s

1. Science
Quarter 2
Self Learning Module (SLM) 6
The Interactions among Living
and Non-living Things in an Intertidal
Zone and Estuarine Ecosystem
5

2. This Self-Learning Module (SLM) was designed and written with you in mind to help you
master the Interactions among Living and Non-living Things in an Intertidal Zone and
Estuarine Ecosystem. The scope of this learning material focuses on many different learning
situations. Moreover, the language used recognizes the diverse vocabulary level of learners
and the lessons are arranged following the standard sequence of the course. Hence, the
order in which you read them can be changed to correspond with the textbook you are now
using.
The SLM contains:
Lesson: Interactions among Living and Non-living Things in an Intertidal Zone and
Estuarine Ecosystem
It is subdivided into three sub-lessons, namely:
Lesson 1.1 – Abiotic Factors in an Intertidal Zone and Estuarine Ecosystem
Lesson 1.2 – Biotic Factors in an Intertidal Zone and Estuarine Ecosystem
Lesson 1.3 –Feeding Relationships in an Intertidal Zone and Estuarine
Ecosystem
After going through this SLM, you are expected to:
1. Identify the abiotic factors in in an intertidal zone and estuarine ecosystem.
2. Explain how the abiotic factors affect the intertidal zone and estuaries.
3. Identify the biotic factors in an intertidal zone and estuarine ecosystem.
4. Explain how the biotic factors affect the intertidal zone and estuaries.
5. Identify the feeding relationship in an intertidal zones and estuaries.

3. 3
Pretest
Directions: Choose the letter of the correct answer. Write the letter of your answer on a
separate sheet of paper.
1. It is a biological community where group of biotic factors interact with abiotic factors.
a. ecosystem b. estuarine c. population d. intertidal zone
2. Why are estuaries called “nurseries of the seas”? Because______________________.
a. some organisms used it as their habitat
b. these areas are exposed to high and low tides
c. these areas have a mixture of salt and fresh water
d. some organisms choose to reproduce in these areas
3. Which is not true about the importance of estuaries?
a. filter the salt from the seas c. serve as exit points for floods
b filter sediments and pollutants. d. protect the coast from strong waves
4. Why salinity of water in estuary changes? It changes due to the ______________.
a. amount of sunlight
b temperature of water
c. kind of rocks found in estuary
d. continuous flow of saltwater and freshwater
5. Which group of organisms live in an intertidal zone and estuarine ecosystem?
a. chicken, cat, bird and dog c. crabs, fish, shrimp, and snails
b. carabao, cow, goat and horse d. bees, monkey, snake and flies
6. Which is not a habitat of intertidal zones and estuarine ecosystem?
a. coral reefs b. grassland c. mud flats d. rocky shore
7. Using the given example of a food chain, which is the primary consumer?
Algae shrimp fish heron decomposers
a. algae b. fish c. heron d. shrimp
8. How does food chain become a food web?
a. when it is overlapping and interlinked
b. when it is repeated eating and being eaten
c when only follows just one path as animals find food
d. when linear sequence of organisms pass as one organism eats another
9. How consumers get their energy?
a. by feeding on plants and animals
b. by converting the energy from the sun
c. by breaking down dead organisms and their waste
d. by providing energy and nutrients to other organisms
10. Which are examples of decomposers?
a. snail and crabs c. fungi and bacteria
b. fish and shrimp d. algae and diatoms

4. 4
The Interactions Among Living and Nonliving
Things in an Intertidal Zone and Estuarine
Ecosystem
Living things interact with the non-living things around them such as sunlight, temperature,
water, and soil. The living things in an ecosystem are interdependent. This means that living
things depend on their interactions with each other and also non-living things for survival.
Lesson 1.1 Abiotic Factors in an Intertidal Zone and Estuarine Ecosystem
Intertidal zones are areas which are constantly exposed to the changing tides. Areas where
freshwater from the rivers and streams meets the coastal water are said to have a brackish
water.
Estuaries are a mixture of fresh and saltwater. They are very important to the lives of many
animal species. They are called the “nurseries of the sea” because many animal species
depend on estuaries for nesting and breeding. It also filters out sediments and pollutants
from rivers and streams before they flow into the ocean, providing cleaner waters for
humans and marine life.
Intertidal zones and estuaries both provide habitat for many organisms. These habitats have
a lot of abiotic factors that can affect the organisms thriving in them.
Abiotic factors are the non-living parts of the environment that can often have a major
influence on living organisms.
Abiotic factors include waves, amount of sunlight, salinity, type of soil and temperature.
●waves -refer to the movement of the surface of the water and these strong forces that
organisms must survive with it.
●amount of sunlight – the main source of energy on Earth which makes it an extremely
important abiotic factor. It is necessary for photosynthesis which seaweeds, sea grasses and
other marine animal depend on it.
●salinity- is the saltiness or amount of salt dissolved in a body of water .The salinity of
estuarine water varies from estuary to estuary, and can change from one day to the next
depending on the tides, weather, or other factors.
●soil-have an effect on the kind of living organisms that lives in it .The plants and animals in
an estuary must adapt to the rough conditions that exist in it.

5. 5
Lesson 1.2 Biotic Factors in an Intertidal Zone and
Estuarine Ecosystem
Biotic factors in an ecosystem in an intertidal zone and estuary are also habitat for animals,
plants and microorganisms. Biotic factors include the following:
●Coral reefs
A coral reef is an underwater ecosystem
characterized by reef-building corals. It provides
shelter and food to fishes, sea turtles, crustaceans
and invertebrates.
●Salt marshes
A salt marsh is a coastal ecosystem in the upper
coastal intertidal zone between land and open saltwater
or brackish water that is regularly flooded by the tides.
Crabs, snails, shrimps and sea grasses are some
organisms found in this place.
●Mud flats
Mud flats are areas where mud from the river or seas
deposited. Usually the areas are for migratory birds,
shellfish, mussels and fish. Algae provide food for some
herbivore organisms.
●Rocky shores
Rocky shores are areas where solid rocks are found.
Prawns, starfish, molluscs, shore crabs and shrimps
found in this area. Seaweeds provide food for them.
●Mangrove forest
Mangroves forests are areas filled with mangrove trees. It
protects coast against erosion and also serve as breeding
grounds for fishes and shellfish.

6. 6
Lesson 1.3 Feeding Relationships in an Intertidal Zone and Estuarine Ecosystem
Study the pictures of the following living things below. Which picture should come
first, second, third, fourth?
Living things consist of the producers, consumers and decomposers. Through
feeding relationships energy and nutrients are transfers from producers to decomposers.
Producers make their own food. They make up the first level of every food chain.
Autotrophs are usually plants or one-celled organisms. Nearly all autotrophs use a process
called photosynthesis to create “food” (a nutrient called glucose) from sunlight, carbon
dioxide, and water.
Consumers eats other plants or animals for energy and nutrients. The organisms that eat
the producers are the primary consumers and they are called herbivores. The organisms
that eat the primary consumers are meat eaters (carnivores) and they are the secondary
consumers. Carnivores that feed on other carnivores are tertiary consumers and they
are called omnivores.
Decomposer is an organism that decomposes, or breaks down, organic material such as
the remains of dead organisms it includes bacteria and fungi.
Food Chain is the sequence of transfers of matter and energy in the form of food from
organism to organism which starts from producer and ends with decomposer species.
Food Web is made of interlinked food chains, which consist of two or more food chains.

7. 7
Strong waves current Habitat food Low tides
Shelter high tides Deposited solid rocks erosion
General Directions: Read and analyse the instruction carefully. Write your answer on a
separate sheet of paper.
Activity 1. Abiotic Factors
A. Read each item carefully and identify what is being described. Choose your answers
from the box.
_________1. A community or group of living organisms that live in and interact with each
other in a specific environment.
_________2. An area where a freshwater river or stream meets the ocean.
_________3. Result from mixing seawater with fresh water together.
_________4. Main source of energy on Earth and necessary for photosynthesis.
_________5. The amount of salt in water.
_________6. Area where the ocean meets the land between high and low tides
_________7. Non-living chemical and physical parts of the environment that affect living
organisms and the functioning of ecosystems.
__________8.The hotness or coldness of water.
__________9.Where nutrients are found and have an effect on the kind of organisms that
live in it.
_________10. The movement of the surface of the water.
Activity 2. Biotic Factors
A. Fill in the blank with the correct answer. Choose your answer from the word pool
below.
1. Biotic factors in an ecosystem in an intertidal zone and estuary are ___________ for
animals, plants and microorganisms.
2-3. Coral reefs provide _________ and __________to many fishes, sea turtles,
crustaceans and invertebrates.
4-5. Salt marshes are filled with seawater during ______________and drained
during______________.
6. Mud flats are areas where mud from the seas and rivers are ______________.
7. Mangroves not only for breeding grounds for different marine species but it also protect
the coast against _________________.
8. Rocky shores are areas where _______________are found.
9-10.Coral reefs protect the coast from _____________and ______________.
Intertidal zone temperature Ecosystem waves Estuaries
Soil Abiotic sunlight Salinity brackish water

8. 8
B. Match column A with column B by identifying the correct habitats of the animals in each
picture. Write only the letter of the correct answer.
column A Column B
______1.
a. rocky shore
______2.
b. salt marshes
_____3.
c. mangrove forests
_____4.
d. coral reefs
_____5.
e. mud flat
C.In the table below, list 3 biotic and 3 abiotic factors shown in the picture.
Abiotic Biotic
1. 1.
2. 2.
3. 3.

9. 9
Activity 3. Feeding Relationships
A. Match column A with the correct answer in column B.
Column A Column B
1. A sequence of transfers of matter and energy in the form of food from
organism to organism.
a. producers
2. Made of interlinked food chains, which consist of two or more food
chains.
b. Food Chain
3.Organisms that create their own food through the process of
photosynthesis
c. consumers
4. Organisms that eat other plants or animals for energy and nutrients d. Food web
5. Organisms that eat only plants. e. omnivores
6.Organims that eat only meat of other animals f. decomposers
7. Organisms that decompose or break down, organic material such as the
remains of dead organisms which includes bacteria and fungi
g.Tertiary
consumers
8.Carnivores that feed on the other carnivores h.Secondary
consumers
9.Carnivores that feed on herbivores i. carnivores
10.Organisms that eat both plants and meat of other animals j. herbivores
B. Draw an example of food chain in an intertidal zone and estuarine ecosystem and label
the producer, primary consumer, secondary and tertiary consumer.
Rubrics Points
Concept application 5
Following directions 3
Use of creativity 2
Total 10

10. 10
D. Study the food web. Identify each organism as producer, primary consumer, secondary
consumer, tertiary consumer, or decomposer then check ( / ) the appropriate column in the
box below.
Organism Producer Primary
consumer
Secondary
consumer
Tertiary
consumer
Decomposer
1. algae
2. shrimp
3. crab
4. snail
5. fish
6. duck
7. bacteria
E. Using the food web in activity 3 -D, identify the following consumer as herbivore, carnivore
or omnivore, then check ( / ) the appropriate column.
Consumer Herbivore Carnivore Omnivore
1. shrimp
2. crab
3. snail
4. fish
5. duck

11. 11
Directions: Complete the 3-2-1 Chart about your discoveries in the Interactions among Living
and Nonliving Things in an Intertidal Zone and Estuarine Ecosystem. Write your answers on
a separate sheet of paper.

12. 12
Directions: Choose the letter of the correct answer. Write your answer on a separate sheet
of paper.
1. Which is not true about the importance of estuaries?
a. filter the salt from the seas c. serve as exit points for floods
b filter sediments and pollutants d. protect the coast from strong waves
2. Why estuaries called “nurseries of the seas”? Because______________________.
a. some organisms used it as their habitat
b. these areas are exposed to high and low tides
c. these areas have a mixture of salt and fresh water
d. some organisms choose to reproduce in these areas
3. Why salinity of water in estuary changes? Due to the __________________________.
a. amount of sunlight c. kind of rocks found in estuary
b temperature of water d. continuous flow of saltwater and freshwater
4. Which are examples of decomposers?
a. snail and crabs c. fungi and bacteria
b. fish and shrimp d. algae and diatoms
5. Which group of organisms live in an intertidal zone and estuarine ecosystem?
a. chicken, cat, bird and dog c. crabs, fish, shrimp, and snails
b. carabao, cow, goat and horse d. bees, monkey ,snake and flies
6. Which is not a habitat of intertidal zones and estuarine ecosystem?
a. coral reefs b. grassland c. mud flats d. rocky shore
7. How does food chain become a food web? When it is________________
a. overlapping and interlinked
b. repeated eating and being eaten
c. only follows just one path as animals find food
d. linear sequence of organisms pass as one organism eats another
8. It is a biological community where group of biotic factors interact with abiotic factors.
a. ecosystem b. estuarine c. population d. intertidal zone
9. Using the given example of a food chain, which is the primary consumer?
Algae shrimp fish heron decomposers
a.algae b. fish c. heron d. shrimp
10. How consumers get their energy?
a. by feeding on plants and animals
b. by converting the energy from the sun
c. by breaking down dead organisms and their waste
d. by providing energy and nutrients to other organisms
Post test

13. 13
Pretest
1.a
2.d
3.d
4.d
5.c
6.b
7.d
8.a
9.a
10.c
Activity
2
A.
1.
habitat
2-3
shelter,
food
4-5
high
tides,
low
tides
6.deposited
7.
erosion
8.
solid
rocks
9-10
strong
waves,
current
B.
1.c
2.d
3.b
4.e
5.a
Activity
1
1.Ecosystem
2.Estuaries
3.Brakish
water
4.Sunlight
5.Salinity
6.Intertidal
zone
7.Abiotic
8.Temperature
9.Soil
10.Wave
Activity
2-C
Abiotic
Biotic
1.water
1.plants
2.soil/rocks
2.animals
3.sunlight
3.microorganisms
A.
1.b
2.d
3.a
4.c
5.j
6.i
7.f
8.g
9.h
10.e
B.
food
chain
(
Learners
answers
may
vary)
Post
test
1.
d
2.d
3.d
4.c
5.c
6.b
7.a
8.a
9.d
10.a
Reflection
Learners
answers
may
Vary
Activity
3
(Cont.)
D.
Organism
Producer
Primary
consumer
Secondary
consumer
Tertiary
consumer
Decomposer
1.algae
/
2.shrimp
/
3.crab
/
/
4.snail
/
5.fish
/
/
6.duck
/
7.bacteria
/
E.
Consumer
Herbivore
Carnivore
Omnivore
1.shrimp
/
2.crab
/
3.snail
/
4.fish
/
5.duck
/
Answer Key

14. 14
References
Books:
Sarte, Evelyn T., Garcis, Ednaliza R., Lopez, Eliza A., dela Cruz, Mary Jean G.,
Arradaza, Harold A., Science 5 Beyond Boarders. Pasig City: Department
Of Education, 2016, Pages 84-100
Websites:
https://www.sunnyvaleisd.com/cms/lib3/TX01001155/Centricity/Domain/388/STEMs
copedia5.9A.pdf
https://en.wikipedia.org/wiki/Salt_marsh
https://www.google.com/search?q=estuarine+philippines++public+domain&tbm
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.publicdomainpictures.
https://www.google.com/url?sa=i&url=https%3A%2F%2Fwww.publicdomainpictures.
https://www.google.com/search?q=mud+flats+public+domain&sxsrf
https://www.google.com/search?q=rocky+shore+philippines+public+domain&tbm
https://www.google.com/search?q=mangrove+public+domain&tbm
https://www.google.com/search?q=ecosystem+clip+art+public+domain&tbm
Icons credit:
Ivin Mae N. Ambos, Division of Surigao del Sur
Published by the Department of Education, Caraga Region
Schools Division Office of Surigao City
Schools Division Superintendent: Karen L. Galanida
Assistant Schools Division Superintendent: Florence E. Almaden
Printed in the Philippines by the Schools Division Office of Surigao City
Office Address : M. Ortiz Street, Barangay Washington
: Surigao City, Surigao del Norte, Philippines
Telephone : (086) 826-1268; (086) 826-3075; (086) 826-8931
E-mail Address : surigao.city@deped.gov.ph
Development Team of the Self-Learning Module (SLM)
Writer : Roxanne P. Ceniza
Editor : Yvonne B. Choco
Evaluators : Grace D. Nahial,
Aicel K. Ibarra
Illustrator :
Lay-out Artist :
Management Team : Karen L. Galanida
Florence E. Almaden
Carlo P. Tantoy
Noemi D. Lim