Well here we go again, you know the drill. Global warming at fault, other possibilities ignored, multiple press releases. Lake Tanganyika is the second largest lake in the world for fresh water, so naturally any change it is cause for “alarm”. Unfortunately in these press releases there is no mention of a possible increase in turbidity due to human action on and around the lake, decreasing the albedo to absorb more sunlight on the lake surface, warming it. At least somebody has already asked that question previously in peer reviewed literature where they describe the Lake Tanganyika problem as “watershed deforestation, road building, and other anthropogenic activities result in sediment inundation…“.
But in our current press releases, there is this hat tip to anthropogenic: “The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.”
First from Brown University:
Brown Geologists Show Unprecedented Warming in Lake Tanganyika
PROVIDENCE, R.I. [Brown University] — Lake Tanganyika, the second oldest and the second-deepest lake in the world, could be in for some rough waters.
Geologists led by Brown University have determined the east African rift lake has experienced unprecedented warming during the last century, and its surface waters are the warmest on record. That finding is important, the scientists write in the journal Nature Geoscience, because the warm surface waters likely will affect fish stocks upon which millions of people in the region depend.
The team took core samples from the lakebed that laid out a 1,500-year history of the lake’s surface temperature. The data showed the lake’s surface temperature, 26 degrees Celsius (78.8°F), last measured in 2003, is the warmest the lake has been for a millennium and a half. The team also documented that Lake Tanganyika experienced its biggest temperature change in the 20th century, which has affected its unique ecosystem that relies upon the natural conveyance of nutrients from the depths to jumpstart the food chain upon which the fish survive.
“Our data show a consistent relationship between lake surface temperature and productivity (such as fish stocks),” said Jessica Tierney, a Brown graduate student who this spring earned her Ph.D. and is the paper’s lead author. “As the lake gets warmer, we expect productivity to decline, and we expect that it will affect the [fishing] industry.”
The research grew out of two coring expeditions sponsored by the Nyanza Project in 2001 and 2004. Cores were taken by Andrew Cohen, professor of geological sciences at the University of Arizona and director of the Nyanza project, and James Russell, professor of geological sciences at Brown, who is also Tierney’s adviser.
Lake Tanganyika is bordered by Burundi, the Democratic Republic of Congo, Tanzania, and Zambia — four of the poorest countries in the world, according to the United Nations Human Development Index. An estimated 10 million people live near the lake, and they depend upon it for drinking water and for food. Fishing is a crucial component for the region’s diet and livelihood: Up to 200,000 tons of sardines and four other fish species are harvested annually from Lake Tanganyika, a haul that makes up a significant portion of local residents’ diets, according to a 2001 report by the Lake Tanganyika Biodiversity Project.
Lake Tanganyika, one of the richest freshwater ecosystems in the world, is divided into two general levels. Most of the animal species live in the upper 100 meters, including the valuable sardines. Below that, the lake holds less and less oxygen, and at certain depths, it is anoxic, meaning it has no oxygen at all. What this all means is the lake is highly stratified and depends on wind to churn the waters and send nutrients from the depths toward the surface as food for algae, which supports the entire food web of the lake. But as Lake Tanganyika warms, the mixing of waters is lessened, the scientists find, meaning less nutrients are funneled from the depths toward the surface. Worse, more warming at the surface magnifies the difference in density between the two levels; even more wind is needed to churn the waters enough to ferry the nutrients toward the fish-dwelling upper layer.
The researchers’ data show that during the last 1,500 years, intervals of prolonged warming and cooling are linked with low and high algal productivity, respectively, indicating a clear link between past temperature changes and biological productivity in the lake.
“The people throughout southcentral Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” noted Cohen, an author on the paper. “This resource is likely threatened by the lake’s unprecedented warming since the late 19th century and the associated loss of lake productivity.”
Climate change models show a general warming in the region, which, if accurate, would cause even greater warming of the Lake Tanganyika’s surface waters and more stratification in the lake as a whole. “So, as you move forward, you can imagine that density gradient increasing,” said Russell, an author on the paper.
Some researchers have posited that the declining fish stocks in Lake Tanganyika can be attributed mainly to overfishing, and Tierney and Russell say that may be a reason. But they note that the warming in the lake, and the lessened mixing of critical nutrients is exacerbating the stocks’ decline, if not causing it in the first place. “It’s almost impossible for it not to,” Russell said.
Other authors on the paper are Brown graduates Marc Mayes and Natacha Meyer; Christopher Johnson at the University of California, Los Angeles; and Peter Swarzenski, with the United States Geological Survey. The National Science Foundation and the Nyanza Project funded the research.
=======================================
Here is the University of Arizona version
=======================================
Twentieth-Century Warming in Lake Tanganyika is Unprecedented
Warming in the last century threatens one of Africa’s largest inland fisheries.
Lake Tanganyika’s surface waters are warmer than at any time in the previous 1,500 years, a University of Arizona researcher and his colleagues report online in Nature Geoscience.
The rise in temperature during the 20th century is driving a decline in the productivity of the lake, which hosts the second-largest inland fishery in Africa.
“People throughout south-central Africa depend on the fish from Lake Tanganyika as a crucial source of protein,” said study co-author Andrew S. Cohen, a UA professor of geosciences. “This resource is likely threatened by the lake’s unprecedented warming since the late 19th century and the associated loss of lake productivity.”
This is the first detailed record of temperature and its impacts on a tropical African ecosystem that allows scientists to compare the last 100 years with the previous 1,400 years, Cohen said.
The team attributes the lake’s increased temperature and the decreased productivity during the 20th century to human-caused global warming.
“We’ve got a global phenomenon driving something local that has a huge potential impact on the people that live in the region and on the animals that live in the lake,” he said.
The annual catch of the Lake Tanganyika fishery is estimated at about 198,000 tons per year, more than 20 times greater than the U.S. commercial fishery in the Great Lakes, he said. The nations of Burundi, Tanzania, Zambia and the Democratic Republic of Congo border the lake, which is the longest lake in the world and the second deepest.
The surface waters of Lake Tanganyika are the most biologically productive part of the lake. For the 1,400 years before 1900, those waters were no warmer than 75.7 F (24.3 degrees C). Since 1900, the lake’s surface waters warmed 3 degrees F, reaching 78.8 degrees F (26 degrees C) in 2003, the date of the researchers’ last measurement.
The researchers used sediment cores from the lake bed to reconstruct the 1,500-year history of the lake. The scientists analyzed the cores for chemicals produced by microbes and left in the sediments to determine the lake’s past temperature and productivity.
Because sediment is deposited in the lake in annual layers, the cores provide a detailed record of Lake Tanganyika’s past temperatures and productivity and of the regional wildfires.
The instrument record of lake temperatures from the 20th century agrees with the temperature analyses from the cores, Cohen said.
The cores were extracted as part of the UA’s Nyanza Project, a research training program that brought together U.S. and African scientists and students to study tropical lakes. The National Science Foundation funded the project.
“A big part of our mandate for the Nyanza Project was looking at the interconnectivity between climate, human activity, resources and biodiversity,” said Cohen, who directed the multi-year project.
Lake Tanganyika and similar tropical lakes are divided into two general levels. Most of the fish and other organisms live in the upper 300 feet (about 100 meters). At depths below that, the lake waters contain less and less oxygen. Below approximately 600 feet, the lake water, although nutrient-rich, has no oxygen and fish cannot live there.
During the region’s windy season, the winds make the lake’s surface waters slosh back and forth, mixing some of the deep water with the upper layers. This annual mixing resupplies the lake’s food web with nutrients and drives the lake’s productivity cycle, Cohen said.
However, as Lake Tanganyika warms, the upper waters of the lake become less dense. Therefore, stronger winds are required to churn the lake waters enough to mix the deeper waters with the upper layer. As a result, the upper layers of the lake are becoming increasingly nutrient-poor, reducing the lake’s productivity.
In addition, warmer water contains less dissolved oxygen, reducing the quality of the habitat for some fish species.
Other lakes in Africa are showing similar effects to those the team found in Lake Tanganyika, he said.
The finding has implications for lakes in more temperate climates.
“Increasingly, lakes in the U.S. are warming and they’re behaving more like these African lakes,” Cohen said. “There’s a potential for learning a lot about where we’re going by seeing where those lakes already are.”
The team’s article, “Late twentieth-century warming in Lake Tanganyika unprecedented since AD 500,” will be published in the June issue of Nature Geoscience.
Cohen’s co-authors on the paper are first author Jessica E. Tierney of Brown University in Providence, R.I.; Marc T. Mayes, Natacha Meyer and James M. Russell, also at Brown University; Christopher Johnson, a former University of Arizona student now at the University of California, Los Angeles; and Peter W. Swarzenski of the U.S. Geological Survey in Santa Cruz, Calif. The National Science Foundation funded the research.
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BillD says:
May 19, 2010 at 6:23 pm
I did both Google and Google Scholar searches on Patrick and did not find anything beyond blog posts.
I’m wondering why you do not use your full name? If you need my CV I’m more than happy to provide and perhaps for your comfort some academics who know me.
Writes BillD:
Bill, it’s not only not necessary to provide one’s vitae in fora like this one but in a particular way quite perverse.
One of the adverse factors with which human beings must always deal in discourse of any kind – and scientific discourse is no exemption – is the logical fallacy of argument from authority, where credentials are used as clout. There is a temptation to conduct a sort of “pecker contest” in which the background of a disputant is used to clout an opponent instead of obliging reliance on lucid argument based upon supported assertions.
What gets posted in venues like this one can be more valuable than the usual-and-customary academic cockfighting that establishes which professor gets to crow at the top of one university’s or professional society’s dungheap, for the level of personal anonymity imparted by an online nickname compels the individual to attend to the intrinsic validity of his statements while at the same time freeing him from what are, in truth, quite damnable limitations required by the need to get a living.
Bear in mind that when John Locke (yet another physician) published his Two Treatises of Government – the second of these being undeniably the “crib sheet” from which our Declaration of Independence was written – he did it anonymously. And when Trenchard and Gordon later uttered their series of Essays on Liberty, Civil and Religious, they did it using the joint pseudonym of “Cato.”
Thus we speak today of Cato’s Letters, bound collections of which could be found in roughly half of the personal libraries in the American colonies by the time the bullets began to fly across Lexington green.
If you try to use your curriculum vitae as a club in this forum, you will not only be defeating the purpose of this kind of discourse but cheapening yourself to do it.
—
Rich Matarese
You may have the order of comments mixed up. BiilD started off a refutation to a comment of mine by saying he did not find my name in a “scholar” search – implying as such my comments were without merit. Not only an obvious appeal to authority but an attempt to restricting knowledge, scholarship, merit etc to those that publish academic work -rejecting those who labor in the equally challenging practical applications of science. While I agree with your comments on a rational level- it does get tiresome if not irksome at times. The need (and consequences) for anonymity of the Cato letters is far different than a blog. I don’t have a problem with anonymity- but little tolerance for those that snipe at qualifications while hiding their own. We all have our buttons.
—
Pat Moffitt concludes his recent post with:
Given that our Mombasa Messiah and his sputniki have been making much in recent months of their desires, plans, and goals with regard to “Internet fairness” – in actuality, the active governmental suppression of dissent and information flow online – I think that we are in very much the same condition as had been experienced by John Locke, by John Trenchard and Thomas Gordon, by Richard Overton, by Algernon Sydney (who literally went to the scaffold for having uttered his Discourses Concerning Government).
We are really not in a purely scientific exchange here, but rather in what is a truly political discussion. What is posted on this Web site affects – even if only in a small way – decisions being made in the capitols of nations. I need not remind you of the pernicious impact upon government policies that has been imposed by the anthropogenic global warming fraud, nor of the effects we have seen over the past six months in particular as the result of the work of Internet gadflies like McIntyre, Delingpole, Monckton, and Anthony Watts.
Anonymity, pseudonymity – these are all valuable, reasonable, necessary protections for people here and now. We are not living in an era when the private citizen may simply speak his mind to the greedy, the powerful, and the corrupt without very real efforts being made at his utter ruination by those who serve the forces of corruption and political power.
Beyond that, however, it must be understood that a disputant’s qualifications are irrelevant when it comes to speaking sense. This is true not only of those who seek to flaunt their credentials as if these provided real, meaningful support for their ex cathedra assertions but also for those who “snipe at qualifications while hiding their own.”
Any such “snipe at qualifications” is, after all, just as lacking in validity. Not so?
—
I don’t think one necessarily need a PHD in Climatology to disprove global warming or a number of issues.
I myself do not have a PHD in anything however I have done a lot of research and I have a wonderful BS (Bad Science) detector and when see and hear things that don’t make sense to me, I refuse to back down to a bully in professor’s clothing.
I have a wordpress blog so if anyone really has to know my name that badly one can also click and click again to see my ugly mug and my name.
I think to harass someone because you doubt his name and credentials is to be a pompous windbag and not serious about debate!
History tells us that the sciences were for all with an education, the only people never included by Plato or Socrates were those who were uneducated because they didn’t care or weren’t able to be educated. Today anyone is able to be educated, from those who were given full scholarships to Harvard by their communist mentors like President Obama or like myself who has gone into major debt and almost died twice in the last 3 years due to poor health conditions from working too much and staying up too late doing research and homework.
Don’t you dare tell me that I don’t have the ability to carry on a conversation about global warming merely because I don’t have a PHD. What you aim at one person here, you aim at all, be forewarned.
Any refutation of a good and valid point or set of comments based on mere ad Homonym attack or Red Herring flinging only increases the ignorance of the accuser in the eyes of the masses.
Rich Matarese
you have really got to read the chronology of the posts–as I used to say to my parents- it wasn’t me who started it
Part 1.
I have been researching this whole issue for the last couple of days.
At someone’s suggestion I went to check out the following article but unfortunately they only provide Abstracts through ProQuest and I can’t afford to sign up for their membership. Hydrothermal vents in Lake Tanganyika, East African Rift system
Pflumio, Catherine, Castrec, Maryse, Boulegue, Jacques, Gente, Pascal, et al. Geology. Boulder: Jun 1993. Vol. 21, Iss. 6; pg. 499
One would think that if there are active thermal vents that we’ve known about since at least 1990 this could have something to do with the issue.
It would also appear that there is a massive overharvesting of fishing going on that makes the gillnetting/long lining of salmon look like a drop in the bucket.
Also there is a massive problem with land use issues.
Granted the last two issues are man caused but have absolutely nothing to do with AGW.
I also read an article that shows that there have been higher than normal wind conditions which inevitably dry out the surface which is going to cause conflicting temperature anomalies.
I’ve also read about Gustave the killer Croc which could be eating up large amounts of fish. A much more viable option than AGW, especially since the authors admit that they only took two samples from a huge body of water. http://search.ebscohost.com/login.aspx?direct=true&db=f5h&AN=38995750&site=ehost-live
The above is a link to a scholastic database of a National Geographic Article.
Is an interesting article about how the two major species of fish have major variances in population.
Limnological variability and pelagic fish abundance
(Stolothrissa tanganicae and Lates stappersii)
in Lake Tanganyika
P.-D. Plisnier Æ H. Mgana Æ I. Kimirei Æ A. Chande Æ L. Makasa Æ
J. Chimanga Æ F. Zulu Æ C. Cocquyt Æ S. Horion Æ N. Bergamino Æ
J. Naithani Æ E. Deleersnijder Æ L. Andre´ Æ J.-P. Descy Æ Y. Cornet
Received: 24 June 2008 / Revised: 12 December 2008 / Accepted: 2 January 2009 / Published online: 2 February 2009
_ Springer Science+Business Media B.V. 2009
Part II –
The effects of windstorms on nutrient of Lake Tanganyka
Effect of wind induced water movements on nutrients,
chlorophyll-a, and primary production in Lake Tanganyika
V. T. Langenberg,1∗ J. Sarvala,2 and R. Roijackers1
1Aquatic Ecology and Water Quality Management Group, Agricultural University, Wageningen, The Netherlands
2Department of Biology, University of Turku, Turku, Finland
*Corresponding author: Aquatic Ecology and Water Quality Management Group, Agricultural University, PO Box 8080,
Wageningen, the Netherlands; Tel.: +31-629433225; Fax: +31-317484411; E-mail: victor.langenberg@wur.nl
Climate change decreases aquatic ecosystem productivity of Lake Tanganyika, Africa.Full Text Available By: O’ReiIIy, Catherine M.; AIinl, Simone R.; Plisnier, Pierre-Denis; Cohen, Andrew S.; McKee, Brent A.. Nature, 8/14/2003, Vol. 424 Issue 6950, p766, 3p; DOI: 10.1038/nature01833;
There have been numerous peer reviewed articles that have talked about an increase of fish, including the one above. The only species of Cichlids that are declining are the rock fish that are suffering from their habitation being destroyed by erosion of rock shelve strata by over use of the area.
Nature and Science are the only two journals that have any articles about global warming causing issues and they’ve been by the same authors, using similar test methods to this recent one. The latter not using any surface temperatures across the lake or more than two core samples. This lake is over 10,000 sq. miles.
That is like going to Alaska and turning a hair dryer on a patch of ice and taking only measurements of that patch and saying Alaska is suffering from an incredible heat wave.
After reading about 5 different peer reviewed articles. I see a trend Information from Nature and Science pretty much always push an AGW them onto Lake Tanganyka and other articles talk about the Chiclids thriving in certain areas and that high winds are changing surface temperatures in a cyclic nature during different periods of the 4 seasons.
the only thing anthropogenic that I can see is greedy African oil companies and massive overharvesting of fish populations.
Of course that’s my humble non PHD, opinion of course.
I grovel at the feet of the masters and beg thy forgiveness and ask a boon of thee to permit my salvation for speaking within thy hearing?
grovel, grovel, grovel
OK here is some more very interesting information.
Based on this information I would be very embarassed to have my name on the article that started this thread.
The thermal vents are putting off a tremendous amount of heat. I would strongly suggest googling the below article.
Thermophilic Sulfate Reduction in Hydrothermal Sediment of
Lake Tanganyika, East Africa
LARS ELSGAARD,l* DANIEL PRIEUR,2 GASHAGAZA M. MUKWAYA,3 AND BO B. J0RGENSEN4
Universite Pierre et Marie Curie, Paris 6,1 and Centre National de la Recherche Scientifique,2 Station Biologique de
Roscoff, F-29682 Roscoff; France; Centre de Recherche en Sciences Naturelles, Station d’Uvira, Uvira, Zaire3;
and Max Planck Institute for Marine Microbiology, D-2800 Bremen 33, Germany4
Received 21 October 1993/Accepted 18 February 1994
I just discovered this article that could possibly shed some light on this issue.
I know I’m no PHD but it makes one curious.
The Max Plank Institute is a pretty respected organization so it’s not like I’m speaking out of my ear.
I googled: Hydrothermal vents in Lake Tanganyika, East African Rift system Pflumio, Catherine, Castro, Maryse, Boulegue, Jacques, Gente, Pascal, et al. Geology. Boulder: Jun 1993. Vol. 21, Iss. 6; pg. 499
And I came up with the above article from the Applied and Environmental Microbilogy journal.
This has some very interesting information in it that could also be a cause of any increased warming that would deny AGW
Science 313, 1419 (2006);
Pierre Sepulchre, et al.
Tectonic Uplift and Eastern Africa Aridification
DOI: 10.1126/science.1129158
I’ve posted 5 articles in peer reviewed journals that are respected by both sides of the AGW coin in the http://www.skepticalscience.com/news.php?p=2&t=73&&n=201#comments thread.
They are so blinded by their religious worship of the AGW mantra that the best they could come up with is what is the wattage of the volcanic thermal vents?
Really? They take two core samplings from the lake bed from undisclosed locations with thousands of thermal vents in the lake bottom as well as volcanic tectonic shifting giving off heat trends in the area and the best they can come up with is what is the wattage of the volcanic thermal vents?
I feel like Christopher Lloyd in Back to the future 1…. 20,000 gigawatts? my gosh what was I thinking?
What is the wattage of volcanic thermal vents? “what was I thinking?”
Here I present 5 articles from well known and respected peer reviewed journals that present a viable possibility of other natural sources besides AGW and the best I get is what is the wattage of volcanic thermal vents.
Could they be playing a delayed April fools joke on me?
1personofdifference
The claim by Tierney and others is that in this relatively nutrient poor lake- primary productivity is a function of upwelling of the nutrient stores from the lake’s deeper waters. The lake has a relatively low thermal (density) gradient meaning it takes a good deal of wind to disrupt the lakes stability and bring the relatively more nutrient rich waters to the surface.
Tierney assumes that winds are higher in periods of aridity (cooler periods) and thus lake productivity. Her cores assume that productivity is linked to biogenic silica (BSI) production– basically diatoms. Tierney shows a correlation between BSI and the TEX86 lake surface temperatures as support for the link between increasing temperature and declining productivity. Tierney assumes that the increasing water temperatures have led to greater stability of the water column making it both more difficult to turn over the water column and cycle the nutrients as well as reducing the intensity of the required winds. She draws on support from Verburg of increasing lake clarity as further evidence of declining production. She then links this decline in primary production to a possible decline in fish biomass.
There are a number of concerns with Tierney’s basic assumptions and best summarized in Victor Langenberg’s 2008 thesis (Wageningen University) On the Limnology of Lake Tanganyika:
-The highest productivity on the lake is found on the end with the lowest winds- contradicting a major premise of Tierney’s that productivity and lake stability are linked
– there is no measured evidence by Secchi disc that the lake has been getting clearer(less productive)
-There is no evidence of a climate and fish biomass link
-There is evidence of severe overfishing
-The simple association of wind speed and temperature lake stability and lake upwelling-is not so simple (A wind model in the hydrodynamics of the Lake showed that temperature is of only secondary importance-LT Regional Fisheries Management Programme)
-Found that allochtonous (outside the lake) sources of nutrients were more important than assumed by Tierney
-Found no evidence for a decline in lake productivity and that the lake’s current production is within the expected range for this type of lake
-Phytoplankton chlorophylla has not materially changed from the 1970s to 1990s
Tierney draws heavily on the BSI (biogenic silica index) as evidence for the TEX86 lake surface temperatures (LSTs) being related to productivity. She assumes that diatoms are a major component and a representative proxy for productivity from the work of Verbum. Langenburg contradicts Verbum’s finding that diatoms are an indicator for Lake Tanganyika productivity finding picocyanobacteria may be the Lake’s dominant form of phytoplankton. A 2009 paper in Journal of Plankton Research by Stenuite et al supports this position . A paper by Hecky and Kling 1987. Phytoplankton ecology of the great lakes in the rift valleys of Central Africa. Arch. Hydrobiol., Beih. Ergebn. Limnol., 25, 197–228 found that in Africa rift lakes upwelling is associated with diatom production and stratification stability with the production of cyanobacteria.
A presentation by Hecky and Verburg http://www.espp.msu.edu/climatechange/…/Physical%20and%20Ecological%20Responses%20of%20the%20Great%20 showed the switch from cyanobacteria in the wet season (warm) to diatoms in the dry season (cool) on an annual basis. The cyanobacteria do not appear as biogenic silica in the cores and as such will not be measured as productivity.
Tierney’s correlation of BSI with LST may be nothing more than diatoms being relatively more plentiful in periods of lake upwelling (aridity and high T) and cyanobacteria during periods of low upwelling (wet, low T and stable stratification). Tierney’s BSI as a result may say nothing about the overall changes in productivity of the lake. (The BSI simply reflecting the Lake’s primary productivity mode switching between cyano bacteria and diatoms.) Without a reliable proxy for total productivity the assumed correlations to temperature and fishery catch becomes less grounded.
You have commented on the heat from thermal vents- and direct you to comments made by Coulter (1968?) before the Banza vents were discovered. http://www.aslo.org/lo/toc/vol_13/issue_2/0385.pdf He proposed the possibility of heat flow at the bottom of the lake to explain the apparent lack of an expected salinity gradient and that given the depth of the lake and hydraulic residence time only small inputs of heat would be required to produce deep lake convection currents. Deep water generated convection currents would make the nutrient dynamics far more complicated than that proposed by Tierney’s simple wind/temperature mixing.
Tierney has acknowledged a “potentially” large role for overfishing in her Nature paper- however the media interviews have tended to diminish the relative threat of overfishing. There have been over two decades work trying to get the multiple interests and nations involved in the Lake fishery to agree to an enforceable/workable fishery harvest plan. Pointing a misguided finger of blame at global warming may very well undo these vital efforts. If so- the threat of global warming may have a far greater impact on the Lake and the food supply to its residents than any warming- real or imagined.
I read one article that in the whole lake there is an expectation of 3,000,000 cichlids populating the lake. The expected harvest is 2,000,000,000. I know I’m no scientist but wouldn’t that be considered as over harvesting to the max?
Now you’ve got two different oil companies trying to get drilling rights on the lake and that’s going to screw up the environment even more. This is one area that you could point the finger at mankind. However it’s not AGW that is at fault here. It’s mankind’s quick attempts to point fingers where they shouldn’t be pointed to gain notoriety. There is over harvesting of the soil and plant/tree life, which is causing loss of rock outcropping which is a major home and foraging area of several types of cichlids in the lake. There are also now efforts under way to get drilling rights, which means for years there have been studies going on and this and that which has no doubt disturbed the environment. Now you have this team run by Tierney pointing efforts away from the fisheries to AGW. Does she not think that the fisheries agencies that have already showed greed and avarice aren’t going to take advantage of this?
Lake Tanganyika is suffering from an anthropogenic effect but it is not global warming, it’s stupidity personified.
Attention Pat Moffit, I would like to put your comment on my blog if you don’t mind.
1personofdifference says:
May 22, 2010 at 2:44 pm “Attention Pat Moffit, I would like to put your comment on my blog if you don’t mind.”
Not a problem
The important fishery in the lake are not the cichlids but the clupeids (a landlocked anchovy or herring) and to a lesser extent the latids (Nile perch type species). Most people don’t realize that there are mechanized purse seine fisheries in operation on this lake. It is really not known what the harvest rate is on the lake. I have seen estimates of high 20s to over 50% of the target biomass. All are too high.
I would be careful in calling the problems stupidity. It is actually following incentives— which may be perverse- but parsing this difference is not for this post. It is really hard to tell hungry people to stop fishing and difficult to tell the government sponsored factory ships to stop. Corruption in the US and corruption in some of the Lake’s adjacent countries operate on two different scales. It is a very difficult problem -especially given the population growth rates in this area -which are extremely high. Allowing all sides to blame it on climate however may make a a difficult problem next to impossible to correct.
I didn’t know about the oil exploration. My general feeling is that overfishing- especially highly mechanized- is often more dangerous to long term ecosystem health than is oil development. As an example- as bad as the Gulf BP spill may be- it is my opinion the spill can have nowhere nowhere near the long term negative ecosystem impact of the current shrimp fishery. (The impact of the oil is visible- shrimping is not- think of marine “clear cutting” where the trees don’t grow back) But again- another subject.