Biological Assay

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Biological Assay

• Lesson Plan Indicator Species

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What is an Indicator Species?

• An indicator species is any biological species
  that defines a trait or characteristic of the
  environment.
• Basically, these species have certain reactions
  to indicate changes in environmental conditions.
• They may react to conditions such as disease
  outbreak, pollution, species competition or
  climate change
• Obviously, they are among the most sensitive
  species in a region, acting as an early warning
  to monitoring biologists.

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What is an Indicator Species (contd)

• a species whose presence indicates the presence
  of a set of other species and whose absence
  indicates the lack of that entire set of species
• a keystone species, which is a species whose
  addition to or loss from an ecosystem leads to
  major changes in abundance or occurrence of at
  least one other species
• a species whose presence indicates human-created
  abiotic conditions such as air or water pollution
  (often called a pollution indicator species
• a species thought to be sensitive to and
  therefore to serve as an early warning indicator
  of environmental changes such as global warming
  or modified fire regimes (sometimes called a
  bio-indicator species)

Left Leopard frogs are often used as
environmental indicator species because of their
heightened sensitivity to chemical pollutants
found in the air and water
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Examples

• Many indicator species of the ocean systems are
  fish, invertebrates, periphyton, macrophytes and
  specific species of ocean birds (like the
  Atlantic Puffin).
• Amphibians are also common indicator species, as
  they may have become repositories of bioindicator
  chemicals, or of ecological conditions relating
  to global warming, air pollution chemicals, newly
  extant diseases (fungus), or environmental
  pressure on the ecosystem, which affect the
  population numbers, and the quality of the
  individuals.
• Lichens are indicators of air quality. They are
  particularly sensitive to sulfur dioxide, a gas
  emitted from exhaust and industrial fumes, and so
  are rarely found in large cities and towns or by
  roads. Filamentose, fruticose and foliose
  varieties are particularly sensitive. Their
  presence indicates air very low in sulfur
  dioxide. Crustose, leprose and squamulose
  varieties are more tolerant of poor air.

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Visual Depiction
E8.3 Know how to indentify local trees, shrubs,
grasses, forbs and wildlife species by common name
Indicators of Air Quality
Lichens
Fruticose
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Visual Depiction
Indicators of Ocean Quality
Atlantic Puffin
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Introduction to Ceriodaphnia Dubia

• Scientific Name Ceriodaphnia dubiaCommon Name
  Water Flea
• Physical description Very small (one
  millimeter).  When in good health, they appear to
  be a brownish-orange color.  Males and females
  can be distinguished from each other by their
  shape and size.  Males are smaller and less
  rotund than are the females the males are almost
  triangular in shape.  Movement is achieved by a
  powerful set of second antennae.  Because of
  this, movement is generally vertical and jerky.
• Ecology Can be found in littoral areas lakes,
  ponds, and marshes throughout most of the world. 
  
• Other Uses Live food source in freshwater
  larviculture and in the ornamental fish industry.

Kingdom - AnimaliaPhylum - ArthropodaSubphylum
- CrustaceaClass - BranchiopodaOrder -
CladoceraSuborder - EucladoceraFamily -
DaphnidaeGenus - Ceriodaphnia
E8.1 Understand the scientific method of animal
classification, including order, family, genus
and species
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Visual Dissection of an Aquatic Organism
Head Small and Depressed
Cervical Sinus Present
Rostrum (Tail) Absent
Postabdominal Claw with Pecten
Presence of Eggs
Daphnia
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Visual Dissection of an Aquatic OrganismContd
E6.2 Know the major body parts, digestive systems
and reproductive organs of aquatic species
Ceriodaphnia dubia
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Uses of indicator species Ceriodaphnia
E6.4 Analyze the relationship between water
quality and aquatic species habitat

• This tiny aquatic invertebrate is used as an
  indicator organism to measure toxicity in water.
• It is considered to be a representative of
  important creek organisms at the bottom of the
  food web.
• Toxicity to this species is believed to indicate
  poor water quality.
• Diazinon and chlorpyrifos have been identified as
  impairing water quality because they are
  occurring at levels toxic to Ceriodaphnia dubia.
• These pesticides can cause toxicity to
  Ceriodaphnia at very low levels.

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Arcade Creek Project Ceriodaphnia

• Ceriodaphnia is very sensitive to pesticides,
  heavy metals, and other toxic substances used by
  humans discharged into surface waters as well as
  many naturally occurring substances and
  conditions.
• These properties make Ceriodaphnia a good
  organism for testing the toxicity of freshwater.
• Natural waters can become poisonous to the
  organisms that live in these waters when
  pollutants enter the water in too high a
  concentration.
• In a toxicity test, the Ceriodaphnia is placed in
  the water being tested and in an amount of clean
  water called the "control."
• If the organisms in the control live and the
  organisms in the test sample die, we know that
  they were initially healthy and something which
  is present in the sample (but not in the control)
  had caused their mortality.
• The water sample is considered "toxic." It does
  not, however, differentiate between naturally
  occurring g toxins or conditions, and man-made
  toxins or conditions. 
• Each water quality test is carried out using
  special instruments and water samples are taken
  from the river by the different teams.

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Water Management, The Environment and Human Needs
E2.6 Analyze the way in which water management
affects the environment and human needs

• Water management is an essential part of our
  every day lives
• By monitoring toxic levels and the survival rates
  of indicator species in water sources can help
  predict trends in the water
• This is extremely important because humans
  interact with these various water sources on a
  daily basis whether it be through recycled water
  used in sprinklers or by human interactions with
  water sources

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Field Activity

• Investigate Role of Indicator Species by
  Observing Effects of Toxic Chemicals on
  Developing Seeds
• Purpose The purpose of this field activity is to
  create a lab in which a certain plant will act as
  an indicator species by modeling harmful effects
  of chemical leaks in soils.
• Background- Toxicity Assays
• In toxicity assays, we attempt to determine the
  dose of a chemical substance required to cause
  acute effects on living organisms. In performing
  toxicity assays, there are many considerations in
  experimental design.
• Choose an indicator species to be used in the
  laboratory to act as an indicator for what may be
  happening in a more complex ecosystem. The choice
  of indicator organisms varies depending on the
  problem. For example, if we were concerned with
  water pollution, we would use aquatic organisms.
  So in this lab we are concerned about a chemicals
  leaking into the soil, so we use plants.
• When examining the results of a toxicity assay,
  we can use simple statistical methods to evaluate
  data. For example, the average (mean) is
  calculated. This average can be the number of
  surviving organisms, average shoot length,
  average life span, average egg laying rate, etc.
  In addition, we can calculate a standard
  deviation and the coefficient of variation (CV)
  for each average.

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Works Cited

• Aliberti, Maria A. "Image-Based Key to the
  Zooplankton of Northwestern USA." Ceriodaphnia
  Dubia. 2007. Center for Freshwater Biology. 27
  May 2008 lthttp//cfb.unh.edu/CFBkey/html/anatomy/d
  aphnia/daphnia.htmlgt.
• Belanger, S. E. and D. S. Cherry.  1990. 
  Interacting Effects of pH Acclimation, pH, and
  Heavy Metals on Acute and Chronic Toxicity to
  Ceriodaphnia dubia (Cladocera).  J. Crust. Bio.
  10 225-235.
• "Daphnids Ceriodaphnia Dubia, Daphnia." MBL
  Aquaculture. 2005. Marinco Bioassay, Inc. 26 May
  2008 lthttp//mblaquaculture.com/content/organisms/
  daphnids.phpgt.
• Draper, Alison. "Toxic Seeds Part 1 2007."
  Effects of Toxic Chemicals on Developing Seeds.
  2007. 27 May 2008 lthttp//www.trincoll.edu/jgourl
  ey/ENVS20149 20Toxic20Seeds/Toxic20Seeds20Par
  t201_2007gt
• Pennak, R. W.  1978.  Fresh-Water Invertebrates
  of the United States Second Edition.  John Wiley
  and Sons, New York.  Pg. 371.
• "Toxicity Test." Lodi's Storm Disease Detective.
  27 May 2008 lthttp//www.lodi.gov
  /Storm_Drain_Detectives/toxicity.htmgt.