Glossary

Acid mine drainage: Effluent created by oxidation of pyrites in rocks during mining operations, resulting in the production of sulphuric acid.

Affected drylands: Areas other than polar and sub-polar regions, in which the ratio of annual precipitation to potential evapotranspiration falls within the range of 0,05 - 0,65.

Agrarian: Agricultural, or farming.

Agrochemicals: Chemicals used to fertilise soil, and to control animal pests and weeds in agriculture.

Agronomic: Crops that are grown with the application of scientific principles to agricultural practices.

ALCOM: Aquatic Resource Management for Local Community development programme - regional water resource management programme of the Food and Agriculture Organisation of the United Nations.

Alien Species: Animals and plants invading and becoming established in areas where they do not normally occur.

Algae: Any group of chiefly aquatic, non-vascular plants (i.e. without roots, stems and leaves). Typical examples are pond scums and phytoplankton.

Algal: Pertaining to algae.

Alkalination: Conversion of soils to ones that are high in sodium chloride, often with a high pH.

Alkaline: Having a pH above 8,4.

Alkalinity: The sum of the anions of weak acids, plus hydroxyl, carbonate and bicarbonate ions in water.

Aloe: Succulent-leaved shrub of the family Asphodelaceae, well represented in southern Africa.

Anions: Negatively charged ions.

Anthropogenic: Man-induced, caused by humans.

Anti-equitable effect: An effect leading to more inequality.

Aquifer: Underground accumulation of water in certain types of geological formation.

Arsenic: Highly toxic chemical element.

Artisinal: Within the context of resource use, the term is used to define small-scale resource users or harvesters (e.g. fishermen) who use or harvest the resource mainly for household consumption but also sell the surplus for commercial gain.

B 

Balance of Payments (BOP): Account of all the transactions with the rest of the world. BOP consists out of two accounts, namely the current account and the capital account.

Ballast water:Water carried in ships to make them heavier and so less likely to roll. Upon entering a port the water is discharged from the ship.

Bantu: A group of 500 African languages including Swahili, Congo, Rwanda, Makua and Nguni.

Basin state: Country through which a river runs, or within which part or all of the catchment is situated.

Benguela Upwelling System:Ocean current off south western Africa rich in nutrients and hence biodiversity.

Benthic:Aquatic organisms that live on the bottom of a river, lake or ocean.

Biodiversity: A measure of the number and relative abundance of biological species. The variability among living organisms from all sources including, infer alia, terrestrial, marine, and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species, and of ecosystems.

Biological oxygen demand (BOD): The amount of oxygen consumed by biota in water. It is a measure of the portion of organic carbon that is relatively easily oxidised by micro-organisms. It is used as an indicator of dissolved organic carbon, often in conjunction with chemical oxygen demand (COD). Total organic carbon (TOC) = BOD + COD. Alternative:The chemical oxidation (adding of oxygen) to certain chemical components by bacteria in order for them to obtain energy (ammonium nitrogen can, for example, be oxidized to nitric acid by nitrifying bacteria).

Biome: (noun) large ecological region characterised by similar vegetation and climate (such as the deserts, tundra, etc.) and all living organisms in it.

Biota: Living organisms of a region or system.

Bottom and midwater-trawling:Type of fishing that nets fish from deep waters.

Buffered: Resistance to change in pH as a result of the presence in water of a weak acid and its salts

Bush Encroachment: Conversion of a grassland dominated vegetation type to one that is dominated by woody species, through selective grazing, overgrazing, or invasion by aliens.

Capital account: Value of all financial transactions, in-flows and out-flows.

Capital/Labour ratio: The relative size of the capital and labour content of inputs. The bigger the ratio the more capital-intensive the production process becomes.

Carbon dioxide equivalent:See GWP.

Carbon Sequestration: Setting apart of carbon in a relatively stable form in plant material, or in the organic fraction of soil.

Catchment: The land area from which a river or reservoir is fed, also known as a drainage basin or watershed.

Chlorofluorocarbons:Man made compounds containing chlorine, fluorine and carbon mostly used in aerosols, refridgerators and airconditioners. The vast quantities of CFC's used have contributed to breakdown of the ozone layer.

Chemical oxygen demand (COD): A measure of the oxygen requirement of organic matter in water. It is used as an indicator of dissolved organic carbon, often in conjunction with biological oxygen demand (BOD). Total organic carbon (TOC) = COD + BOD.

Climate Change: The United Nations Framework Convention on Climate Change (UNFCCC) defines climate change as a change which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. Any factor which alters the radiation received from the Sun or lost to space, or which alters the redistribution of energy within the atmosphere, and between the atmosphere, land and ocean, can affect climate.

Commodity Forums & Trusts: Groups formed by farmers and producers which regulate trade and prices of commodities.

Compaction: Compression of the soil such that it is difficult to plough, and water cannot drain through it effectively.

Conductivity: The ability of water to conduct an electrical current. This depends on the number of ions in solution and is a measure of the total quantity of salts dissolved in the water. It is used as a measure of salinity.

Conservation tillage: Cultivation of soil with minimum disturbance (no ploughing).

Contiguous: Connected without breaks.

Continental shelf: This area is part of the sea floor adjoining a land mass over which the maximum depth of sea water is 200 m (600 ft).

Control Boards: Government marketing structures which control the price and amounts sold of various commodities e.g. wheat, maize, meat.

Corridors: Strips of natural habitat joining two or more larger areas of natural habitat, but surrounded by transformed land, and therefore acting as a corridor for the movement of animals and plants within the natural habitat.

Crusting: Hardening of the surface layers of soil, making seed emergence difficult and promoting water run-off.

Cumulative effects: Effects which result from the incremental impact of the action when added to other past, present and reasonably foreseeable future actions.

Current account: Value of imports and exports of merchandise and services.

Cycad: Hard-leaved shrub or small tree of the order Cycadales. These plants are cone-bearing (gymnosperm, or non-flowering plant) with an ancient heritage, thought to have first evolved about 100 million years ago.

Decile: A group of 10% of the population.

Deforestation: Removal of trees and other woody vegetation.

Degradation:Reduction in capacity of the vegetation or soil to support life, through damage to physical, chemical or biological properties.

Demersal fishing grounds: Stocks found on or near the sea-bed.

Desertification: Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.

Dissolved solids: Inorganic salts dissolved in water.

Diurnal: Active during daylight hours.

Dobson Unit: one Dobson Unit (DU): is defined to be 0.01 mm thickness of the ozone layer if it were all compressed into a single, pure band of ozone at standard sea level pressure and temperature. i.e. 274 Dobson units equal 2.74 millimetres of ozone at standard temperature and pressure. It is the most basic measure used in ozone research.

Economic growth: Percentage change in GDP, generally measured in terms of a calendar year.

Ecosystem: Interacting organisms plus their environment.

The combined effect of processes such as photosynthesis, respiration and nutrient cycling, that make an ecosystem a functioning whole.

Elf (Pomatomus saltatrix): This fish species attain 1.2 m and 14.4 kg. They spawn off the Natal coast from September to December. Closed season in Natal includes September to November in an attempt to conserve stock. Elf are delicious eating, both fresh and smoked.

Effluent: That water which flows out of a man-made system into a river, usually waste water.

El Niño: El Niño is a disruption of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe. El Niño was originally recognized by fisherman off the coast of South America as the appearance of unusually warm water in the Pacific ocean, occurring near the beginning of the year. El Niño means The Little Boy or Christ child in Spanish. This name was used for the tendency of the phenomenon to arrive around Christmas. El Niño is often called "a warm event". El Niño is characterized by a large scale weakening of the trade winds and warming of the surface layers in the eastern and central equatorial Pacific Ocean. El Niño events occur irregularly at intervals of 2-7 years, although the average is about once every 3-4 years. They typically last 12-18 months, and are accompanied by swings in the Southern Oscillation, an inter-annual see-saw in tropical sea level pressure between the eastern and western hemispheres. During El Niño, unusually high atmospheric sea level pressures develop in the western tropical Pacific and Indian Ocean regions, and unusually low sea level pressures develop in the southeastern tropical Pacific. Southern Oscillation tendencies for unusually low pressures west of the date line and high pressures east of the date line have also been linked to periods of anomalously cold equatorial Pacific sea surface temperatures sometimes referred to as La Niña. There has been a confusing range of uses for the terms El Niño, La Niña and ENSO by both the scientific community and the general public, which is clarified in the following web page, http://darwin.bio.uci.edu/~sustain/ENSO.html

Employment: Number of people employed in jobs in the formal sector of the economy

Endemic: Occurring in a particular region, and nowhere else.

Endorheic pans: Temporary water bodies with a typically seasonal fauna.

Enhanced greenhouse effect: The additional absorption of solar radiation caused by the increased concentrations of greenhouse gases in the atmosphere due to human activities over the past two centuries. It is over and above the radiation absorbed by the atmosphere in pre-industrial times (the natural greenhouse effect), that is essential for life on earth.

ENSO: The terms ENSO and ENSO cycle are used to describe the full range of variability observed in the Southern Oscillation Index, including both El Niño and La Niña events.

Environmental economics: Environmental economics includes the monetary costs and benefits to human well-being and the well-being of the biosphere as a whole, plus the sustainability of the system, when studying the flow of money in the economy.

Epidemiological studies:Studies of diseases which are prevalent on a large scale either permanently or sporadically

Epipelagic:Microscopic algae living on sediment in shallow waters.

Erosion: Wearing away by physical or chemical action, leading to removal

Erythema: The potential biological effect of UV-B measured as the minimum amount of exposure required to produce a perceptible reddening of the skin.

Estuaries:The area where a river enters the ocean.

Eutrophic: Water with an excess of plant nutrients.

Eutrophication: The process whereby nutrients accumulate in a body of water.

Exchange rate: Rate at which one currency trades against another.

Exponential population growth:Growth in which the rate of increase is not limited by any external factor, but is dependant on the number of individuals and their potential net productivity rate.

Exponentially:Unlimited rate of increae.

Externalities: Side-effects of production or consumption activities.

Faecal coliforms: Bacterial indicator of faecal pollution.

Fauna: Animals.

Fertility rate: The number of children born in a year, usually expressed per 1 000 women in the reproductive age group.

Fish trapping and beach seining:Methods of subsistence or small scale fishing using traps and nets.

Fixed investment: Investment in physical capital, such as machinery, equipment, factories, stores etc.

Floodplain: Low-gradient land onto which a river regularly overflows its banks.

Fossil fuel: Coal, oil and natural gases (and various forms of these, such as oil shales, methane, clathrates and lignite) used as fuels.They are carbon-containing compounds formed when dead plants were buried many millions of years ago under sediments.

Fragmentation: Splitting up into many smaller sections, which are not joined.

Gini-coefficient: This is a measure of income disparityy. Should everyone receive the same income, the Gini-coefficient would equal zero. The lower the index, the more evenly income is distributed. Conversely the greater the disparity, the closer the Gini-coefficient approaches the value of one.

Global climate change:The United Nations Framework Convention on Climate Change(UNFCC) defines climate change as a change which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods. Any factor which alters the radiation received form the Sun or lost to space, or which alters the radiation received form the Sun or lost to space, or which alters the redistribution of energy within the atmosphere, and between the atmosphere, land and ocean, can affect climate.

Globalisation: The transition from national and regional economies to global economies.

Global warming: Gradual rise in temperature over the whole of the earth's surface, caused by the greenhouse effect.

Global trade forum:Group of representatives from various countries that meet to discuss trade issues.

Greenhouse effect: Effect produced by the accumulation of carbon dioxide crystals and water vapour in the atmosphere which insulates the earth and raises the atmospheric temperature by preventing heat loss.

Greenhouse gas: A gas which is transparent to short wavelength radiation from the sun, but absorbs the long wavelength radiation emitted from the earth, causing the earth's surface to warm up. Examples are water vapour, carbon dioxide, methane, nitrous oxide, ozone and chlorofluorocarbons.

Gross Domestic Product (GDP): Total value of final production of goods and services within a specific time frame, usually a calender year.

GWP: Global Warming Potential which is the ratio of the radiative absorption per unit mass of this gas, relative to an equal unit mass of CO₂, integrated over a 100 year period.

Habitat: The normal abode or locality of a living organism defined by the set of physical, chemical and biological features. Alternative: a place or environment in which specified organisms live (e.g. an elephant's habitat is the savanna)

Hidden Economy: Informal trade generating large amounts of income.

Homelands: The areas known as Transkei, Bophuthatswana, Venda and Ciskei which were previously part of South Africa, then granted nominal independence and later reincorporated into South Africa.

Hoop-net:Method of subsistance or small scale fishing whereby fish are caught in a net suspended from a hoop on a pole.

Horticultural: Use of plants for ornamental purposes (e.g. planting in gardens).

Hotspots: Areas of extraordinarily high biological diversity.

Hydrographs: Graph showing the level of water or the flow of water in a river or lake.

Hydrological: Pertaining to water flow.

Hydrological Cycles: The flow of water, from rainfall to rivers, to evaporation and cloud formation.

Hypersaline:Containing excessive salts.

Hypertrophic: Excessive nutrients.

Hypoxic: Oxygen deficiency in bodily tissue (short of anoxia).

Indigenous: Native to an area, occurring naturally.

Industrial: Resource use patterns linked to or influenced by commercial / industrial benefits.

Infant mortality rate: The number of deaths of children under the age of one year expressed as a proportion of the number of live births (per 1 000) during the same calender year.

Informal settlement: Houses (often of a temporary nature) erected on land of which the mayority have not formally been proclaimed and serviced for residential use.

Inflation: The sustained change in general price level in a country measured as a percentage change in the consumer price index (CPI).

Integrated Catchment Management (ICM): A systems approach to the management of natural resources, particularly water resources, within the bounds of a geographical unit based on the catchment area of a river system. ICM. recognises the need to integrate all environmental, economic and social issues within a catchment into an overall management philosophy, process and plan.

Integrated Water Resource Management (IWRM): Philosophy of managing the water resources of a catchment in an integrated manner. It relies on the recognition that components of the hydrological cycle are intimately linked, and each component is affected by changes in other components. It is inherent in the concept of ICM.

Interbasin transfer: Conveyance of water across a drainage or river basin divide. Also called transbasin diversion.

Interest rate: Price of money at a given point in time, i.e. the rate at which one borrow funds.

Intertidal organisms: Also know as the eulittoral zone, it occurs between the high and low water mark.

ISO 14001: The international standard relating to good environmental practices.

Lacustrine wetland: Area of permanent water with little flow, i.e. relatively shallow lake.

Land invasion: The (often planned) illegal occupation of land by a group of people for residential purposes.

Land transformation: The conversion of land usually from natural habitat to human uses such as agriculture or settlements.

La Niña: The cold-water version of El Niño. La Niña means The Little Girl. La Niña is sometimes called El Viejo, anti-El Niño, or simply "a cold event" or "a cold episode". There has been a confusing range of uses for the terms El Niño, La Niña and ENSO by both the scientific community and the general public, which is clarified in the following web page (http://darwin.bio.uci.edu/~sustain/ENSO.html)

Life expectancy: The average number of years that a person can expect to live, often stated as from birth.

Limnology: Originally the study of lakes; now the physical, chemical and biological properties of inland waters.

List of gases:

• CO₂: Carbon dioxide
  
• CH₄ Methane
  
• N₂O: Nitrous oxide
  
• NO_x: Oxides of nitrogen
  
• CO: Carbon monoxide
  
• NMVOC: Non-methane volatile organic carbon
  
• SO₂: Sulphur dioxide
  
• CFC: chloroflurocarbons. CFC-11: CFCl3 or equivalently CCl3F. CFCs were used in fridges, plastics industry and spray cans.
  
• HCFC: hydrochlorofluorocarbons. A temporary replacement for CFCs, will eventually be replaced by hydrofluorocarbons. HCFC-22: chlorodifluoromethane (CF2HCL)
  
• CH₃Br : Methylbromide is used as a soil sterilant in agriculture.
  
• CCl₄ : Carbon tetrachloride is used in dry cleaning.
  
• Trichloroethane: used in solvents and adhesives.

Littoral drift: Movement of sand and other material along the coastline due to wave and wind action.

Livestock: Domestic animals kept for meat or dairy production (e.g. cattle, goats, chickens, pigs).

Local Extinction: Extinction of a species from an isolated population in a particular area (e.g. an island) although other populations may occur elsewhere.

Long-term capital: Financial capital transactions with a duration of more than three years.

Lorenz curve:Is a measure of the disparity in income received between different sectors of the population. Where there is no disparity and everyone receives the same remuneration, the Lorenz curve is equal to 1. Where there is great disparity the Lorenz curve value approaches 0.

Macroeconomics: A study of national economic aggregates.

Macrophyte: A large plant, as opposed to microscopic algae.

Manganese (Mn): A metal found in several oxidation states. It is essential for humans and animals but is neurotoxic in excessive amounts.

Marginalisation: Expansion of agriculture into areas that are not suitable, due to economic or survivalist pressures.

Mariculture/Aquaculture: Mass production of aquatic organisms by human effort for commercial purposes.

Market and policy failures: Market failures refer to the failure of the market to add to the price of a commodity the additional costs to human-wellbeing and to the environment. For example, the price of electricity in South Africa fails to include the cost of air pollution caused by the coal-based generation of elecricity. Air pollution causes ill health in people and animals in the vicinity of the power stations, which causes them to require medication and often hospitalisation, and acid rain which affects adversely the production of agricultural crops and forests. Coal is non-renewable, could well be put to better use in the chemical industry, so it is an expensive way to generate electricity, which is not reflected in the price. Policy failures usually refer to price controls or import controls established by government to protect certain sectors of the market - at a cost to taxpayers generally, and often of no benefit or actually harmful to the market as a whole. For example, the government might guarantee to buy maize from farmers at a price higher than they would pay for maize on world markets. Taxpayers thus subsidise the farmers and as consumers pay higher prices for maize and maize products. Whether the cost to guarantee fresh maize products each year and food supplies in general in a more stable agricultural market as a result is worth it depends on the price fixed on by government.

Mass units: kilo ton: thousand metric tons or one gigagram which equals 1x109 grams; mega ton: million metric tons or one teragram which equals 1x1012 grams.

"Mean Annual Runoff: The amount of water on the surface of the land that can be utilised, in a year.

Medicinal: Used to prevent or cure illnesses and diseases.

Meiofaunal communities: Group of animals of the size between roughly 0.1 and 1 mm living in the spaces between sediment grains.

Mesic: Moist.

Metabolites: Substance that forms part of the metabolism, and whicvh may be taken in from the environment (e.g. amino acids and vitamins).

Metal: An element that is a good conductor of electricity and whose electrical resistance is directly proportional to absolute temperature. Heavy metals are those with an atomic mass > 40,08 (i.e. greater than that of calcium).

Microbial contamination: Generally, contamination of the water source by pathogenic (disease-causing) micro-organisms.

Microeconomics: A study of consumer and firm behaviour.

Midwater:Water below the surface but above the bottom of the water body.

Migration: The number of people entering and leaving the country. Internal migration refers to the relocation of people within the country.

Minimum Viable Population: Smallest number of individuals which will ensure the survival of a population through sustainable reproduction.

Monoculture: Cultivation of only one type of crop over a long period of time.

Montane: Occurring in mountainous regions.

Montreal Protocol: It is a protocol for the protection of the ozone layer. Agreed upon in 1987. South Africa became a signatory in 1990 and has also ratified the subsequent London Amendments (restriction of the use of CFCs and halons) in 1992. South Africa has acted in full compliance with the Kopenhagen Amendments although these have not been ratified yet.

Mortality rate: The number of deaths per year, usually expressed per 1 000 of the population.

Native Species: Species that occur naturally in an area.

Natural environment: With regard to rivers, aquatic ecosystems and those ecosystems dependent on them.

Natural Resource Accounts (NRAs): A set of accounts correcting the Systems of National Accounts (SNAs) for the costs of resource depletion and environmental degradation

Natural greenhouse effect: See enhanced greenhouse effect.

Net present value: Today's value of future costs and benefits.

Nitrogen: A plant nutrient that is present in a variety of forms (ammonia, ammonium, nitrate, nitrite).

Nuclear family: Primary social unit consisting of parents and children (sometimes grandparents) in the same home.

Nutrient: In aquatic biology usually a limiting nutrient, an element whose scarcity can limit plant growth (e.g. phosphorus, nitrogen and sulphates).

Nutrient Depletion: Reduction of essential nutrients ( through plant uptake and removal of plant residues, or through leaching) to a level at which they become unavailable for further uptake.

Optimum Yield: The largest amount of material that can be produced from a given area under cultivation, under optimal conditions.

Over-exploitation: Use of / harvesting of an environmental resource at a rate which exceeds the natural growth / regeneration rate. This might then result in an organism / resource being (locally) extinct.

Opportunistic: Having a rapid reproductive cycle under the correct environmental conditions.

Palatable Species: Plants that are preferred by grazing/ browsing animals, usually because they are sweeter or softer.

Palustrine wetland: Ecosystem occurring between an aquatic and terrestrial habitat (e.g. permanent marshes and swamps, springs).

Pelagic stocks: (Fish) stocks in the top and middle layers of the sea.

Per Capita Consumption: The amount of a commodity used by each person.

Perennial rivers: Rivers that flow throughout the year.

Perimeter: Area Ratio: The amount of "edge" in comparison to the amount of "centre".

pH: The negative log10 of the hydrogen ion activity (pH= 7 is neutral; pH < 7 is acid; pH > 7 is alkaline.

Phosphorus (P): Plant nutrient that is present in water bodies in a variety of forms (e.g. particulate phosphorus, orthophosphates and soluble reactive phosphorus). Excessive P in water bodies leads to eutrophication.

Photochemical smog:Combination of pollutants (volatile organic carbons, nitric oxide, carbon monoxide) which react in sunlight causing a layer of ozone and other gases which reduce visibility and are toxic to plants and animals.

Phytoplankton: Plant plankton, found floating in the water body.

PM10: Particulate Matter with an average diameter smaller than 10 micro metres ( m) (10-6 m) which is considered respirable.

Pollutant: A substance that contaminates.

Pollution: Defilement or unfavourable alteration of the surroundings, normally as a result of human actions. In the water environment, any foreign substance that impairs the usefulness of water.

Pollution prevention: Complete prevention of releasing hazardous substances having polluting properties to any public stream or water body.

Poly-aromatic hydrocarbons (PAH's): (Benzene) - Hydrogen and Carbon containing compounds.

Population growth rate: The annual percentage increase in the size of the population.

Potential Evaporation: The amount of evaporation that takes place from open water.

Poverty: A certain level of material deprivation below which an individual suffers physically, emotionally and socially. There are a number of methods of determining this level of deprivation.

Precipitation: Rain, hail and snow.

Precautionary Principle: Assumption of the worst case scenario with respect to actions whose outcomes are uncertain.

Prime Agricultural Land: Best available land capable of producing acceptable yields with acceptable inputs and minimal environmental damage.

Primary activities: Agriculture and mining activities.

Primary Production: Conversion of water and nutrients to food, by plants, using the sun's energy.

Productivity: The output of an organisation or individual in relation to the materials, labour, etc. it employs or consumes.

Purse-seining:Type of fishing net.

Radiative forcing: An increase in the energy absorbed by the atmosphere from the sun.

Ramsar Convention: Convention on Wetlands of International Importance especially as Waterfowl Habitat (Ramsar 1971).

Rare & Endangered Species: Species which have naturally small populations, and species which have been reduced to small (often unstable) populations by man's activities.

Reduced sources of nitrogen: Nitrogen chemically bound with hydrogen (such as X-NH2 : amino-N, or NH4 : ammonium). Can be oxidized by bacteria to nitric acid, with the release of energy.

Restitution: The act of restoring something to its former state, in this case its former ownership.

Receiving Water Quality Objectives: Objectives set to achieve a desired water quality of the receiving water body. This includes control of point and non-point sources of pollution to maintain the desired quality.

Receiving waters: Waters receiving effluents.

Recreational (consumptive or non-consumptive): Related to tourism or recreational dependence on the resource(s).

Renosterveld: A vegetation type of the fynbos biome characterised by small, tough, grey leaves, and predominance of the Daisy family (Asteraceae).

Reserves: Net balance between current and capital account, accumulated over time.

Ribbon development:A narrow strip of development all along the coast.

Riparian: Related to the river bank.

Riparian Habitats: Habitats along water courses (e.g. the banks of a river).

Riverine wetland: Wetland situated in a river channel, containing moving water either continuously or periodically (e.g. floodplain).

Runoff: Water running into a river, dam or wetland from the surrounding area or catchment

Salinisation: Increase in the amount of salts or dissolved solids in the water. Alternative: - the process by which salts accumulate in soils, to the detriment of cultivated plants

Salinity: The amount of dissolved inorganic solids, or salts, in the water.

Secondary activities: Manufacturing activities.

Sectoral composition: A break-down of economic activity into sectors.

Sectoral production methods and techniques: Production methods and techniques used per sector.

Sectoral rate of growth: The rate of economic growth per sector.

Sensitive population: people who have a medical history of respiratory problems, for instance because they suffer from asthma, emphysema or tuberculosis, or have heart conditions or lung cancer; also the elderly and children.

Sequestrated carbon: Carbon removed temporarily or permanently from the carbon cycle as for example when it is forms coal.

Seventy-four (Polysteganus undulosus): Attaining 1.0 m and 15 kg, seventy-four spawn during late winter and early spring over reefs off the Natal coast. At one time abundant, even taken by shore anglers from deeper waters, this elegant fish has become scarce in recent years. The flesh is greatly esteemed. The name is supposedly derived from lines on body resembling rows of gun ports along the sides of the old "seventy-four" man- of- war ( a cannon).

Sodicity: The accumulation of sodium in soil, resulting in structural deterioration and toxicity to plants.

Soil acidification: Soils that become acid, due largely to the bacterial production of nitric and sulphuric acid, followed by leaching.

Soil Formation: The process by which soil is formed through the interaction of parent material (rock), climate, topography, and organisms, over time.

Soil Organic Matter: Material in soil which is derived from once-living organisms.

Soil salinisation: Soils that become affected by large quantities of salts, usually from poor quality irrigation water, under conditions of poor or impaired drainage.

Soil Sterility: A situation in which soil cannot sustain life.

Soiling Index: The darkening potential of smoke and soot suspended in one cubic meter of atmospheric air.

Species, biological: Group of interbreeding individuals reproductively isolated from other groups (having common characteristics). Species alternative: - a biological category. Species consist of individuals which may vary slightly in appearance and genetic structure, but they do not breed with individuals of another species

Species diversity: A measure of the number and relative abundance of species (see biodiversity).

Species Richness: The number of species in an area or habitat.

Stratosphere: The upper part of the earth's atmosphere i.e. above about 12 km.

Structural Deterioration: The process by which soil structure deteriorates or is lost, mostly associated with a decline in soil organic matter.

Subsistence Agriculture: The cultivation of crops and livestock in order to provide basic food and energy requirements, amongst people whose incomes are too low to afford to purchase these goods.

Succulent Plant: A plant adapted to life in very dry conditions (e.g. desert cacti). These plants are able to store water in their cells, making them "juicy" or "succulent".

Subsistence: In the context of resource use, this suggests harvesting and use of marine resource(s) strictly for household consumption.

Sulphate (SO₄): Ion found in salts formed by the action of sulphuric and sulphurous acids on compounds containing metals. It is a good indicator of mining and industrial pollution.

Suspended solids: Particles suspended in the water column.

Sustainability: Or Sustainable development have been described as ‘meeting the needs of the present without compromising the ability of future generations to meet their own needs.

System on National Accounts (SNAs): A set of accounts measuring the production and use of manufactured goods and assets that are bought and sold in the market.

Tertiary activities: Services, e.g. trade and transport.

Terrestrial Ecosystem: A system of plants, animals, nutrients and elements, and the interactions between them, that is found on the land.

Tolerance Limits: The limit to which a plant or animal can withstand changes in the environment (e.g. the maximum amount of pollution that a plant can withstand, and still grow in that area).

Tonnes: Unit of measuring weight and is equal to 1000 kilograms.

Total dissolved solids (TDS): Amount of inorganic salts dissolved in water. TDS is directly proportional to electrical conductivity of water.

Total suspended particulate matter: Particulates of all sizes present in ambient air.

Toxicity: Measure of poison.

Traditional Healers: People with knowledge of healing using indigenous plant and animal remedies.

Transformation: Conversion of land from one system or use (e.g. natural savanna systems) to another (e.g. cultivation of crops) so that the previous system or use can no longer be detected.

Trace metals: Metallic elements that are essential for growth but only in very small quantities.

Transmission mechanism: The chain of events linking the money market and real economic activity.

Troposphere: The lower portion of the earth's atmosphere in which we live i.e. within about 12 km of the earth's surface and it is characterised by decreasing temperature with height, appreciable water vapour and vertical motion, and weather.

Ultra violet B radiation:Radiation from the sun, usually screened out by ozone, which can cause skin cancers.

Unbuffered: No resistance to change in pH.

Unemployment: Number of people within the economically active population (people between 15-65 years), who are willing to work, looking for a job, but unable to find a job.

Unemployment rate: The percentage of the economically active population who are not working but want to work and are actively looking for employment.

UNFCCC: United Nations Framework Convention on Climate Change which is a global commitment to take collective responsibility for climate change and is a mandate for action to address the problem. South Africa has signed the Convention in 1994 and ratified it in 1997.

Ungulate: Grazing animal that has hooves (e.g. cattle, antelope).

Uniform Effluent Standards: Standards set to regulate the discharge of point sources of pollution by enforcing compliance with effluent quality standards. Often leads to a cummulative pollution effect.

Upwelling system: Upwelling occurs when a drift current transports water away from the coast, the deficit hat occurs will be supplied from deeper layers under the influence of the pressure gradient that develops. Upwelling also carries nutrients and promotes productivity in other regions of the ocean.

Urbanisation: The process by which an increasing proportion of an area's population becomes concentrated in (legally or statistically defined) urban areas.

UVB: Ultra Violet B is short wave radiation and causes eye damage and skin cancer in humans and animals and damages the photosynthetic pathways of plants.

Urban: Use or harvesting of marine and coastal resources pertaining to developed or built up areas.

Vascular Plant: Any plant containing a system of vessels which transport water and nutrients between different parts of the plant (e.g. from the roots to the leaves).

Veld: Southern African term for natural vegetation, usually grassland or wooded grassland.

Volatile organic compounds: Carbon compounds which evaporate at everyday temperatures.

Volume units:

• kilo litre: thousand metric litres or one cubic metre (m³)
• Mega litre: million metric litres

Water quality: The value or usefulness of water, determined by the combined effects of its physical attributes and its chemical constituents, and varying from user to user.

Water quality standard: A rule establishing, for regulatory purposes, the limit of some unnatural alteration in water quality that is permitted or accepted as being compatible with some particular intended use or uses of water.