Activity - Field Trip to an Aquaculture Operation
Materials
Marking pens, pencils, clipboards, collecting containers for both plants and water samples, preservative
for insects (80% denatured ethanol), tape measure, magnifying
glass (l0 X), thermometers,
water test kit, copies of the Field Trip Report Sheet
Background Information
When you eat fish, is it a local product or one from another province or even country? What kind of fish is it? Was the fish caught in the wild or 'grown' at a fish farm? This activity will allow you to see how fish farming, or aquaculture, helps to increase the number of fish that are in high demand in the marketplace. Visiting any one of the fish farm operations, private or commercial, is a great experience. Take along a pair of waterproof shoes, as the trip can be a wet one!
On any field trip, the first observation skill is learning to ask good questions.
Effective questions serve to focus your observations on only those
things that might give you an answer. A clearer picture of the
fish farm can emerge with the answers to just a few questions. For
example, what kind of fish are raised there? Are there more of
some kind than of others or is there only one species of fish (and if only one kind, why this one)? Once some basics are established, observations
can develop progressively and begin to probe more deeply into
the subject. Questions can help.
Determine the presence and influence of abiotic factors on the life of the fish. For example, what is the water like? Is the water clear and cold, or is the water murky?
Questions about biotic factors begin to show interrelationships.
What signs are there of a healthy habitat? Is there aquatic vegetation, insect and amphibian life? The pattern progresses from
a simple inventory to a look at some of the relationships between
the parts. The answers to effective questions provide the first
qualitative survey of the waterbody and ultimately of the quality of the fish raised in the water. Then, quantitative measurements
can be made by collecting samples of water and insects for later study or identification in the lab. With proper
preparation, the necessary equipment, and some good questions,
a field trip can be both an adventure and an education.
Teaching Notes
1. This field trip may be conducted within the study of ecosytems and alternative forms of farming,
but not before students have some basic information about aquaculture operations. Sufficient
classroom instruction is necessary to make the trip meaningful. The best time to view an aquaculture operation is after fish have been stocked and are at the fingerling size (in the case of yearly stocking) or during harvest. Check with the farm you are intending to visit for the appropriate information.
2. Review the sample Field Trip Report Sheet. It is designed to
help students start observing details and asking questions. Make
one copy per pair of students. You may wish to produce your own Field Trip Report Sheet.
3. Discuss ways to measure the different factors on the Field
Trip Report Sheet in preparation for
the field trip.
4. Prior to going on the field trip, discuss with students the
importance of proper behaviour and appropriate dress; of keeping
together; of not lighting matches or flames; of collecting material
without damaging it or the surroundings; of not polluting the water; of safety; and of making
proper notes in the field (pencils are best in case of rain).
Activity - Field Trip to an Aquaculture Operation
1. Take the class to the fish farm and have students complete their
Field Trip Report sheet. The students may use a subjective measuring
system, such as word descriptions. (e.g., water clarity is 'poor' in fish raising area, 'moderate' along water edge). Use all
the skills the students have acquired to date to describe the fish habitat and fish farm operation. When at the 'farm', walk slowly in small groups around the water or pens
and observe the overall nature of the operation.
Record the positive and any negative aspects of the operation that you
notice; and/or environmental factors at work.
2. Designate an area of the waterbody to each pair or group of students. As students study the area, distribute collecting containers
(one per pair) with blank labels on them (masking tape) and have
students collect insects or other invertebrates. Have them record
on the container a description of the insect and exactly where
it was found. Insects can be found under vegetation, on shore, or on top of the water.
Alternately, suggest
using a magnifying glass to observe insects and their natural
habitat, sketching individuals and describing their actions. Record the types of plants present, but do not remove any as this may disturb the delicate fish habitat. Create a list of any modifications that were made to the site to incorporate the fish.
3. If you have the equipment, measure such factors as temperature,
pH, salinity, oxygen and dissolved mineral content. Take each of these measurements at two or more different
locations.
The following are some suggestions for measuring water temperature.
Water Temperature
An adequate measure of water temperature can be obtained with a
clinical thermometer but extra care has to be taken to get a good
reading. Place the bulb of the thermometer about 15 cm below the
surface to escape surface temperature influences.
Don't forget to shake the thermometer down beforehand and to allow
time for it to adjust properly.
4. Have students look for and record signs of larger animals in
the area, such as scat, tracks, evidence of animals feeding on bank vegetation. Note any
signs of human activity in the area, and try to determine if it
has had any impact on the waterbody. What steps (if any) have been taken to control the 'intrusion' of animals close to the water?
5. Have students create tables and graphs to summarize the data
recorded for both the biotic and abiotic parts of the ecosystem and fish farm.
Interpret this information by proposing relationships between
sets of data. For example, how do the abiotic factors affect the
vegetation? What relationships are there between plants and the fish?
Between sun and plants? Did the students discover any food
chains? Have students predict (and support their predictions through
graphing) what would happen if any one of the biotic or abiotic
factors were to be removed from the water environment.
Extensions
1. Use identification books to name specimens collected on the
field trip. Conduct observations and experiments on some of the
living invertebrates to discover, for example, their preferences
in food, light intensity and pH. Test the water samples. Is there a need for improvements to be made to the water? If so, can you make some suggestions?
2. If possible, have students make a video to accompany their
reports. Students may want to conduct an interview with the owner of the fish farm. Explore the possibility of contacting schools in other
countries (or even in other parts of Canada) and sharing this
project. Cooperate and exchange aquaculture information with them.
Evaluation
1. Using a flow chart or chain-link diagram, indicate the major considerations necessary for a successful aquaculture operation.
2. Have students write reports that summarize and interpret the
data collected.
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