Action Pack 1 – Science
Sea Vision is the nationwide campaign working to raise awareness of the interesting and diverse career
opportunities available in the maritime sector. This Action Pack is sponsored by Trinity House, the
organization responsible for aids to navigation and the UK's largest endowed maritime charity.
Curriculum Links:
 Key Stage 3
 Key Stage 4
 Key Stage 3
 Key Stage 3
Science
Science
Science
Science
Unit
Unit
Unit
Unit
3.3 (4) Variation and classification
2.4 Effects of human actions can be assessed using living indicators
7k (2a): Forces and their effects (Why do things float?)
3.1 (Energy, electricity and forces)
The pack contains four parts:
1. A Healthy Sea
2. Sustainable Human Food Supplies
3. Density
4. Electrical Circuits
It explores some of the research work and careers to be found within marine biology. It also poses some
important questions about the maritime environment and its conservation as well as exploring some marinespecific examples of science in action: forces, electricity and the density of water. It can be used to run a
complete lesson or a small group of lessons in science at KS3, KS4 or GCSE level. Elements are also useful at
KS2. The exercises have been set by young people working in the maritime sector, they are real exercises
and show the range of exciting challenges encountered every day in and around the sea.
The presentation will be of particular value to KS3 students and above, investigating:
 Climate Change
 Conservation
 Habitats
 Food Webs
 Classification
 Forces
 Density
 Volume
 Electrical Circuits
We recommend that you use the Action Pack either as entire lesson, or choose elements useful to your
teaching and incorporate them into your own slide presentations.
Whilst the exercises were designed with upper KS3 and KS4 in mind, they can be adapted to any age range.
You can choose to use one or more exercises to fit in with your own lesson planning, or you could set your
students homework based around some of the themes we have chosen.
The content was created with the help of:
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The National Oceanography Centre, Southampton
The Hampshire Wildlife Trust and their Sea Search Volunteers
Divercol Video Productions
Trinity House vessel Galatea
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Pack Overview
The online presentation falls into four distinct parts. Each could form a full lesson, or part of a series of
lessons with students viewing the challenges online before answering the questions set in-class.
Part 1: A Healthy Sea
The presentation starts with a short video clip introducing the importance of the marine environment in
providing resources and regulating climate change. We are then introduced to some young volunteers who
are helping to survey the seashore and improve their knowledge of food chains.
Students are shown a typical food chain and then meet a young researcher who is investigating a key part
of any food chain – the role of chlorophyll and plankton in absorbing the sun’s energy.
This part ends with a short class discussion about the warming oceans and their likely impact on the future
health of the seas.
Part 2: Sustainable Human Food Supplies
In this part we explore some of the ways marine biologists are helping to conserve sustainable fishing in the
oceans. We look particularly at work being done to track crab populations in the English Channel, which
leads to some interesting class work on animal kingdoms and the classification of species in order to better
understand them.
Part 3: Density
In this part we offer a means of assessing your students’ knowledge of density and volume to make a simple
calculation relating to the way ships float in salt and fresh water. We join the crew of Trinity House vessel
Galatea as she prepares to enter the River Mersey. Will she rise in the water or lower as she meets fresh
water from the river?
Part 4: Electrical Circuits
In this final part we join an Electro-Technical Officer on board Galatea, which is one of the most innovative
and modern ships at sea. She spends her time travelling around the British coast maintaining light buoys
and other navigational structures. Her navigation and computing power are immense and the challenge we
have set is a simple exercise relating directly to your students understanding of basic electrical circuits
Teaching Preparation
You will need a computer, audio system and whiteboard to gain full value from this pack.
There are no Fact Sheets associated with this pack.
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Part 1: A Healthy Sea
This section introduces the importance of the marine environment in providing resources and regulating
climate change. It explores the basic concepts of food chains and food webs before stimulating a discussion
about the warming oceans and their potential impact on the future health of the seas.
Key Words:
Phytoplankton – microscopic algae, which are the basis of most marine food chains. They tend to absorb
blue light
Zooplankton – small animals, which are also the basis of many marine food chains
Trophic levels – feeding levels
CTD – Conductivity, Temperature and Depth sensor, a device to measure these attributes at different depths
of water
The filming for these videos was done during mid-winter in the English Channel. The underwater
photography was created by specialist divers in the Solent area, even though the fish look as though they
are swimming in the Caribbean! The richness and diversity of marine life shown here is a topic for
discussion in itself.
Video: The Marine Environment
In this introductory video clip, Lisa Chilton, a marine biologist with the Wildlife
Trusts, explains the importance of the seas and oceans. She explains that
humans use the seas in many different ways and that we are only just
beginning to understand the role seas have in climate change.
She is followed by Jolyon Chesworth, a marine biologist with the Hampshire
Wildlife Trust, who is working with volunteers to record sea life changes on a
strip of shoreline in the English Channel. His team are recording where
different forms of life live so that scientists can work out which ones need
protecting.
Energy comes from the Sun
This generalised diagram shows some of the main energy links in the seas,
always starting with the sun and moving through plants and simple organisms
to the food chains which feed humans.
The marine environment is a complex one and protection is vital.
Some of the most important scientific work being carried out is to understand
the complex relationships between different organisms in and around the sea,
and how they ultimately affect humans.
In the next video clip Lisa Chilton introduces some of the elements of a typical
seashore food web.
Video: Typical Seashore Food Chain
In this video, Lisa Chilton explains that in the marine environment, like in any
natural habitat, everything is connected to everything else.
On any beach you can find all the elements of a FOOD CHAIN.
Lisa shows an example of the elements of a very simple food chain
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First of all a producer from the bottom of a food chain – seaweed.
Then she shows us a mussel which feeds on plankton, which are also
producers.
And signs of predators, a sea gull and the eggs of a ray.
Food Webs
Food chains are important to many of the industries relying on the sea.
Fishing, for example.
Tiny floating phytoplankton (microscopic algae) are the basis of most marine
productivity. These convert sunlight and water-borne nutrients into plant
matter. These are fed upon by the tiny animals called zooplankton. Small fish
feed on both and larger fish feed upon them in turn.
Class Discussion
On the left is a simple food chain with four trophic (feeding) levels. The
plants are the primary producers at the base level. The herbivores that eat the
plants are at level two. The carnivores that eat the herbivores are at level
three. The top carnivores are at level four.
However, there are only a few such simple straight food chains. Most
connections are much more complex, forming a food web. The links are
intricate and vary according to life stage. For example, a larval cod may feed
upon eggs and larvae in the zooplankton while becoming prey for both
juvenile cod and adult herring.
If humans remove, or seriously deplete by fishing, a major part of the web, it
is likely that several other components in the rest of the web will be altered.
This might be either through depletion of food of a predator, or removal of
predators, or through removal of a competitor. Fishing usually affects a
number of components in the marine food web, so the food web effects of
fishing are therefore complex and, usually, it is difficult to prove cause and
effect.
On the right is a more complex FOOD WEB.
Class Discussion
Discuss the webs with your group and lead them in a short debate about the
value of research and conservation in the marine environment.
What would happen if anyone element of the food web was removed through
habitat change or pollution?
(Illustrations and notes thanks to the Joint Nature Conservation Committee)
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Chlorophyll and Plankton
This image shows two important links in any food web.
Chlorophyll is a major constituent of one of the most available producers – the
phytoplankton.
Like plants on land, plants growing in water contain chlorophyll, a molecule
that allows the plant to trap the energy in sunlight for photosynthesis.
Chlorophyll absorbs blue and red light, so it looks green to us. That is why
grass and leaves are green.
The most important plants in the sea are phytoplankton - microscopic plants
that float suspended in the water.
Where there are a lot of phytoplankton, most of the blue light is absorbed, so
the water looks green. Where there are none (or very few), the blue light is
not absorbed, so the water looks blue.
Scientists use the balance between blue and green (the blue-green ratio) to
calculate how much chlorophyll the water contains. This allows them to create
world-wide maps of chlorophyll from satellite images of ocean colour.
The next video clip introduces Sara, a student at the National Oceanography
Centre, who is about to collect samples of chlorophyll from phytoplankton in
the English Channel. She wants to find out the abundance of chlorophyll at
different depths, and the way different water currents affect their distribution.
(information courtesy of the National Oceanography Centre, Southampton)
Video: Sea Water Sampling
In this clip Sara describes two of the research projects she is engaged on:
both related to taking samples of the water column at different depths in
Southampton Water.
She uses a specialist piece of equipment to help her, known as a “CTD”, an
acronym for a Conductivity, Temperature, and Depth sensor, which helps
determine the essential physical properties of sea water. This tool gives
scientists a precise and comprehensive charting of the distribution and
variation of water temperature, salinity, and density that helps to understand
how the oceans affect life.
Sara is finding out how much chlorophyll exists at different depths. She
samples the water at various levels and filters it to trap chlorophyll from the
water. The sample is then analysed to give a rough idea of the amount of
chlorophyll at different levels of the water column. Chlorophyll is one of the
main markers for life and helps cells convert sunlight into energy.
Another element of her research is to gain an understanding of how fresh and
salt water mix, especially with the action of tides, and how long it takes the
different waters to mix.
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Class Discussion
Why is research of this type important? What would happen if the research
wasn’t undertaken?
The Warming Oceans
Sara’s research shows the salt content of the sea water in this location and its
average temperature.
We know that fresh (or river) water does not contain salt and its temperature
varies from season to season, location to location.
Different species have learnt to adapt to live in different conditions.
But global warming is changing the oceans’ average temperatures.
Class Discussion
What effect do you think global warming could have on marine life?
Discuss this with your students and then watch the next video clip, where Sara
gives her personal response. You may want to discuss issues surrounding
adaptation as that could also be as a result of global warming. Your
discussion could examine the negative aspects but also whether there might
be any positive aspects too.
Video: Habitat Extinction
Sara explains that if global warming affects the temperature of different
habitats, the species that live in those habitats won’t be able to survive any
longer, and might become extinct (although new species might fill the voids
left).
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Part 2: Sustainable Human Food Supplies
In this part we explore some of the ways marine biologists are helping to conserve sustainable fishing in the
oceans.
We look particularly at work being done to track crab populations in the English Channel, which leads to
some interesting class work on animal kingdoms and the classification of species in order to better
understand them.
Key Words:
Radio tags – wireless devices used to send signals from moving objects
Sustainable fishing - fishing at a reasonable level that is in balance with the local ecology, can be sustained
by the fish stocks indefinitely, and support those working in the fishing industry in the long term
Unsustainable fishing - overfishing that causes the depletion of fish stocks, or unacceptable impacts on the
marine environment, and subsequently has negative economic and environmental impacts
Kingdoms – the five main groupings of living things
Sustainable Fisheries
Creating sustainable fisheries is an important task facing the marine industry.
The Marine Stewardship Council is the world's leading certification and
ecolabelling programme for sustainable seafood – see www.msc.org/.
Sustainable fisheries use good management practices to safeguard jobs,
secure fish stocks and help protect the marine environment. Seafood products
that meet the MSC’s standards can display the MSC’s blue eco-label.
As well as knowing how food chains work, and how marine habitats link
together, we need to know how marine populations move and migrate.
In the next video clip Adam Reeds, a student at the National Oceanography
Centre, describes the work he is doing on the movement of crab populations...
Video: Tracking Crabs
Adam describes the research he is doing into the ecology of different systems,
including the tropics and the Antarctic.
He demonstrates some of the work he is doing with tracking crabs by radio
tags in the English Channel, trying to find out how and why they move, with
the eventual aim of guiding the creation of sustainable fisheries for crabs.
He ends by asking students to think about how crabs fit into the wider marine
environment.
The Five Kingdoms
To answer Adam’s question, students need to understand how scientists break
down life on earth into a simple index or classification system.
Carl Linnaeus, who developed the classification system we use today, divided
all living things into five main KINGDOMS:
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Protoctists: simple cells like amoeba
Prokaryotes: the beginnings of more complex organisms like bacteria
and blue-green algae
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•
•
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Fungi: moulds, mushrooms and yeast
Plants: all green plants, from the simplest algae and ferns to the most
complex flowering plants
Animals: all multicellular animals, from jellyfish and worms to
arthropods, fish, reptiles, birds and mammals
Class Question
In which Kingdom does a crab sit?
Answer
Based on the classification system, the answer is ANIMALS.
Crabs
Animals are divided again into those with and without backbones.
Class Questions
Does a crab have a backbone? How do we know whether it does or not? Could
we see one from its skeleton?
Answer
No it doesn’t and if it doesn’t have a backbone it is classified as being an
INVERTEBRATE.
Invertebrates and Arthropods
Invertebrates cover a huge area of life, from flies to crabs, jellyfish to snails
and tadpoles.
Class Question
Flies, crabs, spiders, and centipedes are in a group called arthropods. What do
they have in common that could be summed up in that one word
ARTHROPOD?
Answer
They all have jointed feet. The Greek for jointed feet is arthropod. So that is
the answer.
A sub group of arthropods covers marine species with hard shells. We call
them CRUSTACEA.
So, to answer Adam’s question in the video we need to focus on one main
feature which clearly distinguishes a crab from, say, spiders.
In this case it’s the number of legs.
Class Question
Look at this picture and count the legs. There are 10 legs. In Greek the word
for 10 is Deca. So having 10 legs can be classed as being a ....
Answer
The answer is in the next video clip!
You don’t need to know Greek to understand all of this. The detail of the
classification system provides the information needed to work it out.
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Video: Crabs Have 10 Legs
Adam says that crabs belong to the group of Crustacea, have 10 legs and are
therefore DECAPODS (meaning 10 legs) the same as shrimps and prawns.
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Part 3: Density
In this part you can assess your students’ knowledge of density and volume to make a simple calculation
relating to the way ships float in salt and fresh water.
The video clips were filmed aboard Trinity House vessel Galatea, one of the fleet of modern ships used by
Trinity House to maintain lightships, buoys and other structures around the coast to help navigators travel in
safety, especially at night and in fog. Trinity House has a fascinating history and you can find out more by
visiting http://www.trinityhouse.co.uk.
Key Words:
Buoy – a floating navigational aid which is used to identify dangers or obstructions at sea
Trinity House – the organisation responsible for providing navigational aids around the coast of England and
Wales
Galatea – one of the Trinity House vessels, which maintains and renews navigational aids
Salt and fresh water – sea water contains salt which makes it denser than fresh (meaning lake or river
water)
Lightship – a Lightship is a special ship with a massive flashing light and foghorn, which is used to warn
shipping of dangers. The Lightship is towed to its position and anchored to the sea bed with huge chains
and anchors
Draft – the draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull,
with the thickness of the hull included. Draft determines the minimum depth of water a ship or boat can
safely navigate
Hull – the hull of a ship is the main body of the ship floating in the water. It has to be watertight to stop the
ship sinking
Video: Density question
The ship’s first officer explains that a ship floats because it is less dense than
the water it rests on.
The density of water varies especially between salt and fresh water.
He asks students to decide if Galatea will actually rise or sink a little as she
enters the Mersey Estuary – from salt to fresh water with different densities.
Density and Volume
The depth of the ship’s hull below the waterline is known as the draft.
To calculate the change of draft of the Galatea when moving from salt water
into fresh water, we need to know the density of salt water (1025 kg/m3)
and of fresh water (1000 kg/m3) and the draft in salt water, which we will
assume to be 4 metres.
To calculate the change of draft, we use the formula:
density of salt water
new draft =
Therefore:
new draft =
_______________________
x old draft
density of fresh water
1025
______
x 4
1000
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=
4.1 metres
Therefore, the ship will sink 0.1 metres deeper into the water when moving
from salt water to fresh water.
Video: Density answer
Galatea will not float as well in fresh water as she will in the salty sea. She will
sink about 3-4cm into the water
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Part 4: Electrical Circuits
In this part we join an Electro-Technical Officer on board Galatea, which is one of the most innovative and
modern ships at sea. She spends her time travelling around the British coast maintaining light buoys and
other navigational structures. Her navigation and computing power are immense and the challenge we have
set is a simple exercise relating directly to your students understanding of basic electrical circuits.
Science is applied to many different challenges at sea. The ability to track down electrical faults is an
important part of the life of an electro-technical officer. This requires an understanding of basic electronic
circuits and the symbols used to describe a circuit.
Key Words:
Bow thruster – a propulsion device, a propeller driven by a motor
Propulsion – the name given to the ships movement when controlled by an engine
Video: Electrical circuits question
Some circuits have lights and buzzers. This circuit’s light works but not the
buzzer. What could be the reason?
Circuit Testing
This slide shows the circuit for the bulb and buzzer shown in the video. Which
components could have failed?
A broken fuse is the most likely cause because it will create an open circuit.
Video: Electrical circuits answer
The fuse protecting the buzzer part of the circuit has blown, stopping
electricity reaching it.
This example is just one of many encountered every day by the technical
members of a ship’s crew and was chosen to show the importance of a basic
electrical circuit to the smooth running of a hi-tech modern ship.
The Electro-Technical Officer is a very important member of a modern ship’s
crew and is responsible for the ship’s electrical and computer systems.
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Careers in the Maritime Industry
Maritime is the careers guide produced by Sea Vision UK, it provides an unrivalled overview of the sector
and the different job and career opportunities available. The publication outlines the different sub-sectors
and then uses different people as case studies to show what they do and how they got there.
Click here to read more about careers in the maritime sector.
Visit www.seavisionuk.org and click on ‘publications’ to read Maritime, the
biggest industry guide to jobs and career opportunities across the maritime
sector.
Sea Vision UK would like to thank all those organisations who took part in the
filming for this Action Pack:
www.trinityhouse.co.uk
www.mntb.org.uk
www.noc.soton.ac.uk
www.wildlifetrusts.org
www.divercol.co.uk
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If you have any thoughts on this Action Pack, ideas for new education resources using the maritime sector
that would be useful to you, or would like to join our teacher feedback panel, please contact Sea Vision on
info@seavisionuk.org or 0207 417 2888. Thank you.
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