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Cyanobacteria Risk Profile: bring together knowledge, data, risk assessment

and management

Bala Vigneswaran and Grant Tranter

Sydney Catchment Authority

Fourth National Cyanobacteria Workshop

Adelaide

22 - 24 September 2014

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Presentation Outline / Scope

• SCA

• Cyanobacteria Management Strategy

• Cyanobacteria Risk Profile

• Cyanobacteria Action Plan

• Cyanobacteria Risk Forecasting

• Cyanobacteria Response Plan

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SCA Area of Operations

Warrragamba

Shoalhaven

Upper Nepean

Prospect Blue

Mountains

Woronora

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SCA Network

Provides raw water for

over 4.5 million people

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Cyanobacteria Management Strategy

Cyanobacteria Risk Management Strategy (2005)

• issues and species of concern

• guidelines and standards

• monitoring

• SCA practices relating to cyanobacteria

• short-, medium- and long-term management and control

• trends in trophic status

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Cyanobacteria Management Strategy

Cyanobacteria Management Strategy (2012 – 2015)

• maintain and improve monitoring for changes in the nutrient and

algal status

• improve scientific understanding of cyanobacteria, including the

environmental conditions favouring the growth

• identify and manage interventions that improve the trophic

condition of reservoirs and reduce the potential of blooms

• ensure effective response capability by incorporating research

and reviews conducted for improvement of operational response

• ensure that SCA stakeholders have a high degree of confidence

in the SCA to appropriately and effectively manage the risks

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Cyanobacteria Risk Profile

Likelihood

• trophic status

• recent trends in

chlorophyll-a

• probability of potentially

toxic cyanobacteria

blooms

• probability of blooms

producing T&O

compounds.

Consequence

• contamination of raw water supplied

to customers for drinking water

• contamination of stored waters

causing health problems for

recreation users

• public perception / community and

customer confidence

• constraints in supplying source water

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Reservoir Vulnerability Assessment

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Cyanobacteria Risk Profile

Cyanobacteria risk for each reservoir

Consequence

Like

liho

od

Minor Moderate Major Severe

Very Likely

Likely

Fitzroy Falls Wingecarribee

Yarrunga (Kangaroo)

Bendeela

Possible

Warragamba (Junction)

Warragamba (Coxs)

Warragamba (Wollondilly)

Warragamba (Gorge)

Unlikely

Cordeaux

Cataract

Yarrunga (Shoalhaven)

Woronora

Nepean

Prospect

Cascades

Avon

RISK Low Medium High Very High

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Activities to reduce cyanobacteria risks

To reduce risks related reservoirs and raw water supplies:

• implementation and continual improvement in the water

monitoring program

• implementation of actions under the Healthy Catchment Strategy

to reduce nutrient delivery to the reservoirs

• implementation and ongoing review of the cyanobacteria

response plan for each reservoir

• review of operational triggers

• dissemination of timely information about system changes and

operation matters to the stakeholders.

Priority ranking: high – medium - low

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Cyanobacteria Action Plan

• Developed in consultation with SCA’s internal stakeholders

• Communicated with external stakeholders

• A list of activities focusing on prevention and management through:

o Monitoring

o Research

o Investigation

o Management initiatives

Large number of projects, big and small

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Cyanobacteria Action Plan: case studies

Develop an annual forecasting method and tools…

• quantitative / semi-quantitative / qualitative

Early warning of local outbreaks and dispersal of cyanobacteria blooms in

drinking water reservoirs by multi-objective evolutionary computation

Recknagel et al. (2014)

SCA (in-house)

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Cyanobacteria Action Plan: case studies

Degradation of cyanobacteria metabolites in water….

• Physico-chemical / microbial

Determination of rate constants and half-lives for the

simultaneous biodegradation of several cyanobacterial

metabolites in Australian source waters

Ho et al. (2012)

Fate of microcystins and nodularins in

a reservoir

Khan et al. (2013)

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Cyanobacteria Action Plan: case studies

Factors responsible for cyanobacteria to produce toxins…

• Nutrient stress proteome in toxic and non-toxic Microcysis sp.

• Comparative protein expression in different strains

• Fe-uptake and toxin synthesis under Fe-limitation

Determination of factors responsible for cyanobacteria genes to produce toxins

Neilan et al. (2013)

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Cyanobacteria Action Plan: case studies

Key drivers to occurrence of blooms of cyanobacteria…

• Iron uptake in dark and bright conditions

• Nutrient uptake rate under iron limitation

• Microcystin production and nutrient levels

Physico-chemical control on cyanobacteria in SCA reservoirs

Waite et al. (2013)

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Cyanobacteria Action Plan: case studies

Taste and odour compounds in Prospect Reservoir…

• MIB and geosmin

• cyanobacteria and actinomycetes

• water column and benthic

Investigate sources of MIB and geosmin in Prospect Reservoir

SCA (2013)

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Summary

• Cyanobacteria Management Strategy:

– facilitates a structured approach for knowledge and

operational tasks

– ensures that SCA stakeholders have a high degree of

confidence in the SCA to manage the risks

• SCA has a robust cyanobacteria risk prioritisation process

• SCA has enhanced its capacity to predict cyanobacteria

risks and the means to avoid them

• SCA revises Cyanobacteria Risk Profile in 2015 using

updated information

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Still…

• All the name changes…

– From a well known Anabaena to an unfamiliar Dolichospermum…

• Analytical challenges…

– From individual names to Coccoid Blue Greens

• In-situ probes

– Chlorophyll-a

– YSI / BBE

– Cytobuoy