I. INTRODUCTORY TERMS AND CONCEPTS:
Because this WWW page examines several of Hawaii's endangered and threatened
marine species including the Humpback whale, Hawaiian monk seal, green sea
turtle, and dolphins, it seems appropriate to first become familiar with
some of the key terms and concepts you will encounter.
Endangered refers to a species whose population is declining drastically,
and is in danger of extinction.
Threatened applies to those species whose population levels are declining
and that are likely to become endangered in the forseeable future.
A species is a group of living organisms (plants, animals, or microbes)
that breed under natural conditions and are reproductively isolated from
other populations. If species considered endangered or threatened are not
protected they may become extinct. Species become extinct when all individuals
of that species die. When this occurs, the species and all the genes
of that particular species' genetic line are lost forever. To prevent extinctions
it is important to protect and show respect for the earth's biodiversity.
Biodiversity refers to the total number of species, genes, and ecosystems
found on our planet. It is a representation of the wealth of life on earth,
a wealth which has undergone hundreds of millions of years of evolutionary
history, and to which many human cultures have become adapted. Biological
resources provide mankind with all of its foods, and form the basis of many
medicines and industries. The enormous variety of life in the form of genes,
species, and habitats has incredible value as it allows humans to successfully
meet the demands of the ever-changing environment in which we live.
Scientists estimate the total number of living species to be close to 10
million, yet little more than 10% of these species have been identified.
The full potential of our biological wealth therefore remains unknown and
untapped. Nonetheless, largely due to human activity, we are currently experiencing
the greatest loss of diversity of species, genes and ecosystems since the
mass extinctions of prehistoric times, some 65-500 million years ago. Recent
estimates indicate that 50,000 species become extinct each year. Many losses
occur without man knowing their complete role within the earth's ecosystem
and the impact that their absence will have. Major causes for the increased
loss of biodiversity involve trade or consumption of endangered species
and loss of habitat and resources through human development.
II. HOW AN ECOSYSTEM WORKS:
An ecosystem refers to all the living organisms and their non-living
environment within a given area. Note that this definition includes two
components; the living component which consists of the animals, plants and
microbes, and the non-living component which refers to the air, water, rocks,
soil and weather.
There is no limit to how large or small an ecosystem can be. An ecosystem
can be as large as an ocean or as small as a puddle. Very large ecosystems
are known as biomes. An important point to recognize about ecosystems
is the interaction between a grouping of plants and animals and their
non-living environment and how the two strive to achieve a balance.
Ecology relates to the study of ecosystems. Scientists who study
the different components of ecosystems and how they are related to one another
are called ecologists. Ecologists have determined that the populations
of many species if left undisturbed by humans will remain relatively unchanged
over time. Why then are so many species becoming extinct? Today, extinction
rates are thousands of times greater than the natural rate.
To better understand the reasons for this, it is first important to learn
about the different factors affecting the living and non-living components
of ecosystems and how they are interelated.
One factor which has a great impact on an ecosystem is the number of living
organisms there are in a particular ecosystem. The number of individuals
of each species present in the ecosystem is determined by that species'
rate of population growth. There are three factors involved in how
the size of a species population changes over time. They are:
-Migration into (immigration) or out of (emigration) the population
A change in the population size of a given species can be determined by
subtracting the number of individuals that leave a population (through death
or emigration) from the number of individuals that join a population (through
birth or immigration).
Change in Population Size = # Individuals that JOIN - # Individuals
(birth + immigrants) -
(death + emigrants)
From this we can see the following:
- That a population will remain unchanged if as many individuals
leave as join.
- That if more individuals join a population than leave population growth
- That if more individuals leave a population than join a population
decline will result.
The rate at which the population of a given species grows or declines is
also affected by a number of factors related to the species' life history
strategy . These include:
- The age at which the species is first able to reproduce
- The frequency with which reproduction occurs
- The number of offspring produced per reproductive effort
- The number of years a species is able to reproduce
- The average life expectancy of the species
Another factor which has a great impact on the balance of an ecosystem is
the availability of resources. Resources are those things necessary
for a species' survival and successful reproduction. Resources can be of
two types: renewable and non-renewable.
Renewable resources are those which are able to be renewed or replaced.
These include food (nutrients), water, mates and light.
Non-renewable resources are those which are not able to be replaced.
Only a finite amount of these resources exist. Space and territory (habitat)
are examples of non-renewable resources.
The number of living organisms an ecosystem is able to support is directly
related to the amount of renewable and non-renewable resources present in
the ecosystem. Under natural conditions, most populations will stabilize
at a level known as the carrying capacity of the ecosystem. The carrying
capacity is the maximum number of organisms that an ecosystem can support
on a continued basis. In most cases, an ecosystem's carrying capacity is
determined by the availability of resources such as space, nutrients, water
Interactions between species or between members of the same species often
determine who will be successful in obtaining resources and who will survive.
Such types of interactions include competition and predator-prey relationships.
Competition occurs when two individuals (or species) both attempt
to utilize a resource (such as food or space) that is limited relative to
the demand for it. Predator-prey relationships occur when one organism
(the predator) kills and eats another living organism (the prey). In predator-prey
relationships, one organism is the resource! Once all members of a prey
species are gone the predator will have to look for alternative sources
of food for energy.
This brings us to the next factor that affects how an ecosystem functions--
this is how energy flows within an ecosystem. Regardless of their size,
the energy flow within all ecosystems is pretty much the same. The sun
is the ultimate source of energy in most ecosystems and for almost all living
things. Energy from the sun flows through ecosystems allowing nutrients
to be produced.
Nutrients in turn, cycle and recycle within the ecosystem in the following
way: Plants are the primary producers in most ecosystems. They are
able to use the light energy from the sun to produce carbohydrates through
a process called photosynthesis. In addition to sugar which is a
carbohydrate, oxygen is given off as a by-product as shown in the reaction
Sun + H2O+ CO2 ----------> C6H12O6 + O2
Organisms that rely on the carbohydrates produced by plants for their means
of energy are called consumers. There are usually several levels
that energy flows through from producers to consumers. Each level is called
a trophic level. As mentioned, all of the organisms (mostly plants
and some bacteria) that obtain their energy directly from the sun and use
it to produce carbohydrates are called primary producers. Primary producers
make up the lowest trophic level. The second level consists of those organisms
which feed entirely on plants. These organisms are are known as herbivores
or primary consumers. Carnivores are those organisms that
feed on herbivores and other animals. They are referred to as secondary
consumers and make up the third trophic level. Occasionally some carnivores
eat other carnivores. When this happens, they form the fourth trophic level:
tertiary consumers. Organisms from each of these four levels feed on
one another with each level feeding directly on the level below it, making
up a series called a food chain. The length and complexity of food
chains vary greatly. In the wild, it is rather rare for one type of organism
to feed on only one other kind of organism; usually, each will feed on two
or more kinds, and in turn will be fed on by several other kinds of organisms.
This type of complex feeding arrangement within an ecosystem is referred
to as a food web.
III. HUMAN IMPACT AND RESPONSIBILITY:
Humans are continually having an effect on and being affected by the environment.
We are an integral part of nature. The ways which people interact with the
environment directly reflect how they understand and care for it. We must
all learn the importance of E malama ia Hawai'i: to take care of
our island home and the organisms which inhabit it. Hawaii is home to more
unique species than any place of similar size on Earth. It also has the
distinction of being the place on Earth with the highest concentration of
species that are seriously threatened with extinction. For many of Hawaii's
endangered species, loss of habitat through human activity is the primary
cause for population decline. Over 50% of Hawaii's natural communities are
considered critically endangered. Although the loss of single species is
a serious concern, the loss of entire ecosystems represents a crisis for
all of Hawaii's living organisms, even humans, as we also depend the natural
resources they provide. Loss of a single species is only an indicator that
something very serious is happening to the environment and to the world.
Our day-to-day survival depends on the maintenance of a healthy, natural
environment. We must learn to better balance our needs with those of nature
in order to care for Hawaii's future.
What is man without the beasts?
If all the beasts were gone, man would die from loneliness of spirit.
For whatever happens to the beasts, soon happens to man.
All things are connected.
Chief Seattle, 1854
It is important of course to care for all of the Earth, but taking care
of Hawai'i is a good way to begin. You can think of the Earth as an island,
just like Hawai'i. Just as there is only one Hawaii, there is only one Earth.
Just as Hawaii floats in the middle of the Pacific Ocean, the Earth floats
in space; and, just as Hawaii has only so much space and so many resources
that must be shared with all creatures, large and small, so does the Earth.
Once our territory and resources are used or damaged, they are difficult,
if not impossible to replace. Many of our actions have consequences that
affect the environment today and will continue to do so for a great many
years. It is important for us to incorporate responsibility for the environment
into our daily lives, not only for our future, but for the future of those
to come. This is what stewardship is all about.
IV. Hawaiian Perspectives on the Ocean
Ancient Hawaiians recognized the importance of stewardship, but perceived
it as more of a "kinship". They believed that humans are related,
or are "kin", to the oceans and all of their living components.
They believed that man's relation to the oceans deserves the same kind of
protection and respect that relationships among humans require. Hawaiians
saw the ocean as more than an "environment" or "resource".
They felt the ocean was a living being- a home to other living beings and
to living gods- something that should be shared, not controlled. The traditional
Hawaiian perspective on the oceans and relationship to them is perhaps best
illustrated through the Kumulipo, or Hawaiian chant of creation.
The Kumulipo not only follows the evolutionary progression of living
creatures from the oceans to the land, but also illustrates how the oceans
are an integral part of air, land, weather, and of plants and animals found
everywhere. In addition, the Kumulipo reminds us that the oceans
are a source for many things beyond those of economic or transportation
value. The Kumulipo describes how the oceans are also a source of
health, providing a variety of medicines for physical and emotional well
being, as well as serving as a source for cleansing, healing and nourishing
the spirit, and for learning the ways of nature.
The full chant is over 2,000 lines, and too long to be included here in
its entirety. To get a better sense of what the Kumulipo is all about,
portions of it (in both Hawaiian and English,) along with a more detailed
summary have been provided as part of the supplementary materials that accompany
this curriculum. The entire chant is found in Kumulipo, Hawaiian Hymn
of Creation by Rubellite Kawena Johnson.
[Suggested Activities for the Teacher Utilizing
This Curriculum as a Teaching Tool]
Return to Table of Contents of "Hawaii's Marine