A very interesting read for the AMPHILOPHUS people

[dogofwar]

Yes, please email it to me (PM'd you).

Not sure if anyone else cares but it sounds like the introduced Tilapia are really impacting the native fish... Not good.

Interested in the management recommendations and whether they're being followed!

Matt

 

[Miguel]

we woild all like to see that study...isn't there a link we can use?

 

[RD.]

Miguel ........ there are links to various studies on the crater lake amphilophus genus in this past discussion that you may be interested in reading. Much along the lines of this paper.
http://www.monsterfishkeepers.com/f...f-citrinellus-A-potential-case-of-F1-Midevils

The paper on tilapia can be found here, perhaps in a cleaner format elsewhere but this will get the job done. http://www.bio-nica.info/biblioteca/McCrary2006TilapiaNicaragua.pdf


IMO the following comment from that paper pretty much sums the situation up.......

Yet in poor,governmentally weak countries such as Nicaragua, avoidance of externalities is not well-developed, leaving the country open to risk-taking activities without accountability when environmental damage occurs (Jenkins 2001).

And there you have it. Tilapia destroying the native fish & fauna, while for several decades the locals dumped tons of raw sewage & chemicals into some of these lakes on a daily basis. The pollution has become so bad that most researchers will no longer even dive in some of the lakes mentioned in that tilapia paper, such as Lake Masaya & Lago Managua.

Here's some additional reading on that subject that was posted on a site based out of Grenada, Nicaragua. http://granadanicaragua.biz/lake-managua.html

The western section of Nicaragua along the Pacific Ocean is the more densely populated area and the site of the larger cities: Managua (the capital), León, Granada, Masaya and Chinandega. The country's few industries are congregated in this area and many empty their waste into Lake Managua.It was found that 32 tons (70,000 pounds) of raw sewage was being released into Managua daily. Industry located along the lake’s shore had been dumping effluent for an extended period of time. Pennwalt Chemical Corporation was found to be the worst polluter.It is more true than ever: though the city’s decrepit north side still crumbles against the shore of Lake Managua, the capital claws its way relentlessly southward towards Masaya.

Another article on that subject: NICARAGUA: Cleaning Up ‘World’s Biggest Toilet’

http://www.ipsnews.net/2009/03/nicaragua-cleaning-up-lsquoworldrsquos-biggest-toiletrsquo/

"For 82 years we have turned Central America’s largest lake into the world’s biggest toilet," Jaime Incer Barquero, a scientist and environmentalist, told IPS. "We poison it every day with tons of feces and garbage, and now, at this pace, it will take 50 years or more to salvage."

A great big toilet filled with invasive species, probably not exactly what the local tourist board is promoting.

 

[woofy]

As a person whos stepped foot in nicaraguad lakes. I can tell you its gross. My .2 lol ill tell you what i said there looking into the garbage and smelly seeage filled water... I wouldnt make my worst enemy go swimming in there.

Maybe it would be cool to ask local fisherman how the difference in catches of invasives vs local fosh have been changing over the years?

 

[Miguel]

Thank You Ryan, and Wofy.

What a waste. what a pity, the way our world is being destroyed and the pace of it.

 

[Source310]

It Will Be Very Difficult To Get Rid Of The Tilapia

 

[the animal guy]

Tilapias are more beneficial. We can eat them. Having food is more important.

 

[RD.]

The locals have been eating the native species of fish for hundreds of years. There was no shortage of food. Most of the tilapia produced in Central America is exported to the USA.

 

[RD.]

And on that note .......

http://fairwhistleblower.ca/content/another-side-tilapia-perfect-factory-fish

Environmentalists argue that intensive and unregulated tilapia farming is damaging ecosystems in poor countries with practices generally prohibited in the United States — like breeding huge numbers of fish in cages in natural lakes, where fish waste pollutes the water. “We wouldn’t allow tilapia to be farmed in the United States the way they are farmed here, so why are we willing to eat them?” said Dr. Jeffrey McCrary, an American fish biologist who works in Nicaragua. “We are exporting the environmental damage caused by our appetites.”

Known in the food business as “aquatic chicken” because it breeds easily and tastes bland, tilapia is the perfect factory fish; it happily eats pellets made largely of corn and soy and gains weight rapidly, easily converting a diet that resembles cheap chicken feed into low-cost seafood.

Compared with other fish, farmed tilapia contains relatively small amounts of beneficial omega-3 fatty acids, the fish oils that are the main reasons doctors recommend eating fish frequently; salmon has more than 10 times the amount of tilapia. Also, farmed tilapia contains a less healthful mix of fatty acids because the fish are fed corn and soy instead of lake plants and algae, the diet of wild tilapia.

“It may look like fish and taste like fish but does not have the benefits — it may be detrimental,” said Dr. Floyd Chilton, a professor of physiology and pharmacology at Wake Forest Baptist Medical Center who specializes in fish lipids.

In farmed tilapia, raised largely on corn and soy, omega-3 levels depend on how much fish meal or fish oil the farm’s breeders mix in. While most fish species need a good helping of these fatty acids to grow, herbivorous tilapia grow decently with little or none. And there are compelling reasons to skimp on fish meal or oil additives: they are costly and create more pollution.

Dr. McCrary has spent the past decade studying how a small, short-lived tilapia farm degraded Lake Apoyo in Nicaragua. “One small cage screwed up the entire lake — the entire lake!” he said of the farm, which existed from 1995 to 2000.

Waste from the cages polluted the pristine ecosystem, and some tilapia escaped. An aquatic plant called charra, an important food for fish, disappeared, leaving the lake a wasteland. Today, some species of plants and fish are slowly recovering, but others are probably gone forever, said Dr. McCrary, who works for the Nicaraguan foundation FUNDECI.

That experience explains why Dr. Salvador Montenegro, director of Nicaragua’s Center for Aquatic Resource Investigation, has spent a decade fighting to close the much larger Nicanor tilapia farm in a remote corner of Lake Nicaragua. “This kind of intensive fish farming jeopardizes a lake that is a national treasure, already under stress from pollution,” he said, once comparing its effect to allowing 3.7 million chickens to defecate in the water. Weaker fish, like the rainbow bass, have been disappearing from Lake Nicaragua as the number of tilapia has increased, said Ben Slow, a local fisherman.

 

[rodald]

Its sad to see that foreign species are taking over native species, I can see it here in Guatemala, you can find either Tilapia or P. managuensis in almost every river and lake, there are proyects to breed Vieja maculicada instead of Tilapia but the reason people likes Tilapia is because they are almost tasteless so people can give them the flavor they want and thats the reason why they are so profitable plus they are really easy and cheap to feed I have even heard that people feeds them with the waste that comes out of the chicken farms