MARINE FOOD WEB BY, ARABINDA PAL MARINE BIOTECHNOLOGY PART-I 1
MARINE FOOD WEB
BY,
ARABINDA PAL
MARINE BIOTECHNOLOGY
PART-I 1
INTRODUCTION
In nature food chains are not isolated. Most
ecosystem contain several inter connected
food chains which forms a food web.
Food web is the feeding relationship in an
ecosystem.
Food chain is a linear sequence of feeding
relationship, where as food web is the
complex relation between different food chain
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TROPHIC LEVEL
A position in a food chain or Ecological Pyramid occupied
by a group of organisms with similar feeding mode.
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ENERGY FLOW
Sun is the all source of energy. Producer take light
energy from the sun and converted it into the
chemical energy. When primary consumer feed on the
producer energy transfer occur.
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CONNECTANCE
The complexity of food web can vary greatly & express
this complexity by a measure called connectance of
the food web.
πππππππ‘ππππ =πππ‘π’ππ ππ. ππ πππ‘ππ π πππππππ πππ‘πππππ‘ππππ
πππ‘πππ‘πππ ππ. ππ πππ‘πππ πππππππ πππ‘πππππ‘ππππ
If there is species no. is βnβ, the potential no. of
interspecific interactions
=π π β 1
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TYPES OF FOOD WEB
Food webs are of three types-
a.Connectedness or topological or static
food web
b.Energy flow or biogenetic food web
c.Functional or interactional food web
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DIFFERENT TROPHIC LEVELS OF
MARINE PLANKTONIC FOOD WEB
Producer β The primary producer are mainly
phytoplankton. They include single cell dinoflagellates,
diatoms, cyanobacteria and some algae.
They absorb the light energy from the sun and
converted into the chemical energy in the form of
carbohydrate
They account for the 95% of the oceanic productivity
and the half of the earth productivity.
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Zooplankton β They are primary consumer.
Phytoplankton are eaten by the primary consumer.
They include-
o single cell ciliates
o Copepods
o Shrimp
o Larvae of mollusk, etc.
Small predators - They are the secondary consumers.
They are feed on the zooplanktons. They includes-
oKrill
o Some small fish such as herring,
sardine, etc.8
Top Predators - They are eat both secondary predators
and zooplanktons.They includes-
oCephalods(octopus)
o Large fish such as tuna, shark etc.
oMarine mammals such as Whales, seals,
dolphins etc.
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Marine planktonic Food Web10
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Types of Marine Food Chain
According to John Ryther 3 types of food chain
found in marine ecosystem β¦
I. Oceanic type
II.Continental shelf type
III.Upwelling zone type
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Oceanic Type
Oceanic system have five-e trophic levels with a low
production of about 50 g C m-2 y-1.
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Continental Shelf Type
This type has 3 trophic levels and the primary production
is about 100 g C m-2y-1.
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Upwelling Zone Type
This type has only two trophic levels. Upwelling provided
higher and more continuous nutrient supply leading to a
primary production of about 300 g C m-2y-1.
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EFFECT OF HUMAN IN MARINE
ECOSYSTEM AND FOOD WEB
oExtreme fisheries
oOcean pollution
oAcidification
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CONCLUSION
Marine phytoplankton produced half of the world
primary productivity. The different variation of
the marine food web shows the wide diversity of
marine ecosystem. Due to the extreme fisheries,
pollution the marine ecosystem very much
affected. Many species are extinct due to this
which destroy the equilibrium of the food web.
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ACKNOWLEDGEMENTβ¦.
T, K, Saha. Ecology and Environmental Biology
Jeffrey S. Levinton, Marine Biology
Ivan Valiela, Marine Ecological process
Wikipedia
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