Ecological indicator( Bio indicator)
- 3. ECOTOXICOLOGY Ecotoxicology Study of the effects of toxic chemicals on biological organisms especially at the population, community and ecosystem level is called ecotoxicology.
- 4. PCBs (polychlorinated biphenyls) Pesticides Mold makes Mycotoxins Phthalates VOCs (volatile organic compounds) Dioxins Asbestos Heavy metals Chloroform Chlorine Dirty Dozens Common Environmental Toxicants:
- 5. Toxin emitte d Contact by organism Ingest Reache s an organ Metabolized and/stored Molecular mechanis m Physiologi cal chain of events Advers e health effect Populatio n effect Communit y effect Ecosystem effect
- 6. WAY OF PREVENTION 1.FRAME WORK FOR WASTE: MEMBER STATES MUST TAKE NECESSARY MEASURE TO ENSURE THAT THE WASTE IS DISPOSED OF WITHOUT ENDANGERING HUMAN HEALTH OR HARMING THE ENVIRONMENT.MEMBER STATES THAT- DRAW UP WASTE DISPOSAL PLANT SUBJECT INSTALLATION THAT TREAT ,STORE ,OR DISPOSE OF WASTE FOR THIRD PARTIES TOA PRIOR PERMIT APPLY THE “POLLUTER PAYS” PRINCIPLE 2. ENVIRONMENTAL PROTECTION AGENCY (EPA) PROVIDES A DEVICE FOR CONTROLLING PESTS. IF ANY PESTICIDES REDUCED IT MUST HAVE TO BE REGISTERED BY EPA. 3.FOOD QUALITY PROTECTION ACT AND SAFE DRINKING WATER ACT WHICH REQUIRED EPA TO SCREEN PESTICIDES CHEMICALS FOR POTENTIAL
- 7. 4.The users must keep close trade of the labeling when using fertilizer or pesticides. 5.The Products which have less impacts on environment should be selected. 6.The laws which are implemented for using pesticides should be regarded. 7.The wastes should properly disposed
- 8. Testing of Ecotoxicity Aquatic toxicity test are used to detect and evaluate the potential toxicological effect of chemical on aquatic organism. Acute and chronic toxicity tests are done by two ways- 1.LC50 2.EC50.
- 9. LC50: LC50 is the acute toxicity test which is done for the concentrate of tissue at which it is lethal to 50% within 96 hours. The test may start with eggs, embryos or juveniles and last from 7 to 200 days.
- 10. EC50: EC50 is the effective concentration at 50% of the test organisms. It has many ways- a)Endocrine Disruption Screening Program (EDSP) b)Endangered Species Assessment. c)Persistent Bioaccumulative and Inherently Toxic ( PBiT) Assessment. d)Bioaccumulation in Fish Using the Bio-concentration Factor (BCF) method
- 11. Ecotoxicity Acute toxicity is directly related to classification of toxicity. Class- lll : The range of concentration in that’s class is 10-100 ppm Class- l: The range of concentration in that’s class is <1 ppm Class- ll : The range of concentration in that’s class is 1-10 ppm
- 14. Dissolved oxygen(DO) is a measure of the amount of oxygen dissolved in the water. Measured in either milligrams per liter (mg/L). Used to determine if aerobic or anaerobic conditions present DO ≥ 1mg/L - aerobic DO < 1mg/L – anaerobic DO fluctuates seasonally & even within 24hr period . Oxygen levels are lowest just before sunrise and highest sometimes in mid day. Temperature dependent Cold water can hold more DO than warm water
- 15. Faster moving water has more DO than slower moving water . Some species require high Do such as trout and stoneflies. Other species like Catfish, worms, and dragonflies do not require high DO If there are not enough DO in water, the following Death of adults and juveniles Reduction in growth Failure of eggs or larvae to survive Changes of species in a given water body.
- 16. pH – “power of hydrogen” Logarithmic scale from 1 to 14 pH = 7 is neutral pH < 7 is acidic; soft water; unhealthy to drink pH > 7 is basic; hard water pH determines solubility & biological availability of chemicals in water • Increased metals solubility at lower pH Safe level of pH ranges 6.5-8.5
- 17. High acidity or alkalinity deteriorates water quality for both aquatic and recreational purposes.
- 18. Generally relates to air temperature, but decreases with depth Remarkably stable parameter Impacts water chemistry High temperature low DO Rate of chemical reactions increases at higher temperatures Increased solubility with higher temperatures Increased temperature results in higher electrical conductivity because of more dissolved constituents. Some compounds are more toxic at higher temperatures Each species of fish has an optimum water temperature. It has become an important indicator , especially in light of climate change.
- 19. Conductivity is the ability of water to conduct an electrical current, and the dissolves ions are the conductors. Measured in micromhos per centimeter (µmhos/cm) or microsiemens per centimeter (µs/cm) When water has dissolved substances in it, it becomes more conductive. Conductivity increased by inorganic dissolved solids chloride, nitrate, sulfate,-phosphate anions (negative ions) sodium , magnesium, calcium, iron, aluminum cations (positive ions) Conductivity lowered by organic compounds (oil, alcohols, phenols)
- 20. Conductivity typically pretty constant so a change in conductivity may indicate an impact to groundwater. Distilled water conductivity of 0.5-3 µmhos/cm Industrial wastewaters conductivity of 10,000µmhos/cm Warmer the water the higher the conductivity Affected by geology water flows through Lower conductivity if water flowing through granite Higher conductivity if water flowing through clay
- 22. Measurement of suspended & dissolved matter in water; measure of clarity of water Measurements dependent upon color of dissolved constituents, particulate matter, particle size, and density. More particulate matter in water, the higher the turbidity . Suspended particles diffuse sunlight and absorb heat. This increase temperature and reduce light availability for photosynthesis. If the turbidity is caused by suspended sediment, it can be an indicator of erosion.
- 23. Higher groundwater flow rate, the higher the turbidity Lower flow rate, the lower the turbidity Shallow groundwater typically more turbid than deep groundwater Precipitation event may result in higher turbidity Construction/digging near wells may result in higher turbidity
- 24. Turbidity can also include colored dissolved organic matter (CDOM), also known as humic stain. Humic stain refers to the tea color produced from decaying plants and leaves underwater due to the release of tannins and other molecules. Turbidity can come from suspended sediment such as silt or clay, inorganic materials or organic matter such as algae, plankton and decaying material.
- 25. Direct measures of the health of the fauna and flora in the waterway. Commonly used biological indicators in water include various measures of… Macro invertebrate Algae For estuaries, biological indicators are less developed. Commonly used biological indicator in estuaries is chlorophyll-a Which is a measure of phytoplankton population density.
- 27. A species whose presence, absence or abundance reflects a specific environmental condition, habitat or community. Indicator species may: Provide information on the overall health of an ecosystem. Reflect a particular environmental condition, such as pollution. Be indicative of a particular habitat type or biological community.
- 28. How might indicator species show changes in the environment? Increase or decrease in abundance Presence or absence Change in behaviour Change physiologically or chemically
- 29. Indicator species can provide an early warning of environmental changes. They can be used to assess the health of an environment or ecosystem – they are often termed ‘bioindicators’. They can be a useful management tool. Why use indicator species?
- 31. StonefliesMosses
- 33. Air pollution- Lichens Lichens are formed from a symbiotic relationship between a fungus and an alga. They often grow on exposed rocks and trees, and need to be efficient at absorbing water. Air pollutants dissolved in rainwater, especially sulphur dioxide, can damage lichens and prevent them from growing.
- 34. Shrubby and bushy lichens are usually the most sensitive to pollution and are often absent from polluted areas. Crusty lichens are usually more tolerant of pollution and can grow in more polluted areas.
- 35. Water pollution Many aquatic animals can’t survive in polluted water, so their presence / absence can indicate the level of pollution in a water body.
- 36. Different invertebrate species are able to tolerate different levels of water pollution. The composition of species within a study area can indicate the level of pollution.
- 37. Species such as the rat-tailed maggot and sludge worm can tolerate very high levels of pollution. The water louse can tolerate high levels of pollution Freshwater shrimp can tolerate low levels of pollution Mayfly and stonefly larvae prefer clean water Water pollution - Invertebrates
- 38. Mussels are suspension feeders and accumulate heavy metals and toxins in their tissues. Mussels are often used as indicator species for monitoring the health of coastal environments.
- 39. A major form of water pollution comes from excess nitrates and other nutrients being washed into rivers and lakes. The nitrates in the water result in the rapid growth of algae, which is known as an algal bloom. As a result of the increase in algae, less sunlight can reach other aquatic plants, many of which then die. Bacteria begin to break down the dead plant material, using up oxygen as they do so, resulting in the death of fish and other organisms. This process is known as eutrophication The composition and total amount of algae species can indicate the amount of organic pollution. Water pollution - Algae
- 41. Amphibians Amphibians breathe through their skin so are easily affected by changes in water quality. For example, some chemicals may potentially cause physical abnormalities and malformations. Amphibians live both on land and in water.
- 42. Where amphibians have declined, There have been an increase in invertebrate pests. That damage crops and carry human disease. Water pollution - Amphibians
- 44. Care must be taken when using indicator species as there are some potential pitfalls: Judging an ecosystem based on the response of a single indicator species may not be enough to properly assess it. Need to be sure any correlation shown is real. The indicator species must be linked to the environmental condition studied in a scientifically sound manner to justify its use. The species may be difficult or time-consuming to survey. It can be hard work to identify a suitable indicator species! C o n s i d e r a t i o n s
- 45. Some organisms are very sensitive to changes in the environment and can be used to measure the impact of human activities. Indicator species can be useful in helping to assess different environmental conditions, such as pollution and climate change. Scientists, industrial companies and landowners may wish to use indicator species to monitor the health of a particular ecosystem. Care must be taken when choosing an indicator species to ensure that the results of a study accurately reflect the environmental conditions.