Saturday, April 5, 2014
Friday, March 14, 2014
Wednesday, August 28, 2013
A FIELD TRIP REPORT
A FIELD TRIP REPORT
LED BY DR. B.E. EMMANUEL
Department of Marine Sciences
University of Lagos, Nigeria.
The field
trip commenced at about 6:20 pm on the 5th of June 2013, on arrival
at the Lagos lagoon Jetty, we tried to loose the tangled net that was meant to be used for fishing. The net is set
in the evening and hauled the next morning to collect the entangled fish.
Matthew, Paul and Abdul Ismail volunteered to help in loosing of the rope then
the girls Tairat, Zainab and Bola also join them. The essence of loosing the
tangled net is to make it easier when
setting it in the water. It is usually set across the river, or transverse to
the path of migrating fish, so that when a fish tries to swim through the net
wall, it gets entangled in the mesh. This net is made of float (a Dunlop
slippers material), a sinker and a buoy; it is made to fit the desired target
species.

An
entangled net.
Then after
we were meant to understand that there are two various colors of net, which are
the green and the grey net. The green net attract more fish than the red.
Before the
boat was let into the water, the lead lecturer Dr. Emmanuel ordered one of the
students to open the valve of the rear base of the boat to enable water into
the boat for buoyancy, to prevent boat from capsizing.
After the
loosing of the net, at about 6:35pm, the boat was pushed into the water with
the help of a bamboo stick placed underneath to enable it move into the water
easily, at which seven students joined aboard including the lecturer. According
to the student that went on board on getting to the under of the Lagos third
main land bridge, they flung the net into the water and tied it to sticks to
avoid it from becoming a ghost net.
The next
day (6th of June 2013)
As at 6:15am,when
we the third year students of the Department of Marine sciences, University of
Lagos were already assembled at Lagos lagoon Jetty alongside with our lecture
Dr. Emmanuel. Some students also went aboard and collected the fishes which is
caught in the net twine behind the operculum, or have been caught between the
head and the body.
The essence
of coming very early the next day to check on the fish is to avoid them being
eaten by crabs. It was even noticed that some of the fish have been eaten by crabs.
fishes caught mainly consist of Grunters and Tilapias.

A fish been
eaten by crab.
Other photographs
taken during the process....

An entangled fish

A fish that was caught



A fish caught in the net twine
behind the operculum.
conclusion
With the help of this field work, I believe the majority of us are now
capable of setting gill nets on their own.
Saturday, August 24, 2013
YOUTH EMPOWERMENT AND DEVELOPMENT CAN DRIVE AN INVALUABLE STEP TO SECURE NIGERIA’S FUTURE PROSPERITY.
YOUTH EMPOWERMENT AND DEVELOPMENT CAN DRIVE AN
INVALUABLE STEP TO SECURE NIGERIA’S FUTURE PROSPERITY.
Introduction
Youth
empowerment is an attitudinal, structural and cultural process whereby young
people gain the ability, authority and agency to make decision and implement
change in their own lives and the lives of other people, including youth and
adults.
Nigerians perspectives of youths
In Nigeria’s settings today, it is mostly
ill-defined and wrongly perceived by parents, the youth themselves and the
government. The youth themselves neglect self-development and empowerment,
wholly depending on white-collar jobs; the parents who are the major
stakeholders often sees youth empowerment as the sole responsibility of the
government , while the government sees youth empowerment as an avenue to
initiate policies and programmes although the programmes make little impact on
their lives.
Youths
constitute a large proportion of Nigeria’s population but despite their
critical role in nation building, it is often observed that the country has not
invested seriously in youths, thereby making them an army involved in un
profitable activities.
According to the
exact words of Dr. Ngozi Okonjo-Iweala “we realise that unemployment has become
a major issue in the country. Figures from the national bureau of statistics
indicate that an average of 1.8 million Nigerian youths finds themselves in the
labour market annually, out of which 250,000 to 300,000 are graduates”.
Nigeria’s now and tomorrow
With an
estimated population of 170 million Nigeria have vast oil wealth, an
entrepreneurial energy and a booming economy, growing at 6.6percent in the
first quarter this year. It also has among the world’s highest burden of health
problems, including malaria, under nutrition and mother and child death rates.
Despite ample uncultivated land, it imports over U.S. $1.1 billion worth of
food. Clearly Nigeria is a country of potential in search of solutions.
Hope for Nigeria
Things seem
bleak at the moment, we are having a government that is incompetent and incapable
of tackling challenges of our time, everybody milks the public goat to buy a
mansion in Dubai,and the nation is being run aground by a generation that has
over stayed its welcome although some are colossus. These are the reason why Nigeria is reeling from crisis to crisis. That is why we
have gone from a strong economy to a weak economy , our oil resources
notwithstanding.
The solution to
this anarchy is having youths that can move beyond the divisive politics of
destruction, rise above ethnic leanings, nepotism and godfathers and unite for
the collective interest of our people.
The essence of youth empowerment
Of recent it is
globally realised that youth empowerment is integral for national development
especially for under developing countries like Nigeria where youth constitute
majority of overall population. If Nigeria can invest heavily in the youths,
they are guaranteed of getting high returns on their investment in every
sector.
The task of
nation building is very challenging and can be divided into phases. Everyone
(both old and young) can contribute towards it according to his or her own
capabilities.
Conclusion
Two issues are
paramount in youth’s calls for reforms, the need to enjoy the full rights they
are entitled to as citizens and the need to have their voices heard within the
family, the community and the decision making process.
Monday, July 29, 2013
BUOYANCY
BUOYANCY
DEFINITION
OF BUOYANCY
Buoyancy is defined as the upward
thrust acting in the opposite direction to the force of gravity. The more
deeply immersed you are in water, the less you weigh; when immersed to hip
height in water, you weigh only 50% of your weight on land.
Many fish control their buoyancy
through gas filled bladders. Enlarging the bladder by adding gas enlarges the
whole fish slightly and so increases the amount of water pushed out of the way.
This increases the buoyancy and makes the fish rise.
Some fish which live at a shallow
depth can increase the gas content of their swim bladders by gulping air at the
surface. Other fish that live at a greater depth have a gas gland to produce
gas and a resorption area to remove it.
Whether a fish floats or sinks depends
on two forces. The fish is pushed upwards by a force equal to the weight of
water it displaces. This is the force which causes buoyancy. The second force
is gravity which pulls the fish downwards.
If the buoyancy force is greater than
the force of gravity, the fish rises. If the forces are equal, the fish remains
at the same level.
Submarines can control the amount of
air and or water in ballast tanks to control their buoyancy in the ocean.
The human body only just floats,
because the force of gravity and the buoyancy force are almost the same. To
increase your buoyancy force, one can wear a life jacket. A life jacket becomes
part of your body without adding much to your weight. In the water, your life
jacket displaces a lot of water to increase the upward buoyancy force . the
life jacket helps you to float higher out of the water.
The buoyant property of water is used
in rehabilitation therapy to assist in movement, as resistance to movement, and
to support movement on the water’s surface. In simpler terms, buoyancy lets
participants experience a partial floating feeling when they enter the pool.
When a person is in water, the water will naturally want to push the person up.
This is particularly helpful to someone who does not want to place their entire
body weight on an affected joint or body part. The deeper the person goes in
the water, the less weight they will have to support with their own body.
The center of buoyancy is defined as
the center of all buoyancy force movements. The human center of buoyancy is in
the mid-chest. The center of gravity is a point at which all force movements
are in equilibrium. The human center of gravity is located in the pelvic area,
although the exact location can shift when the body is in different positions.
When both centers are aligned
vertically, we can perform flotation. When the points are not aligned vertically,
a rotational force result. This rotational force can help you to maintain an
upright, head-out posture during aquatic therapy. These same forces also affect
your limbs and become a vector continuum as the limb moves through water.
Archimedes'
Principle
The
Mathematics and Science of Buoyancy
The Buoyant Force is a very
characteristic force that acts upon all submerged bodies. This is how
Archimedes' Principle explains buoyancy:
“A body immersed in a liquid, either
wholly or partially, is buoyed up by a force equal to the weight of the liquid
displaced by the body."
The following mathematical equation
is based on Archimedes' Principle:
Submerged body buoyancy = displaced
liquid weight minus body weight.
Therefore, we may conclude that:
The body will float if the buoyancy is positive
The body will be suspended if the buoyancy is neutral
The body will sink if the buoyancy is negative
A body immersed
in seawater will, therefore, be buoyed up by a greater force than a body
immersed in fresh water, so it is easier to float in seawater than in fresh
water.
Fresh water
density = 28.3kg / 0.03m3
Seawater density
= 29kg / 0.03m3
The buoyancy of
water can reduce your “weight” by about 90 percent depending on body
composition, size, muscular structure and depth of water. For exercisers with
lower body or spinal injuries, pregnant exercisers, people with fibromyalgia,
and participants with physical limitations, the buoyancy of the water is a
welcome benefit. The buoyancy also adds a challenge to exercisers to maintain
control of their body position while in the water.
Tuesday, September 25, 2012
TARKWA BAY-NIGERIA (A REPORT)
Led
by Prof. D.I. Nwankwo
The
field trip was held on the 29th August 2012 and was led by Professor
D.I Nwankwo, at which we departed at exactly 9:47am through the University of
Lagos Lagoon jetty.
The field work was at Tarkwa bay which
lies at Lagos Island Nigeria and its geographical co-ordinates are 60 24
10’’ North, 300 23’’ 39’’ East. The
Ave. elevation (DEM) 11m (36ft)
Time
zone: Africa/ Lagos UTC/GMT + 01:00’
(According
to Google 3D map).
The place is inhabited by the three main
tribes of Nigeria, the Hausas, Ibos and Yorubas and their main means of survival
are through fishing, boating, and tourism and mini trades.
At the field trip Professor D.I. Nwankwo
taught us that Tarkwa bay is the only bay in Nigeria and it is an artificial
bay (man-made) (a bay is a body of water surrounded by Land, a bay is the
opposite of a peninsula), it was constructed by the Nigerian government to
protect the Apapa wharf from wave action because waves are induced by wind. The
government also created a mole to protect the jetty from getting shallow
because when it is shallow there is no way ships can enter, it only berth’s
there.
We have three types
of moles, which are;
1. Victoria
mole
2. East
mole
3. Training
mole
The
Western mole faces the sea. According to professor Nwankwo, the sea have 3
conditions, they are
1. The
sea must have no birds on it
2. It
must be free from debris
3. It
must be blue.
Mangroves
found at the bay are the;
White
mangrove- langucularia avicennia
Red
mangrove- Rhizophora mangle,
Rhizophora racemosa and rhizophora Harriosoni.
Black
mangrove- Avicennia Africana
Red
mangrove acts as a barrier which possess a pneumatophore(breathing root).
Black
mangrove props out it root.
The
lagoon is just like a sink where Lagoons from other state flush into, that’s
the reason why it has this brownish colouration and contains a lot of debris.
Sand from bar beach deposits at Tarkwa bay and its causes aggregation. Eco-Atlantic
city was created by the Nigeria government because Tarkwa bay was protruding
into the sea; it is the part facing the sea.
Tarkwa
bay is so sandy that plant can’t grow on it, except for insects that burrow
into it; the insects are called the sand binders, because they transform the
sandy soil into land with the aid of their humus and holds the sand together.
The fine sand is also much more
comfortable to walk and lie on, Tarkwa bay is the only maintained beach in
Lagos, it is only accessible by boat, it also has a safe bathing even for
children.
It
was a pleasant outing.
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