Stressor: Anything that has negative impact on situation you are assessingPhys, chem, bioSource: Origin of the stressorExposure: Contact between stressor and receptorReceptor: The entity exposed to a stressorWaquoit Bay: Watershed risk management case studyMassachusettsSeptic tanks causing eutrophication in the water waysScallops and fin fish fisheries are impactedStressors: nitrogen, pharmaceuticals, noise pollution, sludge, habitat modification, release of oil/wasteSource: Urbanization, boating, septic tanksPathways: Permeable sand, waterwaysReceptors: Eelgrass, fish, humansEcological Effects: Algae compete with primary producers, habitat loss, toxicity from pollution1. Problem formulation phase: Discussion between people who want or are required to have risk assessment and risk assessorsa. Create hypotheses regarding stress, risk to ecosystems, and ecological effectsb. Endpoint selection: Example is salmoni. Be sure they are ecologically relevantii. How susceptible is the endpoint to the stressoriii. Want endpoint to have societal relevance1. Be sure it effects people so they want to support itUsually want to measure multiple endpointsc. Build a conceptual model2. Analysis phase: How to characterize exposure, what will the impacts be on the ecosystema. Determine strengths and limitations of datab. Two key components: Characterize exposure and ecological effects1. Ecosystem characterization: soil, flora, fauna, climate, etci. Past damage, boundaries, climate changes, biotic interactions, food webs, pathways2. Stressor characterization and evaluation of relevant effects3. Exposure AnalysisDistribution, extent, timingTransport pathwaysDifficulties: Non-point sources, boundaries, secondary stressorsExposure dose equationDose = Contaminant concentration x Intake rate x Exposure factor (fraction of the year or day) /Body weight70 kg = average weight of an adultLower body weight  higher risk4. Ecological response analysis5. Stressor/response analysisSame as dose/response but uses single species toxicity to extrapolate to population/community level responsesLD50 o ED50CausalityStrength and consistency of association between stressor/responsePredictive performance of modelsObserved biological gradientsLab/field congruenceThreshold: Ecosystem is resilient until it hits a certain amount of stressor3. Risk characterization: What is the probability of the riskFinal stage of ERA1. Risk estimationIntegrationUncertainty analysis: How confident you are based on how much data there is, etcUncertainty caused by: Unclear communication, collection errors, small data pool, aggregate data (lose precision), natural variabilityQuotient method: Expected environmental concentration/concentration producing an unacceptable environmental effect>1 potential of high risk~1 potential risk<<1 low risk2. Risk descriptionEcological risk summary: What are the effects and do you believe themInterpreting the ecological significance and relating it to the general publicRisk Management: Manage risk while considering environmental, social, and economic effectsMonitoring is the most importantOur main goal is to protect and stimulate eelgrass growth.Improve septic tank structurePossibly switch to pipeline plumbing by a certain time periodMonitor boating: license to boat, quota on how many at one timeLimiting fertilizer/pesticide use to certain typesEducate the community on awareness and importance of eel grassHalt urbanizationRisk, continued 03/28/2013Stressor: Anything that has negative impact on situation you are assessing -Phys, chem, bioSource: Origin of the stressorExposure: Contact between stressor and receptor Receptor: The entity exposed to a stressor Waquoit Bay: Watershed risk management case study-Massachusetts -Septic tanks causing eutrophication in the water ways -Scallops and fin fish fisheries are impacted -Stressors: nitrogen, pharmaceuticals, noise pollution, sludge, habitatmodification, release of oil/waste -Source: Urbanization, boating, septic tanks-Pathways: Permeable sand, waterways -Receptors: Eelgrass, fish, humans -Ecological Effects: Algae compete with primary producers, habitat loss, toxicity from pollution1. Problem formulation phase: Discussion between people who want or are required to have risk assessment and risk assessorsa. Create hypotheses regarding stress, risk to ecosystems, and ecological effects b. Endpoint selection: Example is salmon i. Be sure they are ecologically relevant ii. How susceptible is the endpoint to the stressor iii. Want endpoint to have societal relevance1. Be sure it effects people so they want to support itoUsually want to measure multiple endpoints c. Build a conceptual model 2. Analysis phase: How to characterize exposure, what will the impacts beon the ecosystema. Determine strengths and limitations of datab. Two key components: Characterize exposure and ecological effects1. Ecosystem characterization: soil, flora, fauna, climate, etci. Past damage, boundaries, climate changes, biotic interactions, food webs, pathways 2. Stressor characterization and evaluation of relevant effects 3. Exposure AnalysisoDistribution, extent, timingoTransport pathways oDifficulties: Non-point sources, boundaries, secondary stressorsoExposure dose equationDose = Contaminant concentration x Intake rate x Exposure factor (fraction of the year or day) /Body weight70 kg = average weight of an adult Lower body weight  higher risk 4. Ecological response analysis 5. Stressor/response analysis oSame as dose/response but uses single species toxicity to extrapolate to population/community level responses LD50 o ED50oCausality Strength and consistency of association between stressor/responsePredictive performance of models Observed biological gradients Lab/field congruence Threshold: Ecosystem is resilient until it hits a certain amount of stressor 3. Risk characterization: What is the probability of the risk -Final stage of ERA 1. Risk estimation oIntegrationoUncertainty analysis: How confident you are based on how much data there is, etc Uncertainty caused by: Unclear communication, collection errors, small data pool, aggregate data (lose precision), natural variabilityoQuotient method: Expected environmental concentration/concentration producing an unacceptable environmental effect >1 potential of high risk ~1 potential risk<<1 low risk 2. Risk description oEcological risk summary: What are the effects