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 : TEST ON SECTIONS G.1., G.3., G.4.1

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

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

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

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

Sentinel species

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

Biological Monitoring is frequently used to evaluate marine or aquatic pollution

Advantages of Biological Monitoring 1.We can detect intermittent pollution 2.A specific change in the Biotic index can indicate a specific type of pollutant 3.Food chains can accumulate pollutants (biomagnification) – particularly in higher trophic levels

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

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

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

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

Quadrat Sampling How large is the Quadrat? That depends on the region being sampled! 0.5 m 2, 1 m 2 How do we decide where to sample? Random sampling Stratified sampling Systematic sampling

Quadrat Sampling

How do we ensure that our data is collected in a ‘random’ method? Random Number Table

Transect Sampling

‘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’

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

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

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