2. 2
THE COASTAL FOREST.
Make your own observations during this field trip and answer the following
questions.
a) Name the dominant plant species in the coastal bush.
b) List down the animals that live within the bush.
c) Attempt a classification of one named species of plant or animal
according to the taxonomic groups below.
kingdom _________________________
Phylum __________________________
Class ___________________________
Order ___________________________
Family ___________________________
Genus ____________________________
Species ___________________________
3. 3
d) Identify and explain the adaptations of the plants to avoid
excessive water loss.
e) Draw a possible food web for the forest.
4. 4
The Ghost crab
Carefully examine the behaviour of the ghost crab as the tide returns and
suggest scientific explanations for such unique behaviour.
Catch one of the crabs and examine it carefully using the hand lens. Draw a
diagram of the specimen and identify any adaptive features of the organism
to life on the shore.
Write down a food chain including the ghost crab
5. 5
Dissect the ghost crab and examine the respiratory and digestive
system
Draw a diagram of the digestive system
6. 6
Collection, examination and identification of organisms.
It is impossible to make an exhaustive survey, counting and mapping every individual
organism on the shore, so we will need to sample just part of the area. If this is
done carefully, then you can assume that your sample provides a fair picture of the
overall species distribution in the area.
Using forceps or gloves collect a sample of each representative plant and animal
species and put them in your sample containers for examination and identification
later. You should work in pairs to avoid removing many organisms from their natural
habitats.
Make a list of the organisms collected, arranged taxonomically and identified
as far as possible.
Use the sketch map of the area to mark places on the map where the
organisms identified were located.
7. 7
Use the general collection sheet to fill in names, location and
adaptations of the organism and a sketch drawing of the organism
General collection sheet
Organism Location and adaptations Sketch Diagram
12. 12
A Belt transect of the sand island lagoon.
This is a method of systematic sampling which should demonstrate the
distribution of organisms and how it changes as we move down the beach and
further into the intertidal zone.
Method:
Make a measured profile of the shore indicating the low and high tide
levels.
Lay down the rope to mark the position of your transect on the shore.
It should run at right angles to the sea and where possible should
avoid big pools.
At 5 metre intervals, lay down the quadrat. Mark the position of the
quadrat on the profile chart. The quadrat is a sample area. Examine
each sample and estimate the abundance of each alga or plant as:
1. A – Abundant – more than 30 % cover
2. C - Common - 5- 30 % cover
3. F- Few Less than 5 % cover
4. O – Occasional – scattered
5. R- Rare/ very few.
Record the information on the data collection sheet provided. Animal
numbers should be determined by direct counting in bands 5 m long and 0.5
m wide all along the length of the transect.
On completion of your observations, present your results on a graph paper.
13. 13
Transect across sand island lagoon
Record for plants A C F O R and actual numbers for animals.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Angiosperms
Green algae
Brown algae
Red algae
Echinoderms
Molluscs
Crustacea
Fish
15. 15
Rotational activities
Star fish garden visit. Take notes and use the notes and the materials
in the text book to write an essay on the star fish. The essay should
include, the different species, nutrition, reproduction (life cycle) and
locomotion.
16. 16
Snorkelling
Examine the coral heads and associated plants and animals by
completing the snorkelling transit. This transit gives you the opportunity to
study the biodiversity of a small part of a coral reef. Write up a short
summary of the biodiversity of organisms within the corals in this transit.
17. 17
K. IMMUNITY
- This is the protection of the body against pathogens provided by
the body’s defence system
- The cells involved in the immune system originate form the stem
cells in the bone marrow
There are 2 groups:- (i) Phagocytes (ii) Lymphocytes
Phagocytes
- Produced by the bone marrow and distributed around the body in
the blood.
- They engulf pathogens by a process called phagocytosis
Neutrophills
- These are a kind of phagocyte which are short lived and have a
lobed nucleus
- They can squeeze through capillary walls into an infected area
- They are smaller than macrophages
Monocytes (Macrophages)
- Also phagocytes but are long-lived cells with a circular nuclei
- Produced in the bone marrow and migrate to organs such as the
lungs, spleen, kidney and lymph nodes where they remove foreign
matter from these organs.
- They leave the bone marrow and travel in blood as monocytes
which later develop into macrophages
18. 18
Phagocytes recognize, attach to, engulf and digest pathogens that enter the body.
This is the response by lymphocytes to the introduction of an antigen in the
body
Lymphocytes
T- Lymphocytes (T-cells)
Produced in the bone marrow and migrate to the thymus gland where they mature
Mature T cells express specific antigen receptors called T cell receptors
Only mature lymphocytes can carry out immune – responses
19. 19
B- Lymphocytes
B-Cells are produced in the bone marrow where they develop and mature and are
released directly into the blood stream.
Fighting infections (An immune response)
During an infection, many B and T cells with specific receptors to the invading antigens
are activated
- The selected B and T cells divide by mitosis. Some of the daughter B cells
develop into plasma cells and others into memory cells.
- T cells produce cytokines which stimulate the B cells to divide by mitosis and
differentiate to produce plasma cells.
- Plasma cell secrete antibodies that specifically combine with the antigens that has
entered the body
- If antigens enter the body for a second time, the memory cells produced earlier
respond and divide to form more plasma cells which secrete antibodies.
- The secondary response is much faster than the primary response because of
many memory cells in the body
These are very important in secondary infection. Since they have specific receptors to the
antigens, they quickly divide by mitosis producing many plasma cells which secrete
large numbers of antibodies making the secondary response much faster and
vigorous.
Antibodies
Are all globular glycoproteins made up of 4 polypeptide chains; 2 light chains and 2
heavy chains . They have a constant region and a variable region. The variable region is
where an antigen fits.
20. 20
Function of Antibodies
- Prevent entry of bacteria, viruses or toxins
- Immobilize bacteria by attaching to its flagella
- Agglutinate bacteria by sticking them together in clumps
- Together with complement proteins make membrane channels allowing water to
enter bacteria by osmosis
- They label bacteria and viral infected cells for phagocytosis
- Neutralize toxins making them harmless
Active and passive immunity
Active immunity
(a) Natural active immunity – This is an immunity initiated when a pathogen
invades the body, causing lymphocytes to be activated against its antigens.
(b) Artificial active immunity: This is an immunity initiated by injecting antigens
into the body i.e. vaccination
Passive immunity
(a) Artificial passive immunity: - This is the introduction of antitoxins
(antibodies) into a person to give protection against infection before B and T
cells are produced in sufficient quantities.
(b) Natural passive immunity: Immunity passed over from mother to child during
pregnancy through the placenta or through breast feeding.
Vaccination
- This is the introduction of vaccine into the body to stimulate the lymphocytes
against infections.
Problems with vaccines
21. 21
Poor response – Different immune system which cannot develop B or T
lymphocytes
Malnutrition, especially of proteins and so don’t produce antibodies
Antigenic variation
Some organisms have different strains making it impossible to develop vaccines
against them
Antigenic concealment
Some pathogens evade attack by the immune system by living in cells
Eradication of small pox
Reasons for success in eradication of small pox
- The variola virus was stable (didn’t mutate or change its antigens)
- The vaccine was made from a live harmless strain of a similar virus
- Vaccine was freeze – dried and so could be kept at high temp for long periods of
time.
- Infected people were easily identified
- Vaccine was easy to administer and more effective after the use of stainless steel
needles
- The virus didn’t linger in the body after an infection and then become active later
- The virus didn’t infect other animals, making it easier to break its transmission
cycle
- Many people were unmobilised to be vaccinators.
22. 22
L. ECOLOGY
Definitions
Habitat – This is the place where an organism lives e.g. the habitat of an oak tree
is the woodland.
Niche – The role or function of an organism in its environment e.g. the niche of
the oak tree is to produce food for other organisms, to remove carbon dioxide
from air and replace it with oxygen etc
Population – A group of organisms of the same species which live in the same
place at the same time and can interbreed to produce fertile offspring e.g. all the
oak trees in the woodland make a population
Community – All organisms of all the different species living in a habitat e.g. the
woodland community.
Ecosystem – An environment consisting of living organisms whose interactions
with their environment results in a stable, self-sustaining community.
23. 23
Energy flow in food chains and webs
Tropic levels – Theses are specific feeding levels in a food chain. The term tropic
means feeding or nutrition
Producers – Organisms which convert light energy into chemical energy (plants)
Primary consumers – Organisms that feed on procedures (herbivores)
Secondary consumers – Organisms, which feed on herbivores. (Carnivores)
Tertiary consumers
Quaternary consumers
Decomposers – they form the end of a food chain and include bacteria and fungi
which breakdown dead organisms.
Energy losses along food chains
In every link energy is lost somehow
From sun to producers, energy is lost in the following ways:-
1. Some light is reflected from leaves
2. Some fall on the ground
3. Some fall on non-photosynthetic surfaces
4. Some are not suitable wavelengths
5. Some light passes through the leaves without being trapped by
chlorophyll
Losses from plants to Pri. Consumers
Not all parts are eaten
Not all eaten parts are digestible
Energy losses as heat within the consumers digestive system
Some energy is used by plants for respiration
Energy is lost in the same way from consumer to consumer.
24. 24
Nitrogen cycle
Stage of the cycle
Nitrogen fixation
This is changing of nitrogen gas into nitrates so it can be available to plants
1. Nitrogen fixing bacteria – live free in soil or in root nodules. Convert nitrogen
into nitrates
2. Lightning – light energy causes nitrogen to combine with oxygen forming
nitrogen oxides, which are reduced to nitrates in the soil
3. Haber process – This is the industrial process of combining nitrogen to hydrogen
to form nitrogenous fertilizers.
Ammonification
This is the decomposition of nitrogenous compounds in dead plants and animal tissues by
fungi and bacteria forming ammonia.
Nitrification
This is the conversion of ammonia into nitrites then nitrates by nitrifying bacteria.
Denitrification
This is the conversion of nitrates into nitrogen gas and oxygen by denitrifying
bacteria
Ecology Glossary
1. Ecosystem: interactions between the biotic (living) organisms and the abiotic (non-
living) materials and how materials and energy are transferred.
a) biotic – living or dead organisms; made up of cells.
(examples: plants, animals)
b) abiotic – non-living materials; basic unit is elements also includes
energy. (examples: plastic, oxygen, water, rocks, light, heat)
2. Producers: turn the sun’s light energy into chemical (food) energy.
They make their own food by the process called Photosynthesis.
Only find Producers on the first trophic level.
(examples: plants, algae, bacteria)
3. Consumers: can not make their own food (chemical energy)
They use the chemical energy from other living organisms.
Consumers need to eat Producers or Consumers to get their food energy.
Consumers are found on the second or higher trophic levels.
a) Primary Consumer – first consuming organism in a food chain.
SECOND TROPHIC LEVEL
(examples: herbivores or omnivores)
25. 25
b) Secondary Consumer: second consuming organism in a food chain.
THIRD TROPHIC LEVEL
(examples: carnivores or omnivores)
c) Tertiary Consumer: third consuming organism in a food chain.
FOURTH TROPHIC LEVEL
(examples: carnivores or omnivores)
4. Trophic Level: feeding level
5. Types of Animal Consumers:
a) Herbivores: only eat PRODUCERS (such as plants)
b) Carnivores: eat CONSUMERS (herbivores or carnivore or omnivores)
c) Omnivores: eat PRODUCERS or CONSUMERS
6. a) Food Chain: starts with a producer and only connects with single links
(arrows) to the consumers.
example: a typical food chain in a field ecosystem might be:
grass ---> grasshopper --> mouse ---> snake ---> hawk
b) Food Web: multiple (many) food chains that interconnect showing many
feeding relationships.
7 a) Scavengers – feed on the bodies of larger dead animals.
(examples: vultures, eagles, ravens, hyenas, some ants, and beetles)
b) Detrivores – feed on bodies of smaller dead animals and plants and dung.
(examples: crabs, earthworms, wood beetles, carpenter ants
· Decomposers: feed on any remaining dead plant and animal
matter; they break down the cells and get the last remaining energy.
(examples: bacteria, fungi)
8. Population – organisms that belong to the same species that live in the
same ecosystem. (ex: people-species in Halifax-ecosystem)
9. Carrying Capacity - largest population of a species that an ecosystem
can support.
a) Competition: demand for resources (ex: food, water, mates, space)
· Intraspecific Competition: competition within a species.
(example: wolves vs. wolves)
· Interspecific Competition: competition between species.
(example: wolves vs. coyotes)
b) Population Density: the number of organisms within a given space.
· Denisty dependent factors: have a greater effect limiting
population size when population number increases; especially play a
role when the carrying capacity is reached
(example: food supply, predation, competition, disease)
26. 26
· Density independent factors: limit population size no matter the
size of the population (whether 10 or 1000 organisms)
(example: climate, oxygen level, natural disasters like
hurricane, tornado, forest fire, earthquakes, floods)
10) Biological Magnification - the process whereby substances for example poisons collect in
the bodies of organisms and progressively higher concentrations towards the top of the food
chain example: DDT
Biological Magnification Activity in class: Each blade of grass gets DDT when they take in
water. DDT gets stroed in the plants along with stored energy. The grass gets eaten by the
rabbits but rabbits eat many blades of grass and get all the DDT present. Now the fox eats many
rabbits and the DDT from each rabbit goes to the fox. Therefore, the fox has more DDT than any
organism below it on the Food Web.
11) Nutrients - chemical elements used by organisms to build and operate their bodies.
example: carbon (C), oxygen (O), hydrogen (H), nitrogen (N)
12) Nutrient Cycles - movement of nutrients through the environment.
example: Carbon cycle; nitrogen cycle
13) Closed system - an environment in which substances do not enter or leave
example: Earth if often referred to as a closed system
14) Photosynthesis - the change of light energy to chemical energy (sugars) by producers.
Chemical Equation:
H2O + CO2 (in presence of Light) ---> C6H12O6 + O2 REACTANTS
PRODUCTS
15) Cellular Respiration - the change of chemical energy (sugars) into energy that is used by
organisms such activities as metabolism (maintaining body temperature, repairing cells,
growth); reproduction and movement.
Chemical Equation: C6H12O6 + O2 -----> ENERGY + H2O + CO2
REACTANTS PRODUCTS
16) Nitrogen Fixation - the changing of nitrogen gas (N2) in the atmosphere into ammonium
(NH4
+
); nitrogen fixation is done by bacteria that live in the soil or on the roots of legumes.
17) Nitrification - the changing of ammonium (NH4
+
) in the soil into nitrates (NO3
-1
);
nitrification is done by bacteria that live in the soil.
18) Denitrification - the changing of nitrates (NO3
-1
) into nitrogen gas (N2) that returns to the
atmosphere; denitrification is done by bacteria that live in the soil.
19) Eutrophication - a water system that has been enriched by nutrients (in particular nitrates)
needed by plants; often nutrients from sewage and run-off over-enrich the water system causing
an increase in bacterial growth and oxygen depletion that can result in the loss of
organisms that live in the water system.
27. 27
What is Biological Diversity or Biodiversity?
Biodiversity or biological diversity is defined by the United Nations Convention on
Biological Diversity as:
The variability among living organisms from all sources, including, inter alia [among
other things], terrestrial, marine and other aquatic ecosystems and the ecological
complexes of which they are part: this includes diversity within species, between species
and of ecosystems.
This convention was ratified by all countries worldwide with the exception of: Andorra,
Brunei Darussalam, the Holy See, Iraq, Somalia, Timor-Leste, and the United States of
America.
Species diversity: diversity among species present in different ecosystems. This is the
diversity of populations of organisms and species and the way they interact.
Genetic diversity: diversity of genes within a species and processes such as
mutations, gene exchanges, and genome dynamics that occur at the DNA level
and generate evolution.
Ecosystem diversity: genetic, species, and ecosystem diversity of a given region.
This is the diversity of species interactions and their immediate environment.
Today's biodiversity is the result of billions of years of evolution, natural processes, and
in more recent years, human activity. Before the advent of Homo sapiens, the Earth's
biodiversity was much greater than it is today. Human activity has had a tremendous
impact on biodiversity due to use of Earth's resources and exponential population growth.
The total number of species on Earth today is estimated to be around 10 million different
species, but could be as low as 2 or as high as 100 million. New species are discovered
often, and many that have been discovered have not yet been classified. The richest
sources of biodiversity on Earth are found in tropical rainforests and the ocean.
Why is biodiversity important?
All species are an integral part of their ecosystem by performing specific functions that
are often essential to their ecosystems and often to human survival as well. Some of the
functions different species provide are to:
Capture and store energy
Produce organic material
Decompose organic material
Cycle water and nutrients
Control erosion or pests
28. 28
Help regulate climate and atmospheric gases
Ecosystem diversity is important for primary production in terms of:
Soil fertility
Plant pollination
Predator control
Waste decomposition
Removing species from ecosystems removes those important functions. Therefore, the
greater the diversity of an ecosystem the better it can maintain balance and productivity
and withstand environmental stressors.
Biodiversity is important economically in terms of:
Food resources: agriculture, livestock, fish and seafood,
Biomedical research: coral reefs are home to thousands of species that may be
developed into pharmaceuticals to maintain human health and to treat and cure
disease,
Industry: textiles, building materials, cosmetics, etc., and
Tourism and recreation: Beaches, forests, parks, ecotourism.
Biodiversity has an intrinsic value because all species:
Provide value beyond their economic, scientific, and ecological contributions,
Are part of our cultural and spiritual heritage,
Are valuable simply for their beauty and individuality, and
Also have a right to life on this planet.
We have an ethical responsibility to protect biodiversity. Biodiversity is important to
science because it helps us understand how life evolved and continues to evolve. It also
provides an understanding on how ecosystems work and how we can help maintain them
for our own benefit.
29. 29
Habitat Conservation
Habitat conservation for wild species is one of the most important issues facing the
environment today — both in the ocean and on land. As human populations increase,
land use increases, and wild species have smaller spaces to call home. More than half of
Earth's terrestrial surface has been altered due to human activity, resulting in drastic
deforestation, erosion and loss of topsoil, biodiversity loss, and extinction. Species cannot
survive outside of their natural habitat without human intervention, such as the habitats
found in a zoo or aquarium, for example. Preserving habitats is essential to preserving
biodiversity. Migratory species are particularly vulnerable to habitat destruction because
they tend to inhabit more than one natural habitat. This creates the need to not only
preserve the two habitats for migratory species, but also their migratory route. Altering a
natural habitat even slightly can result in a domino effect that harms the entire ecosystem.
The following is an example illustrating this point by Dr. Peter Moyle:
Habitats don't exist in isolation; most of them have inputs and outputs connected to
other habitats and ecosystems. Take Mono Lake, for instance, a spectacular lake on the
east side of the Sierra Nevada in California. Its water source is streams fed by winter
rains and melting snow in the mountains. In its natural state, water leaves the lake only by
evaporation. The balance between the inflowing streams and evaporation created a saline
lake with many unique features, including a species of brine shrimp found only in Mono
Lake. As a large, food-rich body of water in a desert area, the lake is a major fueling stop
for migratory water birds and a major nesting area for other species, such as California
gulls. When water from the lake's inflowing streams was diverted to quench the ever-
growing thirst of Southern California, the lake level dropped drastically. Islands in the
lake became connected to the mainland, giving coyotes and other predators access to an
easy source of food: nesting California gulls. With adequate inflowing water, the islands
were good nesting habitat; without the water they were unsuitable as nesting habitat.
Without adequate inflowing water, the lake also would become too saline for the Mono
brine shrimp to survive and for migratory water birds to feed in. Recognition of this
fundamental relationship between inflow and habitat for many species was the partial
basis of a successful court action that reduced the diversion of water from the inflowing
streams.
The Problems
Habitat destruction is a huge problem in the marine environment. Habitats are destroyed
by:
Destructive fishing activity: bottom trawling and dynamiting coral reefs destroy
entire ecosystems.
Coastal development: habitats are destroyed when marshes are dredged for real
estate development. Soil runoff and erosion result in excess nutrients from
30. 30
fertilizers and domestic sewage, which then leads to harmful algae blooms that
block sunlight and deplete the water of oxygen. It also causes silt to build-up on
coral reefs, which blocks sunlight necessary for coral to grow.
Pollution: development near coastal waters contaminates the Ocean with toxic
substances, such as industrial chemicals, pesticides, and motor oil.
Dredging ship channels: Removes accumulated sediment and pollutants, re-
suspending them into the water. Dredging can also destroy sea grass beds and
other habitats that provide food, shelter, and breeding grounds. The dredged
material must be disposed of, and is often dumped into salt marshes, damaging
very productive marine habitats in the process.
Solutions
Marine Protected Areas (MPAs): marine sites such as sanctuaries, fisheries
management areas, state conservation areas, and wildlife refuges established to
protect habitats, endangered species, and to restore the health of marine
ecosystems in areas jeopardized by habitat and species loss. Examples: NOAA
National Marine Sanctuaries: USA
Marine Reserves: marine sites that provide a higher degree of ecosystem
protection by prohibiting fishing, mineral extraction, and other habitat-altering
activities. Marine Reserves are far more effective than MPAs, but unfortunately,
they are not as common. Example: Marine Reserves in New Zealand
Land use and development regulation: An integrated approach to land use and
management based on scientific knowledge is needed to protect coastal areas.
Policy makers need to be informed on the impact coastal development is having
on marine habitats through accessible and evidence-based information.
Monitoring and reporting: some conservation efforts are empowering the citizens
with the responsibility for monitoring water quality in their coastal communities
through sampling and testing, photographing fouled areas, and providing
information to local policy makers for action.
Zoning: related to integrated land use and development management, zoning
coastal areas into MPAs, Marine Reserves, approved fishing areas, with varying
levels of use has the potential to slow some of the habitat degradation caused by
development. The Great Barrier Reef is managed in this way. Through
cooperation among local, state, and national governments, this approach may
provide a viable solution to all stakeholders from tourists, to the fishing industry,
to conservation efforts, etc.
Although habitat destruction has been increasing for many years, the protection of marine
habitats has only recently become an issue of critical importance to conservation efforts,
local and national governments, and international marine conservation groups. The
Ocean's invulnerability to human activity is now being realized as a myth. Coastal
regions are still experiencing intense pressure by exploding coastal populations; however,
there are solutions at hand to prevent further damage from occurring.
