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SUSTAINABILITY INDICATORS
Chapter 2:
Sustainability Indicators in Practice
Tamara Belyakhina
Imtiaz Ahmed
Agenda
− Maximum Sustainable Yield (MSY):
● Introduction
● Carrying Capacity
● Animal population models
● Problems with MSY application
● Collapse of Peruvian anchovy fishery
− AMOEBA
Introduction to MSY
− MSY: Maximum Sustainable Yield
• Number or biomass of individuals that can be removed from an
ecosystem without driving the population down
• Major idea was introduced in 1930s
• Important consideration of exploiting a resource for gain
• State SI for the ‘Protection of the Oceans, all Kinds of Seas and
Coastal Areas’
Carrying Capacity
− The maximum number of individuals of a species that an ecosystem
can sustain.
− If the carrying capacity is exceeded, the population will be limited
through lack of resources.
− How many animals can be taken without destroying the stock? =>
Models of species population
Animal population models
N - population size
r - indicator of the multiplication rate of each
individual in the population
K - carrying capacity
Problems with MSY application
− Doesn’t fully take account of the complex nature of the ecosystem:
• competition, symbiotic or commensal relationships with other
species
• tropic relationships
• changes in carrying capacity due to pollution or other human
influences
− Highly dependent on the choice of starting point
− r and K are assumed to be constant, and are difficult to estimate in
practice
− Doesn’t take into account difference between individuals in
population in size, age, etc.
The collapse of the Peruvian anchovy
fishery
− The collapse of the Peruvian anchovy fishery in 1972:
• the largest fishery till 1971
• fishing at or below MSY
• heavy fishing in 1960-1970 => excessive removal of fish at
reproductive age
• warm water phase in 1972 => negative effect on the anchovy
population
Sustainability indicators in marine
ecosystems:
The AMOEBA approach
− AMOEBA is an acronym which in Dutch stands for ‘general
method for ecosystem description and assessment’.
− Highly visual approach to encapsulating sustainability
− It has been created with non-specialists in mind
− Ten Brink et al (1991) took a broad view of sustainability and
concluded that there were three categories of ‘valuable
characteristics, whose sustainability is desirable’:
• Yeild
• Bio-diversity
• Self-regulation
Advantages of AMOEBA Approach
− Its appeal of measuring sustainability is not difficult
to understand
− Sustainability is summarized in visual terms as
AMOEBA with a clear, even if subjective, sense of a
target
− It has a very practical feel, primarily because it was
designed to be used as a decision-making tool in
environmental management
Criticism on AMOEBA Approach
− The AMOEBA is fundamentally based on numbers
(population sizes), it does not in itself provide any
information on the mechanisms involved in the changes (the
pressures)
− The approach is based on simple addition (all indicators are
combined into one diagram)
− The third problem with the AMOEBA approach is centered
on the choice of a reference condition
Conclusion
− This chapter has examined two levels of SI: an
individual SI (MSY) and an attempt at collecting
individual indicators together as a single diagram
(AMOEBA).
− the main problem with such SIs is that they attempt
to encapsulate a very complex system in a few
simple measures
Thank you for your attention!