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μια ενδιαφέρουσα συνέντευξη του
Laif DeMason (
http://www.aquatek.gr/vb/showthread.php?t=86330)
που αντιμετωπίζει το θέμα από μια δική του οπτική (και μ' ένα ελπιδοφόρο υστερόγραφο
)
The Big Picture – Often as happens, individuals and hobbyists alike get their information from the internet and in a piecemeal fashion that doesn’t allow the reader to see the big picture on how everything fits together and really works. I know there is a lot of controversy recently in forums about certain Tanganyika aquarium fish. Any information given may not be exactly correct and there is no way for the reader to actually know what is happening and why it doesn’t seem correct.
First of all, ornamental fish in both Lakes Malawi and Tanganyika are caught manually by divers with a basic hand netting technique. It is not mechanized nor done by chemicals. So it is virtually impossible to catch every last fish even after many years of catching. The divers usually go to areas where catching certain fishes exist in good numbers and actually can be caught given the technique and underwater terrain. Many areas do not have enough of any type of fish needed without spending all day to catch a handful. This is not cost effective given the distances and the price of fuel and equipment in remote locations! Other times the rocky reefs where the fish are caught are just too problematic with current or non-uniform rocks sizes. So divers pick the best spots to collect and ignore other areas where the same fish exist that are usually nearby. Other times these cichlids get used to divers and learn to elude their hand nets. When the pickings get too very difficult and certain fish are just not around, then the divers come back empty handed and the exporter doesn’t bother to go back time and time again wasting money for nothing. I’ve been to the both lakes diving a dozen times and with over one hundred hours of diving, I am still terrible at catching these fish with their nets. Have you ever tried to catch a fish in open lake water with a hand net? Not so easy! The fish easily eludes the catcher. Yes these African divers use a 30 ft x 4 ft barrier net to slow the fish down enough to snag them, but that is only for a tiny portion of real estate in a 400 mile long lake! The only way these cichlid catchers actually succeed is the fact that there are so many individuals in the local area population that they just can’t miss!
Second, there has been a considerable amount of study on fish populations and dynamics. Population models are well known to fisheries scientists. All fishes, whether harvested for food, reduction, or ornamental reasons have population dynamics well documented with population models with mathematical equations. That is how fisheries institutions can predict how many harvestable fish there are in a given area without over harvesting and thus destroying the fish populations. A big topic in today’s world: over harvesting. So fisheries scientists are able to suggest measures to put in place, like fish size limits, bag (or catch) limits, or seasonality thus managing the fish population for sustainable yields. Ornamental fish are no different in these respects than food fish. There is a harvestable limit for all wild fishes and is practiced in Brazil and other place for fish like cardinal tetras. The local catchers do not want to end their seasonal livelihood by over harvesting. Take what is manageable and leave the population stable for the next year. In the same way this principle of over harvesting unchecked will reduce the population of the fish so low that manual catching is impossible in practical way. If the African cichlid catchers over harvest any fish in one area, not only do the same cichlid species spread into these areas over time from neighboring crowded areas, but the divers cross off the fish from their possible catch list for that small areas and do not come back for months and years because it is a waste of their time. Cichlid divers only usually collect to a
depth of about 60 feet, leaving any fishes untouched below this depth. Slowly the fish move into areas that were harvested since there is little competition in these fresh areas for their niche. In other words, there is then little to no competition for this fish in newly harvested areas for space or food. So the population will eventually come back with time and lack of catching because of low yields. This is again because no group of divers with hand nets can catch ALL of any one species in any particular area of any one species of cichlid. There are plenty of examples of this in both Lake Malawi and Lake Tanganyika. One example is Altolamprolous yellow calvus. Discovered and collected since the early 1990’s, supplying hobbyists worldwide for over 15 years. Eventually by about 6 or 7 years ago the relatively restricted population area near Nsumbu Zambia could only yield a handful of brownish individual fish at any given time. I thought the fish was gone for sure. However, since there were no yellow calvus, no one bothered to collect there for nearly five years and when teams of Zambian divers came to collect other fish nearby, they discovered the population had re-bounded in a big way. There were then hundreds of yellow calvus near Nsumbu again! What is in play here is simply fish population dynamics and the practicality of hand collecting African cichlids. Divers cannot ever collect all of any kind of one fish and once the collecting pressure is reduced, the population can rebound from those fish that elude the hand nets.
Third, the demand for African cichlids by hobbyists is not limitless. The demand is not like the demand for gasoline or food where all mankind buys these hobby fishes. What is popular now, will be unwanted in five years. What was popular five years ago, no one wants now. What keeps African cichlids of interest to hobbyists is that there are so many different groups of species! Dozens of species in dozens of sub family groups gain and lose popularity of time. This is perfect for wild populations as the fad fades, so does the collecting pressure by divers. And what about sources of purchased cichlids? Not all cichlids sold to hobbyists are wild. In fact 90% of all tropical fish sold world wide are from bred sources (thus 10% being wild) and 90% of all wild caught tropical fish sold worldwide are marine fish. So most cichlids sold world wide are also from bred sources. In fact there are dozens of fish farms in the Far East breeding African cichlids and dozens of farms in south Florida breeding African cichlids as well as dozens of commercial breeders elsewhere in Europe breeding the same. If there were no bred African cichlids from commercial sources, there would certainly be a several fold increase in wild collections. But in fact there is not because bred fishes are cheaper and in better health. A prefect example of this is the Pseudotropheus demasoni. Thousands of these fish are bred world wide each month. If the same number were collected annually, the Ps. demasoni would surely be difficult to find on tiny Pombo Reef in Tanzania. But you can still go there and easily find this fish twenty years after its discovery. Why? Because bred fish has replaced the need for wild caught fish in this case. One thing I do know is the best way to relieve collecting pressure on any fish species is to breed that fish! One thing to increase collecting pressure is to say a cichlid is a new and rare fish and no one else has them! That will cause an instant increase in demand! The solution, breed that fish for future sales.
Some people have criticized me for importing the so-called Tanzanian Murago Tropheus recently. I can tell you I imported them twice, 12 fish and then five months later 15 fish.
Why? First to put them in the hands of capable breeders, but also I believe it is the best way to reduce the collecting pressure on this fish. I think 28 fish is a prudent harvestable number for this fish given it’s population size. Further I have never asked any collector or exporter in Africa to collect this fish for me since their appearance in Konings Tropheus book. If a Tanzanian exporter has this newly discovered fish on his availability list, my choices are then simple, not buy the fish and if the exporter cannot sell them to anyone else, they would then be disposed of unceremoniously out the back door of their fish house to die struggling in the dirt. These exporters are hundreds of miles away from Lake Tanganyika so any unsold items are never returned to their natural location. It is not practical and probably best for the ecology of the lake. Or otherwise my choice is to buy this fish and breed it. A much better choice given the circumstances.
Fourth, there are other things to consider for a better sense of what is really happening. U.S. and European hobbyists are NOT the biggest buyers of wild caught African cichlids, the Far East hobbyists are, especially China! What we do or do not buy here will make no difference to what hobbyists do in China. Also Tanzanians should be in charge of how they use their own natural resources. We as outsiders can only suggest and enlighten, but they will do as they see fit. How can we criticize other countries for not doing enough to maintain and preserve their resources when we ourselves have made such a big mess in our own land? Further, no cichlid importer anywhere is “getting rich” from importing “rare” cichlids. It is just not happening. Even the rarest African cichlid does not have the price or the overall appeal for anyone to make millions. Cichlids are not like ivory and diamonds, there is no unlimited demand. As they say, “How do you make a small fortune in tropical fish? Start with a BIG fortune!” You can make a living off tropical fish, but not a fortune. The work is just too difficult and demand too small. Any private cichlid breeder can tell you that.
Lastly, the idea that collecting any tropical fish can lead to its extinction has just not been shown historically. What DOES lead to tropical fish (or any other organism) extinction is HABITAT DESTRUCTION! Sadly, there are plenty of examples of this. We all know about the devastation and extinction of a couple of hundred species of Lake Victorian cichlids. This was essentially caused by habitat destruction. Not by ornamental fish collections! Wouldn’t it have been nice if there were some ornamental fish collectors on site before the collapse of the haplochromine population there? Then many of these extinct fishes could still be bred and kept. Sadly, this is not the case and still no chance to make Lake Victoria back to its original pristine condition. What about the other rift lakes? A couple of years back Mireille Schreyen wrote an article in Cichlid News magazine about the alarming loss of fish populations along the Burundi coast of Lake Tanganyika. She attributes losses due to human over population along the coast and habitat destruction. Several fish populations that occur on limited habitats there were drastically reduced over the last 15 years. This was not by ornamental fish collecting but the need to eat by locals. Is anyone sounding the alarm for those fishes? Not hardly… As far as I know the Tanzanian Director of Fisheries has declared that four cichlids not be exported, although none of the current cichlid exporters with permits even know about this ruling. The four are: Maswa duboisi, Red Bulu Petrochromis, Op. boops, and the Tanzanian Murago. Some of these fish were sold in big numbers in the past. Curiously
Op. boops occur in several places but the ones found near Nkondwe Island are said to have limited numbers now. There are other varieties of Op. boops that do not show the neon blue streak mid-body. Not a problem with those locations apparently. However, Tanzanian collectors have told me they can catch several boxes of Op. boops neon streak with no problems leading me to believe their collection point is NOT Nkondwe Island since it would not be practical to catch so many there. So likely there is yet another large population of identical Op. boops neon streak somewhere nearby.
For the casual cichlid forum reader, this information hopefully fills in the gaps for background information to judge how likely written words in other forums actually ring true. Most often than not, only a one-sided view is presented to persuade the reader. In high school I had a teacher (Mr. Carrigan) who always said, “I only believe in what I see myself, and none of what I hear, and only half of what I read”. A good lesson for the internet today. People can actually write whatever they want even if it is not true.
L. DeMason
PS: Good news from Ad Konings just back from Tanzania. He states while the Tanzanian Murago Tropheus population has been reduced, there are still many wild individuals there, enough to still organize a captive breeding effort. Just like I thought there would be.