malacca straits name: poon tsz ha, wendy fu, vivian tf tse
TRANSCRIPT
Presentation Outline Background of the project Methodology of the project Data Analysis Recommendations
Purpose Demonstrate ERA – risk management
as a viable framework for managing land- & sea-based sources of marine pollution in subregional sea areas
Packaging the approach, methods & experience for the similar environmental management in E Asian region
Unique ecological system High productivity & diversity Rich mix of fauna & flora Intricate hydrodynamics Complex interactions within &
between water body & land-based activities
Geography Natural channel
between Indian & Pacific Ocean
Bounded by 3 littoral States
2nd busiest shipping lane in the world (300 vessels/day) Source:
http://en.wikipedia.org/wiki/Strait_of_Malacca
Geography Euryhaline condition
Rich nutrient level Shelter from strong currents & wave
action High & uniform temperature Adequate tidal flushing
High biological productivity & diversity Rich mix of fauna and flora from Indian &
Pacific Ocean
Natural biological resources Mangrove: 80% at Indonesian side Seagrass bed: patchy and abundant
Nursery grounds for many fish species Shows relationship between availability of
habitats, fish stocks & sustainable yield Corals: patchy but not very abundant
Natural biological resources Exploited along both coasts of the
Strait Fisheries for demersal & pelagic
species: NW half of the Strait Mangrove removal for timber &
aquaculture : entire length Extensive aquaculture: cause potential
problem to environment through release of organic waste & chemicals
Population & Employment Indonesia: 11m; predominant on
agriculture & fisheries, derivative industries based on natural resources
Malaysia: 10m; mix of agriculture, fisheries, heavy & light manufacturing industries
Singapore: 3m; manufacturing & commercial activities
River system Similar numbers of river
catchments on Indonesian & Malaysian coasts
Similar amount of rainfall Similar volume (90million m3)of
outflows & runoffs from both coasts (presumption)
Sewage facilities & Quality of inputs
Area Sewage facility Quality of inputs
Indonesia very limited agricultural
Malaysia limited industrial
Singapore very complete industrial
Impacts to the Strait Increase of total suspended solids in the
water column & sedimentation Mangrove removal (esp. NW half of Strait)
increase erosion River load Agricultural runoff Aquaculture
O2 depletion, light attenuation & physical cover impacts on mangroves, seagrass beds & corals
Impacts to the Strait Volume: 1012 m3 Considerable dilution & removal of
contaminant loads by flushing Dominant surface movement: SE
to NW
Temperature and its impacts Constant high temperature (26 –
30 。C) Exposure side: rate of
biodegradation contaminants Effect side: rate of contaminant High level of metabolism (Ecotoxicological effect)
Rainfall and its impacts High intensity but Short duration Considerable contamination of dissolved
and particulate materials from storm water runoff
Reduce in salinity Osmotic stress in marine species contaminant exposure
Reduce in salinity Alter bioavailability of many contaminant (e.g. Cd fraction of dissolved metal exits as free ions)
Target Human health
Fish / seafood consumption Contamination of fish / seafood by metals,
pesticides & hydrocarbon Habitat
Mangroves, peat swamps, seagrass beds, coral reefs, soft-bottom habitats
Species Commercial & non-commercial marine
species
Addressing the questions Evidence for problems with human
health, habitats & species (incl. commercial fish stocks)
Problems caused to human health, habitats & species by conditions exist now or in the future
Identify assessment & measurement Endpoint
Risk = f(H)(E)Where: H = Potential harm E = Likelihood of exposure to
potential harm
Initial risk assessment Screening mechanism: identify priority
environmental concern on a Strait-wide basis, related data gaps & uncertainties
Objective: Utilize available information on sources,
exposure & effect of land- & sea-based activities, and pollution derived therefrom on living & non-living resources
Program outline for initial risk assessment Preparation of draft report
Major polluting sources & activities, and their effects on living & non-living environment
Delineation of the significant indicators of ecological, human health & social risk from pollutive land- & sea-based activities
Spatial & temporal scales of assessment
Program outline for initial risk assessment
1. Preparation of draft report (cont) Interaction between land- & sea-
based activities and interactions with living & non-living resources in & along the Straits
Combine effects of multiple & diverse stress on ecology
Systematic effect of a catastrophic event, e.g. oil / dangerous chemicals spillage by shipping accident
Program outline for initial risk assessment
2. Identify data gaps & uncertainties that need comprehensive risk characterization
3. Formulation of action plan for comprehensive risk assessment Utilize available expertise & resources to develop risk management program for the subregion
Refine risk assessment The Strait as a whole
The Strait as a single compartment and estimate a single average exposure concentration for the entire Strait)
Selected contaminants, risk to local areas within the Strait Local exposure concentration in the
vicinity of specific human activities or natural resources
Refine risk assessment Complete refined risk assessment
of land- & sea-based sources of pollution & their effects on living & non-living resources
Using results of initial risk assessment & updated information from the 3 littoral states to produce a comprehensive document on ERA
Program outline for refined risk assessment
1. Review & analyze available data provided, update and/or verify the methodologies, conclusions & recommendation of initial risk assessment
2. Model development & demonstration of series of scenarios. Analysis of scenarios
3. Test techniques for improving uncertainty analyses and report the results
Others Uncertainty assessment
Qualitative & quantitative method Society risk
Environmental degradation & its impact to the economy
Risk-benefit analysis Prioritize risk assessment in the
society, as a key in risk management
Consideration Relation between potential causes
of problems for human health and the environment
Consequences in the Strait Analysis of risk pathways: high
economic importance, incl. social, national, governmental commercial interests
Consideration Sources of hazards related to economic Knock-on effects to economy by
pollution Influence judgment about priorities for
action Direct risk assessment Weigh benefits to human health and the environment with costs to economy Influence management actions taken
Key ingredients Identifying targets and endpoints
precisely Identifying significant adverse changes
Evidences to show the problems Identifying possible causes of the changes
Identifying possible consequences of the changes for ecosystems and human welfare
Key ingredients In this paper: Evidences of decline on the Straits
Habitats Biodiversity
Attributed causes Based on expert judgment and weight of
evidence rather than experimental sciences
Possible consequences
Habitat loss and consequences
Habitat Areal extent
in quantity
in quality
Consequences
Ecological
Economic
Mangroves L L M *** **Peat swamps
L L NI *** **
Coral reefs S NI M ** *Seagrass beds
M NI M ** *
Soft bottoms L No M ** **
Habitats - Mangroves Evidences of decline
Sumatra (Indonesia): loss 24% of mangrove coverage in 7 years (1987-1993)
Malaysia: loss 17% of mangrove coverage in 2 decades (1965-1985)
Singapore: loss approximately 81% of mangrove coverage in the last 2 decades
Habitats - Mangroves Attribute causes
Clearance for brackish water ponds Over-exploitation for timber and charcoal Clearance for development Sedimentation and pollution
Consequences Reduced protection from coastal erosion and
natural disaster Reduced nursery grounds for commercial and
non-commercial fish and invertebrates Loss of habitat for endangered species Economic loss for the timber industry
Habitat: Peat swamp forests Evidences of decline
Sumatra (Indonesia): 7.3-9.3 million hectares to 3.6 million hectares (50% reduction)
West coast of Peninsular Malaysia: 299,145 hectares (77% of this area are indicated as “disturbed and logged-over”)
Habitat: Peat swamp forests
Attribute causes Logging of commercially valuable
tree species Land conversion to rice, palm and
coconut plantations Consequences
Loss of biodiversity Similar to the consequences of the
loss of mangrove coverage
Habitat: Coral reefs Evidences of decline
No data on the total area of coral reefs in the Straits and the loss of coral reef area
Indonesia: Poor condition: 42%; Fair condition: 29%;
Good condition: 24%; Excellent condition: 5% Malaysia:
Most of the coral reefs are rated as fair condition
Singapore: Among the most stressed in Asia coral reef
Habitat: Coral reefs Attributed causes
Fishing damage Pollution e.g. metals, oil spills and pesticides Massive land reclamation in Singapore
Consequences Reduced in physical protection of shorelines Loss of biodiversity Reduced in fishery production Loss of tourist attraction
Habitat: Seagrass beds Evidences of decline
No quantitative data on areal coverage or its loss
Singapore: Extensive seagrass beds Isolated patches
50 known seagrass species Indonesia:12 species West coast of Peninsular Malaysia: 9 species Singapore: 9 species decline to 7
species(1990s)
Habitat: Seagrass beds Attributed causes
Destruction due to the conversion to coastal aquaculture
Natural disaster e.g. storm and disease Deposits of mining spoils and tailings Excessive sediments due to deforestation Pollution
Consequences Loss of buffering zone from wave action Reduced stabilization of sediment Reduced in biodiversity Loss of harvestable invertebrates, macroalgae and
grass loss of nursery grounds for fishes
Habitat: Soft-bottom habitats Evidences of decline
Straits: covered by sandy and muddy bottom extensively
* Quality in supporting species An examination of effects on female
reproductive systems in gastropods in terms of percent female imposex
Negative correlations between females with imposex and distance to the nearest shipping route
Habitat: Soft-bottom habitats
Attributed causes Physical disruption by trawling Contamination of sediments from pollutants
Consequences Loss of tourism attraction e.g. sandy beach
Decline for fisheries production
Biodiversity Evidence of decline on on-commercial
species Population density: Two indigenous
fish species (Alosa toil and Lactarius lacarius) are getting rare in Singapore
Species diversity: 52 species of fish, 13 species of coral and anemones, 12 specie of crustaceans – extinct; >50 other species – threatened in Singapore
Biodiversity The increasing deterioration of
environmental conditions in the Straits and increasing human activities result in changes of species composition (disappearance of other species and the increasing number of endangered species)
Biodiversity Attributed causes
Loss of major habitats Contamination
Consequences Loss of tourist attraction Increase in instability of the
ecosystem
Biodiversity Evidences of decline on commercial
species: Indonesia: Decline in catch-per-
unit-effort (CPUE) Malaysia: fall in total catch and
catch rate
Biodiversity Attribute causes
Over-fishing Losses of nursery grounds Pollution
Consequences Economic loss Reduction of fish species
Prospective risk assessment Identify the likely problems for harm
to ecological Scientific and objective measurement
Risk quotient Risk quotient
Provide indices of risk for further detailed analyses
Risk Quotient (RQ) Measurement
RQ = PEC / PNEC RQ = MEC / STD
Certain substances that occur naturally i.e. background concentrations BQ = MEC / background
concentration
Uncertainty analysis Carried out for the prospective risk assessment
to the varying levels of sophistication PNECs and STDs
Depend on the reliability of the ecotoxicological and toxicological data
MECs Depend on the reliability of sampling and
analytical techniques PECs
Depend on the assumptions of the models used in making predictions and the reliability of input data
Prospective risk assessment
In this paper Estimate the likelihood of adverse
effects from environmental conditions within the Straits
By comparing measured environmental concentrations (MECs) and predicted environmental concentrations (PECs)
Likely problems for harm to ecological
Various heavy metals in the water and sediment
Pesticides in the water and sediment
Problems arising from suspended solids
Concentration of heavy metals in water
Metal Highest mean MEC
RQ (table 7-3)
RQ (Danish std)
BQ(MEC/BV)
As 8 0.08 / 8
Cd 114 11 46 28500
Cr 62 0.12 / 413
Cu 34 0.34 11.7 567
Hg 68 68 227 136000
Pb 108 1 19 108000
Concentration of heavy metals in water RQ analysis
RQ > 1 = High risk Metals of Pb, Hg, Cd and Cu >1 Results of BQ is consistent with RQ
Concentration of heavy metals in waterUncertainty analysis Variability among standards
Purpose for use Variability in MECs
Values above or below the critical value (Log RQ = 0)
Data of RQ have to be transformed and presented as mean log value
Log RQs for all metal > 0
Concentration of heavy metals in water
West Coast of Peninsular Malaysia
Klang River
Metal
Highest mean PEC
RQ (Danish std)
Highest mean PEC
RQ (Danish std)
Zn 0.334 0.004 / /
Cu 2.6 0.9 25.8 9.9
Hg 0.0007 0.0002 / /
Pb 0.404 0.007 0.089 0.016
Concentration of heavy metals in water Klang River
Greatest density of manufacturing industry along the west coast of Peninsular Malaysia
Heavy Metal contamination in coastal waters was limited to certain areas close to industrial sites and estuaries
Concentration of heavy metals in sediments No general accepted sediment quality
standards RQ estimation
Based on water quality Csed = (Cw X Ksw) / r Critical concentration of metal in sediment
= (concentration of metal in water X solids-water partition coefficient) / empirically derived concentration ratio between suspended matter
Concentration of heavy metals in sediments
MetalsCd RQ (table 7-3) RQ (Danish std)
As 0.0400
Cd 0.0060 0.03
Cr 0.0007 0.36
Cu 0.0700 2.40
Ni 2.10
Pb 0.0030 0.06
Zn 0.07
Concentration of heavy metals in sediments Lack of concordance between water
column and sediment data The water and sediment samples were
taken from different sites Different metals were included in the 2
types of analysis Periodically dredged of sediment Dissolved and particle-bound form of
sediments
Heavy metals and human health RQ = daily metal intake / tolerable daily
intake (TDI) Daily metal intake = daily intake X
metal content of the intake Level of concern (Action level) =
Tolerable daily intake / Seafood consumption
Likely problems for harm to ecology and human
Heavy metals and human health
Uncertainty analysis Uncertainty in tolerable daily
intakes TDIs standard varies between
countries Dermal exposure to metal e.g.
bathing
Conclusion
Retrospective Risk Assessment Decline in mangroves, peat swamp
forests, coral reefs, seagrass beds and soft bottom habitats
Mainly caused by habitat destruction such as coral reef were affected by increased sediment loads
Reduction in fish stocks due to overfishing Pollution was probably a contributory
factor
Prospective Risk Assessment Various heavy metals were found in
water column and sediment, pesticides TBT or nutrients were not identified
Human Health Prospective Risk Assessment
No indication that health problems might arise from oil and hydrocarbon exposure
Oil and Hydrocarbon PollutionLong term exposure – land based industrial activities
Short-term exposure – accident was calculated on the basis of historical experience
RecommendationsGeneral Recommendations
Standards used in future risk assessment should be agreed by all littoral States
E.g. definition of ecological targets on both scientific and societal issues
E.g. definition of thresholds (standards and PNECs)
General Recommendations
Regional monitoring programs should be available for future risk assessments
Exposure models should be developed for future risk assessment.
Needs in human health risk assessment to reduce the uncertainties with both threshold effect values and exposure information
Recommendations to Risk Management agreement on the approach
between littoral States to mangrove clearance
controlling fishing intensity food contamination monitoring from
metals and pesticides should be considered
Recommendations to Risk Management prevention of the exposure on the
most contaminated beaches to avoid sewage infection
Management strategies should be more proactive to reduce the potential for contact between high risk vessels and vulnerable habitats
Risk Management ActionsRetrospective Assessment
The loss of mangroves, peat swamps and seagrass beds
The declining fishing Protection of other species