OCEAN CURRENT

- Animal adaptation

- Humans and technology

- Exclusive Interview ( Emily Penn )

- Ecosystems

- Dangers

Contents

Over Fishing

Green sea turtle adaptations

Humans and technology

Interview with Emily Penn

Ecosystems

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EDITOR’S COMMENTS This magazine shows you the in and outs of the

threats of the sea and how much we as Humans

depend on the oceans and its diverse inhabitants.

It tells us how much we are ruining are Ocean

and its decreasing wildlife. We are looking into the

adaptations of the Green sea turtle. And we have

an exclusive interview with marine biologist expert

Emily Penn.

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Over Fishing Over 100 million sharks are killed every year

by humans, that’s just over 3 sharks per

second that are killed by Humans. Most of the

sharks that are killed just have their fins

brutally cut off and are then just thrown back

into the ocean. It is predicted that in just 2

decades sharks will become extinct due to the

alarming rate of shark killings.

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Most of the waste we produce on land eventually reaches

the oceans, either through

dumping or through drains and rivers. This includes:

Oil

Oil spills cause a huge amount of damage to marine life in the

oceans. Many people believe that

most of the oil has come from spillages or wreck but in fact

only 12% of the oil in the ocean has come from this and 36%

has come from the drains and rivers inland.

Sewage disposal

In many parts of the world, sewage flows untreated, or under

-treated, into the ocean. For example, 80% of urban sewage

discharged into the Mediterranean Sea is untreated.

Garbage

Solid garbage also makes its way to the ocean. Plastic bags,

balloons, glass bottles, shoes, almost eve-

rything we throw away can reach the sea if

it isn’t disposed of properly 4

Green sea turtle Adaptations SWIMMING

Sea turtles are strong swimmers. The cruising speed for green sea turtles is about 1.5 to

2.3 kph (0.9-1.4 mph). Leatherbacks have been recorded at speeds of 1.5 to 9.3 kph (0.9-

5.8 mph).

Forelimbs are modified into long, paddle-like flippers for swimming. Neck and limbs are

non-retractile. The shell adaptations necessary for retractile limbs would impede rapid

swimming. With the exception of females that come ashore to nest, sea turtles spend

their entire lives at sea and are well adapted to an aquatic existence.

DIVING

Sea turtles are excellent divers. Leatherbacks routinely dive more than 305 m (1,000 ft.).

They may reach depths of more than 1,190 m (3,900 ft.) seeking jellyfish for prey. Since

they are cold-blooded, sea turtles have a slow metabolic rate. This slowed metabolism

allows them to stay submerged for long periods of time.

o Hawksbill turtles have been known to remain submerged for 35 to 45 minutes.

o Green sea turtles can stay under water for as long as five hours. Their heart rate slows

to conserve oxygen: nine minutes may elapse between heartbeats.

In the north-central Gulf of California, black sea turtles return each year to specific areas.

They bury themselves in sand or mud under water and may remain dormant from

November to March. Although they can remain submerged for long periods, sea turtles

must return to the surface for a breath of air. During long dives, blood is shunted away

from tissues tolerant of low oxygen levels toward the heart, brain, and central nervous

system. Leatherbacks have high concentrations of red blood cells;

therefore, their blood retains more oxygen. The muscle of

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Green sea turtle Adaptations SWIMMING

Sea turtles are strong swimmers. The cruising speed for green sea turtles is about 1.5 to

2.3 kph (0.9-1.4 mph). Leatherbacks have been recorded at speeds of 1.5 to 9.3 kph (0.9-

5.8 mph).

Forelimbs are modified into long, paddle-like flippers for swimming. Neck and limbs are

non-retractile. The shell adaptations necessary for retractile limbs would impede rapid

swimming. With the exception of females that come ashore to nest, sea turtles spend

their entire lives at sea and are well adapted to an aquatic existence.

DIVING

Sea turtles are excellent divers. Leatherbacks routinely dive more than 305 m (1,000 ft.).

They may reach depths of more than 1,190 m (3,900 ft.) seeking jellyfish for prey. Since

they are cold-blooded, sea turtles have a slow metabolic rate. This slowed metabolism

allows them to stay submerged for long periods of time.

o Hawksbill turtles have been known to remain submerged for 35 to 45 minutes.

o Green sea turtles can stay under water for as long as five hours. Their heart rate slows

to conserve oxygen: nine minutes may elapse between heartbeats.

In the north-central Gulf of California, black sea turtles return each year to specific areas.

They bury themselves in sand or mud under water and may remain dormant from

November to March. Although they can remain submerged for long periods, sea turtles

must return to the surface for a breath of air. During long dives, blood is shunted away

from tissues tolerant of low oxygen levels toward the heart, brain, and central nervous

system. Leatherbacks have high concentrations of red blood cells;

therefore, their blood retains more oxygen. The muscle of

tissues tolerant of low oxygen levels toward the heart, brain, and central nervous

leatherbacks has a high content of the oxygen-binding protein myoglobin.

Myoglobin transports and stores oxygen in muscle

tissue.

RESPIRATION

In studies conducted on green sea turtles, lung capacity exchange in one breath

exceeded 50%.

SALT SECRETION

Sea turtles can live in seawater with no need for a freshwater source. They obtain

sufficient water from their diet and from metabolizing seawater. Like other marine

reptiles and seabirds, sea turtles have a salt gland to rid their bodies of excess salt.

This gland empties into the sea turtles' eyes. The secretion of salt and fluid makes

them look as if they are "crying" when they come ashore. These "tears" also help

keep the eyes free of sand while females dig their nests. A special gland empties

excess salt and fluids into a sea turtle's eyes. These tears help keep the eyes free of

sand.

SEA TURTLES ON LAND

For the most part, the only time sea turtles leave the sea is when females haul out

to lay eggs. On some uninhabited or sparsely-inhabited beaches, turtles have been

observed basking on land. Many adaptations that make sea

turtles successful in the sea make them slow and vulnerable

on land. Sea turtles are slow and vulnerable on the land.

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Interview with Emily Penn Emily Penn is an expert in marine biology, she has

travelled many of the worlds oceans, surveying and

protecting our oceans and beaches. So we decided

to ask her a variety of questions…

What effect will rising sea levels do to our oceans?

“From my experience in the Pacific islands shows

that it is really having an impact. It’s making their

fresh water supplies contaminated with salt”.

What can we do to prevent overfishing?

“well, you could look closely at the fish you eat.

There are many websites which can tell you about

what fish are sustainable, and which types of fish

you should eat. By eating fish that is caught on a

line is much better than eating fish caught by a net.”

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What do you think of the state of the beaches

around the world?

“There is definitely a lot of plastic siting on them,

there are definitely challenges ahead but there are a

lot of great groups doing a lot of beach clean ups”.

Did you ever have someone who inspired you and

why?

“I think my inspiration was during my trip around

the world on earth race, the founder of the earth

race was Pete Bethuane and he had a great saying

“Be strong and stand up for what you believe in”.

and it really helped me make that decision to do

something different and stand up for what I believe

in.

Ecosystems The definition of an Ecosystem; a biological

community of interacting

organisms and their physical environment.

There are millions of Ecosystems across the world’s

oceans. The biggest and certainly the best known coral

reef in the world is the great barrier reef. The great

barrier stretches along the west coast of Australia for a

huge 1,553 miles that’s over twice the length of Brit-

ain. This gigantic reef that can be seen

from outer space is home to over , 1,500

species of fish, that’s around 10%

of the entire worlds species of

fish, 134 species of

sharks and rays,

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six of the world's seven species of

threatened marine turtles, and more than 30

species of marine mammals. Thirty species of

whales, dolphins, and porpoises have been

recorded in the Great Barrier Reef. Seventeen

species of sea snake live on the Great Barrier Reef.

Reefs play an important role in protecting the

shoreline from storms and surge water Reefs play

an important role in protecting the shoreline from

storms and surge .Most corals and sponges are

filter feeders, which means that they consume

particulate matter suspended in the water column.

This contributes to enhanced quality and clarity of

our near shore waters.

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Adopt a Sea Turtle

From only £3 a month you can adopt a Sea Turtle to stop the cruel killing

of over 250,000 sea turtles a year. You will be helping to Reduce illegal

fishing, promoting sustainable fishing practices, expanding and creating

Marine Protected Areas. Helping local communities conserve and manage

the natural environment. Achieving government agreements to ban

commercial harvesting of marine Turtles. Your support will also help fund

our other essential work around the world.

In association with WWF.