Archive for June, 2018

Sustainability: An Aquarist’s Viewpoint

Tuesday, June 19th, 2018

Global Environment Outlook (GEO)

The Global Environment Outlook (GEO) is a consultative, participatory process, promoted by the United Nations.  It builds capacity for conducting integrated environmental assessments for reporting on the state, trends and outlooks of the environment.  GEO is part of a recent, broad sweep of environmental history which, through a series of reports, informs environmental decision-making and aims to facilitate the interaction between science, policy and practical applications. The fifth edition of the Global Environmental Outlook (GEO-5), was launched on the eve of the Rio+20 Summit, the United Nations Conference on Sustainable Development, in 2012.  It resulted in a focused political outcome document, ‘The Future We Want’, which contains clear and practical measures for implementing sustainable development.  The aim is to combat a deterioration of the the global environment, which is occurring through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat loss; the extinction of wildlife; and pollution of land and sea.

These deleterious ecological patterns are emerging on a planet of 7 billion people, rising to more than 9 billion by 2050.  They tell humanity that the applications of science and technology are running out of control and are driving, year on year, unsustainable economic growth.  Governments claim these ever-increasing demands on Earth’s natural resources are necessary to spread and maintain increasing human wants on a global scale.

The biggest challenge of GEO5 is to develop educational frameworks at all levels to bridge the science-policy-application interface necessary to bring humanity into equilibrium with the limits of Earth’s ecological productivity.  It means translating the findings of science into environmental law and policy to produce societal change required for living sustainably. The aim has to be to move away from the current linear take-make-waste industrial model, which is no longer sustainable in the face of rapid population growth, resource constraints, urbanisation, water insecurity and other trends.

The roles of science/technology, governance/management and education/civil society are the three composite actors of sustainability.  Everyone and every profession is equally important in this global cross disciplinary effort, but technology has the first and last word.  Technology is the best short and long term solution to the sustainability issues we face today that require harnessing flexible managerial survival strategies to re-couple human needs with the limitations of Earth’s ecological food chains and material cycles.  The paradigm is the circular economy, a model that focuses on careful management of material flows through product design, reverse logistics, business model innovation and cross-sector collaboration.

In essence, the circular economy is about moving from a system of ‘accumulating waste’ to one of “endless resourcefulness.” This regenerative model, upon which the growing recycling industry is based, affords a viable business opportunity to successfully tackle environmental priorities, drive performance, innovation and competitiveness.


Educational models for systems thinking

The whole UN process, of which the GEO is one of the latest strategies, originated in the belief that the global impact of endless consumerism could be prevented only by a global solution. The international community never found that solution,  Many would say this attempt at government by global conferences has failed. It will continue to fail so long as agreements made at these meetings of the international community are not accepted by all signatories as binding at an operational level and are not supported by educational frameworks for inculcating the concept of prosperity without growth.  Economic growth is often seen as essential for economic prosperity, and indeed is one of the factors that is used as a measure of prosperity. However, an alternative point of view is that prosperity does not require growth, claiming instead that many of the problems facing communities are actually a result of growth, and that sustainable development requires abandoning the idea that year on year  growth is required for prosperity. The debate over whether economic growth is necessary for, or at odds with, human prosperity, has been active at least since the publication of Our Common Future in 1987, and can be pointed to as reflecting two opposing worldviews.

In 1996, the British ecological economist Tim Jackson outlined the conflicting relationship between human wellbeing and economic growth in his book Material Concerns.  Prosperity without Growth.  It was first published as a report to the UK Sustainable Development Commission in 2008 and comprehensively expanded on the arguments and policy recommendations.

This educational issue has been a challenge stretching back through Rio 1992 to the Stockholm Conference on the Human Environment of 1972.  Yet the world remains on an unsustainable track despite over 500 internationally agreed goals and objectives. GEO-5 assessed 90 key environmental goals and objectives and found that significant progress had only been made in four (ozone depletion, access to fresh water supplies, research to reduce marine pollution and lead removal from fuel). Looking ahead, GEO-5 suggested that six ‘scenarios and transformations’ are needed to help turn the situation around:

  1. Transform human consumption (not only production)
  2. Shift motivations and values
  3. Accelerate the transition to sustainability.
  4. Forge a new social contract
  5. Apply adaptive management and governance (i.e. learn by doing and adjust course accordingly), and
  6. Develop clearer long-term targets and international accountability

These scenarios are bound together as a system that links ecology with culture.  They can only be understood and implemented by systems thinking to help support processes of decision making among stakeholders.  Stakeholders will have different, often contrasting, perspectives on sustainable development and systems thinking is necessary in order to generate purposeful action to improve situations of change and uncertainty.  This is particularly the case regarding action to combat climate change.

Climate change is one of the major interdisciplinary challenges of our time and adds considerable stress to societies and to the environment. From shifting weather patterns that threaten food production, to rising sea levels that increase the risk of catastrophic flooding, the impacts of climate change are global in scope and unprecedented in scale. In this context, behaviour change for combating climate change is a global objective that does not respect national borders. Emissions anywhere affect people everywhere. It is an issue that requires solutions that need to be coordinated at the international level and it requires international cooperation to help developing countries move toward a low-carbon economy operating within the bounds of what Earth can produce.  Because of its multidimensional character the necessary behaviour changes have to take into account relationships and think about wholes. This requires a capacity to unravel complex interactive systems. Mind maps and concept maps are essential formats to make projections and analyze what’s going to happen before decisions can be made. The conceptual complexity of behaviour change to combat climate change is presented in Fig 1. In this map education is part of the concept of a behavioral change toolkit.

Fig 1 Concept map of behaviour change for combating climate change

The toolkit is organised around the following fifteen concepts linking environment, economy and society


  • Use of nonrenewable resources should be “paid for” through increased renewable resource replacement
  • Rates of use of renewable resources should not exceed the rate of their regeneration
  • Rates of use of nonrenewable resources should not exceed the rate at which sustainable renewable substitutes are developed
  • Rates of pollution emission should not exceed the environment’s capacity to counteract
  • Substances (e.g., styrofoam, food waste) produced by society must not be produced at a rate faster than nature can break them down again


  • Resource distribution MUST be fair and efficient WHILE meeting human needs
  • Money should be circulated as long as possible within the community.
  • A living wage should be paid to all employees.
  • Business should give back to the community in proportion to its footprint on the community.
  • Markets should maximize efficiency, discourage the use of disposables, and greatly reduce waste.


  • Cities should grow only within predetermined community boundaries (e.g. current city limits).
  • Adequate food, housing, and medical care should be available to every family
  • Every girl and boy should receive education that teaches the knowledge, perspectives, values, issues, and skills for sustainable living in the community.
  • The present generation should ensure that the next generation inherits a community at least as healthy, diverse, and productive as it is today.
  • Communities should insist upon planned longevity and less conspicuous consumption of material good.

Earth as an aquarium

The central feature of sustainable development is the capacity for life to endure in the closed space of a relatively small planet. The educational concept of Spaceship Earth was invented to reinforce the idea that planet Earth is like a closed spaceship hurtling through space on a very long-duration mission. There is no resupply from outside sources. Recycling is as much a part of the natural order of things as is the sunrise everyday. Pollution occurs when there are outputs that cannot be used as inputs for something else. Pollution is harmful and can be dangerous. The connections between parts of the natural system are imperative to its normal operation. By systems thinking about what it takes to keep people alive on a spaceship, learners should come to understand more fully what it takes to keep people alive on this planet.

Another useful concept of endurance on a smaller scale is the goldfish bowl.  Michael Cottmeyer described it this way:-

“If you are in the bowl, how to you even contemplate doing anything about the water? How do you imagine getting out of the bowl, emptying the water, cleaning the glass, refilling the bowl, and getting back into a healthy environment? The dirty water is all around you and it’s really difficult to understand how we can change.   …changing the water requires leadership… it requires someone who can get their team to believe that the water can be changed… it requires someone that can keep people safe while they are in transition… it requires someone that has the vision to see what’s possible and who is willing to take the necessary risks required to get us there”.

Mary Catherine Bateson, an American cultural anthropologist, recalls how setting up an aquarium began a process of her becoming a systems thinker.  She says:

“One of my favorite memories of my childhood was my father helping me set up an aquarium. In retrospect, I understand that he was teaching me to think about a community of organisms and their interactions, interdependence, and the issue of keeping them in balance so that it would be a healthy community. That was just at the beginning of our looking at the natural world in terms of ecology and balance. Rather than itemizing what was there, I was learning to look at the relationships and not just separate things”.

Within this context of modelling aquatic ecosystems to support education for sustainability the GEO5 outcome document points to the use of captive animals to promote public understanding of the way ecosystems are responding to unprecedented human consumption and production.   This prompted BIAZA to publish a report entitled ‘Environmental Sustainability and Climate Change’.  

BIAZA is the professional body representing zoos and aquariums in the UK and Ireland. It has more than 100 zoo and aquarium members whom they support in their commitment to be at the forefront of conservation, education and research.  Zoos and aquariums are particularly well placed to influence the public to support action in these areas given that they attract large numbers of visitors and engage with a broad socio-economic cross-section of society. The BIAZA report centred on finding practical ways of acting on ’The future we want’.  BIAZA’s starting point is that zoos and aquariums inspire strong emotional connections between animals and the public. These are needed to carry out the proposed ‘social transformation’ role and act as agents of cultural change and as educators for sustainable development. This interaction, the report says, can occur through using endangered caged animals to teach children how zoos, wildlife parks and aquariums are about humankind’s impact on the natural world and how conservation is encouraging respect for living creatures.  

Similarly, AZA, the US Association of Zoos and Aquariums’ Conservation Education Committee (CEC) supports the appropriate use of living animals in zoos and aquariums as an important and powerful educational tool to advance a conservation agenda.  The CEC released a research agenda framework in 2010 after a thoughtful, inclusive development process that involved researchers, practitioners and evaluators. The goals of the framework are to help those in the conservation education and communications field understand how they can contribute to a greater body of knowledge.  The objective is to provide a structure for individual institution and multi‐institutional studies. These have to be interpreted in the larger picture of what we know about zoos and aquariums, their visitors, and their community relationships. The framework also provides an opportunity for all AZA‐accredited institutions and independent researchers to become involved in social science research and to work collaboratively to enhance the impact of zoos and aquariums and the conservation field as a whole.  

In general, zoos and aquaria are seen as places for parents and children to discover new things together. Research shows that parents, in particular, place value on zoos and aquariums as unique venues for informal learning.  To help in this direction, the spaceship Earth concept can be developed as the goldfish bowl/aquarium concept to create a practical home demonstration model of sustainability.


Managing a microcosm

All aquaria are managed as closed technological microfiltration systems. They are aquatic systems in which water is recirculated through filters, detoxified,and reused. A simple technological model of such a microcosm is presented in Fig 2 along with the major processes that keep its inhabitants alive.

Fig 2 Processes in a microfiltration system

  1. Food is given to Fish.
  2. Fish excrete Ammonia.
  3. Bacteria converts it to Nitrite.
  4. Bacteria converts Nitrite to Nitrate.
  5. Water changes carried out to reduce levels of Nitrate.
  6. Sunlight enables plants, including algae to use Nitrate for growth.
  7. Bacteria in the substrate or filter breaks down fish excreta and debris.
  8. Plants give off Oxygen when lit.
  9. Plants absorb Carbon dioxide during the day to grow and  give off carbon dioxide during the night

This system is not a good model of sustainability, mainly because fish food has to be added day after day. Most fish are dependent on complex organic substances (the food substrate).  Such organisms are categorised as heterotrophs.

A new perspective is required to turn an aquarium into a more appropriate experimental model of sustainability.  The approach has to start with the idea that aquaria of any kind are fundamentally algae producers (Fig 3). From this point of view, fish selected to populate the tank should be species that feed on algae which grow naturally in the tank.  Algae belong to a group of organisms capable of synthesizing their own food from inorganic substances, such as nitrate salts using light or chemical energy. Green plants and certain bacteria can also do this. They are called autotrophs.

Food chains of algae-eating fish have evolved in fast flowing tropical streams.  Here, births, growth, reproduction and death of algae and fish are, coterminous with The educational message is that Earth is an ecosystem and Homo sapiens has to survive on what the planet as a whole can produce to fulfil basic needs.

Microalgae as a group exhibit multiple metabolic pathways for different growth regimes depending on availability of organic carbon substrate.  They can adopt autotrophic (photosynthesis), heterotrophic (organic substrate dependent) and / or mixotrophic (auto and heterotrophic) modes of nutrition (Fig. 2). Microalgae can also adapt to changing conditions to become specialized autotrophs or heterotrophs through long-term shifts in the growth conditions. Furthermore, some microalgae can switch between these growth regimes (one is active while the other is inactive) at a particular period depending on the tank’s condition, while other microalgae are capable of using the pathways simultaneously. For example, the presence of a high concentration of CO2 enhances photosynthesis but undermines the utilization of organic carbon substrate, possibly due to retardation of respiration. Besides, absence of light during dark cycles leads to utilization of organic carbon substrate. Microalgae exhibit diverse metabolic pathways when experiencing hypoxic (low O2 concentration) or anoxic (extremely low O2 concentration) conditions in aquatic systems.  This metabolic flexibility of algae is the reason why it is so difficult to control their growth in aquaria.  A tank microcosm based on the productivity of autotrophic algae is depicted in Fig 3.

Fig 3 A tank microcosm based on microalgae as primary producers

Fundamentally, managing an aquarium to stimulate thinking about how we humans can live sustainably has the objective of balancing the growth of algae  to match the food requirements of fish (Fig 4). This concept map is amplified in Fig 5.

Fig 4.  Main factors affecting the growth of tank algae

Fig 5  The aquarium: a bigger picture

The expanded concept map (Fig 5) indicates that no microcosm, natural or technological, can stand alone. The map is but a fleeting partial scenario of the complexity of what is needed to sustain a tank ecosystem populated with fish that can live on algae.   

In the experimental algae/fish/nitrate model, derived from the wild, the aquarist is trying to maintain a steady state concentration of nitrate in a tank.  This concentration is a balance between its production by filter bacteria from waste ammonia excreted by the fish and its uptake by a growing population of algae being cropped by fish for maintenance and growth.  Management consists of adding or subtracting fish so that there is always a film of algae on the surfaces of tank. This is an innovation in understanding.

An aquarium then can be a model of humanity’s target goal of a biogenic carbon/humanity/carbon dioxide planetary equilibrium, powered by sunlight.  In this context, ‘sustainable development’ refers to the holistic approach and temporal processes required to integrate anthropogenic carbon, the cause of climate change, into the biogenic carbon cycle that will lead us to the end point of global sustainability (Fig 6).

Fig 6 A simplified diagram of cllimate change

In the 20th century, we saw Earth in space for the first time.  From space, our planet is a small and fragile ball dominated not by human activity and edifice but by a pattern of clouds, oceans, forests, grasslands and soils. Humanity’s inability to fit its activities into that pattern is changing Earth’s ecosystems, fundamentally. Many such changes are accompanied by life-threatening hazards to all life forms. This new reality, from which there is no escape, must be recognized and managed across the globe.  Aquariums are a reminder of this fact and managing one may be regarded as another educational tool to change humanity’s attitude towards an over-used planet proceeding on a linear take-make-waste industrial strategy. The aquarist models microcosms to illustrate the limits to Earth’s environmental carrying capacity. The objective is to promote the idea that the carrying capacity of planet Earth is better conceptualised as being due to the continuous presence in human systems of entrepreneurial action to solve emergent problems in innovative ways. Prosperity without growth  is the aquarists target.