Quote from Ad regarding overfishing in Lake Tang

[aqc]

FYI - on Cichlids of Lake Tanganyika on FB, quote by Ad Konings response to people's post on overfishing of endangered species. From Chris that owns Lake Shore Lodge in Kipili.

Cichlids of Lake Tanganyika

August 16 at 11:12pm ·

Please Read NNB!! A quote from Ad Konings:

"I would like to clarify some of the misconceptions readers may have about over-fishing and extinction. Some believe that when not the last individual of a certain species/population has been fished out of the lake, there is still hope that the species may recover. Of course it is true that it is almost impossible to catch the very last individual of a species/population when the ornamental fish collectors are extracting fish from the lake, BUT you don’t need to catch the very last to exterminate a species. Every species has a critical minimum population density and below that, it is gone forever. With so many species competing for the same piece of real estate in the lake it is easy to see that each species needs a certain density to hold on to their share. In particular T. duboisi, who shares everywhere the habitat with a more successful congeneric, critical density is likely much higher than “the last individual”.

Another misconception has been raised by those who believe that exporters manage their collection quotas by not extracting a certain species/population when they notice the numbers are dwindling. Chris knows of at least nine (!) different teams that extract cichlids from the lake. Even if there was one that would refrain from collecting a certain species/population, the other eight teams won’t! Believe me, there is NOBODY who would not collect a fish so that it can recover. As long as we want to buy a certain species/form from an exporter, there will be extractors trying to get it, even just a single individual. The local fishermen continue to catch till EVERY fish is gone. There is no alternative for these people. Some studies have been done in Africa’s lakes towards the sustainability of fisheries, words have been spoken, and laws have been made by the country’s fisheries departments, but on the ground it is a free for all with very little measure of control. They even prevent recruitment of young fish by also collecting these with mosquito nets in the very shallow water. Dream on if you think African catchers are “managing their quotas”. Regarding ornamental fish it is OUR demand that drives certain species into extinction; WE have to regulate collections, not the workers in Africa. There are about 200 cichlid species and variants that are or have been exported from the lake; all we ask is to refrain from buying a few of these, less than 3%.

There was a question about the validity of information given on this page because if it was only me saying so it was not acceptable. I wonder whom we should ask about the cichlids in the lake, somebody who has been traveling, observing, and publishing about these fish in the lake for the last 30 years, scientists who have made detailed studies of particular populations, concerned citizen of Tanzania who actually live on the shores of the lake, OR an importer of these fish in the United States who perhaps has never seen a cichlid in its natural habitat? To answer the question about how often Tropheus species breed please read the study by Yanagisawa & Sato (1990) who found in their study area that T. duboisi mouthbroods for about 31 days and females recuperate for about 76 days before they spawn again. For T. moorii/T. sp. ‘black’ the interval is even much longer. It is possible that in the aquarium, where fish get fed twice a day and there are no predators, T. duboisi may spawn perhaps 4 times a year, but in their natural habitat things are a little more competitive. Also during the rainy season hardly any cichlid species breeds because of poor visibility. So, in the wild a Tropheus female spawns on average 2-3 times a year. Therefore catching 50% of a population in a single year is NOT sustainable for Tropheus."

I didn't see many big Tropheus schools or boops nests when diving Nkondwe in the 12 year span from my first Tanzanian safari.

If you are keen to visit this remarkable place, Anton Lamboj will be heading another group next year 2016.

Start planning & saving now.

But best of course is to go with the Ad man himself

[Ged]

A very worthwhile read.

When you see teams of collectors illegally camp on rocky outcrops in the middle of the lake so they they can fish continuously you can understand the pressure that is placed on species is relentless.

[Ged]

Here is the first part of the article that Ad wrote.

https://www.facebook.com/pages/Cichlids-of-Lake-Tanganyika/332333576856531

Endangered cichlids of Lake Tanganyika-Ad Konings

Maswa Duboisi

The cichlid at most risk of extinction is the so-called Maswa Duboisi. This particular form was discovered about 40 years ago by Pierre Brichard near a place known from old maps as Maswa. It is the name of an old fortress, later monastery, located on the shore south of the Malagarasi Delta, though nothing of it now remains.

Since its introduction into the hobby late 1950s, Tropheus duboisi has always been an extremely popular cichlid mainly because of it polka-dotted juveniles. The species is very old, estimated at about 2 million years, and seems less capable of holding territory in the prime rocky habitat as other members of the genus. We therefore find only a few relict populations of this species in the northern half of the lake. By extracting major numbers of this species from such surviving populations, we likely push this cichlid quickly to extinction. This has nearly happened with the Maswa Duboisi which used to live at a few select places around Cape Kabogo. The initially discovered population was virtually wiped out by the end of the previous century and after I found another population near Halembe also that population is nearly gone. T. duboisi is very slowly regenerating species that usually spawns just two times a year when it produces on average nine young. The challenges juvenile cichlids face in the lake are such that almost none of these juveniles make it to maturity. The adults are already challenged by the presence of more successful members of the genus, so that over-collecting this species is a lose lose situation.

There is absolutely no need to extract this species from the wild as it is bred in quantities far greater than can be found in the lake. So, to completely stop collecting the Maswa variant of T. duboisi is a no-brainer.

[simy696]

maybe a bit of topic but have sourced a large species book supposed to be latest addition think i sore konings on it what are these worth at a guess?

[myster619]

What's a duboisi to a hungry african child?

[simy696]

good point myster also im thinking that australia due to its import restrictions is lessinging the damage we cause. where as ive seen england and usa lists of import fish and they can get what they want. even spoke to guy in england the other night who had just moved back there. i asked him why his answer he could get what ever fish he wished and shops stocked wild as the norm our fish would be throw away i guess there.

[yellow]

I wonder how responsible Ad feels for all of this. Having made his living from books, tours, and talks on the fish in the lakes, he's no doubt played his part in it all. After all, he travels the world promoting fish species from the lakes. Enthusiasts watch, read or travel with him, then want to keep species for themselves, which leads to overcollecting.

It's easy for him to say we're taking too many fish (I bet they are!), but he's been one of the biggest promoters of them. Does he ever ponder that? I wonder.

Of course, I've played my part too; we all have.

[Ged]

Jason a very good point. In Chat last night we were discussing this very point.

I was reading this article on introduction of Tilapia into Lake Malawi. It outlines the introduction into other lakes and the affect that it has had on endemic species. One of the reasons given for their introduction is as a food source.

http://www.researchgate.net/publication/263076833_Nile_tilapia_invades_the_Lake_Malawi_catchment

Ged