The document describes the structure and energy flow of aquatic ecosystems. It outlines the key abiotic components, biotic components including producers, consumers and decomposers, and interactions such as food webs, habitat use, and nutrient cycling. Specifically, it provides flowcharts and explanations of the components and flow of energy in both freshwater and marine ecosystems.

1. STRUCTURE OF
AQUATIC ECOSYSTEMS

2. Flowchart of Energy Flow in Aquatic Ecosystem
PRODUCERS
Phytoplankton
• capture sunlight
through
photosynthesis
and convert it into
organic matter
(energy).
Chemotrophs
• near hydrothermal
vents use
chemicals from
the Earth's crust
for energy
production.

3. Flowchart of Energy Flow in Aquatic
Ecosystems
CONSUMERS
Grazers
(Herbivores)
• Zooplankton,
• small fish,
• some
invertebrates
directly
consume
producers.
Primary
Consumers
• Small fish,
• crustaceans,
• some insects
feed on
grazers
Secondary
Consumers:
• Larger fish,
• squid,
• birds,
• some
mammals eat
primary
consumers.
Tertiary
Consumers:
• Apex
predators at
the top of the
food chain
consume
secondary
consumers.

4. Flowchart of Energy Flow in Aquatic
Ecosystems
Detritus Food Chain:
• Dead organic matter sinks and becomes
detritus.
• Decomposers (Bacteria and fungi): Break
down detritus and absorb nutrients.
• Detritivores: Worms, crustaceans, and some
fish feed on detritus and decomposers.

5. Energy Loss:
 At each level of the food chain, a significant amount
of energy is lost as heat due to cellular respiration.

Only about 10% of the energy is transferred to the
next level.


6. Sunlight
enters
Producers (Algae) (capture
energy)
| Consumers | | (grazers, | |
primary, | | secondary, | |
tertiary)
| Detritus & | | Decomposers | |
(recycle nutrients)
Heat (energy loss)

7. 10% LAW IN ECOSYSTEMS ENERGY
TRANSFER
 The 10% Law, also known as the Lindemann Law,
states that only about 10% of the energy available at
one trophic level (feeding level) is transferred to the next
level in an ecosystem's food chain or food web.
 This means that as energy flows through the different
levels, from producers to consumers, a large portion of it
is lost as heat due to cellular respiration and other
processes.

8. Why does this happen?
When organisms at each level consume food, they use
some of the energy for essential functions like growth,
reproduction, and movement.
However, a significant amount of energy is lost as
heat during these processes.
This means that only a fraction of the original energy
available at one level remains to be transferred to the
next.

9. Is it always exactly 10%?
No, the 10% is an average and the actual transfer efficiency
can vary depending on several factors, such as:
Type of ecosystem: Aquatic ecosystems tend to have lower
energy transfer efficiencies compared to terrestrial ones.
Organisms involved: Warm-blooded animals generally
have lower efficiencies than cold-blooded ones.
Food source: Different types of food have varying energy
content, affecting transfer efficiency.

10. What are the implications of the 10% Law?
Limits the number of trophic levels: With energy loss
at each level, food chains typically have a limited
number of levels, usually 3-5.
Importance of producers: As the base of the food chain,
producers play a crucial role in capturing and storing
energy that fuels the entire ecosystem.
Understanding ecosystem stability: The 10% Law
helps us understand why disturbances at lower levels
can have significant impacts on higher levels in the
food chain.

11. Flowchart of the Structure of a
Freshwater Ecosystem
 Abiotic Components:
• Water: Depth, flow rate, temperature, turbidity, pH, dissolved
oxygen, nutrients.
• Light: Penetration depth, availability for photosynthesis.
• Substrate: Bottom composition (rock, sand, mud, etc.),
topography.
• Temperature: Seasonal variations, stratification (layering) in
lakes.

12. Flowchart of the Structure of a
Freshwater Ecosystem
 Biotic Components:
• Producers:
• Phytoplankton: Microscopic algae forming the
base of the food web.
• Macrophytes: Rooted plants like reeds and lilies
providing habitat and food.
• Benthic algae: Algae attached to rocks or other
surfaces.

13. Flowchart of the Structure of a
Freshwater Ecosystem
 Biotic Components:
• Consumers:
• Zooplankton: Microscopic animals feeding on phytoplankton.
• Macroinvertebrates: Insects, crustaceans, mollusks, etc., in
various feeding groups (herbivores, carnivores, detritivores).
• Fish: Diverse species with various feeding strategies.
• Amphibians: Frogs, toads, newts, occupying both aquatic and
terrestrial habitats.
• Birds: Ducks, geese, shorebirds dependent on the ecosystem for
food and breeding.

14. Flowchart of the Structure of a
Freshwater Ecosystem
 Biotic Components:
• Decomposers:
• Bacteria: Breakdown organic matter, recycling nutrients.
• Fungi: Degrade dead plant and animal material.

15. Flowchart of the Structure of a
Freshwater Ecosystem
Interactions:
• Food Web: Energy transfer through producers, consumers,
and decomposers.
• Habitat Use: Different species utilize specific zones (surface,
water column, bottom) for feeding, breeding, and shelter.
• Nutrient Cycling: Nutrients flow through the system,
recycled by decomposers and available for producers.

16. Ecosystem type
Abiotic components | | (water, light,
etc.)|
| Biotic components |
| (producers, |
| consumers, |
| decomposers)
| Interactions |
| (food web, habitat,|
| nutrient cycling)

17. STRUCTURE OF
MARINE ECOSYSTEMS

18. Flowchart of the Structure of a
Marine Ecosystem
 Abiotic Components:
• Water: Salinity, temperature, depth, currents, waves, tides.
• Light: Penetration depth, availability for photosynthesis.
• Substrate: Bottom composition (rock, sand, mud, etc.),
topography.
• Nutrients: Availability, upwelling events.

19. Flowchart of the Structure of a
Marine Ecosystem
 Biotic Components:
• Producers:
• Phytoplankton: Microscopic algae forming the base
of the food web.
• Macroalgae: Seaweeds providing habitat and food.
• Chemosynthetic bacteria: Near hydrothermal
vents, using chemicals for energy production.

20. Flowchart of the Structure of a
Marine Ecosystem
 Biotic Components:
• Consumers:
• Zooplankton: Microscopic animals feeding on phytoplankton.
• Nekton: Fish, squid, whales, and other swimming animals with
diverse feeding strategies.
• Benthos: Bottom-dwelling invertebrates like crabs, mollusks, and
echinoderms.
• Birds: Seabirds utilizing the ecosystem for food and breeding.

21. Flowchart of the Structure of a
Marine Ecosystem
 Biotic Components:
• Decomposers:
• Bacteria: Breakdown organic matter, recycling nutrients.
• Scavengers: Crabs, shrimp, and other animals feeding on dead
organisms.

22. Flowchart of the Structure of a
Freshwater Ecosystem
Interactions:
• Food Web: Energy transfer through producers, consumers, and
decomposers.
• Habitat Use: Different species utilize specific zones (surface,
water column, bottom) for feeding, breeding, and shelter.
• Nutrient Cycling: Nutrients flow through the system, recycled by
decomposers and bacteria, and replenished by upwelling events.
• Physical factors: Water temperature, salinity, currents, and tides
influence species distribution and abundance.

23. Ecosystem type
Abiotic components | | (water, light,
etc.)|
| Biotic components |
| (producers, |
| consumers, |
| decomposers)
| Interactions |
| (food web, habitat,|
| nutrient cycling)