By Jenny, Creative Commons

A recent study has shown that collection for the aquarium trade has negatively impacted wild clownfish populations.

[...]

“Removing breeding adults or even sub-adults could cause the anemone to shrink, thereby reducing the amount of space for new recruits, and it may be up to 6 months before the fishes begin to breed again…”

Read Practical Fishkeeping article here.

The Georgia Aquarium can now boast of having captive bred the endangered weedy seadragon, the somewhat less showy – but equally charismatic – relative of the leafy seadragon. As with seahorses, it is the male weedy seadragon that bears the eggs until they hatch (see picture for line of pink eggs on male’s tail).

The top 10 newly discovered species of 2007 have been named, with Electrolux addisoni - this new genus named after a brand of electrical household appliances – at the top of the International Institute for Species Exploration’s (IISE’s) list.

Read all about it here and here.

‘Anyone who cares about where their fish come from – and this should mean anyone who wants to go on eating them – should take two tools when they visit the fishmonger.

One is the handy guidance provided by the Marine Conservation Society, Fish to Avoid and Fish to Eat (the latter is still the longer); the other is a ruler. My ruler is the type handed out to commercial fishermen by the international advisory body, Incofish, and has pictures of key species with marks indicating when they can be considered mature (and, thus, OK to catch).’

Read The Guardian article here. The Fish to Avoid and Fish to Eat lists are available free online, should you want to print the wallet-sized versions.

See ‘The Coming Hunger’ (Apr 12, The Toronto Star).

I know the focus of this blog was originally meant to be about fish in the context of the aquarium hobby. But I thought this would be an interesting, if depressing, link to share.

Of late there has been much focus on the management (or lack thereof) of our global natural resources, fish being a key issue – in terms of both their exploitation for food, as well as the somewhat more selfish demands of the pet trade. Both of these fish-centered industries constitute a significant aspect of the economy. But with the current food crises, it has become more difficult to ignore non-aquarium related articles on fish. What kinds of articles and topics would you like to see on this blog? Any feedback would be appreciated.

Picture (c) National Geographic.

This time it’s the Mekong River. The problem? A dam, planned for the Khone Falls in Laos, Cambodia. Once the dam is built, it will be difficult for the already endangered giant Mekong catfish to carry out its migration patterns. According to National Geographic, it is illegal to catch this fish, and those that turn up in fishermen’s nets are usually accidental catches. But it looks like fishermen are the least of the catfish’s worries.

‘The giant catfish was once plentiful throughout the Mekong River system, but in the last century the population has declined 95 to 99 percent, according to Hogan of the Megafishes Project.’

Read the National Geographic article here.

ATLANTA (AP) – Norton, one of the original whale sharks at the Georgia Aquarium, died early today, the aquarium’s second whale shark death in five months.

Norton’s death is the third recent loss for the aquarium. Gasper, one of the Georgia Aquarium’s five beluga whales, was euthanized January second after months of declining health. (AP) (See full article)

As revealed in a later press statement (The Atlanta Journal-Constitution), Norton’s death was believed to have been caused by the use of a chemical, Trichlorfon, used to treat fish tanks for parasites – a heinously preventable mistake that might have been avoided, had the aquarium exercised more care with regards to the chemical’s administration and dosage.

Little is known about the biology of whale sharks, and there are precious few specimens in captivity. Much has been said about the ethics of keeping cetaceans such as dolphins and whales in captivity, but the recent loss of two whale sharks in a short space of just five months has outlined the fact that large marine fish, too, are fragile creatures that must be kept in captivity with care, if at all.

More links:
‘06/13/07 – Second whale shark dies at Ga. Aquarium’ (The Atlanta Journal-Constitution)

‘06/16/07 – Aquarium loosens lid on whale shark deaths’ (The Atlanta Journal-Constitution)

’18/6/2007 – Second Whale shark dies at aquarium’ (Practical Fishkeeping)

Georgia Aquarium

“Such trends, coupled with economic importance of the trade for fisherfolk, many of whom count among the rural poor, pose significant challenges for species conservation, similar to those faced for other aquatic biological resources that are harvested artisanally.”

 See full article here.

‘Fisheries authorities in Myanmar have discovered a number of other populations of the Celestial pearl danio, Celestichthys margaritatus, a fish believed to have been driven to near extinction by over-collecting for the aquarium trade.

Myanmar’s Department of Fisheries (DOF) banned further exports of the species in February to allow them to assess the conservation status of Celestichthys margaritatus, and have identified a number of new localities which harbour populations of the species.

The species was previously believed to be endemic to pools in a single wetland area of Myanmar.

Tin Win, Managing Director of Myanmar-based fish exporter Hein Aquarium, told Practical Fishkeeping that a party of 10 officials from the Department of Fisheries and the Myanmar Fishery Federation conducted a survey and found the fish at five locations around Hong Pong.

[...] The fish, which were previously caught for food and sold as dried fish were a food of local poor people, according to Tin Win.

He says that they got a much bigger return on selling the fish for the aquarium trade compared to what they made when they sold the same fish for food:

“Due to this fish, the people in rural areas got some more income, because, previously the fish were dried and sold as dried fish as food for the poor people.”

Tin Win told Practical Fishkeeping that locals received 25 Kyats (approximately 25p) for a can of 500 Galaxy rasboras, but received 1p per fish when they sold them to the aquarium trade.’

What’s particularly interesting is the huge difference in profit that comes with selling the pearl danios (or Galaxy rasboras, as you may prefer to call them) to the aquarium trade instead of as food. From the given figures, 1p per fish works out to 500p for 500 inviduals, a mind-boggling increase of 20 times from the original food price.

The aquarium trade can indeed be very lucrative. Ideally, these monetary benefits would go directly to the ‘people in rural areas’ who collect the fish, and not just to the dealers and middlemen.

If properly managed, these wild fish populations can remain a valuable source of income for years to come.