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Ultimate Secrets To Saltwater Fish

Idiot Guide To The Marine Aquarium

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Accounts of destructive collection practices, the introduction of alien species, over-harvesting, _ the lack of scientific information for many species collected and the threat of extinction of target species have raised concern about the marine aquarium trade among politicians and conservation organizations alike. A number of policy regulations have already been put in place; more are being called for17 and may follow. The US government, for example, is considering 'taking appropriate action to ensure that international trade in coral reef species for use in US aquariums does not threaten the sustainability of coral reef species'12.


Destructive fishing techniques include the use of sodium cyanide and other chemicals to stun and catch fish. Cyanide usually only stuns fish (although high mortality rates are often recorded post-capture), but it may destroy coral reef habitat by poisoning and killing non-target animals, including corals88, 89. Other chemicals, including quinaldine and plant toxins, are also used to capture reef fish alive. Field data are difficult to obtain due to the often clandestine nature of these practices.

During the collection of coral pieces for the coral trade, many more colonies may be damaged or broken than are actually harvested19. The breaking of corals to ease access to fish for capture is also not unusual in many collection areas. This tends to be more common with branching species in which small fish, such as a number of species of the genera Dascyllusand Chromis, often find refuge90. However, there are a number of collection areas that support many species for the aquarium trade that are rocky or 'rubbly' in nature, thus reducing damage to coral reefs. In soft bottom habitats for example, where corals are not attached to the substrate, the use of tools to remove colonies is unnecessary46.

Collection of live rock has been considered as potentially destructive as it may lead to increased erosion and loss of important fisheries habitat91. Some harvesting areas in Fiji, for example, have been converted into

Imperator angelfish, Pomacanthus imperator.

unconsolidated rubble, possibly preventing areas from recovering over the long term19. A study looking at the impact of the collection of coral and other marine organisms for the aquarium trade showed that areas fully utilized for the collection of live rock had experienced severe disruption of the reef flat, leading to algal predominance and potential declines in fisheries45. By contrast other collection sites showed that harvest of live rock had little effect on the relatively sparse coral growth and probably also on the three-dimensional structure of the reef as the entire reef flat had little topographic variability45. Overall, this relatively new trade, and its impacts, have not been well studied and more research should look into the potential impact of live rock removal on surrounding reef habitat and associated fauna. Monitoring of extraction activities and of trade in live rock is also recommended.

Fishing on coral reefs with dynamite and explosives is not part of the marine aquarium trade: this is a common misconception. Dynamite is a method commonly used for food fishing. It causes terrible damage not only to fish populations but also to the reef habitat itself and may be an issue worthy of more concern than the use of cyanide92.


Cyanide fishing involves crushing cyanide pellets into makeshift squirt bottles filled with seawater. The fishers then dive down to coral formations and squirt cyanide into crevices where fish often hide. The poison stuns fish, thus making them easier to catch. Large percentages of fish captured through this method die in transit due to their weakened state93, resulting in more fish being collected than would otherwise need to be, to allow for a fatality margin94. Reports indicate that between as few as 5 per cent95in6 and as many as 75 per cent96 of fish collected using narcotics die within hours of collection, and 20 per cent95 to 50 per cent die soon after that97. About another 30 per cent on average96 die prior to export and it is not unusual for retail outlets in importing countries to register mortalities of 30 per cent or more50. A 1997 survey of US retailers98 found that between one third and more than half of the aquarium fish imported from Southeast Asia died shortly after arrival, most probably due to poisons used in capture and/or the stress of handling and transport.

Cyanide fishing is not without risks to the divers themselves, who often go to considerable depths for extended periods of time and may suffer from decompression sickness, 'the bends', upon return to the surface.

The use of cyanide to capture reef fish originated in Taiwan and/or the Philippines in the 1960s and was specifically targeted at fish destined for the aquarium market94,102,103. Estimates suggest that in the mid-1980s more than 80 per cent of all fish harvested in the Philippines and destined for the aquarium trade were collected using cyanide94. More recent studies in the country indicate that 70 per cent of marine ornamental

102 104

reef fish are ca ught with cyanide102, '°4. Its use then spread to Indonesia (in about 1985105) where, in the mid-1990s, it was estimated that about 90 per cent of vessels transporting live fish in the eastern islands of Indonesia had cyanide on board106. Reports also indicate its use in Thailand6, Papua New Guinea105, 107, Malaysia, Viet Nam,

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the Maldives and Ye men . There are unconfirmed reports that its use may have spread to the Red Sea, Palau, Tanzania, the Seychelles, Sri Lanka, the Marshall Islands, the Solomon Islands, Fiji and Haiti108.

Cyanide fishing is illegal in most countries. In Indonesia, for example, legislation from 1985 includes specific prohibition of the use of destructive fishing practices, such as the use of poison, with penalties up to ten years in prison and/or a fine of 100 million rupiahs110 (equivalent to US$12,000). The marine police and navy, in collaboration with the fisheries service, are in charge of enforcing the law110. However, the high premium paid (often allowing for large bribes), the ease with which a great number of fish can be caught in a short time period, the often poor law enforcement capacities and high levels of corruption have allowed the use of poison to spread rapidly throughout the Asia-Pacific region102 and have made the eradication of this illegal and highly destructive fishing technique nearly impossible.

In 1989, the Haribon Foundation in collaboration with Ocean Voice implemented, in the Philippines, the Alternative to Cyanide Fishing project in order to train aquarium collectors in the use of nets as an alternative to sodium cyanide. Results showed that 29 per cent of the trainees monitored were fully converted net users whilst the majority of fishers persisted in using sodium cyanide, though at a greatly reduced rate111. Subsequently, the Philippines government and the International Marinelife Alliance implemented a second, more aggressive programme to retrain fishers in alternatives to cyanide51,112. Public campaigns in the media and schools are also helping to raise awareness about the values of the reefs of the Philippines and the negative impacts of cyanide fishing113. Five cyanide-detection facilities, capable of detecting low levels of cyanide in fish tissues as well as organs, have also been established. After five years of intensive efforts, live reef fish that test positive for cyanide declined from 80 per cent in 1993 to 20 per cent in 199851,98.

A similar programme initiated in Indonesia for fishers in northern Sulawesi showed that barrier nets did

Cyanide use and corals

Cyanide use and corals

One of the greatest threats posed by cyanide fishing is

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to reef ecosystems ' . Cyanide kills non-target organisms, such as other invertebrates and fish, although only relatively limited scientific data are available on this. Reports have demonstrated that xiv 88 89

exposure of corals to cyanide causes bleaching . Results from a recent study101 demonstrated that exposure of colonies of the commonly traded species Acropora millepora, Goniopora spp., Favites abdita, Trachyphyllia geoffroyi, Plerogyra spp. (grape coral, pictured), Heliofungia actiniformis, Euphyllia divisa and Sarcophyton spp. to varying concentrations of cyanide over different time periods caused mortality in all corals (through, for example, bleaching and progressive tissue detachment from the skeleton). Acropora, the genus most likely to be specifically targeted by fishers for the collection of fish, as these tend to hide amongst its branches, was most vulnerable to cyanide exposure, showing rapid signs of stress and bleaching101.

not prove to be an effective collection method and many collectors have been slow to switch to nets or have reverted to cyanide after the net training programme102. Although considerable demand for 'green' marine products exists in overseas specialty markets, and possibly even locally, the markets have failed to convey this to producers in an explicit way.

Consequently, an ever-increasing percentage of fishes are caught in Australia, Hawaii, Florida, the Greater Caribbean6,102 and the Pacific Islands such as Fiji, where collectors are often the exporters (90 per cent in Australia40) and are known to use more sustainable capture techniques, such as nets. As a result, survivorship postcapture is higher and mortality for the target species following shipping and handling often negligible.

There is hope that the use of cyanide can be curtailed. However, in order to accomplish this a number of major steps are required. The first, and probably the most difficult one, requires governments of source countries to face up to this problem by reforming their policies and strengthening their institutions (e.g. mount public awareness campaigns in the media and schools; regulate the importation, distribution and use of cyanide). Secondly, governments of importing countries must take steps to reinforce measures adopted by the source countries (e.g. monitor imports of live fish and provide data to exporting countries; raise awareness of the impacts of cyanide fishing)102. A reduction in the number of middlemen often involved would help ensure that a greater percentage of the price paid by exporters for ornamental fish goes to collectors. Consumers also have an important role to play: if sufficient numbers of informed consumers demand fish that have been caught using sustainable techniques it is likely that this will have important positive repercussions on fishing methods in Southeast Asia.

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