Bioassessment and Bioassessment and biomonitoring: biomonitoring:

some general principlessome general principles

What’s the difference?What’s the difference?

Bioassessment: Bioassessment: -- the use of living organisms to assess the use of living organisms to assess

aspects of the integrity (condition, aspects of the integrity (condition, ‘health’) of the environments in which ‘health’) of the environments in which they livethey live

OROR

-- the process of determining if human the process of determining if human activity has altered the biological activity has altered the biological properties of an ecosystemproperties of an ecosystem

Biomonitoring: Biomonitoring: the use of living organisms to track the use of living organisms to track conditions in the environments in which conditions in the environments in which they livethey live

OROR

the systematic use of biological the systematic use of biological responses to evaluate environmental responses to evaluate environmental changes [within a quality-control changes [within a quality-control programme]programme]

A metricA metric is a value calculated from a is a value calculated from a particular set of measurements.particular set of measurements.

An indicatorAn indicator is a feature (biological, is a feature (biological, physical, chemical, a metric, an index) physical, chemical, a metric, an index) that reflects specific condition or that reflects specific condition or change in condition.change in condition.

An index An index is a numerical indicator is a numerical indicator derived from a series of metrics.derived from a series of metrics.

Indices can be based on metrics Indices can be based on metrics derived from derived from

the biotathe biotae.g. SASS (inverts); VEGRAI (riparian e.g. SASS (inverts); VEGRAI (riparian

veg.)veg.)or or physical featuresphysical features

e.g hydrological, habitat indicese.g hydrological, habitat indicesorormixed featuresmixed features

e.g. WetEcoservices: derived from e.g. WetEcoservices: derived from socio-economic & biotic indices socio-economic & biotic indices

Bioassessment uses components Bioassessment uses components of the biota to reflect aspects of the biota to reflect aspects of e.g.of e.g.

-- water chemistrywater chemistry

-- hydrology (e.g. water level)hydrology (e.g. water level)

-- availability of nutrientsavailability of nutrients

-- ecosystem integrity (‘health’)ecosystem integrity (‘health’)

-- suitability for particular suitability for particular purposes (i.e. ‘quality’) etc. purposes (i.e. ‘quality’) etc.

e.g. the Saprobien Index: e.g. the Saprobien Index: organicorganic pollution pollution

Why Why biobioassessment?assessment?

While chemical and physical analyses are While chemical and physical analyses are -- reliable (accurate, repeatable)reliable (accurate, repeatable)-- provide ‘instant’ snapshots’provide ‘instant’ snapshots’

They are They are -- limited to the period of sample limited to the period of sample

collectioncollection-- limited to the constituents measuredlimited to the constituents measured-- expensive (if comprehensively done)expensive (if comprehensively done)-- limited by sensitivity of the methods limited by sensitivity of the methods

used: low concentrations cannot be used: low concentrations cannot be detected.detected.

Living organismsLiving organisms

- provide a longer-term view

- are continuous monitors: they integrate effects of time and multiple pollutants

- can be cheap and easy to assess

- can be used for different purposes

- account for synergistic (magnifying) and antagonistic (reducing) effects (e.g.

pH)

Where does ecotoxicology fit in?Where does ecotoxicology fit in?

The study of the effects of toxic The study of the effects of toxic substances on [aquatic] organismssubstances on [aquatic] organisms

usually laboratory-based experimentsusually laboratory-based experiments

link between WQ and its effects on the biota: e.g. used for deriving guidelines

includes field studies:

bioaccumulation / biomagnification “active biomonitoring”

use of biomarkersuse of biomarkers

Protozoa /diatoms – identification specialisedProtozoa /diatoms – identification specialisedAlgae / periphytonAlgae / periphytonMacroinvertebratesMacroinvertebratesFishFishMacrophytesMacrophytesBirdsBirds

Which organisms to use in bioassessment?

First ask,First ask,

WHAT DO WE WANT THE WHAT DO WE WANT THE

BIOTA TO TELL US??BIOTA TO TELL US??

i.e. what are we monitoring FOR?i.e. what are we monitoring FOR?

e.g. it can provide a measure of e.g. it can provide a measure of changechange

We can monitor specific features, usually We can monitor specific features, usually at fixed points: at fixed points:

e.g.e.g. edges between veg. typesedges between veg. typeswater levelwater level degree of degree of

sedimentationsedimentation fixed-point fixed-point photographyphotographygeomorphology of channelsgeomorphology of channelsdensity of density of aliensaliens aspects of aspects of ground waterground water

Individual species as ‘indicator Individual species as ‘indicator species’species’

e.g. halophytes & halophobese.g. halophytes & halophobestolerators of low pHtolerators of low pH

rapid responders to changes rapid responders to changes in in nutrient levelsnutrient levels

those whose eggs must those whose eggs must desiccatedesiccate before hatchingbefore hatching

ruderal speciesruderal species……

Can use assemblages:Can use assemblages:

e.g. diatoms (good for aspects ofe.g. diatoms (good for aspects ofwater chemistry)water chemistry)

odonates (IBI?)odonates (IBI?)

molluscs (IBI?)molluscs (IBI?)

macrophytes (hydroperiod /macrophytes (hydroperiod /water level)water level)

macro-invertebratesmacro-invertebrates(generalized impairment of (generalized impairment of

water quality)water quality)

What criteria are important What criteria are important when selecting techniques / when selecting techniques / indicators?indicators?

-- rapidity (& therefore cost)rapidity (& therefore cost)

-- narrowness of tolerance rangesnarrowness of tolerance ranges

-- common-ness (or even rarity)common-ness (or even rarity)

-- ease of identificationease of identification

-- life cycle of the right lengthlife cycle of the right length

What methods of analysis?What methods of analysis?What taxonomic level of identification?What taxonomic level of identification?

What numerical methods – What numerical methods –

simple arithmetic (e.g. SASS)?simple arithmetic (e.g. SASS)?

multivariate analyses (e.g. multivariate analyses (e.g. AusRivas, AusRivas, Rivpacs): Rivpacs): predictive modelling?predictive modelling?

Validation of proposed indices?Validation of proposed indices?

What level of confidence is necessary?What level of confidence is necessary?

What can biomonitoring NOT do??What can biomonitoring NOT do??

It cannot It cannot replacereplace phys & chem. data phys & chem. data (it complements it)(it complements it)

It does not explain the cause of the It does not explain the cause of the problem, merely indicates that there problem, merely indicates that there is oneis one

It seldom predicts outcomes (but It seldom predicts outcomes (but indicates trajectory of change).indicates trajectory of change).

THE NATIONAL WETLAND RESEARCH THE NATIONAL WETLAND RESEARCH PROGRAMMEPROGRAMME

PHASE II: WETLAND PHASE II: WETLAND HEALTH AND HEALTH AND INTEGRITYINTEGRITY

Development of the WHI research Development of the WHI research programme:programme:

Strategic overview of research needs in Strategic overview of research needs in wetlandswetlands

Malan & and Day (2005) Malan & and Day (2005) Strategic overview Strategic overview of the research needs for wetland health and of the research needs for wetland health and integrity.integrity. WRC Report no. KV 171/05. WRC Report no. KV 171/05.

Malan, Day & Marr (2005) Malan, Day & Marr (2005) Assessment of Assessment of wetland ecological health and socio-wetland ecological health and socio-economic importance: an annotated economic importance: an annotated bibliography.bibliography. WRC Report no. KV 172/05 WRC Report no. KV 172/05

Aims of the WHI research Aims of the WHI research programmeprogramme

To develop tools for assessing To develop tools for assessing

-- ecological conditionecological condition

-- aspects of the biophysical environment aspects of the biophysical environment (e.g. (e.g. water quality, hydroperiod)water quality, hydroperiod)

-- socio-economic importance socio-economic importance

-- loss of wetland function through loss of wetland function through degradation …degradation …

THE INDIVIDUAL PROJECTSTHE INDIVIDUAL PROJECTS

MACROPHYTE INDEX

Development of an index of biotic integrity / ecosystem condition based on macrophytes

- consolidation of plant species lists: individual species as indicators of

specific conditions (e.g. high salinity or low pH)

DIATOM INDEX

Development of an index based on diatoms - commonly used for aspects of water chemistry

INVERTEBRATE INDEX

To investigate the feasibility of developing an index of wetland health using invertebrates- PhD project

DRY CONDITION INDEX

- identification of non-perennial wetlands - assessment of their condition / integrity in the dry state Use of macrophytes? invertebrates? diatoms?

TESTING OF EXISTING TOOLS:critique/gap analysis

- WET-EcoServices (index of ‘functionality’): rapid evaluation

of wetland goods & services

- WET-Health (a type of IBI)

- Ecological Importance and Sensitivity(to be used by DWAF)

DEPENDENCY METRIC

Development of a metric of socio-economic dependency of communities on a wetland

SUSTAINABILITY METRICS:

effect of human use on

- ecosystem functionality

- sustainability use of a wetland

LOSS-OF-FUNCTION METRICRelationship between function and extent of degradation

LANDSCAPE-LEVEL IMPACTS

The cumulative impact of wetland loss at the landscape level