Physical ,chemical and biological indicator.

1. By: Farhan
Shahriar

2. Topic
Ecological
indicatorEcotoxic
ology

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

12. Ecological
Indicators
Physio- chemical
indicator
Biological
indicators

13. DO
Temperatu
re
pH
Turbidit
y
Others
Indicator
Conductivity

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?

30. Indicator species

31. StonefliesMosses

32. Tubifex
Greasewood

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.