The Introductory Biology Program
Educational Microcosm Project
A proposal for the construction of a system
of artificial ecosystems to be used as an educational aid in the teaching
of life sciences.
Prepared by Robert Day
April 2000
Version 2
Contents
General Design
Features of the Proposed IBP Microcosm System
Some specifics on the design
of the IBP microcosms
Some specific suggestions
and strategies; using the microcosms as a hands-on biology teaching aid
Some suggestions for curriculum
ideas and resources taken from the Internet
Estimated Cost Of Microcosm Systems
In order to better serve the students of The Ohio State University's Introductory Biology Program, we plan to construct a system of artificial ecosystems (microcosms) that will be used as a hands-on teaching tool in general biology classes. The microcosms will be built in the four laboratory classrooms currently used to teach Biology 101. The design of the systems will be based on principles pioneered by Walter Adey (1991), modified for classroom use by Robert Day during the development of the microcosms located in Rooms 121 and 129 of the B&Z building. The existing microcosms in the B&Z building are currently used to teach undergraduate animal diversity classes for The Ohio State University Department of Evolution, Ecology and Organismal Biology. The new IBP microcosms will incorporate significant design improvements that will make them a highly biologically diverse, reliable, robust and cost effective teaching tool suitable for teaching a variety of biological concepts to large number of students. The primary objectives of the new microcosms will be as follows:
Many sources have emphasized the need for educational reform in the way that science is taught in the US (for reviews see Lave (1991), Lemke (1990) and Brooks (1993)). Research indicates that the traditional behaviorist or so called "drill and practice" approaches, where science is presented as a collection of immutable facts is fundamentally flawed in that it does not train students to use the scientific method as a problem solving tool. Similarly, such approaches do not encourage students to develop the process skills, vocabulary and culture, observational skills or peripheral real-world connections that professional scientists construct routinely as they go about their daily work.
Several factors have contributed to this shift in educational philosophy. Many educators in the life sciences have realized that memorization of data alone is not an adequate preparation for either a biological career or informed citizenry. The body of data that constitutes the shared knowledge of "scientific experts" has grown far too large and is changing too rapidly for a superficial knowledge of any small part of it to be particularly useful. For this reason, science educators are beginning to emphasize concepts, inquiry and critical appraisal in the classroom, because once these basic tools are mastered, a student should be able to make sense of any scientific data and tackle any new scientific problem. A list of general publications produced by educators who have advocated this (or similar) approaches to teaching biology is given in the references section
When I first arrived at OSU, the Zoology’s Department’s introductory animal diversity class was taught in a very traditional way. Students would observe preserved or dried organisms and study monochrome line diagrams of their internal structure. They were evaluated using lab exams that asked simple questions about only those preserved specimens the students had observed. This is the way that animal taxonomy has been taught all over the world for hundreds of years.
During my first few quarters as an instructor for this class I made the following observations:
1) Students did not enjoy the lab portion of the class. They usually appeared tired, bored, disinterested and disgusted by the poor appearance and bad smell of the preserved specimens. They arrived at class late and left early, saying that they would prefer to learn the material by memorizing the book at home. They were not engaging with class material nor displaying any sign of the natural sense of wonder they may have felt as children when they learned by peering into ponds, rivers and ant nests. The lack of enthusiasm of the students was met with a reciprocal lack of enthusiasm from the TAs.
2) There was generally little interaction between the TA and the students. There was no opportunity to discuss taxonomy or explore the relatedness of living things using spontaneous, field-specific vocabulary and appropriate language structures. There was also no opportunity for TAs to facilitate peripheral learning since TAs rarely strayed from the material explicitly listed in the lab manual and evaluated by the lab exams. Even though the knowledge and process skills of the instructors (and students) constitute the most expensive teaching aid in the room (and the only one that students cannot reproduce through self or home study), this resource was hardly being utilized at all.
3) Living things were never used as learning aids in the original form of this class. On the rare occasions when a living thing did appear it was used strictly as a distraction, almost for comic relief. Students reacted by screaming, running out of the room, leaping on tables etc. Occasionally a brave student might poke the living specimen with a stick or condescend to hold it, but usually under protest. The most common verbal response to living creatures presented in class was; "eww ... gross". Students would usually ask for assurances that live specimens would not appear in the exam and most departed the class completely unprepared to observe, handle or interact with living creatures in any way. I consider this a scandalous shortcoming in a class aimed at life science majors. The fact that some of these students hoped to go on to veterinary or medical school was particularly unsettling.
4) When questioned about their level of discomfort, many responded that they had grown up in an urban area where "there were no animals". Others said that they either chose not to go outside much because they found the natural world dirty and less interesting than television, or they were not were not allowed outside as children because of parental concerns about safety.
5) Students frequently seemed unable to physically see either living or preserved specimens under the microscope.
6) The clearest indications of the limitations of the traditional approach to teaching biological diversity came when I began to take students on field trips to the Florida Keys. Even my brightest students seemed unable to physically see living things in their environment and unable to identify the phylum of most of the specimens we collected, even though they had studied the lab material just a few days earlier.
Observations like these (made independently by myself and others) led the department to conclude that we should embark on a revision of the content of our diversity class so that it would include more live specimens and a more inquiry-based approach to learning.
When our new teaching strategy was implemented
we immediately found that students became far more engaged with the material
and seemed more positive in their class evaluations, (some of which are
enclosed). There was more opportunity for peripheral learning and I observed
students' ability to see and recognize living things began to notably improve
over the course of a quarter. The content of the lab exams changed such
that students were expected to be able to identify living things that they
had never seen before rather than identifying the same specimens that they
saw in lab. Even though this requires a much higher degree of taxonomic
competency on the part of the students, I was relieved to observe that
test scores on the lab practical exams were largely unaffected. Student's
ability to discuss living things using more appropriate scientific language
increased dramatically and their comfort level with observing and handling
live animals also showed improvement, as did their ability to function
effectively in the field.
Some definitions: what is the difference between a "fish tank" an "aquarium" an "ecosystem" and a "microcosm" ?
To the human manager, a fish tank's only "important" inhabitants are fish. When they die, the manager obtains new ones. The system is maintained under close human supervision. Species diversity is very limited and carefully controlled. Primary productivity is non-existent so energy must be added to the system in the form of organic food. Little attempt is made to make the display resemble any natural environment. Artificial life-support ("filtration") of some sort must be maintained at all times. If this fails, the inhabitants die. Animal inhabitants tend to occupy a large proportion of the total available volume. Little or no reproduction occurs. The system is unstable and prone to sudden changes in dissolved chemical concentrations and subsequent mortality. Since only a small number of each species is present and reproduction is rare, loss of small numbers of individuals can massively reduce biodiversity.
An aquarium is primarily designed to display fish, although other animals and some plants may be present. The biological diversity of the system is still controlled by human activities but some unpredictable natural phenomenon may be tolerated. Some attempt is made to make the display look natural, but specimens still generally need to be replaced when they die. Primary production may occur but organic food must still be added to the system. Animal inhabitants tend to occupy a small but measurable proportion of the total available volume. Artificial life-support is usually still required but is less important than in a fish tank. The system is more chemically stable than a fish tank but still prone to fluctuations of dissolved chemicals if the artificial life-support devices fail. Since only a small number of each species is present and reproduction is rare, loss of small numbers of individuals can massively reduce biodiversity.
An ecosystem is a self-sustaining, biologically diverse, dynamic community of plants, animals and protists arranged in a food web, usually powered by sunlight. Humans have little ability to predict how species diversity will change through time because the system is essentially chaotic. Although subject to immigration and local extinction, species are generally present as reproducing, quasi-permanent populations. Inhabitants typically form a "pyramid of biomass" where plants are common and animals occupy a negligible proportion of the total available volume. No organic food needs to be added. The system is highly stable and not prone to fluctuations of dissolved chemical concentrations. Since there are large numbers of individuals present and reproduction is common, loss of small numbers of individuals rarely reduces biodiversity.
A human-initiated, enclosed ecosystem is sometimes
called a microcosm (Adey, 1991). Microcosms are excellent models
of natural ecosystems, but differ from ecosystems in that they require
some human intervention to replace the role of some natural phenomena not
available in an artificial situation.
What are the major differences between a natural ecosystem and a microcosm that affect biodiversity and population density?
The three biggest differences are the dimensions of size and time, and the impact of the sun (and thereby, the weather).
1) Size. Even small natural ecosystems are typically enormous compared to artificial models. Furthermore, natural ecosystems are extensively subdivided into innumerable microhabitats created by physical heterogeneity and distance. Ultimately all natural ecosystems are partially separated sub-divisions of the global biosphere with perpetual migration of species occurring throughout the system. The vast size of the biosphere creates considerable buffering of chemical changes and huge stockpiles of available resources.
2) Time. Natural ecosystems have the benefit of long periods of time to allow chemical equilibration, rare immigration events and adaptive radiation of species to occupy new or unexploited niches.
3) Sunlight. The sun provides the energy for photosynthesis and other important light dependent reactions that allow the biosphere to cycle and process resources such as water, oxygen, carbon and complex organic materials produced by living things. The sun also produces extensive weather patterns that generate a reliable and continuous mechanism for transporting organisms and resources throughout the biosphere.
Recreating these three key factors is crucial
to the success of any attempt to construct an artificial ecosystem. So
far, it has proven extremely difficult for humans to produce an artificial
system that does so in such a way as to make it a permanent, truly independent
system. Even the best examples still depend on occasional human-mediated
export (or processing) of organic wastes, the occasional import of new
species and the addition of at least some organic food, as well as at least
some gaseous exchange with the natural biosphere. A truly self-sustaining,
completely closed artificial ecosystem with permanently stable biological
diversity remains an elusive goal.
How will the Introductory Biology Program's microcosm project recreate these three crucial components in order to present a realistic model of an ecosystem with adequate biological diversity for students to study?
1) Size. Without having to embark on a major renovation of an entire building or hiring a contractor to build a system the size of an actual pond, adequate size can most easily be achieved by using several small modules connected together by PVC pipes. The total volume will be further increased by using relatively cheap PVC drums to hold additional water, out of sight of the main system (see attached schematic). The use of these drums will create a large total volume of each system, far higher than most recreational aquaria, but without negatively impacting the aesthetics or cost of the system. Furthermore, the extensive sub-division of the system using mesh screens to isolate different species, and the deliberate diversity of the physical conditions in each module will make the ecology of the system behave as if it were far larger than it really is.
I have demonstrated this principle in some of my previous systems and in the "multiple microhabitat pond microcosm" units currently on display in the Biology Annex. A discussion of these units is available at: https://www.angelfire.com/ri/skibizniz/papers.html
2) Time. Unfortunately, some of the effects of time cannot be replicated in a microcosm. For example, the systems cannot be maintained for the vast periods of time necessary for biological diversity to be increased by speciation events. On the other hand, some effects of time can be recreated through human management. The most obvious example is the colonization of the system, which might take many years in nature. The long period of time necessary for the initial colonization or the reversal of a local extinction events can be recreated in our microcosms by massively increasing the immigration rate. This can be accomplished by having staff (or students) regularly add new species from the field. Students could be sent on field trips to suitable local sites then return with organisms they have collected. After studying them, these could be added to our microcosms. The staff can assist this process by watching out for specific available niches in the microcosms that could be filled with known local species.
3) Sunlight. The influences of the sun can be reproduced using three primary strategies: a) Electric lighting bright enough to generate rapid primary production. b) Electric pumps to create movement of water through the system. c) The use of electrically produced ozone to break down complex organic materials dissolved in the water. Collectively, these three strategies have enabled us to maintain our systems in the B&Z building for more than five years without any natural sunlight.
Using the strategies outlined above and the additional
maintenance strategies listed in appendix 1, it should be possible to create
a system that will be a good model of a real ecosystem and maintain excellent
biodiversity year round.
General Design Features of the Proposed IBP Microcosm System
The configuration of the microcosm systems in the two teaching laboratories of the Introductory Biology Annex is problematic because of the size and layout of the room. I have discussed the matter with the IBP staff at great length and we have proposed several different ideas, all of which have disadvantages. For a while, we thought we could leave the benches untouched and set the tanks on small tables along the exterior walls. After much consideration we decided that this does not allow enough room for the passage of students around the exterior-wall ends of the benches. We have decided that a better option is to shift all of the benches longitudinally towards the exterior walls and either extend them slightly by the addition of smaller benches or use the lab benches themselves as platforms for the microcosms. The latter option has the advantage that it will be fairly easy and will generate a cost reduction because no (or few) extra benches will be needed.
One disadvantage of this option will be the reduced accessibility of the microcosms because the benches themselves will interfere with the positioning of students and limit the number of individuals who can observe the tanks at once. A partial solution to this problem is to use the money saved by not buying additional benches to buy more tanks. This will allow more students to view tanks at once. Another disadvantage of this configuration is the fact that we will loose about two feet of lab bench space.
The microcosm located in the Southern lab of the Biology Annex will be a marine system consisting of between three and five 40 gallon modules and a single 50 gallon module. Two additional 100 gallon drums will sit at the Southern end of each of the two side (lab prep) rooms. Ideally, the drums will be illuminated from above by powerful metal halide lamps to allow maximum production of phytoplankton. The visible modules will include a shoreline habitat, lagoon habitats (with and without fish), marine sediment habitat and shallow patch reef habitat.
The microcosm located in the Northern lab of the Biology Annex will be a freshwater system consisting of five to six 30 gallon modules and a single 100 gallon drum that will sit in the Western prep room. Modules will include pond, wetland, terrarium and leaf litter habitats.
The construction of microcosms in the labs of
the B&Z building is even more problematic because of constraints imposed
by the room layout. They are likely to consist of three or four 30 gallon
freshwater modules and a 100 gallon drum that will sit in the adjacent
prep room. I have not prepared a schematic of the system for this room
yet because I am still exploring module placement options. For ease of
maintenance and consolidation of supplies, both of these systems will use
only fresh water.
The original microcosms used by EEOB in the B&Z building were prone to frequent leakage because of their poor physical condition and obsolete technology. After performing a $10,000 college-funded upgrade to the same kind of equipment that I am recommending for the IBP systems, the EEOB systems have never again experienced any kind of leakage or spillage due to an equipment failure and have performed flawlessly for at least three years.
Modern commercial aquaria and the bulkheads used to pass pipe-fittings into them are extremely rugged and reliable. I have never experienced, nor even heard of any kind of leak due to a mechanical failure (i.e. a leak due to a faulty seal) in this type of aquarium. I believe that we should not consider this type of failure as a possibility and should consider the outer boundaries of the microcosms as an impenetrable waterproof barrier.
Aquarium spillages from modern systems can really only be caused by faulty plumbing designs that allow water to leave the system, inappropriate differential water levels that cause mass flow in the event of a pump failure, or human error that leads to an overflow. The use of a custom-built system will enable us to make use Pascal’s principle to insure that the flow of water from one system to another in such a way as to create an overflow situation is also extremely unlikely, if not physically impossible. Since all additions of water will occur in the side rooms, there is no reason to ever add or remove water from the systems in the teaching labs and I would say the risk of even a small spillage in this room is negligible. All of the plumbing and the one (or two) pumps used by each system will be housed inside the watertight body of the system itself. This is an extremely spill-resistant design because mechanical failures or electrical outages of any kind will simply cause the water to stop moving around the system and while leaving the continuous external seal unaffected, that is, the system is "fail safe". In addition, there will be NO external pipes or components of any sort that can be tampered with or disrupted by students, thus it will be impossible for them to cause a leak through any action other than a deliberate and extremely powerful impact to the tanks or the connecting pipes. In the unlikely event that a breach did occur, the system is set up such that each module will be independent of the others and only a small volume of water could be lost, NOT the entire contents of the system.
By far the most likely source of spillage is human
error. The possibility that someone might leave a faucet running unattended,
or tip over a container of water is a worrying one, but it seems to me
that the risk of this is not much higher because of the microcosms than
it would be during normal daily laboratory activities. We have few options
available to protect ourselves from this sort of disaster. One option might
be the installation of floor drains. Another might be the installation
of a moisture alarms of the type used by aquaculture professionals to warn
of leakages. A third might be to install some kind of secondary container
or "apron" designed to "catch" minor leaks in the side rooms. Honestly
I think this last option would cause more problems than it would solve
and would add absolutely nothing to the safety of the microcosms if used
in the actual teaching labs.
Some specific suggestions and strategies; using the microcosms as a hands-on biology teaching aid.
1) Usefulness of combining the microcosm with instructional technology.
The most useful property of the microcosm as a teaching aid is its ability to help students develop their observational skills, to help them develop a visual vocabulary of biological images and to force them to discuss what they see with others. Just as student perceptions of knowledge are affected by their practice and mastery of scientific language, (Lemke, 1990) I believe that knowledge and learning are also affected by their ability to recognize, manipulate and interconnect mental images of living things. In other words, the microcosms help to extend students visual "vocabulary", which in turn forces them to extend their linguistic and conceptual vocabularies.
To help students do this more effectively and to help their observations become a more social activity (which Vygotsky (1962) says is essential to all learning) I strongly recommend that the TAs be trained to use the microcosms in conjunction with a video microscopy display system. This has several advantages: It reduces stress on the microcosms by allowing the entire class to view a single specimen. It allows the TA to describe to the entire class what they are seeing. It allows the class to ask interactive questions about the specimens that every student can hear and think about. It encourages the use of technology in the classroom. This should be a goal of any modern science class, since all technical professions of the twenty-first century will require that college graduates be highly adept at using technology to record data and solve problems. It is also way to simply engage the students with the material since they can be asked to use the equipment to display and record images of their own.
Some general publications produced by educators who have advocated this (or similar) approaches to teaching biology are given in the references section.
2) To illustrate diversity of plants, animals and protists.
Students could search for and identify organisms using a microscope, hand lens, magnifying glass or naked eye. This has traditionally been called the "Five kingdoms lab". It could perhaps be coupled to a field trip so that students have the opportunity to look for organisms in the lab first so that their field trip will be more productive. Students could record diversity with sketches, notes, video or digital camera, perhaps over the entire quarter, categorizing what they see as they go. This activity requires a lot of time and it seems impractical to squeeze it all into just one lab session. They could be asked to classify and/or identify organisms in or outside lab time using any scheme they like and with the help of resources that might include the library or possibly a custom field guide presented on IBP's own web site, featuring those organisms that are most common in our particular microcosms.
TAs could referee contests between students or sections to see who can find the most species in a given time, perhaps over the entire quarter.
TA's could introduce students to the art of observing diversity by locating and retrieving examples then displaying them to the class using a microscope, video camera and TV. This has the advantage of allowing students to observe the process skills and listen to the language use of a knowledgeable instructor, who nonetheless will have to strive to overcome the same sorts observational problems and taxonomic uncertainty that the students will encounter.
Homework questions could ask students questions specifically about those organisms that are found in our microcosms, but which are also important elsewhere in aquaria or agriculture. Information about such species is easily available on the Internet, or could be put on IBP's web site. (eg What are the agricultural uses of Azolla ? What are the benefits to humans of Gambusia in tropical regions?). These are just the kind of real world connections that the NSTA recommends and are especially useful when they teach students about species that they are highly likely to encounter during their lives or through the media.
3) Cell biology
Use living things from the microcosms for demonstrations and discussions of cell biology. Organisms like Elodea, macroalgae, and most protozoa are ideal for this, especially if used in conjunction with live video display. The hope here is that students will see cell biology as more relevant and somehow more real, if it is illustrated by a species that they see every time they come into lab.
4) Ecology
Get students to keep logs of behavior and feeding in different organisms or in different microcosm modules (= different tanks). Useful for developing observational skills and scientific note keeping. Students could be assigned to different tanks each week so that they observe as many species as possible.
Have the class construct a chart showing food web and relationship patterns between organisms within the system. This could be a good quarter-long project for the whole class, a small group, or for single individuals. It could also be the basis of a single lab session. If done at home, students might get help from library, TAs and the IBP web site.
In groups of two, have students create a list of ecological terms, natural resources or phenomena that they have observed or that they suspect might be important to the success of the microcosm. They can also include scientific or common names of species or taxa they have seen in the over the quarter. Write each term or name on a single square of paper. These terms might come from lecture, from an assigned reading or from their general knowledge. Have students build a concept map that shows how these quantities are related. A list of suggested relationships could be supplied in class, perhaps also written on index cards. Examples of these relationships might include "is absorbed by", "is released by", "is a close relative of", "is eaten by", "is an example of" and so forth. Later, groups can exchange maps, critique each other’s ideas, then attempt to combine the two into a single, larger concept map. If the text on the cards is in a large, high contrast font, it may be possible to digitally photograph the finished products and put them on the web site so the whole class can see them. Evaluation could be based on a homework assignment in which individuals choose one map from the web site that they think is excellent and another that they think contains misconceptions, then write a summary of their analysis for each. A follow up lab might allow TAs to address any misconceptions revealed by the concept maps.
For prolonged observational exercises, an "open lab" policy may help students come in to study voluntarily. This might be especially likely if the labs are made welcoming because of the appealing aesthetics of the microcosms, and availability of computers, TA tutors, even soft music and coffee?
Have students track chemical changes in the system or a small part of it. Add ammonia, nitrate, or even meat, urine or some other pollutant, then track chemicals over hours or days with test kits. Tests could include dissolved oxygen, ammonia, nitrite, nitrate, pH etc. (Cheap kits are available for aquarium stores that can measure most of these.) Compare with equivalent volume of water only. This investigation could be modified to fit in a shorter time slot by testing chemicals in different places around the system. For example, test different zones of the "concentric ponds" system.
Have students estimate population sizes using capture / recapture technique. Candidate species might include terrestrial isopods (sowbugs) and Gambusia.
Observe, record and explain the decomposition of say, an apple, or a piece of meat in the microcosm over several days or weeks. Compare this with decomposition of the same material in an aquaria filled with a similar volume of tap water or pond water only.
Have students look for specific examples of niche partitioning, competitive exclusion, competition, predator prey interactions and other ecological phenomena from a list supplied to them. They would then write brief explanations of how their observations support the hypothesis that they have seen this specific phenomenon at work. We might also ask them to suggest an experiment to test this hypothesis.
5) As a general source of specimens used throughout the quarter.
Many organisms used in current IBP labs can be raised in the microcosms instead of in separate cultures. These might include isopods, cockroaches, oligochaetes, paramecium, wax moths, mealworms and fruit flies. The invertebrate physiology lab that currently uses frozen squid, earthworms and grasshoppers (which most of them saw in high school) could instead have students look at any two invertebrate animals that they find in the microcosms and try to identify the functions of different structures they see (using the microscope if necessary). To help them we would supply a labeled diagram of some other invertebrate from the same phylum.
Using the microcosm to supply some or all of the material used in the labs allows students see the material comes not from a packet, jar or prepared tray, but from an ecosystem, within which it had a specific function, other than simply keeping them amused.
6) As the basis of a new graduate level class.
I suggest that IBP considers establishing an interdisciplinary class would be aimed at biology grads and educators. It could be cross-listed in the College of Education and EEOB. The title might be something like "Technology, Inquiry and Biological Diversity." In this class, students would work in pairs to locate and record different species from the microcosms using video or digital microscopy and photography. They would then collaboratively investigate the biology and current research literature involving these organisms using library and Internet resources. They would present their findings by building their own web pages (perhaps using a template we would give them) or by giving multimedia presentations. Perhaps every two weeks, students would change partners so that ideas and techniques for using information resources and details about the different specimens observed would spread through the class. Students would be expected to tutor each other on use of the library and Internet search strategies as well as on the biology of the specimens. Assessment would be based on the presentations, a class evaluation of each student’s effectiveness as a tutor, and on knowledge of the biological information accumulated throughout the quarter. The class could perhaps be opened to high school teachers and even high school seniors so that there would be a diverse mix of talents and abilities, ideal for the development of teaching and communication skills.
For a summary of the latest findings on the importance
of incorporating technology into teacher training, see the web site of
the Milken Foundation, a non-profit group dedicated to increasing the use
of technology in the classroom (URL in reference section).
Some suggestions for curriculum ideas and resources taken from the Internet
(URLs available in reference section)
Second Nature
Second Nature is a nonprofit organization that helps colleges and universities expand their efforts to make environmentally sustainable and just action a foundation of learning and practice. Education for Sustainability (EFS) is a lifelong learning process that leads to an informed and involved citizenry having the creative problem-solving skills, scientific and social literacy, and commitment to engage in responsible individual and cooperative actions. Second Nature focuses on colleges and universities because they educate our future teachers, leaders, managers, policymakers and other professionals.
This site features a vast and highly relevant collection of resources including specific tips on "greening the curriculum".
EPA Teacher resource center
This site has a number of downloadable activities that describe activities mean to explore the science of wetlands. Some could be modified for use with our microcosms.
The invertebrate biology site for Dr. G A Pearson
This web site features some ideas that we could incorporate into our own site to make it more useful as a reference source for our students.
The Stream Study’s aquatic biology identification key
This site shows how we might construct our own online key that students could use to identify common specimens that they might find in the microcosms.
University of Michigan Museum Animal Diversity Web
If they can build a site like this, why can’t
we? Again, this is the sort of thing we could do to allow students to find
information about organisms specifically likely to be found in our microcosms
or at our field site.
1) Construction personnel
The systems will be designed and constructed primarily by myself (Robert Day). My previous experience includes exclusive responsibility for the construction of systems of comparable size and complexity in the B&Z building and the construction of a considerably more complex project at the Columbus Zoo. I am also solely responsible for the ongoing construction of a similar system at Tremont Elementary School in Upper Arlington, Ohio. I can supply all necessary tools and skills to complete the job in its entirety although it may be necessary for OSU or other staff to complete or inspect some aspects of construction for purposes of building code enforcement and University liability. This will have to be explored further. For more information on my previous experience, a vitae is available at: https://www.angelfire.com/ri/skibizniz/index.html
2) Estimated construction cost
The estimated cost of the construction of the three systems will depend on the number of modules included, the type of lighting system used and other factors related to the choice of design options. A simple four-module unit would cost about $2200 per room. A more elaborate system with six or more modules and more powerful lighting would cost about $5600 per room. This range translates to approximately $8800-$22400 total for systems in all four rooms. See enclosed table for breakdown of costs.
Funding for this project could come from a number of sources including the IBP budget and external grants from agencies such as the Ohio Sea Grant. I hope to be involved with any grant application that IBP may initiate. I would also like to request that IBP cooperate fully with any efforts to pursue funding avenues of my own that might lead to external graduate support.
3) Estimated construction time
Based on the construction time required for the assembly of the comparable systems in the B&Z building, the estimated labor time required for the construction of each system (per room) will be about forty hours. This would be followed by a period of about one month of ten-hour weeks for the stocking and the inevitable trouble-shooting associated with all new systems. The trouble-shooting and stocking phase could probably be performed by the IBP staff (and students?) under my supervision. I am ready to begin construction of the microcosms as soon as funds become available.
4) Estimated maintenance time
Based on averaged monthly management time required to maintain the systems in the B&Z building, the estimated hours required to maintain the proposed systems will eventually be in the order of 1 hour each day per room (15 hours per week). This figure will probably double during the first two months after construction because it will take a little time to iron out any teething problems and establish a standardized daily routine. This figure represents an upper limit because I have reason to believe that the improved, inter-connected design of the proposed system will significantly reduce maintenance tasks by eliminating the need for individual care of each module. I think it is entirely realistic that once a routine has been established and any mechanical problems solved, the microcosms may require as little as one hour of maintenance time per week, per room.
5) Graduate support for Robert Day
It will be necessary for me to be supported by a Graduate Associateship during the construction phase. The construction schedule is negotiable and could involve either 25% or 50% time support, and might include an arrangement where I would work full- time on the construction for a short period of time over an academic break, then take part or all of the rest of the quarter off.
6) Estimated maintenance cost
Based on the averaged monthly cost of running the comparable systems in the B&Z building, the estimated maintenance cost of the proposed systems will be in the order of $50 per month, per room ($200 dollars per month total for 4 rooms). This excludes the cost of major unforeseen disasters and the cost of the electricity required for the microcosm's lighting system. This figure represents an upper limit because I have reason to believe that the improved design of the proposed system will significantly lower costs by reducing supplemental feeding and eliminating the need for some forms of chemical filtration. I think a reasonable estimate for the lower limit of the monthly expenses would be around $10 dollars per month, per room.
I have discussed these figures with the technician in charge of the daily maintenance and purchasing of supplies for the B&Z systems (Ms. Barbara Shardy, shardy.1@osu.edu). She and I are in agreement that the above figures are reasonable. We are also in agreement that the microcosms kept in each of the two rooms of the B&Z building are comparable in size, workload and probable expense with the systems proposed in this document.
7) Specimen collection
Many species for the freshwater microcosms can be collected locally by staff and students of IBP. It has been my experience that specimens for the marine microcosms (and also, some tropical freshwater species) can be collected most economically and environmentally sensitively using field trips to Florida. I propose that one or more trips be made specifically for this purpose. The trips could be used as an educational experience for selected IBP staff and students and could even become a regularly scheduled event, perhaps part of a class. Dr. Dana Wrensch has a coastal property in Florida that she has offered to let us use as a home base. I have never had any problems obtaining suitable permits from the FDNR. The most significant cost of this trip would obviously be the transportation. I do not recommend the purchase of marine specimens from pet stores or mail order companies because of the inflated prices and the environmental impact of collection techniques.
The microcosms could also be slowly populated
by obtaining and exchanging small samples of living material and pioneer
species with the microcosms already present in the B&Z building, with
other local aquarium hobbyists and with the Columbus Zoo. It may also be
worth exploring a possible joint field trip with the Columbus Zoo. This
is something that has been helpful in the past and may reduce the cost
of the trip.
(Cost per room, upper and lower boundaries dependent on total number and size of tanks used, lighting options and allowance for unforeseen costs.)
(Low: High)
Lighting 300 (fluorescent) 2000 (all metal halide)
tanks, pre-drilled 600 (4 x 30 gallons) 1000 (6 x 40 gallons)
plumbing 200: 400
tables/stands 0: 1000 (6)
pumps 200: 300
electrical 200: 300
misc. 200: 600
total 1700: 5600
2 rooms 3400: 11200
4 rooms 6800: 22400
Adey, W.H., Loveland, K., (1991). Dynamic Aquaria: Building living ecosystems. Academic Press. New York, NY
Baggott, L. M., & Wright, B. (1996). PhotoCD in biology education. The American Biology Teacher, 58 (7), 390-395.
Baggott, L. M. & Wright, B. (1996). The use of interactive video in teaching about cell division. Journal of Biological Education, 30 (1), 57-66.
Bartow, D.H. (1988). Videomicroscopy. The Science Teacher, 55 (3) 44-47.
Belzer, W.R., & Eggleton, K.H. (1988). More efficient and effective histology instruction. The Anatomist/Physiologist, 1 (1), 4-5.
Brooks J. G., Brooks, M. G (1993) The case for the constructivist classrom. Association for Supervision andCurriculum Development. Alexandria, VA
Bruce, B., Levin, J. (1997) Educational Technology: Media for Inquiry, Communication, Construction, and Expression. Journal of Educational Computing research. Vol. 17(1), 79-102. Available at: http://www.ed.uiuc.edu/facstaff/chip/taxonomy/
Clavenstine, R.F., & Humphreys, D. (1987). CCVM instruction - how it affects academic achievement in secondary biology students. The American Biology Teacher, 49 (7), 408-410.
Day, R. (1998) Microcosm Management guide. Available at: https://www.angelfire.com/ri/skibizniz/papers.html
Day, R. (1998) The Multiple Microhabitat Pond
Microcosm Concept. Available at: https://www.angelfire.com/ri/skibizniz/papers.html
Day, R. (1993) "The marine aquarium as an educational tool. Seascope Magazine. Vol. 10. Summer 1993 issue. Published by Aquarium Systems Inc.
Day, R (1996) The aquarium as an educational tool. Freshwater and Marine Aquarium Magazine . February 1996 issue. Published by R/C Modeler magazines
Day, R (1996) Bringing undergraduate biology to life with model ecosystems and imaging technology. Proceedings of the Annual Conference of The American Zoo and Aquarium Association.
Faulkner, S.P., (1993). Videomicroscopy using a home camcorder: An alternative to commercial systems. The American Biology Teacher, 55 (5), 304-306.
Fedak, J., Belzer, W., Wrhen, L., & Walko, D. (1990). Videomicroscopy and improved student attitudes. The American Biology Teacher. 52 (7), 419-421.
Garrison, S., & Gregory, J. (1996). Acquiring video images for biology laboratory exercises. Journal of College Science Teaching, 25 (Dec./Jan 96), 219-224
Hall, D. W. (1996) Computer-based animations in large enrollment lectures: Visual reinforcement of biological concepts.Journal of College Science Teaching, 25 (May 96), 421-425
Huang, S.D., (1989). Professor Sam: The biology classroom of the future. T.H.E Journal, 16 (10), 43-44.
Huang, S.D., & Aloi, J. (1991) The impact of using interactive video in teaching general biology. The American Biology Teacher, 53 (5)281-284.
Lave, J. Etienne, W. (1991) Situated Learning, Legitimate peripheral participation. Cambridge University Press. Cambridge
Lemke J. (1990) Talking Science. Ablex publishing. Norwood, NJ.
Sevenye, W. & Strand, E. (1989). Teaching science using interactive video: Results of pilot year evaluation of the Texas Learning Technology Group project. Dallas, TX: Association for Educational Communications and Technology. (ERIC Document No. ED 308 838.)
Voker, R. P. (1970) Development of a Multimedia System for Teaching High School Biology. Thesis(Ph.D.) Iowa State University.
Vygotsky, L (1962) Thought and Language.
MIT press. Cambridge, MA.
Second Nature, "Greening the curriculum" program: http://www.secondnature.org/programs/programs.nsf/www/currguide
The Invertebrate biology site for Dr. G A Pearson:
http://www.albion.edu/fac/biol/pearson/invert.htm
Milken foundation, analysis of technology in Teacher education:
EPA Teacher resource center:
http://www.epa.gov/region01/students/teacher/world.html
The Stream Study’s online identification key:
http://wsrv.clas.virginia.edu/~sos-iwla/Stream-Study/Key/MacroKeyIntro.HTML
National Science Teacher’s Association (NSTA) standards and content page:
http://www.nsta.org/onlineresources/nses.asp
University of Michigan Museum Animal Diversity Web:
http://animaldiversity.ummz.umich.edu/index.html
Other links to general information and articles of interest about microcosms
https://www.angelfire.com/ri/skibizniz/mcosmlinks.html
The twenty most valuable pointers to success when designing and using a microcosm for use as a teaching aid.
Taken from "microcosm maintenance guide" available at: https://www.angelfire.com/ri/skibizniz/papers.html
1) The golden rule: Maintain the highest possible diversity of plant and animal specimens in every microcosm.
2) Try to keep specimens in a microcosm that closely resembles their natural environment. Maintain strict adherence to ecological principles in all aspects of microcosm design and management. When specimens feel at home and have access to their natural diet, they behave more naturally, reproduce more readily, experience less stress, maintain a more effective immune system and live longer and healthier lives than they would if kept in a sterile or unnatural habitat.
3) Each system should mimic a real world food-chain. This typically includes abundant primary production, driven by a powerful light source. Most captive systems will need the equivalent of five to ten watts of fluorescent lighting for each gallon of volume. Commercial aquarium hoods usually supply far too little light to create the primary production necessary to allow a system to be fully self-contained, therefore most of our displays have a customized light source and make use of as additional natural sunlight wherever possible. Alternatively, an enclosed ecosystem might be powered partially or completely by the import of organic material (food). An example would be the decomposer-based "leaf-litter" community in room 129 which relies on the continuous import of energy in the form of decomposing plant material harvested from other displays.
4) Healthy microcosms are very biologically productive and therefore accumulate organic sediment faster than a "fish tank". A little organic sediment on the floor of your microcosm is desirable as a habitat and nutrient source for some species. In nature, this sediment gradually accumulates into vast layers, but because microcosms have limited volume, this is one natural phenomenon that we cannot allow indefinitely. The best way to counter sediment accumulation is to occasionally vacuum or scoop out the excess.
This may remove some nutrients and trace elements from the system. You can replace these using either natural composting and the return of compost drainage water, or by the addition of nutrients in the form of commercial plant food (nitrate / phosphate based fertilizer) or commercial aquarium trace elements. The practice of adding plant food flies in the face of mainstream "fish tank" maintenance dogma that generally preaches the importance of NOT introducing nitrates or phosphates. A "fish tank" is not an ecosystem and does not use nutrients anything like as quickly as a healthy microcosm. I therefore recommend you occasionally add nutrients to all your systems, especially if plant and macroalgae growth seem limited. It makes a big difference to productivity and diversity. Chemical testing reveals that supplemental nutrients vanish from the water and enter the food chain almost immediately. Avoid using fertilizers that contain copper with marine tanks because it is toxic to marine invertebrates.
5) Use physical sub-division and replicate systems as a substitute for the size of the real world. Three different one-gallon systems will hold a greater total number of species than a single three-gallon system. Physical diversity produces biological diversity. Try to include wet, dry, bright, dark, rocky and muddy areas in the same microcosm. Nested systems (microcosms within larger microcosms) and separate but interconnected systems also work well. Resist the temptation to put vertebrates in every system. They tend to eat almost everything, reducing diversity. Walter Adey's research at the Smithsonian stresses the importance of isolated sub-divisions of his microcosms that are free from predation by vertebrates. He calls these areas "refugia".
6) Choose specimens that are independent, hardy and reproductively successful. Try to maintain breeding populations, not single individuals. Avoid endangered, delicate and highly artificially derived (i.e. domestic or "ornamental" ) organisms. The latter teach students much less about the mechanisms of natural selection and behavior than "real" animals. Don't ignore the small organisms - that's where most of the diversity is. Students should be taught to appreciate this with hand lenses and microscopes. Don't forget that you need more producers (plants) than consumers, so choose plants that will grow and spread quickly. You can always prune them back if they start to occupy so much volume that they exclude other species. If possible, plants should occupy a significant amount of the total microcosm volume. Animals should not. This recreates the pyramid of mass seen in nature. Watch succession events and don't let any one species become too ecologically dominant. If you think you see an unexploited source of food, try to add a new species that will eat it.
7) Multiple small collecting trips from many sites work better, and are less likely to impact the environment than a large collection trip to a single site. Add tiny, diverse samples from local ecosystems often. This represents the constant immigration of new colonists, a common occurrence in nature.
8) We are in the midst of a global environmental crisis. Set an example by maintaining the tanks in an environmentally friendly way. Talk to students about environmental implications of the microcosms and your collection techniques. Help students to value the diversity of living things.
9) Never think of, or refer to the microcosms as "fish tanks". This idea is as outdated and destructive as the Victorian ideas of keeping a lion in a 6 x 6 foot bare cage - a "lion tank", if you will. Nothing can be learned about nature from either a psychotic lion pacing around its cage or a depressed fish laying motionless in a sterile tank.
10) Although available volume must be conserved by pruning plants and occasionally scooping out sediment, microcosms never need to be "cleaned out", any more than a lake or forest floor needs to be "cleaned". Do not wage war on natural processes. NEVER "treat" tanks with chemicals in a misled attempt to reduce algal, plant or cyanobacteria growth. If you need to control a microbe bloom, simply curtail the use of supplemental nutrients, add additional filtration or increase the number of filter-feeders. Alternatively, don’t do anything at all; the bloom will eventually end naturally. They always do when some limiting resource becomes exhausted and a natural equilibrium is reached. Keep at least some of the glass clean enough for viewing by scraping off algae with a razor-blade, but don't obsess about it. Some organisms are best observed while they are attached to, or grazing on the algae-coated glass walls of the microcosm.
Do not fall into the trap of thinking that reproductively successful inhabitants are "pest" organisms that must be eradicated. If a particular species is reproducing explosively, do some detective work to locate and collect it's natural predator. In some cases, population excesses can be physically harvested for use as a food source in another system. If deliberate population control is not practical, don't worry about it. All populations in closed systems are ultimately self-regulating.
11) Be practical. If the microcosms become too expensive or troublesome, your institution will be unwilling to support them. Whenever possible, solicit external funding and donated supplies. Use live aquarium specimens instead of expensive prepared specimens from biological supply companies. Try to make the systems a good financial investment. Learn to build and repair equipment yourself. Always keep surrounding areas clean, uncluttered and safe.
Be especially careful with salt water around electricity. Make it your objective to spill as little water as possible and clean up spills and leaks immediately. Do not wait for the janitor to do it for you, by then the water will be leaking through the ceiling of the room below.
12) Don't take much notice of what pet stores tell you is, or is not, desirable in an aquarium. Pet store staff are not professional biologists. Their main objective is to sell you relatively rare, overpriced specimens and overpriced "restaurant display" equipment, designed to allow a few, large, confused fish to drift around an unnatural fish tank, in full view, behaving unnaturally, wishing they were elsewhere. We want our students to learn how to find living things as they actually would be in the wild: hunting, evading observation, breeding and generally acting like animals do in their permanent home.
13) Strive to perpetually improve and upgrade all the displays. You will find that by constantly devising and testing your own improvements you will come to understand each system better. Some "improvements" will teach you by subsequently turning out to be a disaster. Like Lewis Carol's red queen, who ran as fast as she could to stay in the same place, you may find that a conscious effort to always improve the mechanics of each system will offset what would otherwise be a slow decline as pumps wear out, filters and pipes clog, and bulbs grow dim with age.
14) Be well read in aquarium science, specimen
taxonomy and the principles of ecology, especially the following: food
webs and energy flow, pyramids of numbers and mass, succession, nitrogen
and carbon cycles, typical water chemistry, niche partitioning, island
biogeography, factors effecting productivity and (possibly most important)
factors affecting diversity (e.g., intermediate disturbance, predation,
grazing, extinction, immigration, niche diversity, isolation). You might
also like to read a little of James Lovelock's ideas on "Gaia". Although
his ideas are controversial, they are certainly thought provoking. Try
to see yourself as Lovelock's "earth mother", constantly working to optimize
the environmental conditions for your managed communities.
15) Be familiar with the specific inhabitants of each system. Keep students and other instructors informed as to which specimens are where and who is eating whom. Learn the identities of the various specimens using taxonomic guides, photos and correspondence with authorities in the field. Keep a photographic or video record of as many specimens as you can. Use your own and your student's observations to continuously expand your knowledge of taxonomy. Celebrate every time you cannot identify something, for it is not a failure of your knowledge but a chance to learn something new. Admit freely when you cannot answer student questions, but always let them see you've looked for the answer. It will inspire them to find answers of their own. Draw attention to interesting events (reproduction etc.). These are easily missed by anyone not watching the tanks on a daily basis. Maintaining a close daily watch on your communities is also the best way to spot any potential problems before they become too serious. With experience, you will intuitively recognize when the behavior of your specimens indicates that something is not right.
16) Try to use the microcosms to teach "hands on". Choose species that can be removed and passed around or displayed in a separate dish or tray. Try to be (unobtrusively) available to direct students and instructors towards relevant species and events during classes. Don't be over-protective of the systems The students should have free and unfettered access to the tanks. Encourage the students to get their noses against the glass and their hands in the water. The microcosms are specifically designed to recover quickly and even benefit from mild disturbance. Make sure students work primarily with a microscope or magnifying lens since most species are too small to see clearly using the naked eye. Use video-microscopy and technology-based demonstrations as often as possible to help inexperienced students see what they are looking for. Encourage learning by inquiry as this will teach students how to look at any living thing, not just those in the text.
17) Try to involve students in the upkeep and maintenance of the aquaria. Offer credit for special projects or investigations. Take groups of students on collecting trips to local ponds, or rivers. I've taken several groups of students on collecting trips to Florida where they learned more about animal diversity than anything else they've done.
18) Enthusiastically promote the aquaria and remind
faculty that they are available, otherwise they tend to forget and order
expensive specimens that the aquaria could supply for free. Bring visitors
to see the aquaria. They always enjoy seeing unusual beasties and may discover
that they have a need for them in a class or project. Visitors often arrive
quite spontaneously to see the tanks. Take time to introduce yourself and
answer any questions they might have. By maximizing positive publicity,
you may find that you will receive a steady flow of useful donated specimens
and equipment that will enhance the educational facilities of the department.
(Be careful! Don't add anything too disruptive ! Watch new specimens especially
closely to make sure they are fitting into the community peacefully.)
19) Remember - these tanks are different from those of a hobbyist in that they are permanent and they are for the education of professional biologists. You must insure that they remain healthy in the long term as well as the short term. You must plan your systems accordingly to reduce long-term maintenance and maximize long-term economy and educational value. Don’t include anything that MUST be checked or replaced any more frequently than once per week. Total redesign of a system to eradicate a frequent chore or problem is sometimes more economical that piecemeal tweaking or temporary adjustments. Some key long-term factors to remember include the following: Pumps and lights will have to be accessible so that they can be replaced one day. Sediment will accumulate and must (eventually) be removed. Small pipes will eventually clog — larger pipes rarely will. An emergency water change may be necessary one day. Eventually any piece of equipment can fail, so develop contingency plans ahead of time.
20) If you are ever in any doubt as to the value
of the tanks, just ask the students. In evaluations, students consistently
describe access to diverse living aquarium specimens as a very positive
aid to learning. If they don't, chances are you didn't adequately introduce
them to the specimens and you may have missed the ONLY opportunity to show
students live specimens during their degree course. They may live their
whole lives convinced that animals are "gross", and that biological diversity
has no meaning or value to them, ultimately to the detriment of the environment.
I include here 3 options. Only option two is shown
for both rooms since the plans for each of the two sides of the annex will
be close to mirror images of each other for all three options. The option
numbers correspond the their development history. (1 = original idea, 3
= most recent, preferred idea)
Late Breaking Schematic News:
Please also find OPTION 3 for the tank arrangement
in the biology annex. This idea is yet another modification of the original
concept and has become our best suggestion. Note that it will still require
the purchase of additional benches but will not require ANY modification
to the existing room layout.
