An historical overview of impacts from land-based pollution on community based natural resource management (CBNRM) as it applies to marine fisheries & coral reefs in the tropics.

Industrial effluents appear to be primarily oxygen-consuming organic materials as measured by Biological Oxygen Demand (BOD) from agro-industries in Western Indian Ocean countries (Table 5).

Table 5. Industrial pollutants, western Indian Ocean.

Top-Downers, Blaming the Fishermen versus Bottom- Uppers Blaming Pollution for Demise of Coral Reefs

There are major debates as to which is more important to the demise of coral reefs, land-based pollution (“Bottom-Uppers”) or over-fishing ("Top-Downers"). Many coral reef biologists believe overfishing of herbivores is of greater importance than nutrients in driving algae overgrowth of reefs, though most publications supporting this “top-down” hypothesis lack nutrient water quality data. “Top-Downers” suggest the solution is to stop fishing. If this were the limiting factor in reefs, herbivorous fish populations would crash as fisheries intensified, causing reef algae to proliferate, so preventing fishing should cause corals and fish to recover. But in fact, these patterns were not seen in the Caribbean: overfishing long preceded coastal tourism over-development, while sewage effluents and algae proliferation increased simultaneously whenever new tourism areas were developed, and fish populations changed from being carnivore dominated (the preferred choice of fishermen) to becoming almost entirely herbivore dominated as algae became the only abundant food source. It has been found that a reduction in herbivory from overfishing may enhance the likelihood of inorganic/organic pollution causing a coral-algal phase shift, but a reduction in herbivory in the absence of eutrophication can also lead to the proliferation of algae [14].

While the debate continues, if land-based pollution and overfishing are not addressed, the creation of marine parks will not save the coral reefs nor the fisheries, and any hope of expanding the concept of CBNRM to coastal fisheries will be lost.

Coral Bleaching

Until massive coral bleaching and die-off due to recent ocean warming events starting in the 1980s, a major cause of coral die-off globally had been and continues to be nutrient pollution. Coral bleaching is the whitening of corals that occurs when the zooxanthellae are lost from coral tissues or the amount of photosynthetic pigment in the zooxanthellae is sharply decreased. Because corals can only survive in a limited range of conditions, a slight temperature increase over a prolonged period can result in bleaching. Stresses from pollution (e.g. nutrients, sedimentation), high levels of light, infections, excess shade and fluctuations in salinity levels are also associated with incidents of coral bleaching. If the sea surface temperature (SST) increased 1°C for a month or longer above the long-term average for the warmest months/season, the period was termed “a hot spot” and usually resulted in mass bleaching of coral reefs. If these conditions last only one month and it then cools down, almost all corals will gradually recover. If excessively hot surface water conditions persist for two to three months or if surface water temperatures reach 2°C or 3°C above average for one month, coral mortality becomes significant. In the Caribbean, once seawater temperatures reach about 30°C for a few weeks, corals can begin experiencing “bleaching”, the degree of bleaching appearing to increase with the length of period of elevated surface water temperatures. In 1982-1983, 70-95% of the corals in the Eastern Pacific off of Costa Rica, Panama, Colombia, and the Galápagos Islands died because of bleaching caused by the warm waters brought by El Niño (ENSO - El Niño–Southern Oscillation, irregularly periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean). In the late 1980s and early 1990s, bleaching became a regular and pervasive problem in the Caribbean and began to appear in the Pacific and Indian Oceans -- often related to El Niño events. During the El Niño of 1997- 1998, bleaching began in the eastern Pacific but then expanded to an unprecedented, alarmingly broad region across the Indian Ocean from Kenya to Indonesia and in the Pacific Ocean from Australia to Polynesia [2].

The consequences of coral die-off, be it from land-based pollution or ocean warming are similar; dead reefs, increased beach erosion, decreased fishery habitat, public health issues, declining tourism and ultimate loss of key economic sectors. One might challenge the importance of land-based pollution when the consequences of ocean warming events on coral die-off were as much as 10 times that from other causes in the Seychelles and much of the Western Indian Ocean (e.g. sediment from land or dredging, algae overgrowth, tourist and anchor damage, storm waves, or coral-eating crown of thorns starfish), resulting in 75- 99% loss of live coral. However, corals have begun recovering from this ocean warming event. Recovery can be enhanced by diminishing stresses like land-based pollution. Ocean warming must be dealt with through long-term international negotiations, but land-based pollution can be dealt with immediately at regional and local levels [14] (Figure 5).

Figure 5. Coral bleaching, West Coast, Barbados, 1988/1989; zooxanthellae giving, coral color, have been extruded, but coral is still alive [2].

The following summarizes the author’s experiences in the Caribbean and how they relate to the Indian Ocean along the eastern side of the African continent in the development of coastal tourism. General conclusions drawn are [2]

• Land-based pollution is a primary cause of coral reef degradation. At the September 1988 Regional Seas Conference sponsored by UNEP in Mexico City, land-based pollution was considered the number one environmental problem affecting the Caribbean Basin;

• This is primarily from nutrient enrichment of near shore marine waters associated with improperly or untreated domestic sewage and gray water originating from major urban areas and from tourism developments;

• The world's tropical waters are nutrient poor and ecologically thrown out of balance by this enrichment, resulting in coral reef ecosystems collapsing as a result of being smothered by epiphytic algae (benthic macro-algae), which prevents zooxanthellae (a symbiotic dinoflagellate living within the coral polyp from photosynthesizing (gives coral color & provides colonial corals with 98% of their total food requirements), the rest of its food coming from the polyps filtering micro-organisms out of the water – thus cutting off the coral’s food supply and starving it to death;

• Believed to be secondary in importance in causing coastal degradation are pollutants associated with agricultural runoff including sediment, pesticides and fertilizers, often from ill-conceived donor policies (e.g. subsidized bananas in the Caribbean on many of the “banana islands” such as Grenada, St. Lucia, St. Vincent and Dominica) (Table 6);

Source: Survey by DeGeorges [21], while USAID's Regional Environmental Management Specialist for the Caribbean, (REMS/C), in DeGeorges & Reilly [2].

• The loss of coral reef from sewage/nutrient pollution sets off a cycle of beach erosion as the source of sand, (corals breaking down gradually over time provide a major source of sand along with coralline algae) and because of lost protection from wave and storm action by the collapsing reef. This, along with declining artisanal fisheries from habitat loss and eye, ear and skin infections of bathers/swimmers, has the net result of diminishing tourism attractions;

• Western waste treatment technologies solve neither ecological (e.g. up to secondary treatment removes primarily biological oxygen demand/BOD but few nutrients) nor public health needs (e.g. secondary treatment as commonly used with relatively short outfalls.

• High tech tertiary treatment that removes significant amounts of nutrients suffers along with secondary treatment from high operation and maintenance levels (cost of maintenance, availability of spare parts, qualified technicians, who are even hard to find in the developed world) and as a result is rarely operated up to design capacity;

• One viral particle can make a person sick. Normally, sewer water dumped at sea should not come in contact with a person for at least two days; this period of time allowing for viral dieoff from ultraviolet radiation;

• Land-based discharge of sewage requires secondary treatment and viral aerosols are still an issue (e.g. spray irrigation of golf courses), which is maintained with difficulty in developing countries. On islands, land (e.g. overland flow, crops) is a major constraint as land availability can be an issue, while during the rainy season major holding ponds are needed;

• Solutions such as long outfalls with preliminary treatment, possibly land-based treatment and deep (not shallow) well injection, exist but are ignored by governments and developers, mostly out of ignorance, in favor of simple septic systems and secondary treatment package plants with short outfalls. A report in 2002 by Sealy of the Caribbean Water and Wastewater Association (CWWA) confirms this to still be the case. By 2017, it is hoped this is changing; [(23) ref in (14) ref].

• Once degraded, due to its slow growth rate, the coral reef system could take 100s if not 1,000s of years to come back, even if the source of pollution is removed and transplants of healthy coral are put into place. This is similar to the timeline for wildlife habitat to recover from the over-population of elephants in many land-based CBNRM programs in Southern Africa, once the elephant population is brought under control. If a mistake is made in over-harvesting wildlife, most wildlife populations, including elephant, can recover in ten years, while once the habitat is destroyed, it can take 100s of years for the vegetation and 1000s of years for the soil to recover;

• Most marine parks fail to deal with the major issues of land-based pollution and unless situated in a pristine watershed continue to degrade;

• Local artisanal fishermen are more often victims of degraded coral habitat by developers rather than the cause of the problem due to engaging in over-fishing and/or destructive fishing methods. While there is an increased need to work with artisanal fishermen to sustainably manage their fishery (e.g. breaking up the coastline/reef into fisher community-managed zones), they are not the major problem, which is coastal tourism as currently undertaken and land-based pollution in general;

• As in African parks and safari hunting areas with traditional hunters and pastoralists, hotel owners and dive operators often come into conflict with local fishermen, trying to stop access to areas that their families have fished for 100s of years in favor of exclusive high-paying clientele – SCUBA divers. This is analogous to wealthy tourists visiting Africa’s parks and hunting blocks, while the local community is excluded from the lands of their ancestors - both fisher and rural communities compressed into areas that can no longer ecologically sustain them;

• Coastal tourism in the tropics negatively impacts local cultures, often turning the sons and daughters of fishermen into drug dealers, gigolos and prostitutes from the immoral Western values imported by tourists;

• Most governments and NGOs fail to recognize the problem of land-based pollution, assuming that marine biodiversity can be protected by declaring an area a park, by putting up marker and mooring buoys, banning fishing and educating sport divers not to touch the corals. The problem is orders of magnitude more complex than this, but this simplified approach brings in lots of money to the NGOs from donors and from publicity directed at an ignorant, uninformed public contributing to the wrong cause;

• Dams in Africa have also had major adverse impacts on marine & estuarine fisheries. Freshwater flows help support marine fish production, as many marine fish spawn in the brackish waters of estuaries or deltas, whose salinities range between seawater (35 ppt.) and freshwater. A decrease in freshwater flow and in nutrients due to dam construction affects nursery areas in a number of ways, including increasing salinity, allowing predatory marine fish to invade and reducing the available food supply. Linked to the aquatic food chain, mangrove ecosystems can also be adversely impacted. Thus dams and flow regulation emanating from these dams, if not properly managed, can impact estuarine/near-shore water quality (e.g., salinity, nutrient availability), adversely impacting aquatic life. As a result of dams on the Senegal River, it is estimated that fish production in the river and estuary has dropped by 90% and has probably also adversely impacted marine fisheries through the loss of nursery functions for mullets (Mugilidae), shrimp (Penaeidae), shad (Ethmalosa fimbriata) and other species having an obligatory estuarine life history stage. On the Gambia River, there is a strong risk that a coastal/estuarine fishery yielding about 23,000 metric tons/year valued at Dalasis 66 million (US$ 11 million)/year at mid-1980 conversion rates would be significantly degraded along with a major dieback of mangroves, critical to the detrital food chain, as a result of the proposed Balingho Anti-Salinity Barrage. Dams on the Zambezi River have had a major adverse impact on Mozambique’s shrimp fishery. Prior to the Aswan High Dam (pre-1970), nutrients carried into the Mediterranean during the flood season resulted in large plankton blooms. This supported a large sardine fishery accounting for 30-40% of the annual Egyptian marine fishery yield. With the Aswan High Dam, and the elimination of the annual flood, the sardine fishery fell from 18,000 tons to less than 1,000 tons. The catch has since risen to a few thousand tons attributed to improved catch technologies, not necessarily a return in production. The shrimp yields at the mouth of the Nile also decreased by 67% with the elimination of nutrient supplies. Landings of other fish were 77% below pre-dam levels.

• Other issues include damage to coral reefs by divers (education critical) and boat anchors (permanent moorings, or the dive boat floating with the divers’ bubbles or a diver-towed buoy can solve this), dredging to create harbors, opening lagoons as harbors, filling in salt ponds/lagoons for housing developments, elimination of unsightly mangroves, unregulated harvest of coral and sea life for the aquarium trade, location of tourist lodges and lights too close to the beach affecting turtle nesting and sex ratios (the closer the eggs are laid to the waterline, the lower the temperatures and the more males are among hatchlings), as well as survival of the hatchlings (driven by lights from tourist hotels inland to their death); and • Global issues such as planetary and ocean warming, the breakdown in the ozone layer, etc. have become increasingly important since the late 1990s in determining coral reef health, but often detract from people actually doing something about issues that they can physically address. A second concern associated with the burning of fossil fuels, in addition to global warming, is increased carbon dioxide (CO₂) levels and ocean acidification. Increasing atmospheric CO₂ drives more CO₂ into the ocean, lowering the pH (making the ocean more acidic) and lowers the concentration of carbonate which corals and other marine organisms use, in the form of calcium carbonate, to build their skeletons – these issues have to be dealt with at a global level by states such as through the Kyoto Protocol to the United Nations Framework Convention on Climate Change that addresses the burning of fossil fuels and resulting greenhouse gas (GHG) emissions. There are still major debates about long-term climate changes and to what degree they have been accelerated by humans as opposed to being part of a natural cycle. However, one thing is apparent: recent but temporary increases in ocean temperatures have resulted in major coral die-off and degradation.

• As noted, an important recommendation to ecologists and researchers is to take advantage of the incredible insight and knowledge of fishers and other traditional natural resource users of natural history and the environmental changes impacting these resources. The author has been humbled many times by the incredible knowledge of the fishers in Caribbean/Central America/Africa to the Mandinka hunters in the savannas of West Africa, to the Baka and Batwa Pygmies in the dense humid lowland forests of the Congo Basin, to the Bushmen of Namibia and Botswana. More than any other, in Belize local fishers explained how man, as described above, in Belize and surrounding countries adversely impacted the coral reefs and lobster fishery as a result of land-use changes and resulting land-based pollution. It is imperative that the knowledge of traditional hunters, herders, fishers, etc. be taken advantage of. The ecologist is trying to understand what has happened while looking at a window in time, while the traditional resource user is in the field every day seeing change take place, in addition to generations of knowledge and insight handed down to him/her by their ancestors. Some of the most insightful and intelligent individuals the author has ever met could not read or write. You must take advantage of this insight!

Ultimately, the tropical coastal zones’ long-term economic potential is auctioned off for short-term gains, mostly out of ignorance. If a proper understanding existed by temperate climate developers and tropical governments, the cost of doing it right is likely the same as doing it wrong, especially if developers and governments pooled their resources. However, rectifying the problem once it is recognized can be more expensive. The following sums up fairly well what the principal author has observed over the last 40 years of diving.

“The coral reef crisis is almost certainly the result of complex and synergistic interactions among local-scale humanimposed stresses and global-scale climatic stresses. Both can produce direct and indirect chronic (long-term events such as land-based pollution and now ocean warming), and acute (shortterm events that cause rapid damage on a reef such as storms and dredging, short-term but significant increases in water temperatures) stresses, leaving few, if any, parts of the ocean truly hospitable for healthy coral reef communities. Documented human stresses include increased nutrient and sediment loading, direct destruction, coastal habitat modification, contamination, and the very important chronic indirect effects of over-fishing. The major climate change factor that is becoming increasingly important for coral reefs is rising ocean temperatures, which have been implicated in chronic stress and disease epidemics, as well as in the occurrence of mass coral bleaching episodes. Also of concern are the effects of increasing atmospheric carbon dioxide (CO₂) on ocean chemistry, which can inhibit calcification — the deposition of the calcium carbonate minerals that are the structural building materials of coral reefs. Coral reef communities usually recover from acute physical damage or coral mortality if chronic environmental stresses (such as reduced water quality) are weak, and if the acute stresses are not strong or overly frequent. Coral reefs also withstand chronic stresses in the absence of acute stresses. The combination of acute and chronic stress, however, often results in the replacement of the coral reef community by seaweeds or some other non-reef system...Whereas remote oceanic reefs will be affected primarily by climate change, reefs close to human populations will continue to be affected by combinations of additional stresses (e.g. reduced water quality, physical damage, and over harvesting) that must be considered together to be understood and managed” [(24) ref in (2) ref].

A good example of the problems facing coral reefs is provided in the following set of photos taken over time by the US Geological Survey on one coral head from the Florida Keys (Figure 6).

Figure 6. The Florida Keys coral story: Then and now, 1959-1998. Source: U.S. Dept. of Interior (2002), U.S. Coral Reef Task Force (CRTF), U.S. Department of Interior, public domain in DeGeorges & Reilly [2].

Conclusion

Thus, while the concept of CBNRM, though originally designed for wildlife conservation in Southern Africa, has great merit for conservation in tropical marine environments, unless man-made sources of habitat destruction are addressed and fishermen are empowered to both benefit from, have input into management objectives and solutions, fisheries and their habitat in the near-shore tropical waters are in jeopardy, as are the lives of the many diverse groups making a living from these waters from fishers to tourism/ hotel operators to governments. The solutions are obvious, if the stakeholders are willing to address them.

Another key issue that must be addressed is how foreign aid is used to manipulate economies and politics by donors as a means of obtaining cheap natural resources with little or no beneficiation to the people living with these resources. A fine example is control/manipulation of local currencies, as France with the CFA that was originally pegged to the French franc at a rate of fifty CFA francs to one French franc (since 1994 devalued at 100/1) with each Francophone African country handing over at least 65% of its foreign reserves to the French Treasury. It is estimated that as much as $US 400 billion sits in a French account, many times the GDP of the CFA’s largest economies [25]. Such manipulations help the West obtain cheap natural resources, while making products imported into the Developing World more expensive. The devaluation of the CFA at 100/1 has had a devastating impact on wildlife in many countries (e.g. Cameroon), people turning to poaching as other segments of the economy collapse [2].

Given today’s level of poverty and human population growth, one of the actions that may be necessary in the 21^st century is the reclassification of most neo-colonial protected areas to IUCN Category VI¹, since protected areas classified under other categories are being rapidly encroached upon and/ or poached out by alienated communities opting out for other land uses as a survival mechanism.

Creating classical protected areas of exclusion (e.g. IUCN Categories I-V), with the IUCN goal of 10% of a national territory under such regimes, can only happen at the expense of displacing and compressing rural people, including fisher communities around marine parks into areas where the resource to population is so low that the result is increased impoverishment and habitat degradation in the compressed areas. Once again, one can be sure that poaching and unmanaged mining of the resources by the impoverished communities will be the net result unless appropriate steps are taken as described in this review.

In Africa alone, it is estimated that there are as many as 14 million displaced persons from creation of parks and protected areas, 600,000 alone in Chad during the 1990s from the increase in national land under protection from 0.1% to 9.1%. Based upon a range of 1-16 persons/km², it is estimated using 1997 IUCN protected area categories I-V (1,540,430 km²) that from 1.5 and 24.5 million (900,000 to 14.4 million using categories I-III) people have been displaced from creation of African parks and protected areas, mostly land-based. Using a density of about 25 persons/ km² and the same 1997 data, a range of from 22.9-39.5 million displaced persons is obtained, mostly within the last 3 decades of the 20^th century [2]. Cutting people off from accessing the natural resources they depend upon and compressing them into areas that can’t support them is not sustainable.

In Sub-Saharan Africa alone, human populations increased from about 96-114 million to 622 million people between the years 1900 and 2000 and within the next 50 years are expected to expand to between 1.5-1.8 billion people!

The handwriting is on the "coral" wall. The political leaders of both the Developed World and the tropical Developing World had better wakeup and address both terrestrial and marine resource issues described in this review, integrate traditional resource users into the management of these resources and protected areas through land use planning, and use donor funding for massive educational and nutritional (early childhood nutrition is critical to achieve maximum cognitive abilities) programs. The Developed and Developing World leaders must encourage/facilitate foreign direct investments (FDIs) that result in more transformation of natural resources in the countries of origin, with salaries based upon Purchasing Power Parity (PPP), not slave wages. These steps will help create a large middleclass as a means of taking pressure off mining the natural resource base for survival. Unless such steps are undertaken, the risk is that natural resources will become scarcer, poverty will increase and The Developed World, along with South Africa, will experience mass migrations from the Developing World that were never imagined; with both the Developed World and Developing World heading over the proverbial cliff!

¹ Managed Resource Protected Area: protected area managed mainly for the sustainable use of natural ecosystems. Area containing predominantly unmodified natural systems, managed to ensure long-term protection and maintenance of biological diversity, while providing at the same time a sustainable flow of natural products and services to meet community needs.

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