Environmental Encyclopedia

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Environmental Encyclopedia 3

Sustainable biosphere

soil instead of increasing

pollution

in the

environment

Crop rotation reduces crop loss to insects and also increases

soil fertility. Monitoring

pest

populations helps determine

the best times as well as the best methods for eliminating

them, and using pesticides only when needed lowers pollu-

tion of soil and water and prevents insects from developing

resistances.

China provides one model of good land management.

Through techniques of

sustainable agriculture

which em-

phasize

organic farming

, China has met (though not ex-

ceeded) the nutritional needs of most of its people. On

Chinese farms,

methane

digesters recycle animal wastes,

by-products, and general refuse; the gas produced from the

digesters is in turn used as an energy source. Biological

controls are also used to reduce the number of harmful

insects and weeds. Crops are selected for their ability to

grow in particular locations, and

strip-farming

and

terrac-

ing

help conserve the soil. Crops that put certain nutrients

in the soil are planted in alternate rows with crops that

deplete those nutrients. Forests, important for

watershed

and as a fuel source, are maintained. Fish farming, or

aqua-

culture

, is widely practiced, and the fish raised on these

farms produce about 10 times more animal protein than

livestock raised on the same amount of land. In China,

agriculture relies upon human labor rather than more expen-

sive and environmentally harmful machinery, which has the

added advantage of keeping millions of people gainfully

employed.

Another important aspect of land management is

bio-

diversity

. Each organism is specially suited for its

niche

yet all are interconnected, each depending on others for

nutrients, energy, the purification of wastes, and other needs.

Plants provide food and oxygen for animals, sustain the

hydrocycle, and protect the soil. Animals help pollinate

plants and give off the

carbon dioxide

that plants need

to generate energy.

Microorganisms

recycle wastes, which

returns nutrients to the system. The activity of many of these

organisms is directly useful to humans. Additionally, having

a broad range of organisms means a broad source of genetic

material from which to create new, as well as better, crops and

livestock. However, a reduction in the number of

species

reduces biological diversity.

Hunting

can destroy species, as

can eliminating habitats by cutting down forests, draining

wetlands

, building cities and polluting excessively.

The water portion of the biosphere has two intercon-

nected parts. Freshwater lakes and rivers account for about

3% of the earth’s water, while the oceans contain the other

97%. Oceans are important to the biosphere in a number

of ways. They absorb some of the gases in the air, regulating

its composition, and they influence

climate

all over the

earth, preventing drastic weather changes. Additionally, the

ocean contains a myriad of plant and animal species, which

1367

provide food for humans and other organisms and aid in

maintaining their environment.

However, according to many scientists, exploitation

of the oceans must be curtailed to ensure that they remain

viable. Their argument is that species are too often harvested

until they are destroyed, creating an imbalance in the

ecosys-

tem

, and that fishing quotas that do not allow populations

to be depleted faster than they can be replaced should be

set and enforced. Rather than harvesting immature fish,

the

commercial fishing

industry should release them, thus

keeping the species population in equilibrium. Pressure must

also be taken off individual species, and interactions in the

ocean ecosystem should be examined. A strategy designed

to consider these factors would benefit the whole ocean

community as well as humans. Pollution of the ocean should

also be reduced. Pollution can take the form of

garbage

sewage, toxic wastes, and oil. In excess, these harm the

organisms of the ocean, which in turn harms humans. Dis-

posal of these substances should be controlled through,

though not limited to,

sewage treatment

discharge

re-

strictions and improved dispersal techniques.

Although freshwater is a renewable resource, care

needs to be taken to keep it clean. Wise water management,

which includes monitoring water supplies and

water qual-

ity

, can ensure that everyone’s needs are met. Agriculture

and commercial fishing require water, and manufacturing

industries use water in many of their processes. Households

consume water in cooking, cleaning, and drinking, among

other activities. Without water, certain recreations such as

water skiing and swimming would be impossible to enjoy.

Wildlife

and fish also need water to survive.

Pollutants reduce and damage the freshwater supply.

Pollutants include

chemicals

, sewage, toxic waste, hot water,

and many other organic and inorganic materials. Waste

leaching

from landfills contaminates

groundwater

, and

surface water is corrupted by wastes dumped into the water

by polluted groundwater flowing into the stream or lake, or

by polluted rain. Like oceans, freshwater can break down

small amounts of pollutants, but large amounts place great

pressure on the system. Disposal of potential pollutants re-

quires monitoring and treatment. A useful strategy is to

balance the demands of humans with the needs of the ecosys-

tem, emphasizing conservation and pollution reduction.

As with land and water, the atmosphere has been

adversely affected by pollution. Pollution in the air causes

such phenomena as

smog

acid rain

atmospheric inver-

sion

, and

ozone layer depletion

. Smog lowers the amount

of oxygen in the air, which can cause health problems.

Acid

rain destroys plants, animals, and freshwater supplies. Atmo-

spheric inversion exists when

air pollution

is unable to

escape because a layer of warm air covers a layer of cooler

air, trapping it close to the ground. Certain compounds, such

Environmental Encyclopedia 3

Sustainable development

as chlorofluoromethanes, thin the

ozone

layer by combining

with ozone to split it apart. A thinner ozone layer provides

less protection from the sun’s

ultraviolet radiation

, which

promotes skin

cancer

in humans and reduces the productiv-

ity of some crops. Reducing or eliminating harmful emissions

can also control air pollution.

Sustainable development

is one approach to keep-

ing the biosphere healthy. This method attempts to increase

local food production without increasing the amount of land

taken. It involves

nature

conservation and

environmental

monitoring

, and it advocates encouraging and training local

communities to participate in maintaining the environment.

The goal is to balance human needs with environmental

needs, and proponents of this view maintain that economic

growth depends on renewable resources, which in turn de-

pends on permanent damage to the environment being kept

at a minimum.

The

Ecological Society of America

published the

Sustainable Biosphere Initiative (SBI) in the early 1990s.

This document was an attempt to define ecological priorities

for the twenty-first century, and it is based on the realization

that research in applied

ecology

is necessary for better man-

agement of the earth’s resources and of the systems that

support life. The SBI calls for basic ecological research and

emphasizes the importance of education and policy and man-

agement decisions informed by such research.

TheSBI sets out criteria fordetermining which research

projects should be pursued, and it proposes three top research

priorities: global change, biodiversity, and sustainable ecolog-

ical systems. Global change research focuses on the causes and

effects of various changes in all aspects of the biosphere (air,

water, land). Biodiversity research focuses on both naturally

occurring and human-caused changes in species. It also stud-

ies the consequences of those changes. Research on sustain-

able ecological systems exams the pressures placed on the bio-

sphere, methods of correcting the damage and management

of the environment to maintain life.

Creating a sustainable biosphere requires a cohesive

policy for reducing consumption and seeking nonmaterial

means of satisfaction. Many believe that such a cohesive policy

would provide a much-needed focus for the many diverse en-

vironmental interests currently vying for public support.

[Nikola Vrtis]

ESOURCES

OOKS

Myers, N., ed. GAIA: An Atlas of Planet Management. Garden City, NY:

Anchor Press/Doubleday, 1984.

1368

ERIODICALS

“Biosphere Reserves.” Futurist (May-June 1992): 31–32.

Lubchenco, J., et al. “The Sustainable Biosphere Initiative: An Ecological

Research Agenda.” Ecology 72 (1991): 371–412.

Risser, P. G., J. Lubchenco, and S. A. Levin. “Biological Research Priori-

ties–A Sustainable Biosphere.” Bioscience (October 1991): 625–627.

Sustainable development

Sustainable development is a term first introduced to the

international community by

Our Common Future

, the 1987

report of the World Commission on

Environment

and De-

velopment, which was chartered by the United Nations to

examine the planet’s critical social and environmental prob-

lems and to formulate realistic proposals to solve them in

ways that ensure sustained human progress without deplet-

ing the resources of

future generations

. This Commis-

sion—which was originally chaired by

Gro Harlem Brundt-

land

, Prime Minister of Norway, and was consequently

often called the Brundtland Commission—defined sustain-

able development as “meeting the needs of the present with-

out compromising the ability of future generations to meet

their own needs.” The goal of sustainable development, ac-

cording to the Commission, is to create a new era of eco-

nomic growth as a way of eliminating poverty and extending

to all people the opportunity to fulfill their aspirations for

a better life.

Economic growth, in this view, is the only way to

bring about a long-range transformation to more advanced

and productive societies and to improve the lot of all people.

As former President John F. Kennedy said: “A rising tide

lifts all boats.” But economic growth is not sufficient in itself

to meet all essential needs. The Commission, which was

actually named the Commission on Sustainable Develop-

ment, or CSD, pointed out that we must make sure that the

poor and powerless will get their fair share of the resources

required to sustain that growth. The CSD stated that “an

equitable distribution of benefits requires political systems

that secure effective citizen participation in decision making

and by greater democracy in international decision making.”

The concept of “sustainable” growth of any sort is

regarded as an oxymoron by some people because the avail-

ability of

nonrenewable resources

and the capacity of the

biosphere

to absorb the effects of human activities are

clearly limited and must impose limits to growth at some

point. Nevertheless, supporters of sustainable development

maintain that both technology and social organization can

be managed and improved to meet essential needs within

those limits.

To clarify this concept, a discussion of what is develop-

ment and what is meant by “sustainable” is necessary. Devel-

opment is a process by which something grows, matures,

Environmental Encyclopedia 3

Sustainable development

improves, or becomes enhanced or more fruitful. Organisms

develop as they progress from a juvenile form to an adult.

The plot in a novel develops as it becomes more complex,

clearer, or more interesting. Human systems develop as they

become more technologically, economically, or socially ad-

vanced and productive. In human history, social develop-

ment usually means an improved standard of living or a

more gratifying way of life.

Something is sustainable if it is permanent, enduring,

or can be maintained for the long-term. Sustainable develop-

ment, then, means improvements in human well-being that

can be extended or prolonged over many generations rather

than just a few years. The hope of sustainable development

is that if its benefits are truly enduring, they may be extended

to all humans rather than just the members of a privileged

group.

Some development projects have been viewed by some

as environmental, economic, and social disasters. Large-scale

hydropower projects--for instance in the James Bay region

of Quebec or the Brazilian Amazon--were supposed to be

beneficial but displaced indigenous people, destroyed

wild-

life

, and poisoned local ecosystems with acids from decaying

vegetation and

heavy metals

from flooded soils released

through

leaching

. Similarly, introduction of “miracle” crop

varieties in Asia and huge grazing projects in Africa financed

by international lending agencies crowded out wildlife, di-

minished the diversity of traditional crops, and destroyed

markets for small-scale farmers.

Other development projects, however, worked more

closely with both

nature

and local social systems. Projects

such as the Tagua Palm Nut project sponsored by

Conserva-

tion International

in South America encouraged native

people to gather natural products from the forest on a sus-

tainable basis and to turn them into valuable products (in

this case “vegetable ivory” buttons) that could be sold for

good prices on the world market. Another exemplary local

development project was the “microloan” financing pion-

eered by the grameen or village banks of Bangladesh. These

loans, generally less than $100, allowed poor people who

usually would not have access to capital to buy farm tools,

a spinning wheel, a three-wheeled pedicab, or some other

means of supporting themselves. The banks were not con-

cerned merely with finances, however; they also offer busi-

ness management techniques, social organization, and edu-

cation to ensure successful projects and loan repayment.

Still, critics of sustainable development argue that the

term is self-contradictory because almost every form of devel-

opment requires resource consumption. The limits and

boundaries imposed by natural systems, they argue, must at

some point make further growth unsustainable. Using ever-

increasing amounts of goods and services to make human

life more comfortable, pleasant, or agreeable must inevitably

1369

interfere with the survival of other

species

and eventually

of humans themselves in a world of fixed resources.

While it is probably true that traditional patterns of

growth that require ever-increasing consumption of re-

sources are unsustainable, development could be possible if

it means: (a) finding more efficient and less environmentally

stressful ways to provide goods and services; and (b) living

with reduced levels of goods and services for those of us

who are relatively rich so that more can be made available

to the impoverished majority.

Some economists argue that the physical limits to

growth are somewhat vague, not because the laws of physics

are inaccurate, but because substituting one resource for

another in producing goods and services allows a tremendous

flexibility in the face of declining abundance of some re-

sources. For example, the extremely rapid adoption of

petro-

leum

products as sources of energy and raw materials in the

early twentieth century is a good case study of how quickly

new discoveries and technical progress can change the re-

source picture.

From this perspective, the decline of known petroleum

reserves and the effects of gases from the

combustion

petroleum products on possible global warming—while seri-

ous problems—are also signals to humans to look for substi-

tutes for these products, to explore for unknown reserves,

and to develop more efficient and possibly altogether new

ways of performing the tasks for which oil is now used.

Teleconferencing, for instance, which allows people at widely

distant places to consult without traveling to a common

meeting site, is a good example of this principle. It is far

more energy-efficient to transmit video and audio informa-

tion than to move human bodies.

The issues of distributive justice or fairness between

“developed” and “developing” societies—concerned with

who should bear the burden of sustaining future development

and how resources will be shared in development—raise

many difficult questions. Similarly, the technical problems

of finding new, efficient, non-destructive ways of providing

goods and services require entirely new ways of doing things.

The range of theoretical understanding, personal and group

activity, and policy and politics encompassed by this project

is so vast that it might be considered the first time humans

have tried to grasp all their activities and the workings of

nature in its entirety as one integrated, global system.

The first planet-wide meeting to address these global

issues was the

United Nations Conference on the Human

Environment

which took place in 1972. It was followed by

the

United Nations Earth Summit

held in June, 1992, in

Rio de Janeiro, Brazil. The scope of sustainability issues

taken up at the Earth Summit is in itself remarkable. Agenda

21, a 900-page report drafted in preparation for the confer-

ence, included proposals for allocation of international aid

Environmental Encyclopedia 3

Sustainable forestry

to alleviate poverty and improve

environmental health

Other recommendations included providing

sanitation

and

clean water to everyone, reducing indoor

air pollution

meeting basic healthcare needs for all, reducing

soil erosion

and degradation, introducing sustainable farming tech-

niques, providing more resources for

family planning

and

education (especially for young women), removing economic

distortions and imbalances that damage the environment,

protecting

habitat

and

biodiversity

, and developing non-

carbon energy alternatives.

In June 1997, a follow-up Earth Summit was held

to adopt a comprehensive program to further implement

Agenda 21. Those attending developed a multi-year program

of work that addressed themes and economic sectors each

year. Examples include global attention to freshwater man-

agement, oceans and seas, agriculture and forests, the

atmo-

sphere

and energy. The CSD is made up of elected members

from Member States of the United Nations, and its 2001

chair was Professor Bedrich Moldan of the Czech Republic.

See also Amazon basin; Greenhouse effect

[Eugene R. Wahl and E. Shrdlu]

ESOURCES

OOKS

Leonard, H. J., et al. Environment and the Poor: Development Strategies for

a Common Agenda. New Brunswick: Transaction Books for the Overseas

Development Council, 1989.

MacNeill, J., et al. Beyond Interdependence: The Meshing of the World’s

Economy and the Earth’s Ecology. New York: Oxford University Press, 1991.

Ramphal, S. Our Country, The Planet. Covelo, CA: Island Press, 1992.

World Bank. World Development Report: Development and the Environment.

New York: Oxford University Press, 1992.

World Commission on Environment and Development. Our Common Fu-

ture. New York: Oxford University Press, 1987.

THER

“About Commission on Sustainable Development.” United Nations Sustain-

able Development [cited July 9, 2002]. <http:www.un.org/esa/sustdev/

csdgen.htm>.

RGANIZATIONS

United Nations Commission on Sustainable Development, United Nations

Plaza, Room DC2-2220, New York, NY, USA 10017, 212-963-3170,

Fax: 212-963-4260, Email: dsd@un.org, <www.un.org/esa/sustdev/>

Sustainable forestry

Sustainability may be defined in terms of sustaining bio-

physical properties of the forest, in terms of sustaining a

flow of goods and services from the forest, or a combination

of the two. A combined definition follows: sustainable

forests are able to provide goods and services to the present

without impairing their capacity to be equally or more

useful to

future generations

. The goods and services

1370

demanded of the forest include wood of specified quality;

habitat

for

wildlife

, fish, and invertebrates; recreational,

aesthetic, and spiritual opportunities; sufficient water of

appropriate quality; protection (e.g., against floods and

erosion

); preservation of natural ecosystems and their

processes (i.e. allowing large forested landscapes to be

affected only by natural dynamics); and the preservation

species

To provide in perpetuity for future demands, the pro-

ductivity, diversity, and function of the forest must be main-

tained and enhanced. A listing of key biophysical properties

follows, along with examples of current threats to their main-

tenance: 1)

Soil

productivity (reduced by erosion and

nutri-

ent

depletion from overharvesting). 2)

Biomass

(degraded

in quantity and quality by overharvesting and destructive

logging

practices). 3) Climatic

stability

(possibly threat-

ened by

emission

greenhouse gases

). 4) Atmospheric

quality (lowered by

ozone

and

sulfur dioxide

). 5) Ground

and surface waters (altered by

deforestation

drainage

6) Diversity of plants, animals, and ecosystems (reduced by

deforestation, fragmentation, and replacement of complex

natural forests with even-aged forests harvested at young

ages).

Forest sustainability also depends on the maintenance

and improvement of socioeconomic factors. These include

human talent and knowledge; infrastructure (e.g., roads);

and political, social, and economic institutions (e.g., mar-

keting systems, stable political systems, international coop-

eration, and peace). Also essential are technological devel-

opments that permit wiser use of the forest and substitute

ways to meet human needs. Perhaps the major threat to

forest sustainability arises from an ever-increasing popula-

tion, especially in developing countries, combined with

the ever-increasing material demands of the developed

nations.

Forests have been managed as a renewable and sustain-

able resource by stable indigenous tribes for many genera-

tions. In recent years, some governments have made efforts

in this direction as well. Managing any forest for sustainabil-

ity is a complex process. The spatial scale of sustainability

is often global or regional, crossing land ownerships and

political boundaries. The time horizons for sustainability by

far exceeds those used for “long-term” planning by business

or government.

Some people have even questioned the feasibility

of sustainable forestry. Optimists believe technological

innovation and changed value systems will enable us to

achieve sustainability. Others feel demand will outstrip

supply, leading to spiralling forest degradation, and have

called for conservative and careful management of existing

forests.

[Edward Sucoff]

Environmental Encyclopedia 3

Swimming advisories

ESOURCES

OOKS

Kimmins, H. Balancing Act. UBI Press, 1992.

World Resource Institute. World Resources 1992-1993. New York: Oxford

Press, 1992.

Swamp

see

Mangrove swamp; Wetlands

Swimming advisories

Swimming advisories are warnings to the public that contact

with beach water could cause an illness. Advisories may be

issued after water monitoring, testing that reveals potentially

harmful bacteria levels. Water monitoring assesses levels of

E. coli and fecal coliform contamination in recreational wa-

ters. Local authorities restrict use of water for recreational

activities when the bacteria level exceeds standards for safe

usage.

A beach may be closed when the level of water contam-

ination poses a definite health risk. Mildly polluted water

can cause conditions such as a headache, sore throat, or

vomiting. Highly polluted water can cause hepatitis,

chol-

era

, and typhoid fever.

Swimming advisories are usually issued by governmen-

tal agencies and apply to public beaches at the ocean and

waterways such as bays, lakes, and rivers. Advisories may be

issued for public pools, too. However, not all states had

programs to monitor

water quality

and issue public advi-

sories as of May of 2002.

According to the U.S.

Environmental Protection

Agency

(EPA), state and local governments issued nearly

4,000 beach closings and swimming advisories in 1995.

Those actions involved the ocean, bays, and the

Great

Lakes

. In 2000, there were at least 11,270 beach closings

and advisories in the United States, according to the

Natural

Resources Defense Council

. NRDC also reported 48 ex-

tended closings and advisories that lasted from six to 12

weeks. Also reported were 50 permanent closings and advi-

sories that lasted for more than 12 weeks.

NRDC is an environmental group that has surveyed

beaches since 1990. Each July, the group issues “Testing the

Waters,” a state-by-state assessment of beaches. The survey

covers ocean, bay, and Great Lakes beaches. The report was

based on information from local, county, state and federal

agencies including the EPA.

According to NRDC, 11 states and Guam monitored

water quality at all beaches at least once a week. Regular

monitoring of all beaches was performed in California, Con-

necticut, Delaware, Hawaii, Illinois, Indiana, New Hamp-

1371

shire, New Jersey, North Carolina, Ohio, and Pennsylvania.

Monitoring of some beaches was performed at least weekly

in Alabama, Florida, Georgia, Maine, Maryland, Massachu-

setts, Michigan, Minnesota, Mississippi, New York, Rhode

Island, South Carolina, Texas, Virginia, Wisconsin, Puerto

Rico, and the Virgin Islands.

In states where monitoring improved, there was more

awareness about unhealthy water quality. More monitoring

led to additional advisories and closures. The 2000 NRDC

report ranked California at the top of the state list in terms

of advisories and closures. Nearly one-third of California

advisories and closures occurred in San Diego and Los

Angeles counties.

An example of procedures for swimming advisories

can be found in a San Diego County report for 2001. For

the county, 2001 was the first full year that San Diego

followed regulations in the state Beach Safety Bill. In 2001,

water contamination caused 1,301 advisory and closure days,

according to a report from the San Diego County Depart-

ment of Health.

An advisory was triggered when bacterial levels ex-

ceeded state standards. Sources of bacteria could include

human or

animal waste

soil

, or decaying plant material.

During an advisory, signs on the beach warn, “Contact With

This Water May Cause An Illness.”

Beach closings can be caused by sewage spills. These

pose the greatest health risk to swimmers, and beach signs

warned, “Contaminated Water — Keep Out.”

San Diego County also listed 72-hour general advi-

sories. The three-day advisories occurred after rainfall mea-

suring 0.2 in (0.5 cm) or more. Rainfall washes pollutants

off areas like streets. Pollutants traveled to the ocean through

storm drains. Advisories were posted on the County Web

page and phone tape, and in the local newspaper.

San Diego was typical of beach cities in terms of

what caused

water pollution

and illnesses. Sources of water

pollution

include water

runoff

, malfunctioning

sewage

treatment

plants, and the waste and litter left by people.

People are at risk when they swim or come into contact

with polluted water. The risk of illness increases when a

person swallows water. Furthermore, direct exposure to

water sometimes causes skin and eye infections, according

to the EPA.

The EPA advised the public to visit beaches that are

regularly monitored. Groups including the EPA provide

beach monitoring information on their Web sites. The EPA

also cautioned people against swimming near sewage

dis-

charge

pipes and to avoid swimming in urban beaches after

a heavy rainfall.

Groups campaigning for national water monitoring

policy include

American Oceans Campaign

, an organiza-

Environmental Encyclopedia 3

Swordfish

tion founded by actor Ted Danson. In 2002, American

Oceans Campaign and NRDC were among the groups that

wanted the Bush administration to implement federal

water

quality standards

that President Bill Clinton approved

before leaving office in 2000.

The Beaches Environmental Assessment and Coastal

Health (BEACH) Act of 2000 authorized $30 million for

beach monitoring grants. States with coasts and bays and

those containing the Great Lakes are eligible for grants

allocated through the EPA. States can use the grants to set

up or improve programs to monitor water quality. Grant

money can also be used for programs to inform the public

about water pollution. In 2002, President George W. Bush

budgeted $2 million for BEACH grants.

[Liz Swain]

ESOURCES

RGANIZATIONS

American Oceans Campaign., 600 Pennsylvania Avenue SE, Suite 210,

Washington, D.C. USA 20003, (202) 544-3526, Fax: (202)544-5625,

Email: info@americanoceans.org, <http://www.americanoceans.org>

Environmental Protection Agency Office of Water (4101M), 1200

Pennsylvania Avenue, N.W., Washington, D.C. USA 20460, (202) 566-

0388, Fax: (202) 566-0409, Email: OW-GENERAL@epa.gov, <http://

www.epa.gov/waterscience/beaches/>

Natural Resources Defense Council., 40 West 20th Street, New York,

NY USA 10011, (212) 727-2700, Fax: (212) 727-1773, Email:

nrdcinfo@nrdc.org, <http://www.nrdc.org>

Swordfish

The swordfish, Xiphias gladius, is classified in a family by

itself, the Xiphiidae. This family is part of the Scombroidea,

a subfamily of marine fishes that includes tuna and mackerel.

Tuna and mackerel are two of the fastest-swimming

creatures in the ocean. Swordfish rival them, as well as mako

sharks

, with their ability to reach speeds approaching 60

mph (96.5 kph) in short bursts. Their streamlined form and

powerful build account for their speed, as well as the fact

that their torpedo-shaped body is scaleless and smooth, thus

decreasing surface drag. Swordfish have a tall, sickle-shaped

dorsal fin that cuts through the water like a knife, and their

long pectoral fins, set low on their sides, are held tightly

against their body while swimming. Swordfish lack pelvic

fins, and they have reduced second dorsal and anal fins which

are set far back on the body, adding to the streamlining. It

has been suggested that their characteristic “sword"—a

broad, flat, beak-like projection of the upper jaw—is the

ultimate in streamlining. The shape of their bill is one of

the characteristics that separates them from the true billfish,

which include sailfish and marlin.

1372

Swordfish live in temperate and tropical oceans and

are particularly abundant between 30 and 45 degrees north

latitude. They are only found in colder waters during the

summer months. Although fish in general are cold-blooded

vertebrates, swordfish and many of their scombroid relatives

are warm-blooded, at least during strenuous activity, when

their blood will be several degrees higher than the sur-

rounding waters. Another physiological

adaptation

is an

increased surface area of the gills, which provides for addi-

tional oxygen transfer and thus allows swordfish to swim

faster and longer than other

species

of comparable size.

Swordfish are valuable for both sport fishing and

com-

mercial fishing

. The size of swordfish taken commercially is

usually under 250 lb (114 kg), but some individuals have been

caught that weighover 1,000 lb (455 kg). The seasonal

migra-

tion

of this species has meant that winter catches are limited,

but long-lining in deep waters off the Atlantic coast of the

United States has proven somewhat successful in that season.

Swordfish have only become popular as food over the

past 50 years. Their overall commercial importance was re-

duced in the 1970s, however, when relatively high levels of

mercury

were discovered in their flesh. Because of this

discovery, restrictions were placed on their sale in the United

States, which had a negative effect on the fishery. Mercury

contamination was thought to be solely the result of dramatic

increase in industrial

pollution

, but recent studies have

shown that high levels of mercury were present in museum

specimens collected many years ago. Although still a critical

environmental and health concern, industrial sources of mer-

cury contamination have apparently only added to levels from

natural sources. Today, swordfish is considered somewhat of

a luxury food item, sold at fine dining establishments.

Like any delicacy, swordfish entrees catch a tasty price

for the establishments that serve them, but at what cost to the

environment

? In 1999 alone, global fisheries caught roughly

55,000 tons of swordfish. About 40% of the all swordfish

caught comes from the Pacific Ocean. California fisheries ac-

countfor about 10% of thePacific proportion netted each year.

As mentioned, until the middle of this century, most of the

swordfish caught were relatively large in size. By 1995, how-

ever, about 58% of the Atlantic swordfish caught were imma-

ture, weighing less than half the average adult mass. Juvenile

fish are now caught more frequently because fishing tech-

niques have become very efficient, leading to

overfishing

According to the

Natural Resources Defense Coun-

cil

, an active

conservation

organization, two-thirds of the

swordfish caught by United States fishermen are juvenile.

In 1963, the average weight of swordfish caught was 250 lb

(114 kg). The average weight of swordfish caught in 1999

was 90 lb (41 kg). Among conservation scientists, it is gener-

ally agreed that the minimum weight a female swordfish

must attain for reproductive success is roughly 150 lb (68

Environmental Encyclopedia 3

Symbiosis

kg). Standards set by the International Commission for the

Conservation of Atlantic Tunas (ICCAT), however, set a

minimum weight limit at 50 lb (23 kg), well below reproduc-

tive weight. The ICCAT, a regulatory council consisting of

36 nations that governs global swordfish and tuna fish

catches, has limited overfishing by setting quotas for its

member countries. Unfortunately, scientists believe that

swordfish populations are still in danger because most sword-

fish are not reaching reproductive age before being caught.

Government agencies have warned fisheries that

swordfish populations are in danger. The United States Ma-

rine Fisheries Service reports that the global swordfish num-

bers have decreased by 70% since the 1960s. Also, it is

believed that if the present rate of decline continues, sword-

fish will become commercially extinct (too few in number

to be profitable) within a decade. Despite this, excessive

catching of swordfish remains a problem. In an effort to

limit the rate and extent of swordfish decline, a boycott and

marine conservation campaign was launched. In 1998, the

swordfish became the official symbol of global overfishing

for the National Coalition for Marine Conservation, repre-

senting dozens of

endangered species

. That year, environ-

mental organizations such as the Natural Resource Conser-

vation Council and Seaweb created a partnership with

prominent chefs at famous fine dining establishments across

the nation. Participating restaurants, leading the boycott,

removed swordfish from their menus while the environmen-

tal awareness groups spread the word about swordfish de-

cline. Restaurants in Dallas, Philadelphia, Boston, New York

City, and Baltimore were among the cities that led the

boycott.

Resteraunts also took swordfish off the menu due to

high levels of mercury. The

Food and Drug Administration

has set the level of 1 part per million (ppm), but some

samples of swordfish have come up as triple that regulated

amount. Due to these large amounts, the FDA recommends

that women who are or may become pregnant and small

children avoid eating swordfish. Although it is too soon to

tell, this may have a large impact on the current status of

the fish.

In 1999, Carl Safina, director of the Living Oceans

Program of the

National Audubon Society

, published the

book Song for the Blue Ocean. In response to the dramatic

changes in fish populations that were being observed, his

book urged readers to adopt an interest in the oceans and

the growing threat to their ecological

stability

. Still regarded

by many to be an unchangeable expanse and infinite source

of goods, Safina alerts readers of the threat of human progress

to the ocean, the world’s largest

ecosystem

. Inspiring activ-

ism, and some controversy, Safina’s book exposes how hu-

man activity affects even the ocean’s inhabitants. Among

the list of species discussed as being in peril is the swordfish.

1373

With efforts such as the restaurant boycott, federal conserva-

tion regulation improvements, and social interventions such

as the book Song for the Blue Ocean, it is hoped that swordfish

populations will make a steady come back within the next

decade. Their fate, however, ultimately depends upon con-

sumers, who control demand.

[Eugene C. Beckham]

ESOURCES

OOKS

Burton, R., C. Devaney, and T. Long. The Living Sea: An Illustrated

Encyclopedia of Marine Life. New York: G. P. Putnam’s Sons, 1974.

Hoese, H., and R. Moore. Fishes of the Gulf of Mexico: Texas, Louisiana,

and Adjacent Waters. College Station: Texas A & M University Press, 1977.

McClane, A. Field Guide to Saltwater Fishes of North America. New York:

Holt, Rinehart, & Winston, 1978.

Nelson, J. Fishes of the World. New York: Wiley, 1976.

Wheeler, A. Fishes of the World: An Illustrated Dictionary. New York: Mac-

Millan, 1975.

Symbiosis

In the broad sense, symbiosis means simply “living to-

gether"—the union of two separately evolved organisms into

a single functional unit regardless of the positive or negative

influence on either

species

Symbiotic relationships fall into three categories.

Mu-

tualism

describes the condition in which both organisms

benefit from the relationship,

commensalism

exists when

one organism benefits and the other is unaffected, and para-

sitism describes a situation in which one organism benefits

while the other suffers. Symbionts may also be classified

according to their mode of life. Endosymbionts carry out

the relationship within the body of one species, the host.

Exosymbionts are attached to the outside of the host in a

variety of ways, or are unattached, seeking contact for specific

purposes or at particular times. Similarly, symbionts may

either be host-specific, co-evolved to one species in particu-

lar, or a generalist, able to make use of many potential

partners. In either case, the relationship usually involves co-

evolutionary levels of integration, where partners influence

each other’s fitness.

Symbiosis generally requires either behavioral or mor-

phological

adaptation

. Morphological adaptation ranges

from the development of special organs for attachment, color

patterns that signal partners to chemical cues, and intercellu-

lar alterations to accommodate partners. Behavioral adapta-

tions include a range of body postures and displays that

indicate readiness to accommodate symbionts.

Symbiosis is fundamental to life. The various forms

of relationships between species—principally symbiosis,

Environmental Encyclopedia 3

Synergism

A Javan moray eel with cleaner wrasses on the Great Barrier Reef, Australia. This is an example of a symbiotic

relationship. (Photograph by Fred McConnaughey. Photo Researchers Inc. Reproduced by permission.)

competition

, and predation—create the structure of ecosys-

tems and produce co-evolutionary phenomena which shape

species and communities. At the most fundamental level, the

transition from non-nucleated prokaryotic cells to eukaryotic

cells, which is the evolutionary link to multicellular organ-

isms, is generally believed to be by symbiosis. In higher

organisms, 90% of land plants use some sort of association

between roots and mycorrhizal

fungi

to provide

nutrient

uptake from

soil

. Almost 6,000 species of fungi and about

300,000 land plants can form mycorrhizal associations. In the

next step of the terrestrial food chain, almost all herbivorous

species of insects and mammals use symbionts in the gut

to digest cellulose in plant cell walls and allow nutrient

assimilation. Thus, the energetics of life on earth, and cer-

tainly that of higher life forms, are largely dependent on

symbiotic relationships. See also Mycorrhiza; Parasites

[David A. Duffus]

ESOURCES

OOKS

Margulis, L., and R. Fester, eds. Symbiosis As a Source of Evolutionary

Innovation. Cambridge, MA: MIT Press, 1991.

1374

Synergism

Synergism is a term used by toxicologists to describe the

phenomenon in which a combination of

chemicals

has a

toxic effect greater than the sum of its parts.

Malathion and Delnav are two

organophosphate

in-

secticides that were tested separately for the number of fish

deaths they would cause at certain concentrations. When the

two chemicals were combined, however, their toxicity was sig-

nificantly greater than the individual tests would have led sci-

entists to expect. The toxicity of the mixture, in such cases, is

greater than the total toxicity of the individual chemicals.

In the manufacture of pesticides, toxic chemicals are

deliberately combined to produce a synergistic effect, using

an additive known as a “potentiator” or “synergist” to enhance

the action of the basic active ingredient. Piperonyl butoxide,

for example, is added to the insecticide rotenone to promote

synergistic effects.

The study of unintended synergistic effects, however,

is still in its early stages, and the majority of documented

synergistic effects deal with toxicity to insects and fish. Labo-

Environmental Encyclopedia 3

Synthetic fuels

ratory studies on the effects of

copper

and

cadmium

fish have established that synergistic interactions between

multiple pollutants can have unanticipated effects. Both cop-

per and cadmium are frequently released into the

environ-

ment

from a number of sources, without any precautions

taken against possible synergistic impacts. Scientists specu-

late that there may be many similar occurrences of unpre-

dicted and currently unknown synergistic toxicities operating

in the environment.

Synergism has been cited as a reason to make environ-

mental standards, such as the standards for

water quality

more stringent. Current

water quality standards

for met-

als and organic compounds are derived from toxicological

research on their individual effects on aquatic life. But pollut-

ants discharged from a factory could meet all water quality

standards and still harm aquatic life or humans because of

synergistic interactions between compounds present in the

discharge

or in the receiving body of water. Many scientists

have expressed reservations about current standards for indi-

vidual chemicals and concern about the possible effects of

synergism on the environment. But synergistic effects are

difficult to isolate and prove under field conditions.

[Usha Vedagiri]

ESOURCES

OOKS

Connell, D. W., and G. J. Miller. Chemistry and Ecotoxicology of Pollution.

New York: Wiley, 1984.

Rand, G. M., and S. R. Petrocelli. Fundamentals of Aquatic Toxicology.

Bristol, PA: Hemisphere Publishing Corporation, 1985.

Synthetic fuels

Synthetic fuels are gaseous and liquid fuels produced synthet-

ically, primarily from

coal

and

oil shale

. They are commonly

referred to “synfuels.”

The general principle behind coal-based synfuels is

that coal can be converted to gaseous or liquid forms that

are more easily transported and that burn more cleanly than

coal itself. In either case,

hydrogen

is added to coal, con-

verting some of the

carbon

it contains into ozone-depleting

hydrocarbons

. Coal liquefaction involves the conversion

of solid coal to a petroleum-like liquid. The technology

needed for this process is well known and has been used in

special circumstances since the 1920s. During World War

II, the Germans used this technology to produce

gasoline

from coal. In the Bergius process used in Germany, coal is

reacted with hydrogen gas at high temperatures (about

890°F/475°C) and pressures (200 atmospheres). The product

of this reaction is a mixture of liquid hydrocarbons that can

be fractionated, as is done with natural

petroleum

1375

The processes of

coal gasification

are similar to those

used for liquefaction. In one method, coal is first converted

to coke (nearly pure carbon), which is then reacted with

oxygen and steam. The products of this reaction are

carbon

monoxide

and hydrogen, both combustible gases. The heat

content of this gas is not high enough to justify transporting

it great distances through pipelines, and it is used, therefore,

only by industries that actually produce it.

A second type of gas produced from coal, synthetic

natural gas

(SNG), is chemically similar to natural gas. It

has a relatively high heat content and can be economically

transmitted through pipelines from source to use-site.

For all their appeal, liquid and gaseous coal products

have many serious disadvantages. For one thing, they involve

the conversion of an already valuable resource, coal, into

new fuels with 30–40% less fuel content. Such a conversion

can be justified only on environmental grounds or on the

basis of other economic criteria.

In addition, coal liquefaction and gasification are

water-intensive processes. In areas where they can be most

logically carried out, such as the western states, sufficient

supplies of water are often not available.

Another approach to the production of synfuels in-

volves the use of oil shale or

tar sands

. These two materials

are naturally occurring substances that contain petroleum-

like oils trapped within a rocky (oil shale) or sandy (tar sand)

base. The oils can be extracted by crushing and heating the

raw material. Refining the oil obtained in this way results

in the production of gasoline, kerosene, and other fractions

similar to those collected from natural petroleum.

A fifth form of synfuel is obtained from

biomass

. For

example, human and animal wastes can be converted into

methane

gas by the action of

anaerobic

bacteria in a di-

gester. In some parts of the world, this technology is well-

advanced and widely used. China, India, and Korea all have

tens of thousands of small digesters for use on farms and in

private homes.

During the 1970s, the United States government en-

couraged the development of all five synfuel technologies.

In 1980, the United States Congress created the United

States Synthetic Fuels Corporation to distribute and manage

$88 billion in grants to promote the development of synfuel

technologies. The timing of this action could not have been

worse, however. Within two years, the administration of

President Ronald Reagan decided to place more emphasis

on traditional fuels by deregulating the price of oil and

natural gas and by extending tax breaks to oil companies. It

also withdrew support from research on synfuels.

At the same time, worldwide prices for all

fossil fuels

dropped dramatically. There seemed to be no indication that

synfuels would compete economically with fossil fuels in the

foreseeable future. Unable to deal with all these setbacks,

Environmental Encyclopedia 3

Systemic

the United States Synthetic Fuels Corporation went out of

business in 1992. See also Alternative fuels

[David E. Newton]

ESOURCES

OOKS

McGraw-Hill Encyclopedia of Science & Technology. 7th ed. New York:

McGraw-Hill, 1992.

ERIODICALS

Douglas, J. “Quickening the Pace in Clean Coal Technology.” EPRI Journal

(January-February 1989): 4—15.

Moore, T. “How Advanced Options Stack Up.” EPRI Journal (July-August

1987): 4–13.

1376

Peterson, I. “Squeezing Oil Out of Stone.” Science News 124 (December

3, 1983): 362–364.

Shepard, M. “Coal Technologies for a New Age.” EPRI Journal (January-

February 1988): 5–17.

Systemic

Refers to a general condition of process or system, rather

than a condition of one of the component pieces. For exam-

ple, when a plant wilts in response to

drought

, the entire

organism is responding to the effect of loss. Communities

of plants and animals and their abiotic

environment

com-

prise an

ecosystem

. Whole ecosystems may respond to an

event, such as changes in local

climate

, by undergoing a

systemic change—for example, the composition and abun-

dance of

species

may be altered, and the functional ecologi-

cal processes of those organisms would be rearranged.