"Phytoplankton rapidly disappearing from the Indian Ocean" or not.


Guest post by David Middleton, feature image borrowed from iHerb.


A rapid loss of phytoplankton threatens to turn the western Indian Ocean into an “ecological desert,” a new study warns. The research reveals that phytoplankton populations in the region fell an alarming 30 percent over the last 16 years.



The source of this latest “oh no!” is this paper:



Among the tropical oceans, the western Indian Ocean hosts one of the largest concentrations of marine phytoplankton blooms in summer. Interestingly, this is also the region with the largest warming trend in sea surface temperatures in the tropics during the past century—although the contribution of such a large warming to productivity changes has remained ambiguous. Earlier studies had described the western Indian Ocean as a region with the largest increase in phytoplankton during the recent decades. On the contrary, the current study points out an alarming decrease of up to 20% in phytoplankton in this region over the past six decades. We find that these trends in chlorophyll are driven by enhanced ocean stratification due to rapid warming in the Indian Ocean, which suppresses nutrient mixing from subsurface layers. Future climate projections suggest that the Indian Ocean will continue to warm, driving this productive region into an ecological desert.

It’s pay-walled, of course… However the SI and a blog post by the lead author are free.

After reviewing the SI and the blog post, I have to ask, “Is Chris Mooney doing peer review for the AGU?”

The authors present no evidence of phytoplankton decline or any actual measurements of phytoplankton…

Text S1.

Observed Data. Though marine primary production can be assessed directly using field flux measurements, chlorophyll pigment concentration measured through satellites is used as a convenient indicator of phytoplankton biomass and extent, as it represents the magnitude and variance in marine primary production and captures the first order changes in phytoplankton biomass [Ryther and Yentsch, 1957]. These satellite observations, which are mostly based on the visible bands of the radiance spectra (412-555 nm), lack consistent and accurate measurements of surface chlorophyll whenever cloudy conditions persist, which of course, is an integral part of the Asian summer monsoon season. Though seasonal and monthly mean composites can be derived from satellite data to some extent, it is challenging to derive robust signals of long-term trends of chlorophyll over the Indian Ocean because the current availability of satellite data is limited to a fairly short period since the satellite era [Boyce et al., 2010; Rykaczewski and Dunne, 2011]. Studies suggest that the number of years required to detect a trend above the natural variability in most of the global oceans is 50-60 years, though a shorter period of 20-30 years could be used to extract the trends in the tropical oceans including the western Indian Ocean [Beaulieu et al., 2013; Henson et al., 2010]. The recently available satellite data blended from the multiple sensors of satellites bring the number of years of continuous data up to 16 years, bringing it close to the required trend detection time.

The chlorophyll data is obtained from version 2 of the European Space Agency’s Ocean Color-Climate Change Initiative (OC-CCI) [Sathyendranath et al., 2016]. The OC-CCI uses processors for atmospheric correction and retrieval of in-water properties on the basis of round-robin comparison of candidate algorithms [Brewin et al., 2015; Müller et al., 2015]. The OC-CCI chlorophyll product is generated from merged normalized remote-sensing reflectances from SeaWiFS, MODIS-Aqua, and MERIS satellites at 4 km-by-4 km horizontal resolution, band shifted to SeaWiFS wavebands. The POLYMER algorithm used by OC-CCI for processing MERIS data [Steinmetz et al., 2011] is able to retrieve usable data under sun-glint conditions, which improves the coverage in the Arabian Sea, especially during the summer monsoons. The OC-CCI data is available for the period 1998-2013. However, the last couple of years (2012 and 2013) suffer from data gaps (less than 50% coverage) in the Arabian Sea, which could introduce spurious trends. These two years are presented in the analysis for an overview, but are not utilized for estimating the trends and correlation coefficients in the current analysis.



They have a model relating certain satellite imagery to oceanic chlorophyll content and relating chlorophyll to phytoplankton primary production. Their historical climate data are generally based on models simulations. Without any actual data, they clam that they found “an alarming decrease of up to 20% in phytoplankton in this region over the past six decades.”

Previous work actually measuring phytoplankton primary productivity in the region indicate that it is increasing.

The lead author posted this on an AGU blog…

21 JANUARY 2016

Rapid warming over the Indian Ocean reduces marine productivity

Posted by nbompey

By Roxy Mathew Koll

Roxy Mathew Koll is a climate scientist at the Indian Institute of Tropical Meteorology in Pune, India, and lead author of the new study, “A reduction in marine primary productivity driven by rapid warming over the tropical Indian Ocean” that was recently published online in Geophysical Research Letters.

Increasing water temperatures in the Indian Ocean are taking a toll on the marine ecosystem, according to our new study.

Almost 90 percent of the extra heat generated by increased greenhouse gases in the atmosphere has been absorbed by the oceans. Among tropical oceans, ocean warming is most prominent in the Indian Ocean. Now, a new study by me and my colleagues suggests rapid warming in the Indian Ocean reduced marine phytoplankton up to 20 percent during the past six decades.

Such a decline in the marine phytoplankton may cascade through the food chain, potentially turning this biologically productive region into an ecological desert. It may also impact food security in the Indian Ocean rim countries and also the global fisheries market.



The blog post featured three maps.

The first one indicates that marine phytoplankton are booming in the Indian Ocean:

Marine phytoplankton in the tropical oceans 1998 to 2007. Red indicates large concentrations. From Behrenfeld et al., 2006.

Credit: American Geophysical Union

The second is of sea surface temperature trends from 1950-2012:

Surface warming in the tropical oceans 1950 to 2012. Red indicates strong warming.

Credit: American Geophysical Union

These two maps demonstrate no decline in Indian Ocean phytoplankton productivity nor any correlation between warming and productivity.

The third map and the basis of their absurd claim is of chorophyll trends…

Trend in marine phytoplankton in the Indian Ocean 1950 to 2012. Purple indicates a significant decline.

Credit: American Geophysical Union

Anyone with eyeballs can see that the areas of chlorophyll decline correlate to the areas that haven’t warmed…




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February 2, 2016 8:33 am

Maybe they meant “rapidly appearing” in the headline instead of “disappearing”. Autocorrect is a mean Mother.

The Original Mike M
Reply to  rbabcock
February 2, 2016 9:25 am

Tom Halla
February 2, 2016 8:37 am

Lets see. Dodgy, purely inferential measurements combined with failure to entertain alternative hypotheses. Stereotypical AGW study.

bit chilly
Reply to  Tom Halla
February 2, 2016 1:20 pm

if i had signed off funding for that study i would be asking for my funding to be returned. as for the agu post . that really is beyond the bounds of reality. if that constitutes science ,well no wonder we are where we are.

February 2, 2016 8:44 am

whenever someone says it’s paywalled, i can usually get in. Mostly because i have my Miami University Login and my Cincinnati Children’s logins to draw on for access to journals. If you want, I can download and send to anyone. 😛

Reply to  Eric Slattery (@Technos_Eric)
February 2, 2016 11:42 am

There is a free copy of the paper here.

February 2, 2016 8:51 am

Will the real phytoplankton please stand up and be counted? Failure to do so will get you simulated and modeled instead.

February 2, 2016 9:01 am

If it is a mere observation of the dynamic nature of the planet then it’s legitimate scientific inquiry but if the objective is to get us to cut fossil fuel emissions then a correlation between fossil fuel emissions and climate change must be shown. The IPCC correlation between cumulative emissions and surface temperature may not be used for this purpose because that correlation has been shown to be spurious.

michael hart
February 2, 2016 9:03 am

“It’s pay-walled, of course…”

And probably the best place for it, too. As WUWT rightly noted a few days ago, you can tell a lot by the choice of language in a paper.
Thus, in the abstract, we are given

It’s…an alarming decrease of up to 20% in phytoplankton in this region over the past six decades”

and then

It’s…driving this productive region into an ecological desert.”

I certainly wouldn’t pay to read that paper, and would pay double to avoid being forced to read it.

Reply to  michael hart
February 2, 2016 9:33 am

…an alarming decrease of up to 20%…

Yes the language is telling. “Up to 20%” pretty much means 0% to 20%. It is similar to auto dealers sending out flyers offering “up to” $5,000 off your next car purchase. Good for getting people in the door to try to make a sale, but it is a offer without substance or promise.
Well at least climate change scientists have a backup career in selling cars. Though in my opinion they should quit science and go straight to selling cars.

Tom Judd
Reply to  Alx
February 2, 2016 10:06 am

Um, you need to be specific: ‘used’ cars.
Best wishes.

Reply to  michael hart
February 3, 2016 8:20 am

“As WUWT rightly noted a few days ago, you can tell a lot by the choice of language in a paper.”
“Now, a new study “BY ME” “and my colleagues” suggests rapid warming in the Indian Ocean reduced marine phytoplankton up to 20 percent during the past six decades.”
Roxie, the self centered “ME, ME, ME” scientist. I would always choose ‘by my colleagues and I’, in proper form.

February 2, 2016 9:13 am

Once again we see that an increase in warmth only ever reduces the abundance of life here on earth.
Since all living things hate being warm and prefer to co-exist with mile thick glaciers.
It is a remarkable fact, understood only by the topmost climate boffins, that life only prospers when things are nicely cold. And this must also explain why we refrigerate greenhouses and store perishable food-stuffs in specially heated larders, where bacteria and moulds simply lose interest and die due to the excessive warmth.
Wait a minute!! No we don’t. This surely can’t be correct… 🙂

Jason Calley
Reply to  indefatigablefrog
February 2, 2016 9:36 am

Religious traditions tell us that the first humans lived simply and happily in the Glacier of Eden.

Reply to  Jason Calley
February 2, 2016 1:19 pm

There are serious suggestions that the Garden of Eden refers to an area now situated under the waters of the Persian Gulf. Hence, lost to climate change.
Then, later Noah came on the scene.
The first climate change and sea level rise alarmist.
I am informed that other traditions contain equally delusional references.
However I did not expect that my own generation would jump at the opportunity to create a brand new mythology about the weather.

February 2, 2016 9:16 am

several years ago i was over gulf of Mexico and in the sea was a bright reddish pink/bloom, estimate to be 20 miles long by 5 wide. I always wondered if that was some natural biological event or some pollution ?

Reply to  zemlik
February 2, 2016 10:26 am

Most likely a ‘red tide’ dinoflaggelate bloom. Common in summer, especially near the coasts. Toxic.

Reply to  ristvan
February 2, 2016 12:58 pm

Yes, quite right
As cleaning holds – for bulk carriers carrying iron ore – is now no longer an operation which ends in the dust being hosed down and pumped overboard.
If zemlik had seen that thirty years ago, hold cleaning would have been a one in four chance, I reckon, globally.
Less in some areas and some seasons, when blooms were known, but more chance in others.
Oh – a thought:
First map, red areas, correlate tolerably, by eye, for pirate-infested areas over the last decade or so.
NB Correlation, even by eye, is NOT causation.

February 2, 2016 9:22 am

Once again we see someone that must have received their science degree from K-Mart.
Just look at the abstract. It’s not until the third sentence that you actually see what this “research” is about. And of course that sentence contains “alarming” (not scientific) and “up to” (without giving the actual range and residuals). They don’t say what they actually did to determine this and why it is in disagreement with previous research, something all abstracts should do. Then they end on citing other’s research (climate projection from GCMs) and state that the region will become an ecological desert as if it were fact.
Grading them based on the expectations of a college freshmen, I give them a D.
Asking if Chris Mooney is peer-reviewing this garbage is not even hyperbole. Seriously, is he?

The Original Mike M
February 2, 2016 9:24 am

Two words for this “research” – Epic Failure

Robert Ballard
February 2, 2016 9:47 am

So the erstwhile authors say 60 years is necessary to extract a trend from the natural noise, 20-30 years might due in a pinch, and then go on to say they used 16 years. This is a perfect example of intellectual nihilism -whether the data indicates the hypothesis is right or wrong makes no difference.
Scientific method? -We don’t need no steenkin’ scientific method!
On another front: Why are satellites measuring the specific wave length of radiation good for measuring bio-mass but not temperature?

Reply to  Robert Ballard
February 2, 2016 10:25 am

Simple. Satellites give the right biology answer but the wrong temperature answer.
Warmunists start with the conclusion and work backwards to the data. See Climate Audits post on D’Arrigo for a stunning recent example.

Kaiser Derden
February 2, 2016 9:49 am

without correlation there can be NO causation … they have no correlation so they have NO causation … I assume you have to have a PHD to be this stupid …

February 2, 2016 10:19 am

Lets see. According to them, at least 20-30 years are needed to extract a trend. They say they have 16 sat years, with the last two incomplete. But not realy, since satellites cannot see anything through monsoon clouds. They use that stuff to infer a 20% decline over the past 60 years. Which means they at most found a (16/60 * 20) 5% decline, maybe, using incomplete too short data, and without a sensitivity analysis coupling their spectrum estimates for chlorophyll to ground truth phytoplankton. Maybe their system is good +/- 10%. They assert this maybe result is caused by increasing water stratification, which they do not know because they never got on a ship to go out and measure the euphotic zone, or the mixed layer (roughly 3x the euphotic zone) overturning.
Their result contradicts decades of actual phytoplankton water sampling for primary productivity. So we should believe the new inadequate sat sensing paper rather than decades of actual water sample data? And the new coccolith finding for the Atlantic? Only in the make believe warmunist world. Not in the real world. How did this pathetically inadequate joke ever get published?

Reply to  ristvan
February 2, 2016 1:53 pm

Was it Groucho Marx who said “Who are you going to believe, me or your lying eyes?”

Thomas Homer
February 2, 2016 10:23 am

“A rapid loss of phytoplankton threatens to turn the western Indian Ocean into an ‘ecological desert,’”
I haven’t seen the term “ecological desert” before, but I assume it means an area that does not support life. Since it is the chemical transaction of extracting carbon from atmospheric CO2 that is the essence of all life as we know it (aka carbon based life forms), then since sea ice inhibits the ocean’s ability to support this carbon transaction can we conclude that:
sea ice actually does turn vast amounts of ocean into an ‘ecological desert’?

Reply to  Thomas Homer
February 2, 2016 10:30 am

Watch Deadliest Catch to see the Arctic ecological desert in action.

Steve R
Reply to  ristvan
February 2, 2016 6:42 pm

Perhaps counter-intuitive, but as a general rule of thumb, the most biologically active parts of the ocean are those where cold water occurs in the photic zone.

DD More
Reply to  Thomas Homer
February 3, 2016 8:57 am

They say “We find that these trends in chlorophyll are driven by enhanced ocean stratification due to rapid warming in the Indian Ocean, which suppresses nutrient mixing from subsurface layers.”
But the Western Indian Ocean is one of the up points in the Deep Ocean Current.
Strange that other upwelling areas are also bloom areas. Are they now saying the deep current is changing?

Tom Judd
February 2, 2016 10:33 am

Years ago I was watching one of the ongoing Jacque Cousteau specials on TV. The divers were swimming around a bleached, dead, desolate coral reef surrounding an island in the tropical Pacific. Except for the stone cold dead white coral shapes there was the occasional scavenger fish picking among the scraps. (Sounds a little like what the UN has in store for the middle class, eh?)
As a hobby I had kept salt water fish and some invertebrates, but I’m sure no expert on this. But, one thing I do know is that these creatures are very sensitive to ammonia from normal waste products in the water. Aerobic bacteria inevitably break down the ammonia to nitrites and then nitrates. Generally, fish can tolerate the nitrate but corals absolutely cannot.
Well, guess what the major industry on that island happened to be: mining for fertilizer? Yep. Right there on the Cousteau special you could see cargo ships sitting in the island’s harbor and being filled by open air conveyor belts dropping tons of fertilizer in their holds. And, of course, clouds of this powdered fertilizer were blowing right off those belts in the process. If I saw this on the Cousteau special they saw it too. Hell, they filmed it.
I’m no genius, but I think it’s pretty obvious what killed off those reefs. But, what did these lifetime divers and oceanographers credit the death of this reef to? Do I really have to say this …
… Global Warming!
Now, when I look at those maps above the relatively small regions demonstrating any kind of plankton die off happen to butt smack dab up to land mass coastlines. River run off? Harbors? City sewage outflow tubes? Mischievous teenagers urinating in water storage tanks?

February 2, 2016 10:41 am

I guess they did not get the memo that phytoplankton decline memes do not work and do not hold up against fact checking.

Gary Pearse
February 2, 2016 10:44 am

“correction and retrieval of in-water properties on the basis of round-robin comparison of candidate algorithms..”
Err…no, I’m sure they must have ground-truthed the satellite responses to actual sampling of the ocean. How naughty of me to think otherwise?/sarc. There is something universal about catastrophist science. They seem averse to going out and collecting real data, so much so that I think we have a new phobia that hasn’t yet come to the notice of psychologists.
Remember Mike Mann’s response to McIntyre’s query about why they didn’t go out and collect updated measurements from tree rings to extend the 1998 M.Mann paper. Mike said it was too expensive and time consuming (I’m sure that the divergence and ‘decline’ in tree-ring temperature responses from 1967 to 1998, that was so important to ‘hide’, was the deterrent – they feared the divergence is continuing). Regarding the expense, McIntyre responded with a challenge to himself of going out to sample one of the catalogued tree sites in Colorado after breakfast and being back in time for coffee at Starbucks in the afternoon(?). He did it handily.
I’ve thought since that there should be a ‘Strike Force’ that goes out and crowd sources data ( a la surfacestations.org project). Anyone for a cruise in the Indian Ocean dragging a plankton net? These things are doable with enough crowd support and we could erase 90% of the burden of useless papers that will one day have to go anyway. The Strike Force would also put an end to the “Play Station” science that we are plagued with (I wish I could remember who coined this term on on of the recent threads here at WUWT. It’s a keeper!).

bit chilly
Reply to  Gary Pearse
February 2, 2016 1:27 pm

i love that idea gary. count me in for the east coast of scotland if it ever kicks off. i already do my own small biomass sampling on the inter tidal zone just to keep a handle on what is going on from year to year in relation to my hobby.

Reply to  Gary Pearse
February 2, 2016 6:10 pm

Gary, you and McIntyre totally misunderstood Mann’s issue with the expense and time for extending his 1998 paper. The time and expense lies it cutting down enough trees to find the new “ONE TREE” that extends the hockey stick.

February 2, 2016 11:04 am

Reminds me of the infamous “sixth extinction event” study that the World Wildlife Fund loves to push around. 200 species dying a day! How do we know that? Well, we didn’t actually look for dying species, we didn’t count corpses, didn’t take a headcount or anything…. we calculated “loss of habitat” and then made a totally irrational declaration based solely on that.
But it was published and peer-reviewed! It must be correct!
Hell, the Armegeddon Addicts bought it, didn’t they? Consensus!

February 2, 2016 11:53 am

“Anyone with eyeballs can see that the areas of chlorophyll decline correlate to the areas that haven’t warmed…”
You are matching chlorophyll 1998-2007 with the temperature trend from 1950-2012. Here is their map of similar periods:

Reply to  David Middleton
February 2, 2016 2:46 pm

“I’m matching the maps provided by the author in his blog post, both of which cover the 63-yr period (1950 to 2012) over which they assert a 20% decline in phytoplankton productivity.”
I see – I had read the paper, but not the blog post. You’re right – the blog post fig does show a matching 1950-2012 period for phytoplankton, though it is historical simulation only. The comparison I showed is from observation and is what is displayed in the paper.

bit chilly
Reply to  Nick Stokes
February 2, 2016 1:39 pm

ye, because a tiny increase in temperature much less than typical seasonal variation will have that affect nick. who knows, maybe there are areas this study did not examine ? the alarmism in the following quote may appeal to some of a particular persuasion. the reality is not quite so bad, but it is indeed a growing problem.
Never mind peak oil, or even peak water: Some experts are pondering the possibility of the UAE’s development being limited by “peak salt” – the notional point at which the Arabian Gulf becomes so salty that relying on it for fresh water stops being economically feasible. There is cause for concern, says Dr Shawki Barghouti, director-general of the International Centre for Biosaline Agriculture (ICBA) in Dubai. “Kuwait, Qatar, Bahrain, Saudi Arabia and the UAE all have their desalination plants along the Gulf’s shores,” he said. “The brine that these desalination plants produce is being dumped back into the ocean.” In addition, damming of rivers has cut the flow of fresh water into the Gulf – and the water that does flow in is increasingly polluted.
there are others. ” A subsurface layer (5–10 m) of high oil concentration (∼- 26 ppb) was detected at stations near to offshore oil-fields and extended to cover a larger area.”
an old paper, but relevant to the timescale mentioned, particularly the layer affected.

charles nelson
February 2, 2016 11:54 am

I’ll bet when they were kids their Mom’s stuck their artwork on the fridge and told them it was great.

Reply to  charles nelson
February 2, 2016 1:08 pm

There ya go, 97.1 ; )

Gunga Din
February 2, 2016 3:33 pm

As Paul Harvey used to say, “And now you know the rest of the story.”

February 2, 2016 4:43 pm

This whole discussion is somewhat confused. It is true that the northwestern part of the Indian Ocean is the biologically richest part in terms of primary production (and also the coolest at only 24 degrees centigrade off Dhofar). However this has little or nothing to do with temperatures per se, but is due to these cooler waters being more nutrient-rich, which in turn is because they are upwelling areas where cool, nutrient- and CO2-rich but oxygen-poor water from the deeps comes to the surface.
This upwelling happens largely during the monsoon season and is very dependent on the strength of the summer monsoon, and therefore varies considerably between years, but on the whole warmer climate means stronger monsoons and more upwelling, So actually higher SST in this particular area is, if anything, a sign of a colder climate.
The whole mechanism is well explained in this paper:
Incidentally the coast of Oman is the only part of the tropical Indian Ocean where there are no coral reefs – the water is far too cold, since hermatypic (reef-building) corals typically require water at 28 degrees or warmer to grow.
If upwelling should cease in this area the biological diversity would therefore actually go way up (is the Great Barrier reef a “ecological desert”, one wonders), while primary productivity (and fish catches) would decrease dramatically.
By the way, since the upwelling happens during the monsoon season when cloudiness is high (it actually rains quite a bit in the coastal mountains of Dhofar in summer– the only place in Arabia where this happens) I would not trust satellite measurements in this area during the summer.

Lee Sanders
February 2, 2016 9:33 pm

1. The comparison done here is between observed SST trends and simulated chlorophyll trends. You should compare the simulated chlorophyll trends with their simulated SST trends. Again, it is not necessary that the largest chlorophyll trends appear at the same place where SST trends are. You will see the largest chlorophyll trends where the mean chlorophyll is large.
2. The ship observed phytoplankton records are few to give any insight on long-term trends over a large region. The authors, nevertheless do compare their satellite data with the chlorophyll measured by Argo buoy over the Indian Ocean, during the monsoon. See their SI.
3. Future is debatable.

February 3, 2016 8:19 am

But the warmer the surface, the stronger the typhoons, and the greater the mixing, except in the Bay of Bengal: (6pp) http://onlinelibrary.wiley.com/doi/10.1002/asl.162/pdf –AGF

Reply to  agfosterjr
February 3, 2016 1:51 pm

It is rarely that the tropical western Indian Ocean have cyclones during the northern summer.

Reply to  agfosterjr
February 3, 2016 2:43 pm

Typhoons/cyclones are rare or non-existent in the Arabian Sea – western Indian Ocean region during the monsoon.

February 6, 2016 7:11 am

“Almost 90 percent of the extra heat generated by increased greenhouse gases in the atmosphere has been absorbed by the oceans. ”
Where is the proof of that?

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