Protecting the wet commons
Edward D. Goldberg Scripps Institution of Oceanography University of California-San Diego La Jolh, CA 52093 It has been more than 20 years since Garrett Hardin introduced the paradigm of “the tragedy of the commons’’ ( I ) to illustrate overexploitation of the environment. He argued that an increasing population, resulting from the freedom to breed, leads to the loss of renewable resources for human society. Because the world‘s population will continue to cliib for the foreseeable future and will make increasing demands for material and energy, steps to minimize environmental damage have become CIUcial. Early identification of problems is a first sG. Hardin recognized the problems of the overuse o f h e resourcis of the wet commons, the fresh and salt waters of the Earth: “[Maritime nations] professing to believe in the inexhaustible resources of the oceans. . . [bring] spe450
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ties after species of fish to extinction.” He also was aware of the contamination of the seas with chemical, radioactive, and heat wastes. However, in the subsequent two decades, funher exploitation of the sea that has taken place or is proposed will challenge the continued use of renewable resources. The oceans will be increasingly used for mariculture, waste disposal, recreation, and transportation. In this article, I illustrate both the insults that might result from overuse of ocean space and the conflicts that might arise from competing activities.
Marine ranching, farming Throughout the world there are continuing and dramatic increases in the fanning and ranching of aquatic organisms. On a global basis, aquaculture constituted about 10%of the fish landings in 1985 for a total of about 10.5 million tons (Table 1) (2). The annual fish catch is about 91.5 million tons, according to the United Nations Food and Agriculture Organization. But perhaps more dramatic is the in-
crease seen in worldwide production between 1975 and 1985 (Table 1). Finfish aqUaCUlture, nearly all on land, ~ ~ indoubled, and the C N S ~ ~ C Kcrop creased by just under tenfold. There was a smaller jump in the production of molluscs. Three maridture crops deserve singling out: seaweed, shrimp, and salmon. Asia is the major culturing region for seaweed, which is used principally for human consumption (2). Japan is the largest producer followed by Korea, the Philippines, and China.The Asian region also produces the largest quantity of marine shrimp, followed closely by Latin America (Table 2). Taiwan is a major producer in Asia, and Ecuador in Latin America follows. Western Europe is the major producer of fanned salmon. Norway accounts for nearly 90% of the world‘s production, followed by the United Kingdom (Scotland and the Orkney and Shetland islands). Expansion of salmon farming is likely at existing sites, as desirable areas in coastal waters essentially have been exhausted.
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1990 American Chemical Society
Yet the economic attractiveness of
tivities and with waste disposal. In ad-
mariculture has had its w m e q u e n ~ dition, it can degrade the environment, Overproduction has dueatened wntm- jeopardk the integrity of ecosystems, ued expansion in some areas (4). For and compete for food and habitat with
example, in 1989 the surge in the output of the production of Norwegian salmon reduced by 16% the minimum price, which is regulated by the Norwe gian F i Fanners Sales Organization. Competition is so great that fish o b are sold below wst. In Japan, farmed salmon claimed a larger share of the market than those capmud in the wild (Fim 1). As a consequence, the salmon fishermen suffered employment
natural populations. Competition with natural pop&-
tions. In the case of ranching large numbers of fish, there is the haunting problem of the competition for foodwhich provides sustenance for members of marine food chains-between herded organisms and wild species. Fish ranchers clearly wish to use, fully the carrying capacity (the abundance of prey) of the oceans for their products. It is difficult to ascermn ’ whether that capacity is being exceeded. Increasing salmon re1a.w in the Columbia River are associated with declining adult rehuns (5). Also, the Atlantic Ocean could be supporting a smaller salmon population today than it did in the 1700s. Whether these phenomena reflectoverwhelmingly the carrying capacity of the oceans or other factors has not yet been established. Loss of natural habitats. Another consequence to the wet commons of ranching is the loss of natural habitats. The depletion of mangrove forests, a valuable but dedining marine ecosystem,is associated with shrimp farming in the southeastem Pacific (7).In Panama, there is an apprent areal loss of 1% annually In Ecuadoq 60,oOOof the 177,oOO hectares of mangroves have already been turned over to saltwater shrimp farming. However, in southeast Asia, there is a mitigating factor. The acid sulfate soils associated with mangroves are de&imental to shrimp mariculture, and thus many of the ranches have been moved inland (7). The creation of anoxic environments. F i farming in cages or with
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Prices for medium-priced shrimp also have declined throughout the world. There is a sense that with time aquacnllured shrimp will totally di5 place wild shrimp as an article of wmmerce (6). Shrimp fishermen may become an endangered species. There are two classes of mariculture: ranching and farming, differentiated on the basis of who feeds the organisms. In farming, the organisms are maintained in enclosures in coastal waters, whereas in marine ranching, the young fish are introduced into rivers or est+ aries from which they enter the open ocean. They return tothe entry site to spawn. In the former case, it is the farmer who feeds the fish. In ranching, the fish feed on naturally existing prey. Mariculture can compete for wet wmmons space with recreational acEnvlron. Scl. Technol., Vol. 24, No.4, 1880 4551
some of the island’s cleanest and most beautiful areas (8). This situation has disturbed the Hong Kong Yachting Association, which represents conflicting user communities who desire the space for recreational purposes. Mariculture accounts for 50% of the total live fish consumption in Hong Kong and has an annual value of U.S. $25 million. On the other hand, the intense raft culture of mussels in northwestern Spain (about 0.1 million tons annually) has an overall positive effect on the associated food chain (9). The fecal wastes of the mussels provide sustenance to demersal fish and crabs, although there is a decrease in the diversity of benthic organisms in the area of the rafts, and scallop recruitment may be harmed. To alleviate the problems of mariculture wastes on natural populations, the siting of cages for farming marine organisms in areas of strong tidal flows has been suggested (10).Generally, sea cages have been placed in sheltered zones with low tidal forces. Frid and Mercer studied the abundance of benthic organisms downstream of a mixed salmon farm at Milford Haven, U.K., where tidal currents achieve the relatively high speed of 2.5 knots (10). Five benthic organisms showed no significant changes in abundance going 45 m downstream from the farm. There does remain the concern that the longer residence times of the wastes in the commons can lead to the stimulation of plankton blooms and eutrophication. Therapeutantsand nontarget organisms. Marine mariculture is a form of monoculture and as such is subject to crop failures caused by the invasion of predators. The 1988 black tiger shrimp devastation in Taiwan may have been a consequence of such a phenomenon. The inhibition of such disasters is sought with therapeutants that include the powerful antibiotics tetracycline and streptomycin. There are few investigations concerned with their effects on nontarget organisms. An anticholesterinase agent, Duvan, is used in the control of sea lice on penned salmon (11).Its high toxicity extends to a variety of invertebrates, yet its heavy use in the United Kingdom is not complemented with environmental studies. The continued development of fish farming should be matched with field and laboratory studies of the effects of such agents on organisms in the farming area. Waste disposal. The entry of domestic and industrial wastes into areas of mariculture can seriously affect organisms living near the receiving waters. High levels of plant nutrients, such as nitrate and phosphate, and organic ma452
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terials associated with the wastes can lead to eutrophication and the subsequent population bursts of toxic organisms, the so-called red tides. Such is the case described for Hong Kong Island by Morton (8). From 1980 to 1984, 11 fish kills were attributed to these events (the culprits were Gymnodinium sp. and Gonyaulax s p . , dinoflagellates containing toxins), with a loss of 86 tons of cultured fish. The eutrophication might have been abetted by the mariculture activity itself. Concern is also centered on nearby commercial shellfish that might consume red-tide organisms containing the toxins responsible for paralytic shellfish poisoning, although no cases have been recorded by public health authorities.
Waste accommodation The integration of the oceans into multimedia assessments of waste management has become more and more difficult recently. The mood created by Jacques Cousteau and other environmentalists that the ocean can receive no wastes without suffering unacceptable degradation has been translated into many national and international policies. On the other hand, marine scientists and engineers argue that parts of the oceans can accept some wastes if the wastes are introduced properly. This concept was originally incorporated into the “critical pathways approach” in the United Kingdom, especially for the disposal into the Irish Sea of radioactive wastes from the Sellafield reprocessing plant (12), and later into the “assimilative capacity” approach for domestic and industrial discards in the United States (13). Despite evidence provided by marine scientists and engineers, all ocean dumping must cease in waters under U.S. jurisdiction by 1991, and domestic sewage sludge will not be allowed to enter the U.S. coastal environment after Jan. 1, 1992. Yet in the past successful ocean waste disposal has taken place. For example, the last remaining U.S. ocean site, Deepwater Dumpsite 106, is located over the continental slope off New Jersey. It has been only modestly investigated for effects from the industrial and domestic disposal that has taken place there over the past two decades. Still, its assimilative capacity for wastes can be approximated (14). The limiting factor for industrial waste discharge will be the effect on the biota of the surface waters. The wastes from titanium dioxide production and from the manufacture of organic chemicals created no significant changes in the indigenous organisms, especially the abundant zooplankton. Sublethal effects were noted in the waste plumes at the
site, but they appeared to involve only a very small percentage of the organisms in the water mass. At the rates of dumping in the early 198Os, long-term consequences were judged minimal. The disposition of toxic wastes into the commons is prohibited by the London Dumping Convention, and the thought of such discharges horrifies world citizenry. Yet high-level radioactive waste disposal has been seriously proposed by eminent scientists (15). The fine-grained sediments of the deep sea floor have been suggested as a site to accommodate these highly toxic substances. The areas of such deposits cover about 20% of the Earth’s surface. The radioactive wastes, placed in a chemically stable solid form, would be encased in canisters and introduced to the sediments either gravitationally or by an explosive boosting system that would be activated when the wastes were just above the sediment-water interface (Figure 2). Even hazardous wastes have been successfully disposed of in ocean waters. The classic case involved the ocean disposition in 1970 of around 67 tons of nerve agents held in projectiles (I 6).The munitions were placed in steel-encased concrete vaults and loaded aboard an obsolete World War 11 liberty ship. The vessel was towed to a site about 400 km east of Cape Canaveral, FL, and sunk in 5000 m of water. The ship did not break up on hitting bottom, and there was no evidence that marine biota were subsequently affected by any leakage of toxic agents. As land and air disposal options for waste become less and less attractive, the ocean offers in some instances a reasonable alternative. Land sites are becoming very scarce; incineration of domestic and industrial wastes is fought in many places by environmental groups.
Recreation Residents and tourists are placing greater demands on coastal areas for recreation, primarily as a consequence of their having greater amounts of leisure time. Tourism now accounts for about 10% of the gross world product. Beach activities with water contact encompass swimming, wading, surfing, wind surfing, snorkeling, skin diving, and scuba diving. Non-water-contact, open-beach activities include hang gliding, horseback riding, dune buggy driving, walking, jogging, sunbathing, fishing, and camping. For many countries of the developing world tourism is the main source of income. Thus, maintaining the health of their coastal waters can be economically crucial. Clearly, other coastal water activi-
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ties-mariculture, waste disposal, and mining-can contlict with recreation activities. However, of greatest concern are the serious problems thatarise from domestic waste disposal into marine waters through the entry of enteric microorganisms that jeopardize the wellbeing of recreational users of coastal areas. Exposure in waters and on beaches can result in ear, nose, and h t disorders and in respiratov and gastrointestinal infections. Further, there is a substantial data base that relates illness and even mortality to the collsumptjon of seafood contaminated with toxic viruses and bacteria. Both cholera and viral hepatitis have been associated with the consumption of uncooked or poorly cooked seafoods taken from contaminated areas. For many countries, the expense of upgrading domestic waste management appears great and seems perhaps less important than other economic investments. Whether a government chooses sewer disposal of primary treated waters to the wastal ocean or advanced water treatments with subsequent disposal of sewage sludge, the costs seem inordinately high in light of short-term economic gains. Thus, we can expect but a slow upgrading in domestic waste management and possibly a slower development of tourism in the developing world. ltansportstion The movement of goods from one continent to another will increasingly take place by ship. With the varying abilities of countries to produce products of commerce, he they agricultural, mineral, industrial, or medical, the interdependence of national economies emphasizes the need for ready trade. Further, the rising world population is demanding more materials and energy
to achieve higher standards of living than those now enjoyed. For those countries producing or requiring as imports high-volume, lowcost commodities-such as coal, oil, timber, and wheat-large-hulk, oceantraversing carriers (150,000 dead weight tons or more) appear to be essential. Such vessels now are primarily involved with the -port of petroleum and petroleum products. The need for deepwater ports (those with depths of at least 55 A) to Bccommodate carriers of such goods is well recognized. Large-bulk carriers require them for berthing. Such pons now handle ships in the @tmleG trade; the only A s h wrts are in J a m , and there are none in &e developin; nation~of a c a . yet it is these countries that may be in need of great quantities of large-bulk exports in the fuaue. North America will continue to be a major exporter of grains in the future, primarily to Asia, which has become a major importing region as a consequence of its small and shrinking crop land area per person. Agricultural technologies pro& to &fain the North American countries as producers (xe Table 3).
because the changes in the geometry of a harbor can affect its hydraulic regimes. Circulation patterns can be altered with disturbances to the prevailing compositions of the sea water. The biological productivity of the harbor can be altered. Deepwater ports promise to require additional coastal ocean space in the near future, and the effects on other coastal space users must be considered.
Property in the wet cotnn~ons A haunting problem in the more extensive yet renewable use of ocean space in the future involves the identification of various kinds of property in the commons. The following discussion is based on the problem & considered by Bowden, who charactenz ' es three kinds of property: private, public, and common (18). Attendant to the first are rights given by sovereign authorities (governments) to individuals or groups. Public property is similar except that it is held by a public agency. Common propefil in a ~ a u aresource l is held by a class of users whose rights are equal with one another. Fish, like wild animals, are a fugitive resource. They are treated as public property rather than as common p r o p erty inasmuch as an individual or group first must tind the fish to assert a claim over them. In some instances. such as salmon ranching, governments or commercial commies release b e number~of smo& for subsequent Gpture in commercial or recreational fishing. The sea then is common property, but the fish within a water body are public propertl until caught. Then they become private property. Recently, large corporate salmon ranchers have released smolts and then caphlred the adult fish. This is a justifiable concern to fishermen. who obiect to the use of public property for prhate profit. There is a sense that the resources of of the sea might be overused. Any
Australia, New Zealand
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rafts produces organic residues from uneaten food and from the metabolic wastes. These materials sink to the bottom and lead to eutrophication of the adjacent waters and to anoxia in associated sediments, all of which create serious pollution problems. Hong Kong has degraded environments under rafts that occupy waters in what were once ranching can provide a reasonable example. If too many salmon are introduced into the sea, they can deplete resources of food and harm natural food chains. This clearly would be counterproductive to the salmon ranchers, and controls are essential. The development of extensive mariculture will require the identification of marine property rights. Bowden indicates this might be done in one of three ways (18). First, we can create private property in the sea as we have done on land. Second, we might create public property in the sea; governments would control the resource and could sell off parts as they see fit. Finally, common property can be created and the rights of use can be defined for equal users. State control of a common property resource may in the end be most anractive. Governments can control the use of the resource; they can overxe any potential polluting activities and regulate them. The potential for improving the economies of a coastal area is clear. Already, ranching is posing some problems in need of government control. The deliberate or accidental interception of the ranched fish constitutes one of the challenges to the success of the activity. In open areas of both the Atlantic and the Pacific oceans there have been charges of poaching of ranched salmon. These charges ordinarily are raised against fishermen from outside the home countries. A second problem involves the unintentional capture of the ranched fish during the recovery of other species. A recent case involved the gill-netting of squid and the simultaneous entanglement of ranched salmon. The catches are made with so-called killer nets, primarily by fishermen from Japan, South Korea, and Taiwan (19). In addition, the drifting nets are often lost at sea where they can entangle fish that cross their paths. Consequently, fewer salmon return to fresh waters for spawning. A bilateral agreement between the United States and Japan has allowed US. observers to be placed on about 10% of Japan’s 350 squid-catching vessels to determine the number of fish entrained in the nets. No such agreements have been made with South Korea or Taiwan. There are also concerns about the use of the oceans within the 200-mile zone as waste receptacles. I predict that such 454 Envlron. Scl. Technol.. Vol. 24. NO.4, 1980
use will increase with time. Again, a
common property resource is being used. Here the resolution of use conflicts will be necessary, especially where waste discharges could interfere with aquaculture or recreation. Economics will guide the use of ocean space for the foreseeable future; environmental concerns clearly will exert a moderating influence. MariculNral activities will probably increase to the extent that products will approach both in weight and in monetary value the catches of wild organisms. Because ranching and farming are labor intensive, these developments probably will be more extensive in developing nations than in developed nations. Effluents from industrial activities bordering the fish farms also could introduce toxins. I suspect that such use conflicts will increase as farming further develops in waters adjacent to urban areas. More effective use of the opencommons for the disposal, and perhaps for storage, of noncyclable wasteseven those characterized as hazardous-will probably occur. Economic and social pressures alike will lead to more effective use of marine areas that can be determined by scientists and engineers as able to accommodate waste. Finally, the recreational and aesthetic resources of the oceans will demand more effective waste management. The trade-off of the economic advantages of attractive beach areas, especially as they affect tourism, over the costs of adequate waste disposal strategies will govern the decision-making process. Perhaps the greatest challenge to the successful exploitation of coastal waters involves the unexpected events that can have costly consequences, such as the Erron Valdez oil spill along the Alaskan coastline. Such episodes cannot be predicted. I argue that mitigative reactions to such an event, be it a 100-year flood, the uncontrolled release of high-level radioactivity from a nuclear reactor, the spill of toxic substances, or an earthquake, can best be managed by scientists and engineers knowledgeable about such events. The bureaucratic responses to some recent episodes have been disastrous as various governmental agencies fought for power. The remedial reactions were directed by administrators reacting to their own perceptions rather than to scientific and engineering data. The tragedy of the land commons can be avoided in the wet commons where appropriate actions mitigate overuse and abuse. Recognition of potential conflicts in mariculture, transportation, waste space, and recreation are crucial to effective resource management.
Originally presented as the q l e r Prize Lecture at the University of Southern California, Lm Angeles, CA. Oct. 19. 1989. References ( I ) Hardin, 0 . Science 1968, 75, 1-33. (2) Rhodes. R. 1. Aquaculrure Magazine I7rh Annual Buyer3 Guide 1988,620. (3) “Aquaculture and Capture Fisheries”; US. Department of Commerce: Washington. DC. 1988. (4) Burton. J. Fimmcial Times. Aug. 25, 1989, p. 32. (5) Isaksson. A. AquculNrr 1988, 75, I33. (6) h z o . D. Los Angeles Timcs, Jan. 19. 1989, pp. 8-37. (7) Apuaculrure Digesr 1989,14. 5 . ( 8 ) Morton, B. Mor. Poll. Bull. 1989, 20, 199-200. (9) Tenore. K. n al. In Pmceedings of rhc lnrcrnarionol Symposium on rhr Uriliwdon of Cwsrol Ecosysrcm: Planning. Poilurion Acriviry; Chao. N. L.; Smith. W. K . , as.; FundacPo Universidade de Rio Grande: Rio Grande. Brazil; pp. 321-28. (IO) Frid, C.L.I.; Mercer, 7. S. M ~ Poll. K B ~ I I 1989,20.379-a7. . ( I I) Ross, A. Mor. Poll. Bull. 1989.20, 37274. (12) Preston. A. In Disposal of Rodiwcrive Wastes into Seas, Oceans and Surface Warers. International Atomic Energy Agency: Vienna. Austria. 19-56, (13) Goldkrg, E. D. “Assimilative Capacity of U.S. Coaslal Waters for PoIIulanto**; Environmenlal Research Laboralonss, National Oceanic and Atmospheric Administration: Boulder. CO, 1979. (14) Capuzzo, I. M.; Laneaster, B. A. In Wosres in the Oceans. t’ol. 5; Kester, D. et al., Edr.; Wilcy: New York. 1985: pp. 209-29. (IS) Hollister, C. D. el al. Science 1981,213. 1321-26. (16) Linncnbom. V. 1. Naval Research Laboratory Memorandum Report 2273; Naval Research Laboratory: Washington, DC. 1971. (17) Brawn. L. R. “The Changing World Food Prospea”: Worldwatch Paper 85; Worldwatch Institute: Washington. DC, 1988; p. 14. (18) Bowden. 0. Cwsrol Aqvonrlrure Low ond Policy; Wanicw Press: Boulder. CO. 1981. (19) “Fish Mining..; Tim, May 29, 1989, p. 46.
E1 -< 8
E d d D.
has been associated with the University of California-San Diego 5 Scripps lnstimtion of Oceanography since 1949. He was appointed professSOT of chemistry in 1961. His scienrific interests include the geochemistry of natural wuters and sediments, the utilizarion of radioactive dating techniques in rhe m j a r sedimentary cycle. and historic andprehistoric burning. He received a B.S. degree from rhe University of California-Berke/ey, and a Ph.D. in chemistryfrom the University of Chicago in 1949. In 1989 Goldberg w s a co-winner of the firer Prize for environmental achievemenrs.
