| 1. Technology
and research |
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Resources |
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Conserving
our fisheries resources |
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Fishing
methods |
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Marine
fisheries research |
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Activities |
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a
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Technology
has both positive and negative effects on fisheries resources.
In 30-40 lines state what you think are the advantages
and disadvantages of new technology for: |
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Fish |
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The
fishing industry |
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Recreational
fishers |
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Fisheries
management |
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Fisheries
science |
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How
can technology be harnessed and used so fisheries resources
are sustainable for present and future generations? |
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b |
Design
an improved method for locating and/or catching fish that
would achieve the following objectives: |
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Economically
efficient |
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Environmentally
friendly |
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Minimise
by-catch of unwanted species |
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Support
your design with sketch plans and a brief explanation
of the technologies used and models if appropriate (eg,
a new kind of net). |
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c
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Technology
has revolutionised the fishing industry and research over
the last few decades. Name two new technological methods.
Describe them and say how they have revolutionised catch
or research. |
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d |
Most
fisheries are managed by either input or output controls.
Input controls include limited permitting, gear restrictions,
closed fishing grounds and closed seasons. Output controls
are usually quotas on the amount caught. What are the
advantages and disadvantages of input and output controls?
How could the disadvantages be overcome? |
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| 2.
Principles of sampling |
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Resources |
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Marine
fisheries research |
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Background
information |
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Background
information |
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In
fisheries, the term stock is used in preference to population.
One species, for example, snapper, may have different
stocks living in separate areas. The fish from each stock
have a different genetic composition. |
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A
stock can be defined as: a group of individuals of the
same species, which are living together in the same
area, can intermingle and breed freely, and represent
a single production unit.
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Terms
that are applied to populations generally are relevant
to fisheries. These include: migration, density, distribution,
boundaries and age structure. Two factors controlling
the age structure of any stock are birth rate and mortality
rate. In fisheries resources, mortality is the result
of both natural causes and fishing pressure. Fish stock
sizes are also controlled by environmental factors, such
as temperature, and competition for food. |
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Discuss
the principles of sampling. Look at examples such as TV
ratings, political opinion polls and market surveys. |
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Key
points: |
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In
most cases it is not practical to try to count or find
out the views of the whole population. |
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Samples
are of little use unless they are representative of the
whole area or population. |
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When
collecting samples it is important to have enough to make
an assessment about the whole area or population. |
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The
samples must be chosen randomly. |
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Activity |
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a |
Lawn
analysis |
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Fill
a jar with dried peas, a proportion of which are marked
and mixed in with the unmarked peas. The number of marked
peas is known, but not the total number of peas. Take
several different sized samples of the peas. Each time,
count how many peas are marked and replace the peas in
the jar before taking the next sample. |
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From
the proportions of marked peas in their samples, estimate
approximately how many peas there are in the jar. At the
end of the exercise, consider whether more and bigger
samples give better estimates of the total. Also, consider
what the results would be like if the marked peas were
"clumped" instead of randomly mixed. |
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