Guest Post by Willis Eschenbach
Following on from Anthony’s article, here are my thoughts about the phytoplankton paper “Global phytoplankton decline over the past century”, by Daniel G. Boyce, Marlon R. Lewis & Boris Worm.
I started to write about this earlier, but I decided to wait until I had the actual paper. The paper in question is behind a paywall at Nature Magazine, but through my sub-oceanic channels (h/t to WS) I have obtained a copy. The paper makes two main claims, that: a) the numbers of phytoplankton have been cut by more than half since 1900, and b) the general warming of the global oceans is the reason for the declining numbers of phytoplankton.
First, what are phytoplankton when they are at home, and where is their home? Plankton are the ubiquitous soup of microscopic life in the ocean. Phytoplankon are the plant-like members of the plankton, the ones that contain chlorophyll and feed on sunshine. Phytoplankton are to the ocean what plant life is to the land. Almost all oceanic life depends on phytoplankton. Other than a thin strip of seaweeds and sea grasses along the coasts, phytoplankton are the microscopic plants that are the foundation of the vast entire oceanic food chain. Without phytoplankton there would be no deep water oceanic life to speak of. Figure 1 shows where you find phytoplankton:
Figure 1. Global distribution of phytoplankton. Lowest concentration is purple and blue, middle concentration is green, highest concentration is yellow and red. Source http://www.nasa.gov/vision/earth/environment/0702_planktoncloud.html
So where did the Nature paper go wrong?
The short answer is that I don’t know … but I don’t believe their results. The paper is very detailed, in particular the Supplementary Online Information (SOI). It all seems well thought out and investigated … but I don’t believe their results. They have noted and discussed various sources of error. They have compared the use of Secchi disks as a proxy, and covered most of the ground clearly … and I still don’t believe their results. Here’s exactly why I don’t believe them.
This is their abstract (emphasis mine):
In the oceans, ubiquitous microscopic phototrophs (phytoplankton) account for approximately half the production of organic matter on Earth. Analyses of satellite-derived phytoplankton concentration (available since 1979) have suggested decadal-scale fluctuations linked to climate forcing, but the length of this record is insufficient to resolve longer-term trends.
Here we combine available ocean transparency measurements and in situ chlorophyll observations to estimate the time dependence of phytoplankton biomass at local, regional and global scales since 1899. We observe declines in eight out of ten ocean regions, and estimate a global rate of decline of ~1% of the global median per year. Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures. We conclude that global phytoplankton concentration has declined over the past century; this decline will need to be considered in future studies of marine ecosystems, geochemical cycling, ocean circulation and fisheries.
The first clue to where they went wrong is visible in Fig. 1. Although as you can see there is more phytoplankton in the cooler regions of the north, the same is not true in the corresponding regions in the south despite the ocean temperatures being very similar. In addition, there are many places where the ocean is warm (e.g. tropical coasts) that have lots of phytoplankton, while in other warm areas there is very little phytoplankton.
The rude truth of phytoplankton is this: phytoplankton growth is generally not limited by temperature. Instead, it is limited by nutrients. Where nutrients are plentiful, the phytoplankton grow regardless of temperature. Nutrients are more common along the coastline, where sub-oceanic currents come to the surface bringing nutrients from the deep ocean floor, and rivers bring nutrients from inland. For example, in Fig. 1 you can see the nutrients from the Amazon river causing the red area at the river mouth (north-east South American coast).
Indeed, the fact that phytoplankton are generally nutrient limited rather than temperature limited has been demonstrated in the “ocean fertilization” experiments using rust. If you spread a shipload of rust (iron oxide) out into the tropical ocean, you generally get an immediate bloom of phytoplankton. Temperature is not the problem.
So to start with, the idea that increasing temperature automatically leads to decreasing phytoplankton is not generally true. There are vast areas of the ocean where higher temperatures are correlated with more phytoplankton. For example, the warmer deep tropics generally have more phytoplankton than the cooler adjacent subtropics.
The paper’s most unbelievable claim, however, is their calculation that since 1899, the density of phytoplankon has been decreasing annually by 0.006 milligrams per cubic metre (mg m-3). They give the current global density of phytoplankton as being 0.56 mg m-3. Thus they are claiming that globally the concentration of phytoplankton has dropped by more than 50% over the last century.
Now, a half century ago I learned to sail on San Francisco Bay. Since then I’ve spent a good chunk of my lifetime at sea, as a commercial fisherman from California to the Bering Sea, as a sailboat delivery crewman, as a commercial and sport diver, and as a surfer. And call me crazy, but I simply don’t believe that the sea only has half the phytoplankton that it had in 1900. If that were true, it would not take satellites and complex mathematical analysis to show it. People would have noticed it many years ago.
I say this because phytoplankton are the base of almost the entire mass of oceanic life. They are what almost all other life in the ocean ultimately feeds on, predators and prey as well. The authors of the study do not seem to realize that if the total amount of phytoplankton were cut by more than half as they claim, the total mass of almost all living creatures in the open ocean would be cut about in half as well. No way around it, every farmer knows the equation. Half the feed means half the weight of the animals.
And I see no evidence of that having happened over the last century. It certainly does not accord with my own extensive practical experience of the ocean. And I see no one else making the claim that we only have half the total mass of deep-water oceanic life that we had a century ago..
The other thing that makes their claimed temperature/phytoplankton link very doubtful is that according to the HadISST dataset, the global ocean surface temperature has only increased by four tenths of a degree C in the last hundred years.
Four tenths of a degree … an almost un-noticeable amount. Yet their paper says (emphasis mine):
Our analyses further reveal interannual to decadal phytoplankton fluctuations superimposed on long-term trends. These fluctuations are strongly correlated with basin-scale climate indices, whereas long-term declining trends are related to increasing sea surface temperatures.
These kinds of claims drive me nuts. Is there anyone out there that truly believes that a change of global average ocean temperature of four tenths of a degree C over the last hundred years has cut the total mass of phytoplankton, and thus the total mass of all oceanic creatures, in half? Really?
So that’s why I say I don’t know where their math went wrong, but I don’t believe their results. I don’t believe we’ve lost about half the total mass of all oceanic creatures. Half the planet’s open ocean dwellers? Where is the evidence to support that outrageous claim? And I don’t believe that an ocean temperature change of four tenths of a degree over a century has made much difference to phytoplankton levels, as they grow at all temperatures.
Why don’t I know where their math went wrong? Unfortunately, they have not posted up the data that they actually used. Nor have they shown any of their data in the form of graphs or tables. Instead, they have shown model results, and merely pointed to general websites where a variety of datasets are maintained. So we don’t know, for example, whether they used the 1° grid version or the 2.5° grid version of a given dataset. Nor have they posted the computer code that they used in the analysis. Plus, the very first link in their paper to the first and most important data source is dead.
Grrrr … but dead link or not, pointing to a website as the data source in their kind of paper is meaningless. To do the analysis, they must have created a database of all of the observations, with the meta data, and the details for the type etc. for each observation. If they would include that database and their code in the SOI, then someone might be able to figure out where their math went wrong … my guess is that it may be due to overfitting or misfitting of their GAM model, but that’s just a wild guess.
It is a shame that they did not post their data and code, because other than the lack of data and code it is a fascinating analysis of a very interesting dataset. I don’t accept their analysis of the data because it doesn’t pass the “reasonableness” test, but that doesn’t mean that the dataset does not contain valuable information.
[Update] An alert reader noted that the image in Figure 1 was of a particular month and not a yearly average. So I’ve made a short movie of the variations in plankton over the year.
Figure 2. Monthly movie of plankton concentrations. Click on image to see animation.
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bubbagyro says:
August 1, 2010 at 6:45 pm
BillD says:
August 1, 2010 at 5:27 pm
Bubbagyro:
I can’t dispute your fishing success, but I did some reading about world shark populations. Sharks are slow growing, long lived species that produce only a few young at a time, unlike most bony fish. Over the last 20-30 years, populations of most of the larger species have decreased by 70-90%. This is largely due to the killing of sharks for their fins, which cost $300/lb in Asian markets. There are still sharks and perhaps the high kill rate has less effect in US waters than in other parts of the world, especially in the tropics and Asian waters.
BillD,
Please explain why WE in the U.S. are always assumed to be at fault?
Neither you nor any other alarmist critic ever goes on the warpath against the real polluters in the world like China, Brazil, Russia, India, and over a hundred smaller countries.
It’s always the fault of the U.S.
Hypocrisy.
This from 2008:
Spanish scientists have reported a ten-fold increase in the number of sharks spotted off popular tourist beaches in north eastern Spain.
At least 20 sharks were recorded in Mediterranean waters off the Catalan coast last year, a figure that far exceeded previous years.
In 2003 three were seen, in 2004 five were reported and in 2005 and 2006 only two of the fish were found each year.
A report published by the Foundation for the Conservation and Rehabilitation of Marine Animals (CRAM) revealed that among the unusual visitors to the area were a hammerhead shark and several sandbar sharks, one of which was caught and transferred to Barcelona Aquarium last August where it died several days later.
This next report from 2008 within two months of the previous report:
Reuters) – The number of sharks in the Mediterranean has fallen by 97 percent in the last 200 years, putting the sea’s ecological balance at risk, a report released on Wednesday said.
The report, by the Washington-based Lenfest Ocean Program, used records such as fishermen’s logs, shark landings, museum specimens and visual sightings to estimate the number and size of the Mediterranean sharks over the last two centuries.
There was only enough data on five of the 20 big shark species present in the Mediterranean to be useful to the study — the hammerhead, thresher, blue and two species of mackerel shark, which averaged a decline of 97 percent.
The difference? One is by marine biologists, the other by fishermen. Marine biologists are responsible for the lions’ share of reports. Just like the bulk of “climate science” reports allowed into the media are from the alarmists. Maybe we need more warm-earthers, ecologists, and marine biologists to get more “unbiased” reports? [sarc…]
Vested interests at work, perhaps? I guess everyone has to make a living. You pays your money, you takes your chances. “Fallen by 97% in the last 200 years”? Really – sound familiar?
I recommend not swimming in the ocean after dark, at any rate.
Some background information is in place.
1) I don’t trust any of Boris Worm’s publications. He is too much an activist/politician than a scientist. Check it out for yourself.
2) The Secchi disk (Sd) method consists of lowering a black/white disc into the sea and measuring the depth it disappears. I’ve done some thousands of such measurements myself and soon found out that major improvements were needed. Waves, ripples, sun reflection and clouds can add 50-80% error to the measurement and pollution even more (mud). To do it accurately from a ship is unthinkable. One needs to be in the water with a dark mask, for lowering the Sd. I had to make one that sank fast, and flashed for more accuracy. Even then the correlation between Sd depth and plankton biomass was tenuous. It appears that the method measures light diffusion more so than light absorption, and light underwater does strange things (Raleigh & Tindall diffusion and reflection).
3) Measuring plankton density from satellites will probably never be possible. There are too many interpretations, calculations and corrections to make it a stable method over decades. Then there is the assumption that plankton is green as in chlorophyll, yet most biomass is brown. Then one assumes that the surface is representative of the entire photic depth (sunlit depth). It is not. Then there are the mixotrophs, animals with plant cells in their skins, living mainly in very clear seas, being almost invisible, yet very productive.
4) The plankton ecosystem is the least understood in this world. Some people think that overfishing causes more zooplankton and thus less phytoplankton. Rubbish. The sea does not work like that. What is still being overlooked is that the sea’s main biomass consists of bacteria that decompose biomatter. Bacteria rule the sea (and the land). And then there is the mysterious Recalcitrant Dissolved Organic Carbon (RDOC), a huge inert biomass. Most of our thinking and logic about the sea is totally wrong. http://www.seafriends.org.nz/dda/
To link plankton productivity with a tiny increase in sea temperature, shows arrogance.
5) The published data is erratic and discontinuous and entirely irrelevant. To average it and draw curves through it is not science. This is a failed experiment and should have been recognised as such, and should never have made it to a ‘respectable’ journal.
Smokey says:
August 2, 2010 at 10:55 am
BillD,
Please explain why WE in the U.S. are always assumed to be at fault?
Smokey:
If you read my comment, you should understand that I said that the decline in sharks is mainly due to “finning” for Asian markets. As far as I know, we in the US are not involved in this wasteful and distructive practise. I also stated that the situation for sharks may be better in US waters.
Most of the comments of relevance have already been provided, so my submission
here is unlikely to generate any particular notice. Still, I am surprised that passionate scientifically-minded readers are so partial to this commentary by WE; from what I read, WE has mainly written a personal opinion stating his argumentum ad incredulus regarding the study findings. Several times he states that he “doesn’t believe” the results can be true, and his esteemed opinion seems to hold sway amongst some readers here.
I read three relevant dissenting comments; those of Julian Flood, EW, and BillD. These comments are in line with my own thinking on this subject and the published research paper. Herewith is a short summary of my main thought-points.
1. The technique provides a way to look back into the past of oceanic conditions,
albeit with several caveats, which are noted. Because open ocean seawater optical
conditions are primarily determined by phytoplankton populations, this technique
seems viable under the proper conditions. However, it should be clearly noted that some of the most productive regions, particularly coastal upwelling zones, might not be the proper conditions. In the areas of the ocean with very low phytoplankton populations, there could be a significant reduction of phytoplankton mass without a noticeable effect on higher trophic levels, because the higher predators don’t generally congregate where there is very little to eat. Indeed, the mentioned Grand Banks cod collapse was partly enabled by the predictable cycle of the Grand Banks seasonal productivity, which the cod followed. It follows that if the major upwelling zones have remained just about as productive as they were a century ago, they may provide the vast majority of the plankton utilized by predators, while there could still be an overall decline in the global phytoplankton population as described.
2. It has been noted, in one respect by Myers and Worm with regard to oceanic
megafauna, that our collective memories are short. We of this generation and probably a couple generations back may not remember well the abundance of the nature world before there was significant human impact. This article comments at some length on this:
Ocean Life Of Ages Past Boggle Modern Imagination With Incredible Sizes, Abundance And Distribution
The lead example, that there were 27-32,000 southern right whales around New Zealand (that number is only for southern right whales around New Zealand — not ALL whales in the global ocean) is remarkable. Is there any way to estimate the amount of phytoplankton biomass required to sustain the pre-whaling whale populations of the globe? I doubt it, but this one quoted number indicates that whale populations were orders of magnitude larger than present. Those numbers require a lot of phytoplankton, to feed the baleen whales directly and to feed the toothed whales indirectly. The decimated whale numbers obviously required much, much less; hence, the impact of massive reduction of the base of the food chain is far less
noticeable if higher trophic levels have already been markedly reduced. And this applies not just to whales, but to all manner of top-level open ocean predators, like bluefin tuna, swordfish, sharks, etc.
* Just a note; the well-known high productivity of the Mesozoic enabled the nutritional requirements of the dinosaurs; somewhere out in Webland there is an estimate of the Earth’s extant dinosaur population at any given time based on some assumptions of fossil preservation. Any way that it is sliced, the number is astonishingly large; but fauna grew well back then. So the plant-eaters ate a LOT of plants, and the meat-eaters ate a LOT of plant-eaters.
3. One of the main misstatements here is that phytoplankton growth is not generally limited by temperature. That’s correct, but largely irrelevant. As WE correctly notes, what determines phytoplankton growth is nutrient availability. What he doesn’t correctly follow with is that nutrient availability is a function of ocean circulation, and that is a function of oceanic weather and oceanic climate. The way that stratification works is that a warm stable surface layer forms, where nutrients have been replenished and where sunlight is abundant. (OK, fine, this has been called into question by Behrenfeld, but only at the beginning; the primary growth phase of phytoplankton blooms is still when the surface has stratified.) During that phase, the phytoplankton utilize the nutrients in the warm surface layer, and then the bloom fizzles out, and the waters await winter replenishment. If the waters stay warm, winter mixing is suppressed, and there will be less surface nutrients for subsequent blooms. Furthermore, warm surface waters, particularly as noted for El Nino, deepen the thermocline and make both mixing and upwelling less effective, requiring more energy to bring the nutrients up from below. Surprisingly, there are some areas where there has been a documented increase in winds, causing more mixing and
higher productivity — in some cases, too much productivity, causing the rise of undesirable phytoplankton instead of the apparently nutritionally-preferable dominant diatoms. So, therefore, nutrient availability is determined by ocean winds and ocean currents; and that would be influenced by changes in climate.
My final point has been reinforced and remembered by necessary consultation on the environmental impact of nuclear power plants. While that’s not my primary field of expertise, sometimes you have to help out other guys, and you learn from them. The basics of the biological productivity systems of lakes and oceans are similar.
Thus, to make a concluding statement, I would not think it prudent to dismiss this study prima facie primarily on the basis of what we believe. This study now needs to be examined in the cold impartiality of other fact that can be collected.
Paul Birch says:
August 2, 2010 at 3:02 am
They have dealt in the paper with some of the issues you have raised. The Supplementary Online Information says:
So that puts some limits on the question. Next, if we assume that the reduction is uniform (across the board), mean and median move in tandem. If the reduction is only in the large values (inshore), or only in the small values (open ocean), the median won’t move much at all. Which makes me suspect an across the board decline …
However, as you point out, the median is not the proper measurement. Since we are interested in the total productivity of the ocean, the mean would be a much more valuable measure.
Oakden Wolf says:
August 2, 2010 at 8:39 pm
Oakden, rather than dissing my judgment, perhaps you could take the other side and explain to us why you believe the paper’s claim that a change in ocean temperatures of 0.4°C has caused a 50% decrease in the total production of the ocean. No, I don’t believe that, and if you do, you need to explain why that does not seem as “incredulus” to you as it does to me.
I find that to be an extraordinary claim, and as the old saw goes, “extraordinary claims require extraordinary evidence”. In my opinion, they have not come anywhere near providing that extraordinary evidence.
But I’m always willing to listen. I say their results are not believable, and far from relying on “argumentum ad incredulus” as you say, I have specified exactly why I don’t believe them.
You have said that their results are believable … but you haven’t provided any more evidence for the reality of their claims than the paper did. Where is your extraordinary evidence that we have lost half of the productivity of the ocean because of a 0.4°C rise in global ocean surface temperature?
w.
Dr Floor Anthoni says:
August 2, 2010 at 2:44 pm
Some background information is in place.
1) I don’t trust any of Boris Worm’s publications. He is too much an activist/politician than a scientist. Check it out for yourself.,,,
____________________________________________________________
Dr Anthoni, Thank you for your analysis of this paper.
One of the great things about WUWT is people who actually have detailed knowledge in the field comment. Many here can pick out that a paper does not pass the “smell test” but can not necessarily pin point exactly what is wrong, so thank you.
This paper really had a bad smell to it. So I hope you write a letter of rebuttal to the paper that published it.
The big mistake in this paper is to equate concentration with production rate – a serious mathematical illiteracy. At higher temperatures, both primary production and zooplankton grazing will be at a higher rate, but phytoplankton conentration not necessarily different.
Roy Spencer recently showed that 20th century temperatures could be modeled as a direct function of the ENSO related ocean oscillation cycles. This leads to an interesting causation palindrome – either increasing SSTs influence the ENSO and ocean cycles and cause increased stratification; or ENSO and ocean cycles cause increased SSTs – and more stratification (e.g. El Nino). Take your pick. In any case, with a second big La Nina in a half-decade, it looks like the cycle is changing.
phlogiston says:
August 2, 2010 at 11:47 pm
Thanks, phlogiston. It is true as you say that production rate can change with a stable concentration. My point is slightly different. This is that if you have half the concentration and the same reproduction/predation rate (ceteris paribus, as usual), you will only get half the total production.
Willis Eschenbach says:
August 2, 2010 at 10:44 pm
“Next, if we assume that the reduction is uniform (across the board), mean and median move in tandem. If the reduction is only in the large values (inshore), or only in the small values (open ocean), the median won’t move much at all.”
Oh dear, you’re still not getting it. There is absolutely no reason to assume that the reduction is uniform, because the experiment does not and cannot give reliable data for the coastal waters (where most of the plankton reside and most plankton activity takes place, and which are subject to quite different and differently varying conditions). Because the majority of samples are in ocean waters, the median is determined only by what happens in those ocean waters. Not by what happens elsewhere. Total productivity could have increased a thousand-fold, and this metric would not show it. We have no idea (from these observations) what is happening to the mean, and all the statistical cleverness in creation cannot tell us.
I dont know if anyone is still reading this, but I was given a reference to what is alleged to be the information that Willis is looking for.
http://www.nature.com/nature/journal/v466/n7306/extref/nature09268-s1.pdf
Is this the missing data and methodology?
Hi Willis,
Small knit to pick in an otherwise excellent article. When you say,”The authors of the study do not seem to realize that if the total amount of phytoplankton were cut by more than half as they claim, the total mass of almost all living creatures in the open ocean would be cut about in half as well. No way around it, every farmer knows the equation. Half the feed means half the weight of the animals.” I think in truth if the mass of phytoplankton were to cut in half, the effects on the creatures higher up the food chain would be far more devastating than a 50% reduction. This has to do in part with the density of phytoplankton in the water. For instance, if you put enough feed in a manger to keep a cow alive and maintaining a weight of 1,100 lbs., cutting that feed in half will probably kill the cow rather than just giving you a 550 lb. cow. Now if you take the feed needed to keep the cow at 1,100 lbs. and instead of putting it in a manger, scatter it uniformly over a 100 acre parking lot with no other food source available, once again the cow will not be able to maintain its 1,100 lb. weight because it will take too much effort to gather the food, and at that density much of the available food won’t be usable to the cow.
The bottom line here is: IT’S WORSE THAN WE THOUGHT!!!
Willis Eschenbach, Aug 3, 1:42 am
Point taken, your argument is made stronger by understatement (one could almost mistake you for an Englishman!). Indeed the kind of climate trauma that would result in marine primary production being cut in half would probably qualify as a small to medium sized mass extinction of the era boundary defining type. (The watermelon red-greens would of course claim that humans are achieving just that, but our efforts so far have fallen well short of replacement of the whole macrofauna which is the benchmark for a decent extinction event.)
In characteritic AGW self-contradiction (e.g. every region of the world is the fastest warming) the BBC a few days ago posted an article about eutrophication in the Baltic (sorry no link, I’m writing from a mobile phone). Here we are told that agricultural fertilizer run-off causes increased algal blooms at sea – also photogenically visible from satellite – and that this is one of the more serious anthropogenic impacts on the oceans.
So we are increasing and decreasing primary production, at the same time? Maybe that’s why the reality is probably little if any change.
only thing that this article shows is that,
1: if you start with some preconceived notion, you can create trends that are actually not there.
2: if you are willing to say what the journals/fundGranters want, you can get money and publish that nonsense.
Willis,
You missed a lot of marks with your reply. It is not up to me to prove anything; I was commenting that your remarks on the paper seemed to merely indicate your disbelief in the results, without having any particular factual basis for your disbelief other than anecdote. You have raised question with the results; if you are going to show that your (dis)beliefs have merit, you would support them with an actual research analysis, as would any scientist.
On the other hand, I supposed that the significant reduction in higher trophic level populations, particularly top predators (whales, sharks, 75% or more of fisheries at full capacity or overexploited) would mean that a reduced phytoplankton biomass does not have to support the former abundance of the oceans. I provided a Web reference linked in my previous reply; this was a report preceding a conference of the History of Marine Animal Populations Oceans Past II conference:
History of Marine Animal Populations
Census of Marine Life
Oceans Past I and II
The HMAP compilations indicate a substantial reduction in marine populations. This is consistent with my comments. They have plenty of data that could be used in
research.
Finally, you are asking for support for changes in phytoplankton abundance due to a 0.4 C rise in ocean temperatures. As I noted to Steven Goddard, that is not all there is to it, by a long way. An example: in the Arabian Sea, warming continental temperatures have led to increased monsoon wind speeds, causing an increase in productivity and a species shift, disfavorable to diatoms. The ocean temperature change range of the monsoons has probably not altered much. But the dynamics of the monsoon have.
The Boyce paper itself says: “Long-term trends in phytoplankton could be linked to changes in vertical stratification and upwelling, aerosol deposition, ice, wind and cloud formation, coastal runoff, ocean circulation, or trophic effects.” So if the state of the global ocean system is to be assessed, it will not be assessed simply on the basis of one or two globally-averaged metrics. The oceans aren’t that simple.
I’ve posted a couple of articles in the past on this:
Trophy fish now would have been bait-size decades ago
The ones that got away just aren’t there anymore
(Willis, you are a perceptive individual; your posts are worth reading. This one immediately struck me as offhand and shallow. What’s the point of reading for accurate information if at the times we find it lacking, we don’t note that? Your usual standard is much higher than this.)
Danke – auf Wiedersehen — und gute Nacht.
Prior to the Assuan Dam, the flooding of the Nile each fall brought nutrients to the sea and supported a productive fishing industry. In 1970 the Nile water supply to the sea was cut off by the Dam, no nutrients were delivered and the fishing industry collapsed. However, since the 1980s fertilizer and sewage nutrients have more than replaced the historical levels. The fishing industry has recovered.
Obviously, nutrients were the limiting factor off the Nile delta. Not the seawater temperature.
tallbloke Aug. 1 2010 3.27am
in reply to my post Ziiez Zeburz Aug. 1 3.16 am
Sorry for the delay in answering and I don’t even know if you will see this answer to you questions,
I ‘borrowed ‘ the Barton recorders from my works store as all are on holiday right now and they are excess to our requirements for a few weeks, I did this because of the continual references to decimal point temperatures, having some experience in heat and pressure recording I am always a bit skeptic when reading ” world sea temp. increasing by 0.04c or global temp increasing by 0.2c By placing the recorders in the field ( grass, that had been cut and bailed 2 days before I started) and the 2 recorders at different height’s from the ground I wanted to see the variances in the 3 temp.
As explained in the above post it was 0.097c now 2 days later and having had in that time 6.3 hours of rain and plus 9 hours of above average humidity the differance in the 3 temp. recorders is 0.0948 which to me proves my belief that anyone quoting global or even area temp. of decimal points is not understanding his subject, as a fixed position record shows decimal points in variation.
Ziiex
Correction to the above post
and the 2 recorders different heights from the ground / should read 3 recorders.
“The first clue to where they went wrong is visible in Fig. 1. Although as you can see there is more phytoplankton in the cooler regions of the north, the same is not true in the corresponding regions in the south despite the ocean temperatures being very similar.”
Well, of course, temperature is not the only thing a phytoplankton needs to survive. It also needs sunlight. You seem to be saying that because sunlight ALSO effects it, temperature is not killing it off. That really seems to be your line of argument. (If the image of the concentration of phytoplankton represents an instant or small section of time, then it is clearly taken during the norther summer, when there would be hardly any light in the extreme south for them.)
Hey, I spoke to early when I had just seen the first figure and your first point, and jumped at how weak it appeared. My point still holds, that because you show that phytoplankton are very dependent on nutrients, doesn’t prove the point that temperature does not significantly effect their numbers. The data shows that temperature has coincided with a decline. Perhaps temperature effects nutrients.
You need to show that there is something else that caused the decline or that there has been no decline. Use the same site that they used for data, prove them wrong. But you have to have a specific idea of what’s going on. We need to figure out the 26,000 individual things that are causing the 26,000 lines of “evidence” to occur that all these fools keep attributing to CO2 emissions.
Suzuki has a silly article about this. He says that, “[Phytoplankton] also remove carbon dioxide from the air and produce more than half the oxygen we breathe.”
http://cnews.canoe.ca/CNEWS/Environment/Suzuki/2010/08/04/14920156.html
If the phytoplankton really produce more than half of the oxygen we breathe, and the phytoplankton are down by about 40 percent since 1950, then our oxygen levels would be down by at least 20 percent. That would definately have gotten noticed.
John M Reynolds