Better Tropical Fish Tanks» Fish Conservation

Conservation of the Asian Arawana

Elizabeth — Wed, 11 Nov 2009 00:37:30 +0000

The Asian Arawana, Scleropages formosus, is endangered, mainly due to habitat destruction. It is listed under CITES Appendix 1, which means that trading this species across national boundaries is illegal unless the individual fish are captive bred. The Asian Arawana is captive bred in Kalimantan, Malaysia, Indonesia and Singapore.

Unfortunately, it is also illegally wild caught in various places in Southeast Asia. Captive breeding, poaching, and smuggling are all encouraged by the high prices these fish bring.

Captive bred fish from Singapore usually come with an embedded microchip to prove that they are captive bred and prevent theft. Asian Arawanas are selectively bred for color, especially red or gold variations. There is a tradition in China that this fish, especially if red or golden, brings good luck to its owner. This is one reason for the fish’s popularity and high price.

Because of the prices these fish sell for, farming this species is quite lucrative and has been described as a ‘gold rush’ on the Arowana club website. A very good specimen may be worth tens of thousands of dollars.

Because Asian Arawanas are so expensive, they are sometimes smuggled. This means that if you are looking to buy one, you should check its papers and that it has an identifying microchip. It is all too easy to find stories about Arowanas being confiscated by customs officials, whether in boxes under legal items, or inside a dress being worn at the time. Problems you just don’t get with Neon Tetras…

Sources:

Arowana-care.com

Arowanaclub.com

CITES Convention Text

Fishbase.org

Ng, P., Tan, H. (1997) Freshwater fishes of Southeast Asia: potential for the fish trade and conservation issues. Aquarium Sciences and Conservation. Vol 1: 79-90

UNEP-WCMC. 6 March, 2007. UNEP-WCMC Species Database: CITES-Listed Species

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The Walking Catfish (Clarias batrachus): Pet, Food Fish, and Invasive Pest

Elizabeth — Mon, 05 Oct 2009 22:44:16 +0000

The Walking Catfish, Clarias batrachus, is a very large catfish sometimes seen in the aquarium trade. It is also used as a food fish. It is native to Southeastern Asia, but it has been introduced to numerous other places where it has become an invasive and predatory pest. Once in an area, it is hard to contain because it can walk across land, entering aquaculture ponds and eating the fish, or entering seasonal wetlands not normally inhabited by fish to eat tadpoles.

It has been introduced to Indonesia (Sulawesi), the USA, Hong Kong, Taiwan, China, UK, Papua New Guinea, Guam, Taiwan, Thailand, and possibly the Philippines. This species has been nominated as one of the world’s top 100 invasive species. The method of invasion involves escapees from the pet trade as well as aquaculture. It is illegal to keep this fish in some countries, as well as in many US states.

Very cold water kills Walking Catfish, so if your area goes below freezing in the winter this fish should not become invasive even if some manage to escape. In many areas with warmer water it is often illegal to keep them without a permit. Even if they are legal in a warmer area, it is still very important not to let them escape from their tank. Because of their ability to walk on land, the possibility of escape is much greater than with most tropical fish. Make sure their aquarium has a strong and tightly fitting lid so that they cannot push it up and wander off.

Sources:

Global invasive species database. Compiled by Invasive Species Specialist Group (ISSG)

Brogan, Christine. 2003 Introduced Species Summary Project

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The Fish, the Forest and the Future: how climate change and deforestation in the Amazon are harming our fish

Elizabeth — Tue, 07 Apr 2009 00:43:30 +0000

Many popular aquarium fishes come from the Amazon Basin. These fish include tetras, corydoras catfishes, suckermouth catfishes, dwarf cichlids, discus, piranhas and many others. Some of these species arrive in our fish tanks after being captive bred in many places around the world, but many others are wild caught and some are new imports that have only just been discovered. There are almost certainly more species that have not been discovered yet. What are the effects of climate change and deforestation in the Amazon on wild fish?

Effects on the Amazon

The combined effects of deforestation and climate change are likely to result in significant drying of the Amazon Basin as well as disappearance of half or more of the forest, possibly within the next 20 years (Nepstad et al, 2008). The reasons for the drying are twofold: cutting the forest reduces the ability of the forest to create its own climate, and the warming climate means increased evaporation and more fires. The increased rate of fire reduces the area of forest further, making the situation worse. Loss of the Amazon rainforest would also accelerate climate change by removing one of the world’s most important carbon sinks.

Potentially, deforesting a large part of the Amazon, when combined with climate change is likely to result in a Savannah type ecosystem with much less water over most of the area now covered by the Amazon rain forest. Some models predict the loss of the Amazon from climate change even without deforestation (Harris et al, 2008). These changes are likely to be very difficult to reverse, and drying of the forest has already been observed (Li et al., 2008).

Effects on Fish

Put together, this means fewer streams in which fish can live and breed. Smaller streams will likely disappear entirely while water levels are lowered in larger streams and lakes. A possible preview of some of the effects might be the 2005 Amazonian drought. This drought was primarily caused by unusually warm sea surface temperatures in the tropical north Atlantic. In 2005, streams disappeared and lower water levels in larger streams and lakes caused fish kills as well as increased fire (Marengo et al, 2008).

If these changes occur as predicted by current models, the area of habitat available to the fish species that depend on the forest will be vastly reduced, and many species will probably go extinct. Those that don’t will be scarcer they are now and will need to be bred in captivity if they are to continue appearing in hobbyist’s fish tanks. Considering how many aquarium fish species come from the Amazon, this is likely to have a major impact on the hobby.

What Can We Do?

This is not a scenario likely to be attractive to most fish keepers, but there are things that can be done to make the situation less devastating. The two key variables are climate change and deforestation in the Amazon basin. Therefore, all the usual methods of reducing climate change apply. Information on how to reduce climate change, and links to other informative sites, can be found here, and at many, many other sites on the Internet.

Reducing deforestation in the Amazon is a little more tricky for those of us who do not live in South America. More about the problems plaguing the Amazon, as well as possible solutions to these problems, can be found here.

References:

Harris, P. Huntingford, C., Cox, P. (2008) Amazon Basin Climate under global warming: the role of the sea surface temperature. Philosophical Transactions of the Royal Society 363: 1753-1759

Li, W., Fu, R., Robinson, I., Juarez R., Fernandez, K. (2008) Observed Change of the standardized precipitation index, its potential cause and implications to future climate change in the Amazon region. Philosophical Transactions of the Royal Society 363, 1767-1772.

Marengo, J., Nobre, C., Tomasella, J., Cardoso, M., and Oyama, M. (2008) Hydro-climatic and ecological behavior of the drought of Amazonia in 2005 Philosophical Transactions of the Royal Society 363,1773-1778

Nepstad, D., Stickler, C., Soeres-Filko, B., Merry, F. (2008) Interactions among Amazon land use, forests and climate: prospects for a near term forest tipping point. Philosophical Transactions of the Royal Society 363, 1737-1746

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Conservation Status of the Black Ruby Barb, Puntius nigrofasciatus

Elizabeth — Mon, 09 Mar 2009 23:24:58 +0000

This small barb comes originally from Sri Lanka and is a popular fish in the aquarium hobby. It is designated as low vulnerability conservation dependent by the IUCN, which means that there are some conservation programs in place to protect it without which it would be considered vulnerable (Pethiyagoda, 1996). There are some indications that the most brightly colored population may be being reduced in number by export for the aquarium trade (fishbase.org). Overall, this situation is very similar to that of the cherry barb, Puntius tittaya, which lives in many of the same habitats in Sri Lanka. Both fish are present in the Sinharaja forest reserve (Sinharaja forest reserve).

The black ruby barb is bred in captivity in Sri Lanka as well as being wild caught for export (Ekaratne, 2000). It is also bred in hobbyist’s tanks and instructions for breeding can be found in such places as Mongabay.com. I am not certain to what extent it is bred commercially outside of Sri Lanka.

References:

Ekaratne, S. 2000. A Review of the status and trends of exported ornamental fish resources and their habitats in Sri Lanka. Published by Y.S. YADAVA for the Bay of Bengal Programme.ftp://ftp.fao.org/docrep/fao/007/ad920e/ad920e00.pdf

Fishbase.org

Butler, R. San Francisco, CA Mongabay.com. 1999-2008. Retrieved 09 March 2009 http://fish.mongabay.com/species/Puntius_nigrofasciatus.html

Pethiyagoda, R. 1996. Puntius nigrofsciatus. In: IUCN 2008. 2008 IUCN Red List of Threatened Species.www.iucnredlist.org. Downloaded on 03 March 2009.

Sinharaja forest reserve. World heritage sites. United Nations environment programme and the world conservation union monitoring center. Appears to have been written post-2003. Retrieved 4 March 2009.

http://www.unep-wcmc.org/sites/wh/pdf/Sinharaja.pdf

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Conservation Status of the Guppy (Poecilia reticulata)

Elizabeth — Mon, 12 Jan 2009 18:19:54 +0000

The Guppy is an extremely common fish in the aquarium trade, and is not considered vulnerable in the wild (Fishbase.org). They originally come from South America and the Caribbean: Venezuela, Barbados, Trinidad, northern Brazil and the Guyanas (Fishbase.org), but the guppies seen in pet shops are captive bred. The vast majority of guppies seen in the trade are either fancy guppies that have been selectively bred for beauty, or feeder guppies, which are not bred for beauty and are sometimes used as food for predatory fishes. Guppies breed very readily in captivity. They can interbreed with the Endler’s Livebearer, Poecilia wingei (Poeser et al.), and the two species should therefore be kept in separate tanks.

Unfortunately, guppies have become an invasive species in Asia, Australasia-Pacific, Europe, North America, and South America. They were intentionally introduced to many of these areas in order to control mosquitoes, but some feral populations are probably descended from escaped pets (Global invasive species database).

References:

Fishbase.org

Global invasive species database. Compiled by National Biological Information Infrastructure (NBII) and Invasive Species Specialist Group (ISSG)

http://www.invasivespecies.net/database/species/ecology.asp?si=683&fr=1&sts=

Poeser, F., Kempkes, M., Isbrucker, I. 2005 Contributions to Zoology. Description of Poecilia (Acanthophacelus) wingei, n. sp. from the Paria Peninsula, Venezuela, including notes on AcanthophacelusEigenmann, 1907 and other subgenera of Poecilia Bloch and Schneider, 1801 (Teleosti, Cyprinodontiformes, Poeciliidae) http://dpc.uba.uva.nl/ctz/vol74/nr01/art07

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Aquarium Fish as Invasive Species

Elizabeth — Tue, 25 Nov 2008 17:35:28 +0000

Unfortunately, a number of ornamental fish have become invasive species in various areas of the world. This means that they are living and breeding successfully in areas where their species did not evolve. Species that have become invasive include guppies, gambusia, white cloud mountain minnows, swordtails, walking catfish, goldfish, and oscars. In some cases, invasive species have caused native species to go extinct. A classic example is the Nile Perch, Lates niloticus, which caused the extinction of over two hundred Cichlid species when it was introduced to lake Victoria (Global Invasive Species Database), although this fish was introduced intentionally as a food fish, rather than as an escapee from home aquaria. The guppy, Poecilia reticulata, is a common aquarium fish that is believed to have played a role in the decline of several threatened species, and to be a carrier of exotic parasites (Global Invasive Species Database).

Hotsprings in cold areas that contain endemic species are especially vulnerable to invasion because any species already present are present only in a small area where they can easily be overrun by an aggressive species imported from elsewhere. Also vulnerable are island species, endemic lake species and others with small natural habitats. These are vulnerable for the same reasons as hot springs. Species whose habitat has been disturbed are also vulnerable. Habitat disturbance often occurs along with invasive species problems, since the already changed ecosystem is likely to provide opportunities for invasive species that arrive in the area and many of the native species are stressed by the changes that have occurred in their natural habitat.

This is the main reason why it is important not to release ornamental fish into the wild. There are also a couple of other reasons. If the environment is unsuitable for your fish, they will die. This is cruel to your fish. There is also the possibility of them introducing exotic diseases which transfer to native species.

References:

Global Invasive Species Database http://www.issg.org/database/species/ecology.asp?si=89

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Conservation Initiatives: Project Piaba

Elizabeth — Wed, 12 Nov 2008 03:45:34 +0000

Project Piaba is sited in Barcelos, Brazil. It has multiple aims, the main ones being to learn more about the status of fishes and the ornamental fish trade in the area, prevent overexploitation, preserve fish habitat, and improve the lives of local collectors. The main fish exported from this area is the Cardinal Tetra, which provides approximately 85% of the catch. The catch of Cardinal tetras has remained relatively stable, but it appears that the catch per unit effort may be going down (Chao and Prang, 2002)(Gerstner et al. 2006).

Catch per unit effort measures the number of fish caught per unit of effort. Units of effort are often defined by the number of people or number of ships fishing, or the total amount of time spent fishing, or some combination of the above. A lower catch per unit effort means that it takes more effort to catch the same number of fish. In this case, this could indicate that there is overexploitation occurring, as this has been one of the indications that a fishery is going into decline in major food fisheries such as the Atlantic Cod (Icthyology notes, UVic 2004). However, judging from Chao and Prang’s information, there does not appear to be immediate danger to the Cardinal Tetra’s survival. I hope that they and the rest of project Piaba will pay attention to the situation so that the Cardinal population does not decline severely.

The hopes of the project are that extraction of fish from the forest can prevent deforestation by providing an alternate livelihood, and that this can be done in a sustainable manner. To accomplish this, they provided information about ornamental fish trade to the people of Barcelos. They have also done some basic research on the ecology of the ornamental fish in the area, including some long-term monitoring (Chang and Prang, 2002). This is unusual in the ornamental fish trade and valuable, because there is too little research into ornamental fish populations in the wild.

Overall, it appears a useful initiative that it would be useful to copy elsewhere, although I would like to see more independent research on ornamental fishes conducted by a group that is not connected so closely to the ornamental fish trade, and some attention paid to the decreasing catch per unit effort. Declining catch per unit effort alone is inadequate to fully determine what is occurring with a population (Maunder et. al., 2006), but it is a very bad sign. They probably need to lower their catches to make the fishery truly sustainable.

Chao, N., Prang, G.(2002). Decade of Project Piaba: Reflections and Prospects. Official Publication of Ornamental Fish International 39

http://www.neaq.org/scilearn/research/pdf/14__.pdf

Gerstner, C., Ortega, H., Sanchez, H.,and Graham, D. (2006) Effects of the freshwater aquarium trade on wild fish populations of the peruvian amazon. Journal of Fish Biology. 68:862-875

Monder, M., Sibert, J., Fonteneau A., Hampton, J., Kleiber, P., Harley, S. (2006) Interpreting catch per unit effort data to assess the status of individual stocks and communities ICES journal of marine science 63: 1373-1385

Reimchen, T. E. (2004) Icthyology class notes, University of Victoria

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