Plankton are microscopic organisms that drift or float in aquatic environments. They are categorized into phytoplankton and zooplankton. Phytoplankton are plant-like organisms that can photosynthesize, while zooplankton are animal plankton that consume other organisms. Plankton play important roles in aquatic ecosystems as indicators of water quality, primary producers that form the base of the food web, producers of oxygen through photosynthesis, and major participants in the global carbon cycle. They are studied and classified by size, nutritional requirements, length of planktonic life, and habitat. Understanding plankton communities provides insights into ecosystem health and functions.

1. Presented by
Mahesh Kumar
WT&MD
CSIR-NEERI
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2. What are the plankton?
 “Planktos “ Greak meaning “to wander”
 Planktons are weakly swimming or drifting organisms
 Microscopic or macroscopic in size
 “Plankton” is not a single species but a large group of
organisms that fall into two primary categories-
1.phytoplankton (plant)
2.zooplankton (animal)
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3. Why planktons are important?
Indicators of water quality
Kolkwitz and Marsson (1908) were stated that the presence of certain species of
algae could define various zones of degradation in a river.
Taxonomic composition, size distribution, trophic levels, spatial patterns, and
functional characteristics and quantitative data of Phytoplankton very helpful in
study of water quality of water body. (Andronikova, 1996).
Food source (basics of the food web)
According to Vargas 2006 et al., Phytoplankton is the foundation of the aquatic
food web, meaning that they are the primary producers. From this we can
conclude that Phytoplankton plays an important role in aquatic food web.
Phytoplankton is the foundation of the aquatic food web, meaning that they are
the primary producers (Vargas and others, 2006).
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4. Food Chain of Aquatic Ecosystem
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5. Producer of Oxygen (Photosynthesis)
Recall from biology that autotrophs (primary producers) like plants ,
phytoplankton create carbohydrates (usable energy) from light through
photosynthesis:
CO2 + H2O  C6H12O6 (carbohydrate) + O2(oxygen)
Like plants, phytoplankton produce oxygen during photosynthesis.
It has been estimated that, on a global scale, 50 – 60 % of all photosynthesis is
performed by phytoplankton (Campbell, 1999).
Major players in the global carbon cycle
During photosynthesis phytoplankton use atmospheric CO2 and lead
decrease in atmosphere.
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6. CLASSIFICATION OF PLANKTON
It is possible to classify members of the plankton in
multiple ways.
A. On the basis of nutritional requirements
1. Phytoplankton : microscopic plant like organisms which can do
photosynthesis .
Ex : Diatoms,Dinoflagellates , cyanobacteria, coccolithphores.
2. Zooplankton: are microscopic animal plankton which are
heterotrophic(both detrivores and herbivores).
Ex: copepods, fishlarvae, ctenophores, crustaceans.
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7. B. On the basis of size
• Pico-plankton <o.2-2μm
• Ultra-plankton <2μm
• Nano-plankton <5μm
• Micro-plankton <60-500μm
• Meso-plankton <0.5-1mm
• Macro-plankton <1mm-10mm
• Mega-plankton 10mm or >10mm
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8. C. On the basis of the length of planktonic life
Holoplankton- that zooplankton who spend their entire life cycle as
plankton .They are permanent zooplankton.
Examples include dinoflagellates, diatoms and krill.
Meroplankton- that zooplankton spend only a part of their life cycle
drifting. They are temporary zooplankton.As they mature they become
nekton (free swimmers) or benthic (crawlers).
Examples include fish and crab larvae.
D. On the basis of the habitat
 1. Marine plankton (Haliplankton)
 2. Freshwater plankton (Limnoplankton
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9. Phytoplankton
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10. Zooplankton
Copepod Comb Jelly Larvacean
http://www.flickr.com/photos/manualcrank/3661819626/ http://www.flickr.com/photos/malingering/4009908759/ http://en.wikipedia.org/wiki/File:Oikopleura_dioica.gif
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11. How phytoplankton are different
from zooplankton?
Phytoplankton
 Producers
 Single cells or chains of cells
including the smallest plankton
– picoplankton (0.2 -2 microns)
 Remain near the surface
Zooplankton
•Consumers (including herbivores and
carnivores)
•Include microscopic and macroscopic
organisms.
•May vertically migrate (to a depth )
during the day for protection but
resurface at night to feed.
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12. Plankton
Phytoplankton Zooplankton
Fresh water Phytoplankton
 Cynophyta
 Chlorophyta
 Euglenophyta
 Dinophyta
 Chrysophyta
 Crytophhyta
 Bacillariophyta
Marine water phytoplankton
 Xanthophyta
 Rhodophyta
 Phaeophyta
 Protozoa
 Cladocera
 Copepoda
 Rotifer
 Nematoda
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13. How Planktons are studied
Requirement
 Plankton net
 Apron
 Hand gloves
 Bucket
 Rope
 Plastic sampling bottle of 100 ml
capacity
 Preservatives
 Ice box
 Record book
 Water proof levels
 Van dram sampler
 Preservatives
 Ec , Ph meter
 Glass beaker
 Measuring cylinder
 Centrifuge tubes
 Centrifuge
 Dropper
 Microscope slides
 Cover slips
 Microscope
 Plankton identification key
 Record note book
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14. Plankton net Sampling bottle Van Dorn Sampler
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15. Sampling technique
 Sampling location
 Frequency of sample collection
 Total number of sample
 Size of each sample
 Method of collection
 Study area (Lake, River, Reservoir)
 Depth, time, date, Meteorological condition, turbidity, temperature, salinity.
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16. Site selection
Field study
Primary data collection Secondary data collection
Water sample source
(lake, river, pond)
Depth,temp,turbidity,
Salinity,etc
Sampling
Preserve sample
Centrifugation
Identification and counting
Phytoplankton(100 ml) Zooplankton(50 ml)
5% Formailin or 70 %
ethenol
lLugol’s solution
2000-3000
rpm (20m)
1500-2000
rpm (2m)
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17. Microscopes
 Binocular Compound Microscope- A binocular
compound microscope is used in the counting of plankton
with different eyepieces such as 10×, 20×,40×, and 100× .
Phytoplankton- 40x and 100x
Zooplankton-4x and 10x.
Objective lenses Compound Microscope
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18. Counting method
Phytoplankton- Lackey Drop Count Method (Lackey, 1938; Edmonson, 1963)
Zooplankton- 1 ml of valume for observation in S-R (Sedgwick-Rafter)
counting cell.
Slide and coverslip:
18*18 Cover glass Slide Sedwik- Raftar cell
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19. Counting Units
 Phytoplankton-The number of organisms per 100 ml of
water sample is calculated as given below.
 Number of individuals/ 100 ml= (C x At x 10) / (As x S x V )
Where,
C = No. of organism counted
At= Area of coverslip, mm2
As= Area of one strip, mm2
S= No. of strip counted
V= Volume of sample under coverslip, ml
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20.  Zooplankton-
where:
C = number of organisms counted,
V¢ = volume of the concentrated sample, mL,
V¢¢ = volume counted, mL, and
V¢¢¢ = volume of the grab sample, m3.
To obtain organisms per liter divide by 1000.
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21. Shannon Wiener Index (SWI)
Species diversity
d = −∑𝒍𝒏𝒑𝒊 × 𝒑ⅈ
where,
pi=n/N
n=Number of individuals of particular species
N=Total number of individuals of all species
d= Shannon Wiener Index
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22. Palmer’s pollution index
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23. Index
SWI Shannon Weiner
Index
Plankton Density
PPI Range Palmer’s pollution
Index Status
<1 Maximum <15 Low Organic
Pollution
1-<3 Medium 15-19 Probable evidence
of high organic
pollution
≥3 Minimum ≥20 Evidence of high
organic pollution
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24. Identification
 On the basis of morphological character, color,
motility, colony structure.
 Seasonal variability.
 Flagella number, position, length.
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25. Harmful Algal Blooms
 An algal bloom is a rapid increase in the population of
phytoplankton in an aquatic system.
 Result of excess of nutrients (particularly p and n).
 HAB’S couses negative impacts on aquatic organism
via production of natural toxins.
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26. Factors that can contribute to HAB’s
 Excess nutrients
 Sunlight
 Low water level or low flow condition
 Warmer temperature
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27. Some HAB’s
 Anabaena-Anabaena produces a chemical that is toxic to many species of
animals .
 Spirogyra -A bloom causes a grassy odour and clogs filters at water
treatment plants.
 Oscillatoria -Oscillatoria is considered to be the group of alga that is
the second most tolerant of organic pollution.
 Volvox - An excess of nitrogen encourages the growth of Volvox and may
cause "blooms" during the summer months. During blooms in the shallow
ponds at fish hatcheries, the large numbers of Volvox cause damage to the gills
of young fish
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28. THANK YOU
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