Save a tree, is a conservation slogan that many are familiar with. We know that forests are shrinking, that certain large mammal species are threatened with extinction and that coral reefs are suffering high levels of bleaching. We are becoming increasingly aware too, of the power of green consumerism. We have, for example, the Forest Stewardship Council, which helps us to decide what timbers to use in our new kitchens, the Marine Stewardship Council that helps to guide our eating habits and the Marine Aquarium Council, which is poised to help us find sustainable sources of marine aquarium fish.

 

Furthermore, businesses based on living natural resources and conservationists are beginning to recognise that they have some common interests: such business depends on the survival and sustainability of the natural resources that it exploits and conservation goals can only be successfully achieved if business starts to recognise that development must be based on sustainable use of resources. But we do not seem to be so aware of the threats to freshwater ecosystems and the fish they harbour, or of the potential perverse environmental costs associated with forms of aquaculture. This article will consider both.

 

 

Diversity of Life in Freshwaters
Water is the stuff of life, yet thanks to over-extraction, pollution and river or lake basin development, stocks of freshwater that we take for granted in many parts of the world, are decreasing. The pundits predict that wars in the twenty-first century will be fought over water.

 

The numbers of species of plants and animals that inhabit freshwaters is unusually high in comparison with the numbers found in other ecosystems. Freshwaters support 40% of all fish, some 10,000 species, around 5,000 species of amphibians, 6,000 species of molluscs, 10,000 species of crustaceans, over 35,000 described species of aquatic beetles, as well as numerous species of flies, flowering plants and ferns dependant on this habitat. Alarmingly, the rate of loss of freshwater species in the USA is estimated to be five times faster than the loss of species in terrestrial habitats.

 

In Africa, 28% of amphibians are thought to be threatened with extinction and, in North America, 69% of the unique assemblage of freshwater mussels are thought to be endangered or extinct. Globally, at least 70 species of freshwater vertebrates show, on average, population declines of 50% since 1970. In addition, while the conservation status of only a small number of freshwater fish species has actually been assessed, of those species considered in the 2002 IUCN Red List (IUCN 2002) 20% of amphibians, 30% of fishes (mostly freshwater species), 27% of molluscs (mostly freshwater species), and 20% of crustaceans are classed as threatened.

 

 

Threats to Freshwaters
Threats to freshwater habitats are many and varied, but the over-riding problem is the loss of habitat, whether it be through direct destruction, pollution or the introduction of an invasive species. Consequently, we need to find ways to diminish this habitat loss and one such, is to ensure that people have incentives to conserve freshwater habitats. Perhaps surprisingly, this is where the ornamental fish dealers and hobbyists who keep freshwater fish might play a part. Keeping aquariums is now widespread and although estimates vary, the worldwide export trade in aquarium fish is estimated at US$ 186 million, with the total value of the ornamental fish retail trade valued at around US$ 7.2 billion. The bright colours and relaxation afforded by fish watching, have brought ornamental fish to general attention, and aquariums are now found increasingly in dentists' waiting rooms, shopping malls and smart restaurants.

 

But, where do these aquarium fish come from and how can the industry contribute to the sustainable management of natural habitats?

 

According to trade sources, the majority of freshwater fish in trade are derived from captive breeding or aquaculture, while the majority of marine fish are collected directly from the wild, although, as with any rule, there are exceptions to this. This difference in supply stems largely from differences in biology of the species currently in demand.

 

 

Cost and Benefits of Supplying the Aquarium Trade From Captive-bred Individuals
Many of the ornamental fish produced in aquaculture are now produced in southeast Asia, Singapore, Sri Lanka and, within the US, Florida is a major centre of ornamental fish production. But many of these operations deal in species that do not occur naturally in the countries in which they are bred. This can result in a number of challenges to environmental conservation, including possible introductions of non-native species that may become invasive, threatening the natural fauna or flora (although the threat of invasion is arguably more of a problem for the food-fish aquaculture industry than for the ornamental industry). In addition, aquaculture facilities, unless carefully regulated and monitored, can result in problems with removal of waste water and disease introduction to local populations. BUT, one of the most important and until recently, over-looked effects of buying captive-bred specimens, particularly those produced outside the range state, is that there is no chance for any direct economic return to the conservation of the species in its wild habitat.

 

Intuitively, you would think that, for the hobbyist, the most conservation-friendly source of fish for his/her aquarium would be from captive bred-individuals, particularly where the requirements to keep species successfully in captivity are well known and there is little if any need to collect further individuals from the wild. However, while producing the specimens in captivity may, indeed, reduce direct collection pressure on the wild stocks, it may also remove any incentive or reason to conserve the wild stocks and their habitats at the local level.

 

If there is no direct benefit, such as being able to collect wild fish to sell to the ornamental trade, recent thinking suggests that conservation of the habitat for that fish resource is unlikely to be a priority in areas where basic human needs are not met. Increasingly it is recognised that conservation and human needs go hand in hand. Much of the planet's remaining biodiversity is found in the areas with the greatest human poverty, where people are dependant on the extraction of living natural resources to generate income and broaden their livelihood options. Consequently, it is argued that the best bet for both people and the environment is to enable people to benefit from a well-managed and sustainable use of those resources.

 

It is this type of thinking that drives Project Piaba in the freshwaters of the Amazon and Project Seahorse in the marine realm of the Philippines. Project Piaba's slogan "Buy a Fish Save a Tree" encapsulates this thinking. According to Chao et al (2000), over 20 million live fishes are exported annually from the middle Rio Negro basin, generating 60% of local revenue and US$ 43million of export revenue. This ornamental fishery, which is dependant on maintaining large areas of floodplain habitat and fishery, has provided a subsistence income to local fishers since the 1950's. Chao et al believe that the fishery may have inadvertently discouraged ventures such as logging and gold mining in the region.

 

In a similar vein, Project Seahorse has been working with local communities in the Philippines to set up voluntary marine protected areas, and to bring the management of the harvest and low-technology aquaculture of seahorses for the ornamental and medicinal trades on to a sustainable footing. Workers in Guyana and West Africa are now looking into the potential for wild collection of ornamental fish to provide alternative livelihood options for people in those areas and, thus, to contribute to habitat conservation.

 

However, use of natural resources is far from a panacea for conservation and is associated with many risks. While the wild collection of freshwater fish for the ornamental trade may provide incentives to help maintain freshwater habitats, it can only do so provided that the harvest does not exceed sustainable levels and if frameworks are in place to ensure that the economic benefits from the harvest are shared equitably among the harvesters.

 

Ensuring sustainability has been a major challenge in a variety of extractive harvesting regimes and depends heavily on the type of harvest and management regimes that are in place and appropriate implementation. For example, unregulated trade is blamed for the decline in populations of Dragon Fish or Asian Arowana (Scleropages formosus) and for driving the Redtail Sharkminnow or Redtail Black Shark (Epalzeorhynchos bicolor) to the point of extinction in the wild.

 

It is often argued that trade in wild-collected specimens can stimulate illegal trade, but, conversely, there are some examples where legalising a wild trade appears to have reduced the illegal trade, for example in crocodilian products. Furthermore, there are concerns that the mortality rate of wild-collected specimens may be high in some instances during transport and during acclimatisation to captivity, raising not only welfare issues, but also issues of sustainability of the harvests. The suitability of using trade to provide incentives for conservation will also depend on the species being considered for trade. If a species has a restricted distribution, low population levels, low reproductive rates and low chances of being able to implement management regulations, then proposing trade in wild specimens is likely to be counter-productive. Clearly, each case must be assessed on an individual basis, taking a variety of factors into account to weigh the costs and benefits.

 

 

Assessment of Captive Breeding Benefits
We have yet to review the conservation status of many freshwater species, but in the meantime, we need to think carefully about our consumer power and ensure that our decisions are based on a sound assessment of the options. We are increasingly finding that black and white conservation messages are too facile; as in all aspects of life, situations vary on a case-by-case basis. The answer in one situation will not necessarily hold in a situation with a different set of factors.

 

But we really do need to get people to think about the options before them and the consequences of their choices. From a conservation perspective, captive-bred ornamental fish could serve to reduce the current exploitation rates of wild specimens, but, on the other hand, might reduce the incentives for conservation of those wild stocks. Consequently, the choice of whether to buy captive bred-specimens or wild-collected specimens needs to be assessed carefully as both have a range of costs and benefits for the environment and the species.

 

In the case of the Dragon Fish, listed as Endangered in the 2002 IUCN Red List (IUCN 2002) and included in CITES Appendix I, trade in wild-caught specimens for commercial purposes is prohibited. However, CITES has established a system that allows trade in captive-bred specimens from registered operations where specimens can be micro-chipped, so that a legal trade should not mask an illegal trade. In this case, the trade should not further endanger the wild population, but equally, there appears to be little if any incentives from the trade to maintain the wild habitat.

 

In contrast, in the case of the Cardinal Tetra (Paracheirodon axelrodi) produced in Brazil, population productivity is such that current levels of harvesting of wild-caught specimens do not apparently threaten the population and their sale by local people appears to provide incentives for conservation.