Indigenous peoples living in coastal areas have for centuries depended on the sea for their survival. In the more tropical waters they have not only fished from traditional boats but also engaged in spear fishing and shell gathering activities, diving either from shore or from boats. The waters in the past were plentiful and there was no need to dive deeply for long periods of time. More recently the situation has changed. Overfishing and the destruction of breeding grounds has made it impossible for indigenous peoples to sustain themselves. Many have turned to diving deeper for longer periods of time in order to bring home a sufficient catch. As the capacity of humans to stay underwater without some form of support is quite limited, indigenous divers in several parts of the world have begun using compressors to supply air from the surface or to use self-contained underwater breathing apparatus (SCUBA) to extend the amount of time that they are able to stay underwater (bottom time).

In the developing world, indigenous divers are found in Central and South America, Southeast Asia and the Pacific. It has been estimated by the University of California at Berkeley, Department of Geography’s Ocean Conservation and Environmental Action Network (OCEAN) Initiative, that there may be as many as 30,000 working indigenous divers in Central America, South America and the Caribbean. (It is estimated that the Moskito Indians in Central America may have a diving population as high as 450 divers.) Researchers at the Divers Diseases Research Centre of the United Kingdom estimate that in the Philippines there may be between 15,000 to 20,000 indigenous divers; in Indonesia the number has yet to be determined but it may be as many as 10,000.

In Southeast Asia some indigenous divers use compressors on boats with air lines or hoses attached to the divers. The compressors are normally commercial type compressors used in filling stations or are compressors salvaged from large trucks and driven by gasoline or diesel engines. Depths may range to more than 90 m and dives may exceed durations of 2 hours. Indigenous divers work to gather fish and shellfish for human consumption, aquaria fish, seashells for the tourist industry, pearl oysters and, at certain times of the year, sea cucumbers. Their fishing techniques include using underwater fish traps, spear fishing and pounding two stones together to drive fish into a net down current. Lobsters, crabs and shellfish are gathered by hand (see figure 1).

Figure 1. An indigenous diver gathering fish.

David Gold

The indigenous Sea Gypsy Divers of Thailand

In Thailand there are approximately 400 divers using compressors and living on the west coast. They are known as Sea Gypsies and were once a nomadic people that have settled in 12 rather permanent villages in three provinces. They are literate and almost all have completed compulsory education. Virtually all of the divers speak Thai and most speak their own language, Pasa Chaaw Lee, which is an unwritten Malay language.

Only males dive, starting as young as 12 years of age and stopping, if they survive, around the age of 50. They dive from open boats, ranging from 3 to 11 m in length. The compressors used are powered by either a gasoline or a diesel powered motor and are primitive, cycling unfiltered air into a pressure tank and down 100 m of hose to a diver. This practice of using ordinary air compressors without filtration can lead to contamination of breathing air with carbon monoxide, nitrogen dioxide from diesel motors, lead from leaded gasoline and combustion particulates. The hose is attached to a normal diving mask which covers the eyes and nose. Inspiration and expiration is done through the nose, with the expired air escaping from the skirt of the mask. The only protection from marine life and the temperature of the water is a roll collar, a long sleeve shirt, a pair of plastic shoes and a pair of athletic style trousers. A pair of cotton mesh gloves offers the hands a certain degree of protection (see figure 2).

Figure 2.  A diver off of Phuket, Thailand, preparing to dive from an open boat.

David Gold

A research project was developed in concert with Thailand’s Ministry of Public Health to study the diving practices of the Sea Gypsies and to develop educational and informational interventions to raise the divers’ awareness of the risks they face and measures that can be taken to reduce those risks. As part of this project 334 divers were interviewed by trained public health care workers in 1996 and 1997. The response rate to the questionnaires was over 90%. Although the survey data are still under analysis, several points have been extracted for this case study.

Regarding diving practices, 54% of the divers were asked how many dives they made on their last day of diving. Of the 310 divers that responded to the question, 54% indicated that they made less than 4 dives; 35% indicated 4 to 6 dives and 11% indicated 7 or more dives.

When asked about the depth of their first dive of their last day of diving, of the 307 divers who responded to this question, 51% indicated 18 m or less; 38% indicated between 18 and 30 m; 8% indicated between 30 and 40 m; 2% indicated more than 40 m, with one diver reporting a dive at a depth of 80 m. A 16 year-old diver in one village reported that he had performed 20 dives on his last day of diving to depths of less than 10 m. Since he has been diving he has been struck 3 times by decompression sickness.

A high frequency of dives, deep depths, long bottom times and short surface intervals are factors which can increase the risk of decompression sickness.

Risks

An early random sampling of the survey revealed that the 3 most significant risks included an interruption of the air supply leading to an emergency ascent, injury from marine life and decompression sickness.

Unlike sport or professional divers, the indigenous diver has no alternative air supply. A cut, crimped or separated air hose leaves only two options. The first is to find a fellow diver and share air from one mask, a skill which is virtually unknown to the Sea Gypsies; the second is an emergency swim to the surface, which can and frequently does lead to barotrauma (injury related to rapidly reducing pressure) and decompression sickness (caused by expanding nitrogen gas bubbles in the blood and tissue as the diver surfaces). When asked about separation from diving partners during working dives, of the 331 divers who responded to the question, 113 (34%) indicated that they worked 10 m or more away from their partners and an additional 24 indicated that they were not concerned about the whereabouts of partners during dives. The research project is currently instructing the divers how to share air from one mask while encouraging them to dive closer together.

Since indigenous divers are frequently working with dead or injured marine life, there is always the potential that a hungry predator may also attack the indigenous diver. The diver may also be handling poisonous marine animals, thus increasing the risk of illness or injury.

Regarding decompression sickness, 83% of divers said they considered pain as part of the job; 34% indicated they had recovered from decompression sickness, and 44% of those had had decompression sickness 3 or more times.

An occupational health intervention

On the implementation side of this project, 16 health care workers at the village level along with 3 Sea Gypsies have been taught to be trainers. Their task is to work with the divers on a boat-by-boat basis using short (15 minute) interventions to raise the awareness of the divers about the risks they face; give the divers the knowledge and skills to reduce those risks; and develop emergency procedures to assist sick or injured divers. The train-the-trainer workshop developed 9 rules, a short lesson plan for each rule and an information sheet to use as a handout.

The rules are as follows:

1. The deepest dive should be first, with each subsequent dive shallower.
2. The deepest part of any dive should come first, followed by work in shallower water.
3. A safety stop on ascent at 5 m after every deep dive is mandatory.
4. Come up slowly from every dive.
5. Allow a minimum of one hour on the surface between deep dives.
6. Drink large amounts of water before and after each dive.
7. Stay within sight of another diver.
8. Never hold your breath.
9. Always display the international dive flag whenever there are divers underwater.

The Sea Gypsies were born and raised next to or on the sea. They depend on the sea for their existence. Although they are sickened or injured as a result of their diving practices they continue to dive. The interventions listed above will probably not stop the Sea Gypsies from diving, but they will make them aware of the risk they face and provide them the means to reduce this risk.

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Overview

Fishing is among the oldest production activities of humankind. Archaeological and historical research shows that fishing—both freshwater and ocean fishing—was widespread in ancient civilizations. In fact, it seems that human settlements were frequently established in areas of good fishing. These findings concerning the role of fishing for human sustenance are confirmed by modern day anthropological research of primitive societies.

During the past few centuries, the world’s fisheries have been radically transformed. Traditional fishing methods have to a large extent been superseded by a more modern technology stemming from the industrial revolution. This has been followed by a dramatic increase in effective fishing effort, a much smaller increase in global catch levels and a serious decline in many fish stocks. The industrialization of global fishing has also led to destabilization and decline of many traditional fisheries. Finally, increased worldwide fishing pressure has given rise to international disputes about fishing rights.

In 1993, the world harvest of fish was in the neighbourhood of 100 million metric tonnes per annum (FAO 1995). Of this quantity, fish-farming (aqua- and mariculture) accounted for about 16 million tonnes. So the world’s fisheries produced some 84 million tonnes per annum. About 77 million tonnes come from marine fisheries and the rest, some 7 million tonnes, from inland fisheries. To catch this quantity, there was a fishing fleet counting 3.5 million vessels and measuring about 30 million gross registered tonnes (FAO 1993, 1995). There are few hard data about the number of fishermen employed in the operation of this fleet. The Food and Agriculture Organization of the United Nations (FAO 1993) has estimated that they may be as many as 13 million. There is even less information about the number of workers employed in the processing and distribution of the catch. Conservatively estimated they may be 1 to 2 times the number of fishermen. This means that 25 to 40 million people may be directly employed in the fishing industry worldwide.

Asia is by far the largest fishing continent in the world, with close to half of the total annual fish harvest (FAO 1995). North and South America together (30%) come next, followed by Europe (15%). As fishing continents, Africa and Oceania are relatively insignificant, with combined harvest of about 5% of the annual global catch.

In 1993, the largest fishing nation in terms of harvesting volume was China, with about 10 million tonnes of marine catch, corresponding to about 12% of the global marine fish catch. Second and third place were taken by Peru and Japan, with about 10% of the global marine catch each. In 1993, 19 nations had a marine catch in excess of 1 million tonnes.

The world’s harvest of fish is distributed over a large number of species and fisheries. Very few fisheries have an annual yield in excess of 1 million tonnes. The largest ones in 1993 were the Peruvian anchovy fishery (8.3 million tonnes), the Alaska pollock fishery (4.6 million tonnes) and the Chilean horse mackerel fishery (3.3 million tonnes). Together these three fisheries account for about 1/5 of the world’s total marine harvest.

Evolution and Structure of the Fishing Industry

The combination of population growth and advances in fishing technology has led to a great expansion in fishing activity. Commencing centuries ago in Europe, this expansion has been particularly pronounced worldwide during the current century. According to FAO statistics (FAO 1992, 1995), total world catches have quadrupled since 1948, from under 20 million tonnes to the current level of about 80 million tonnes. This corresponds to almost 3% annual growth. However, during the last few years, the ocean harvest has stagnated at about 80 million tonnes annually. As the global fishing effort has continued to increase, this suggests that the exploitation of the world’s most important fish stocks is already at or in excess of the maximum sustainable yield. Hence, unless new fish stocks come under exploitation, the ocean fish catch cannot increase in the future.

The processing and marketing of the fish harvest have also expanded greatly. Assisted by improvements in transportation and conservation technology, and spurred by increased real personal incomes, ever increasing volumes of catch are processed, packaged and marketed as high-value food commodities. This trend is likely to continue at an even faster rate in the future. This means a substantially increased value added per unit of catch. However, it also represents a replacement of the traditional fish-processing and distribution activity by high-technology, industrial production methods. More seriously, this process (sometimes referred to as the globalization of fish markets) threatens to strip underdeveloped communities of their staple fish supply due to overbidding from the industrial world.

The world’s fisheries today are composed of two quite distinct sectors: artisanal fisheries and industrial fisheries. Most artisanal fisheries are a continuation of the traditional local fisheries that have changed very little over the centuries. Consequently, they are usually low technology, labour-intensive fisheries confined to near-shore or inshore fishing grounds (see the article “Case Study: Indigenous Divers”). The industrial fisheries, by contrast, are high technology and extremely capital intensive. The industrial fishing vessels are generally large and well equipped, and can range widely over the oceans.

With regard to vessel numbers and employment, the artisanal sector dominates the world’s fisheries. Almost 85% of the world’s fishing vessels and 75% of the fishermen are artisanal ones. In spite of this, due to its low technology and limited range, the artisanal fleet accounts for only a small fraction of the world’s catch of fish. Moreover, due to the low productivity of the artisanal fleet, the artisanal fishermen’s income is generally low and their working conditions poor. The industrial fishing sector is economically much more efficient. Although the industrial fleet only comprises 15% of the world’s fishing vessels and approximately 50% of the total tonnage of the world’s fishing fleet, it accounts for over 80% of the volume of marine catch in the world.

The increase in fishing during this century is mostly caused by an expansion of the industrial fisheries. The industrial fleet has increased the effectiveness of the harvesting activity in traditional fishing areas and expanded the geographical reach of the fisheries from relatively shallow inshore areas to almost all parts of the oceans where fish are to be found. By contrast, the artisanal fishery has remained relatively stagnant, although there has been technical progress in this part of the fishery as well.

Economic Importance

The current value of the global fish harvest at dockside is estimated to be about US$60 to 70 billion (FAO 1993, 1995). Although fish processing and distribution may be assumed to double or triple this amount, fishing is nevertheless a relatively minor industry from a global perspective, especially when compared to agriculture, the major food production industry of the world. For certain nations and regions, however, fishing is very important. This applies, for instance, to many communities bordering the North Atlantic and North Pacific. Moreover, in many communities of West Africa, South America and Southeast Asia, fishing is the population’s main source of animal protein and, consequently, is economically very important.

Fisheries Management

The global fishing effort has risen sharply during this century, especially after the end of the Second World War. As a result, many of the world’s most valuable fish stocks have been depleted to the point where increased fishing effort actually leads to a drop in the sustainable catch level. The FAO estimates that most of the world’s major fish stocks are either fully utilized or overfished in this sense (FAO 1995). As a result, the harvest from many of the world’s most important species has actually contracted, and, in spite of continuing advances in fishing technology and increases in the real price of fish, the economic returns from the fishing activity have declined.

Faced with diminishing fish stocks and declining profitability of the fishing industry, most of the world’s fishing nations have actively sought means to remedy the situation. These efforts have generally followed two routes: extensions of the national fisheries jurisdictions to 200 nautical miles and more, and an imposition of new fisheries management systems within the national fisheries jurisdictions.

Many different fisheries management methods have been employed for the purpose of improving the economics of fishing. Recognizing that the source of the fisheries problem is the common property nature of the fish stocks, the most advanced fisheries management systems seek to solve the problem by defining quasi-property rights in the fisheries. A common method is to set the total allowable catch for each species and then to allocate this total allowable catch to individual fishing companies in the form of individual catch quotas. These catch quotas constitute a property right in the fishery. Provided the quotas are tradable, the fishing industry finds it to its advantage to restrict fishing effort to the minimum needed to take the total allowable catch and, provided the quotas are also permanent, to adjust the size of the fishing fleet to the long-term sustainable yield of the fishery. This method of fisheries management (usually referred to as the individual transferable quota (ITQ) system) is rapidly expanding in the world today and seems likely to become the management norm for the future.

The expanding range of national fisheries jurisdictions and the property-rights-based management systems being implemented within them imply a substantial restructuring of fishing. The virtual enclosure of the world’s oceans by national fisheries jurisdictions, already well under way, will obviously all but eliminate distant water fishing. The property-rights-based fisheries management systems also represent increased incursion of market forces into fishing. Industrial fishing is economically more efficient than artisanal fishing. Moreover, the industrial fishing companies are in a better position to adjust to new fisheries management systems than artisanal fishermen. Hence, it seems that the current evolution of fisheries management poses yet another threat to the artisanal way of fishing. Given this and the need to curtail overall fishing effort, it seems inevitable that the level of employment in the world’s fisheries will fall drastically in the future.

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As the world’s population continues to increase, demand grows for more food, but the increasing population is claiming more arable land for non-agricultural uses. Agriculturists need options to feed the world’s growing population. These options include augmenting output per hectare, developing unused land into farmland and reducing or stopping the destruction of existing farmland. Over the past 25 years, the world has seen a “green revolution”, particularly in North America and Asia. This revolution resulted in a tremendous increase in food production, and it was stimulated by developing new, more productive genetic strains and increasing inputs of fertilizer, pesticides and automation. The equation for producing more food is confounded by the need to address several environmental and public health issues. These issues include the need to prevent pollution and soil depletion, new ways to control pests, making farming sustainable, abating child labour and eliminating illicit drug cultivation.

Water and Conservation

Water pollution may be the most widespread environmental problem caused by agriculture. Agriculture is a large contributor to nonpoint pollution of surface water, including sediments, salts, fertilizers and pesticides. Sediment runoff results in soil erosion, a loss to agricultural production. Replacing 2.5 cm of topsoil naturally from bedrock and surface material takes between 200 and 1,000 years, a long time in human terms.

Sediment loading of rivers, streams, lakes and estuaries increases water turbidity, which results in decreased light for submerged aquatic vegetation. Species that depend upon this vegetation can thus experience a decline. Sediment also causes deposition in waterways and reservoirs, which adds to dredging expense and reduces water storage capacity of water supplies, irrigation systems and hydroelectric plants. Fertilizer waste, both synthetic and natural, contributes phosphorus and nitrates to the water. Nutrient loading stimulates algal growth, which can lead to eutrophication of lakes and related reduction in fish populations. Pesticides, particularly herbicides, contaminate surface water, and conventional water treatment systems are ineffective at removing them from water downstream. Pesticides contaminate food, water and feed. Groundwater is a source of drinking water for many people, and it is also contaminated with pesticides and nitrate from fertilizers. Groundwater is also used for animals and irrigation.

Irrigation has made farming possible in places where intensive farming was previously impossible, but irrigation has its negative consequences. Aquifers are depleted in places where groundwater use exceeds recharging; aquifer depletion can also lead to land subsidence. In arid areas, irrigation has been associated with mineralization and salinization of soils and water, and it has also depleted rivers. More efficient use and conservation of water can help alleviate these problems (NRC 1989).

Pest Control

Following the Second World War, the use of synthetic organic pesticides—fumigants, insecticides, herbicides and fungicides—grew dramatically, but a plethora of problems has resulted from the use of these chemicals. Growers saw the success of broad-spectrum, synthetic pesticides as a solution to pest problems that had plagued agriculture from its beginning. Not only did problems with human health effects emerge, but environmental scientists recognized ecological damage as extensive. For example, chlorinated hydrocarbons are persistent in soil and bioaccumulate in fish, shellfish and birds. The body burden of these hydrocarbons has declined in these animals where communities have eliminated or reduced chlorinated hydrocarbon use.

Pesticide applications have adversely affected non-targeted species. In addition, pests can become resistant to the pesticides, and examples of resistant species that became more virulent crop predators are numerous. Thus, growers need other approaches for pest control. Integrated pest management is an approach aimed at putting pest control on a sound ecological basis. It integrates chemical control in a way that is least disruptive to biological control. It aims, not to eliminate a pest, but to control the pest to a level that avoids economic damage (NRC 1989).

Genetically engineered crops are increasing in use (see table 1), but in addition to a positive result, they have a negative consequence. An example of a positive result is a genetically engineered strain of insect-resistant cotton. This strain, now in use in the United States, requires only one application of insecticide as contrasted with the five or six applications that would have been typical. The plant generates its own pesticide, and this reduces cost and environmental contamination. The potential negative consequence of this technology is the pest’s developing resistance to the pesticide. When a small number of pests survive the engineered pesticide, they can grow resistant to it. The more virulent pest can then survive the engineered pesticide and similar synthetic pesticides. Thus, the pest problem can magnify beyond the one crop to other crops. The cotton boll weevil is now controlled in this way through an engineered cotton strain. With the emergence of a resistant boll weevil, another 200 crops can fall victim to the weevil, which would no longer be susceptible to the pesticide (Toner 1996).

Table 1. Genetically engineered crops

Source: Toner 1996.

Sustainable Farming

Because of environmental and economic concerns, farmers have started using alternative approaches to farming to reduce input costs, preserve resources and protect human health. The alternative systems emphasize management, biological relationships and natural processes.

In 1987, the World Commission on Environment and Development defined sustainable development to meet “the needs and aspirations of the present without compromising the ability of future generations to meet their own needs” (Myers 1992). A sustainable farm, in the broadest sense, produces adequate amounts of high-quality food, protects its resources, and is both environmentally safe and profitable. It addresses risks to human health using a systems-level approach. The concept of sustainable agriculture incorporates the term farm safety across the entire workplace environment. It includes the availability and the appropriate use of all our resources including soil, water, fertilizers, pesticides, the buildings on our farms, the animals, capital and credit, and the people who are part of the agricultural community.

Child and Migrant Labour

Children labour in agriculture throughout the world. The industrialized world in no exception. Of the 2 million children under age 19 who reside on United States farms and ranches, an estimated 100,000 are injured each year in incidents related to production agriculture. They are typically children of either farmers or farm employees (National Committee for Childhood Agricultural Injury Prevention 1996). Agriculture is one of the few occupational settings in both developed and developing countries where children can engage in work typically done by adults. Children are also exposed to hazards when they accompany their parents during work and during leisure-time visits to the farm. The primary agents of farm injuries are tractors, farm machinery, livestock, building structures and falls. Children are also exposed to pesticides, fuels, noxious gases, airborne irritants, noise, vibration, zoonoses and stress. Child labour is employed on plantations around the world. Children work with their parents as part of a team for task-based compensation on plantations and as migrant farmworkers, or they are employed directly for special plantation jobs (ILO 1994).

Table 2. Illicit drug cultivation, 1987, 1991 and 1995

Source: US Department of State 1996.

Some of the problems and conditions of the migrant labour and child workforce as discussed elsewhere in this chapter and in this Encyclopaedia.

Illicit Drug Crops

Some crops do not appear in official records because they are illicit. These crops are cultivated to produce narcotics for human consumption, which alter judgement, are addictive and can cause death. Moreover, they add to the loss of productive land for food production. These crops comprise the poppy (used to make opium and heroine), coca leaf (used to make cocaine and crack) and cannabis (used to produce marijuana). Since 1987, world production of the opium poppy and coca has increased, and cultivation of cannabis has decreased, as shown in table 2). Five links are involved in the farm-to-user chain in the illicit drug trade: cultivation, processing, transit, wholesale distribution and retail sale. To interdict the supply of illicit drugs, governments concentrate on eradicating the production of the drugs. For example, eliminating 200 hectares of coca can deprive the drug market of about one metric ton of finished cocaine for a period of 2 years, since that is how long it would take to grow back mature plants. The most efficient means for eliminating the crops is through aerial application of herbicides, although some governments resist this measure. Manual eradication is another option, but it exposes personnel to violent reaction from the growers (US Department of State 1996). Some of these crops have a legal use, such as the manufacture of morphine and codeine from opium, and exposure to their dusts can lead to narcotic hazards in the workplace (Klincewicz et al. 1990).

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