The seasonal distribution of the major components of the zooplankton community, protozooplankton, copepods and cladocerans, along a eutrophication gradient were examined in order to establish if eutrophication through increases in phytoplankton biomass and productivity has an impact on biomass and composition of the zooplankton community
2. Session Overview
1. Session Review: Benthos distribution
2. Session Overview
3. Introduction
4. Distribution of Zooplankton
5. Horizontal distribution
6. Vertical migration
7. Seasonal succession
8. Summary
9. Recommended Books/ Papers
3. Introduction
Simply the animal planktons are
zooplankton.
On the basis of quality of life-
Holoplankton: Permanent plankton ex.
Mysid, lucifer
Meroplankton: Temporary plankton ex. fish
larvae, crab larvae
oevidenced that zooplankton abundant area
are rich in fishery, that’s why we need to
know their distribution mainly.
4. Distribution of Zooplankton
Almost all zooplankton are herbivorous, feed
on phytoplankton, so their distribution are also
confined to the upper layer of the water body
(pond, lake, estuary, oceans).
a)Horizontal
b)Vertical
c) Diurnal
d) seasonal
12. Seasonal Succession
There is a marked change in species composition, this
change in the dominant species from season to season is
called seasonal succession. In this succession, one or more
species of plankton dominate for shorter or longer period of
time and then replaced by another set of species. This pattern
repeats yearly.
Changes in species composition at Swandwip in different
seasons
Swandwip Premonsoon
Zooplankton Number
Mysid 12
Lucifer 8
Acetes 7
Sagitta 22
Calanus copepods 2
Swandwip monsoon
ZooplanktonNumber
Crab larvae 14
Fish larvae 11
Shrimp larvae 5
Swandwip post monsoon
Mysid 11
Lucifer 6
Cyclopoid copepods 4
Daphnia 1
Fish larvae 5
13. Factors responsible for variation in distribution
Physical factors:
Light:
light
e.g. nco2 + nH2O (CH2O)n + nO2
photosynthesis
- Primary Production restricted to lighted zone/ upper zone
-Zooplankton mostly herbivorous
Temperature:
-respiration
- metabolism and reproduction increase with temp.
14. Physical factors:
Current:
influence all life of the ocean
-carries DO
-disperse eggs, spores and adult to suitable area, also play
negative role.
wave:
-increase the uptake of O2
-also destructive effects like carries to the upper part of shore
and die.
Tide: can supply DO
-again a lot can trap during low tide
Upwelling: brings nutrients from deep water to the surface
water- so directly affect the growth
Turbulence : Vertical circulation
-Can mix water between layers, carries nutrients.
16. Vertical Migration/distribution
Periodical movement of an organism from one place to
another in a particular season or time for various purpose
such as feeding, breeding or avoiding adverse situation but
shall come back to their natural habitat at the end of
purpose is served.
Diurnal vertical Migration:
-many plankters in both fresh and marine situations, make
more or less diurnal vertical migration, such migration may
be downwards into depths during day time and towards
the surface at night or in opposite direction
-can be determined by day and night sampling
17. Vertical Migration/distribution
From challenger expedition, some zooplankton can
migrate upto 200 m depth from surface.
Species : Rotifera, copepoda, cladocera, crustacean
larvae
Example: Calanus finmarclicus, undergoes a
considerable diurnal vertical migration, appearing at
the surface in large numbers during the night, but
migrating downwards until it has a midday max.
conc. at 70 m.
Speed of Migration: Difficult to determine
May vary from 29 to 125 m/hr
Daphnia- 10m/hr, Centropages- 82 m/hr
18. Causes:
-Phototropism: optimum level of illumination cond.
-Phototropism-geotropism interaction: swim away from the bottom but
repelled by the light
-Temperature change: depends on sunlight, migrates cooler to warmer
layers (upward) and vice versa
-Hunger for food
-Physiological rhythm: innate P.R drive them to migrate
Factors effects on migration:
Age: young migrates less than adult
Sex: male and female exhibit different patterns, female more.
Environment: Same species may show different patterns in another
locality.
19. Summary
zooplankton abundant area are rich in fishery, that’s
why we need to know their distribution mainly
Distribution of Zooplankton:Horizontal distribution,
Vertical migration,Seasonal succession,
some physical,chemical and biological factors like-Light,
temp., Current, wave, tide, upwelling, predation,
competition etc control the distribution
20. Recommended Books/ Papers
11. Marine Biology- James W. Nybakken. Marine Biology- James W. Nybakken
2. Davis, CC 1955.The marine and freshwater2. Davis, CC 1955.The marine and freshwater
plankton.plankton.
3. Marine Biology- Levinton3. Marine Biology- Levinton
4. Newell and Newell, 1977. Marine Plankton.4. Newell and Newell, 1977. Marine Plankton.
5. Introductory Oceanography- Thurman5. Introductory Oceanography- Thurman
6. Oceanography- Grant Gross6. Oceanography- Grant Gross
7. Introduction to Marine Plankton-Abhijit Mitra et al7. Introduction to Marine Plankton-Abhijit Mitra et al
8. The Oceans- Sverdrup8. The Oceans- Sverdrup et alet al
9.9. Welch, PS 1952. Limnology. Mc Graw-Hill BookWelch, PS 1952. Limnology. Mc Graw-Hill Book
Company, NewYork.Company, NewYork.
