are used as ‘biomonitors’ to assess environmental pollution of coastal waters • Mussel Watch!

4. Indicator species can indicate an increase OR decline in biodiversity • ‘Sentinel Species’ • ‘Keystone species’ • ‘dominant species’

5. Keystone species • These are species which have a disproportionately significant effect on their environment • Sometimes they are predators • Sometimes they are ‘ecological engineers’ • Examples: Grizzly Bear, Sea Otters, Sea Stars

6. Sentinel species

7. Some species can indicate the presence of abiotic factors and/or changes in ecological processes • On land, lichens are often used since they are sensitive to sulphur dioxide • ‘Bushy’ lichens need pristine air • Leafy lichens can survive a small amount of pollution • ‘Crusty’ lichens can survive in heavily polluted air • Regions devoid of lichens may indicate a high concentration of sulphur dioxide

8. Biological Monitoring is frequently used to evaluate marine or aquatic pollution

10. Advantages of Biological Monitoring • We can detect intermittent pollution • A specific change in the Biotic index can indicate a specific type of pollutant • Food chains can accumulate pollutants (biomagnification) – particularly in higher trophic levels

11. Disadvantages of Biological Monitoring • Distribution of organisms may be patchy so sampling must be done carefully • Invertebrate organisms tend to be seasonal • Some indicator species show tolerance to different pollutants

12. Sampling techniques you need to know for IB Biology – Ecology • Quadrat measurement • Transect Sampling • ‘Kick’ sampling methods • Catch and release methods • Biomass measurement

13. Analysis Techniques used in IB Biology • Biotic Indices • Simpson’s Diversity Index • Gross/Net Production calculations* * We will cover Biomass calculations next week

14. Which type of Sampling Method is appropriate? • How to choose your sampling technique

15. Quadrat Sampling How large is the Quadrat? • That depends on the region being sampled! • 0.5 m2, 1 m2 How do we decide where to sample? • Random sampling • Stratified sampling • Systematic sampling

16. Quadrat Sampling • Quadrat Sampling

17. Quadrat Sampling • How do we ensure that our data is collected in a ‘random’ method? • Random Number Table

18. Transect Sampling

19. ‘Systematic sampling’: Transect Sampling • ‘Transect’: a ‘path’ along which the number and occurrence of a species can be counted • There are several different transect methods: • ‘Strip/ Line transect’ • ‘Belt transect’

20. Belt Transect • Sampling is carried out to a strip of fixed width – e.g. 0.5 – 1 m

21. Line Transect Sampling • Transect Sampling • Ssampling is confined to describing all of the organisms that touch the line

22. ‘Kick Sampling’ Techniques • Standard method for collection of aquatic samples