Lakes worldwide are experiencing more severe algal blooms

Climate change is likely hampering recovery efforts

Carnegie Institution for Science

Ho, Michalak, and Pahlevan's study of algal blooms in lakes over a 30-year period found that Florida's Lake Okeechobee deteriorated. Toxic algal blooms resulted in states of emergency being declared in Florida in 2016 and 2018. Credit NASA Earth Observatory image made by Joshua Stevens, using Landsat data from the U.S. Geological Survey.

Ho, Michalak, and Pahlevan’s study of algal blooms in lakes over a 30-year period found that Florida’s Lake Okeechobee deteriorated. Toxic algal blooms resulted in states of emergency being declared in Florida in 2016 and 2018. Credit NASA Earth Observatory image made by Joshua Stevens, using Landsat data from the U.S. Geological Survey.

Washington, DC– The intensity of summer algal blooms has increased over the past three decades, according to a first-ever global survey of dozens of large, freshwater lakes, which was conducted by Carnegie’s Jeff Ho and Anna Michalak and NASA’s Nima Pahlevan and published by Nature.

Reports of harmful algal blooms–like the ones that shut down Toledo’s water supply in 2014 or led to states of emergency being declared in Florida in 2016 and 2018–are growing. These aquatic phenomena are harmful either because of the intensity of their growth, or because they include populations of toxin-producing phytoplankton. But before this research effort, it was unclear whether the problem was truly getting worse on a global scale. Likewise, the degree to which human activity –including agriculture, urban development, and climate change–was contributing to this problem was uncertain.

“Toxic algal blooms affect drinking water supplies, agriculture, fishing, recreation, and tourism,” explained lead author Ho. “Studies indicate that just in the United States, freshwater blooms result in the loss of $4 billion each year.”

Despite this, studies on freshwater algal blooms have either focused on individual lakes or specific regions, or the period examined was comparatively short. No long-term global studies of freshwater blooms had been undertaken until now.

Ho, Michalak, and Pahlevan used 30 years of data from NASA and the U.S. Geological Survey’s Landsat 5 near-Earth satellite, which monitored the planet’s surface between 1984 and 2013 at 30 meter resolution, to reveal long-term trends in summer algal blooms in 71 large lakes in 33 countries on six continents. To do so, they created a partnership with Google Earth Engine to process and analyze more than 72 billion data points.

“We found that the peak intensity of summertime algal blooms increased in more than two-thirds of lakes but decreased in a statistically significant way in only six of the lakes,” Michalak explained. “This means that algal blooms really are getting more widespread and more intense, and it’s not just that we are paying more attention to them now than we were decades ago.”

Although the trend towards more-intense blooms was clear, the reasons for this increase seemed to vary from lake to lake, with no consistent patterns among the lakes where blooms have gotten worse when considering factors such as fertilizer use, rainfall, or temperature. One clear finding, however, is that among the lakes that improved at any point over the 30-year period, only those that experienced the least warming were able to sustain improvements in bloom conditions. This suggests that climate change is likely already hampering lake recovery in some areas.

“This finding illustrates how important it is to identify the factors that make some lakes more susceptible to climate change,” Michalak said. “We need to develop water management strategies that better reflect the ways that local hydrological conditions are affected by a changing climate.”

###

This research was supported by the U.S. National Science Foundation, the Natural Sciences and Engineering Research Council of Canada, a Google Earth Engine Research Award, a NASA ROSES grant, and by a USGS Landsat Science Team Award.

The Carnegie Institution for Science is a private, nonprofit organization headquartered in Washington, D.C., with six research departments throughout the U.S. Since its founding in 1902, the Carnegie Institution has been a pioneering force in basic scientific research. Carnegie scientists are leaders in plant biology, developmental biology, astronomy, materials science, global ecology, and Earth and planetary science.

From EurekAlert!

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78 thoughts on “Lakes worldwide are experiencing more severe algal blooms

  1. If we just wait a few weeks, some real scientist will be able to reveal to us the true cause of this severe algal bloom and it will turn out to be something other than the ubiquitous “Climate Change”

    • “This finding illustrates how important it is to identify the factors that make some lakes more susceptible to climate change,” Michalak said. “We need to develop water management strategies that better reflect the ways that local hydrological conditions are affected by a changing climate.”

      So all other factors get put to one side in favour of a tentative link to “climate change”.

      Fertiliser run-off is pretty obvious main cause if any of the constituents are the limiting nutrient of algae’s ecosystem which they often are. The effect of 0.1 deg/ decade on growth is very unlikely to change anything in a measurable way.

      Instead of doing objective work they are just looking to promote yet another thing they can claim is “linked to climate change”.

      • Seems to me that MIchalak’s last statement contains the key objective of the study. That being to create a new career path for science degree graduates.

        To establish government employed and public sector union organized Water Management or Hydro Algal Mitigators. I see at least a three tiered managment system to administer the crucial work of Yellow Vested Algal Mitigators. Mitigators will be, like alligators without tails and scales

        • In Nebraska I can verify there has been a huge increase in land under cultivation to produce corn for ethanol… Much of it marginal farmland, previously either lightly grazed or in conservation status, that requires lots of irrigation and fertilizer. Many results including reduced biodiversity. And they are mining the great Ogallala aquifer much faster than it is being replenished.

      • When I go fishing I see algae blooms in most lakes that are river/stream fed. These lakes are fed by runoff from ag and urban areas. Most of this water is stained dark and can have silt. No algae blooms in landlocked spring fed lakes. The landlocked lakes are surrounded by high ridges protecting them from ag runoff, they just get runoff from the ridges. Most of the water in these lakes is gin clear (hmmm…I need olives).

        • “Geo Rubik October 16, 2019 at 10:39 am

          When I go fishing I see algae blooms in most lakes that are river/stream fed. These lakes are fed by runoff from ag and urban areas. Most of this water is stained dark and can have silt. No algae blooms in landlocked spring fed lakes.”

          Why do eutrophic lakes have low oxygen?

          In eutrophic (more productive) lakes, hypolimnetic DO declines during the summer because it is cut-off from all sources of oxygen, while organisms continue to respire and consume oxygen. … In oligotrophic lakes, low algal biomass allows deeper light penetration and less decomposition.

          https://www.google.com/search?q=no+oxigen+in+landlocked+lakes&oq=no+oxigen+in+landlocked+lakes&aqs=chrome.

      • Kinda my thoughts, too. More fish food, more fish – more fish, reduction of fish food – less fish food, fewer fish – fewer fish, more fish food. Rinse and repeat.

      • When I was in grade 7 (many dcades ago) I did an experiment for a science fair where I tried to increase CO2 levels in a beaker of algae/cyanobacteria. I got greater growth but my methods were possibly even worse than in the above study. Teachers in small town BC, for the most part, were and remain scientifically illiterate.

      • I thought algae was going to be the NEW biofuel of the future! How’s all THAT investment in clean, green, renewable, energy coming along? Which FIRST!? An algae energy future … or Nuclear Fusion future?

        In a related story … incidents of flesh-eating bacteria are on the rise … because of Global Warming, of course.

    • It is already well known: eutrophication, i e increased nutrient supply, either through sewage or agricultural runoff/erosion.

      Phytoplankton are almost always nutrient-limited, not temperature limited.

      • In South Africa, failure to maintain municipal sewage processing systems is leading to raw sewage running into rivers. This in turn leads to eutrophication of water supply dams. Not good!

  2. Here the discrimination between anthropogenic general causes and CO2 increase is essential.
    The environmental movement takes a “It must be stopped at any/all cost” approach simply because they are always dealing with spending OPM.

    The blooms are almost certainly anthropogenic in cause… that is, nutrient run-offs.
    But little if nothing to do with elevated CO2 as casual.
    And NOAA’s rural-located CRN stations show little if any warming in the US lower-48 over the last decade.

    The study notes “recovery” is slowed by warmer temps.
    But again are warmer water temps due to CO2-GW (not likely) or is heightened water temps due to power generation heated cooling water discharge increases?

    And then there are obvious cost:benefit problems with these studies.

    “Studies indicate that just in the United States, freshwater blooms result in the loss of $4 billion each year.”

    What is the benefit-cost of trying to stop them? What are the economic benefits of agricultural fertilizer use and the benefit-cost of alternative strategies to stop agricultural run-offs? Likely they far exceed $4Billion in the aggregate from higher produce costs to diminished agricultural production that far exceeds $4 Billion. If the costs to benefits directly stop these problems exceeds that cost, then alternative adaptation/mitigation strategies are warranted.

    This is algal bloom problem presentation is similar to Social Cost of Carbon illegitimate exercise employed by past EPA administrations where no fossil fuel and CO2-benefits were calculated in a trade-off study. Simply all “CO2” costs were one-sided presentations without the enormous benefits of fossil fuel usage or enhanced CO2 fertilization effects.

    And while there may be no “up-side” to an algal bloom in a lake, the costs for any proposed remedies to stopping it must be considered.

    • “And NOAA’s rural-located CRN stations show little if any warming in the US lower-48 over the last decade.”

      They ought to look at all the local CRN stations near the lakes studied in the United States. It’s a good bet those local CRN stations will show it has been cooling around those lakes since the 1930’s. In fact, the entire United States has been cooling since the 1930’s. We don’t have a CO2-induced climate change/global warming problem here.

      Unfortunately the Keepers of the Temperature Data are bastardizing the U.S. surface temperature chart even as we speak with the aim of turning it into a Hockey Stick.

      A stop must be put to this blatant bastardization of the historic and current temperature records. The Keepers of the Data are creating lies with which they hope to fool the people into doing something very foolish and destructive by trying to fix th non-existent problem of human-caused climate change . The bastardizers need to be called out. They need to be required to justifiy the changes they have made to the temperature record. Right now they sit there under the radar and manipulate the data to their hearts content. This should change. Transparency is what we need, and we need it now when Society-shattering decisions are being put forward which depend on the accuracy of this data.

      What a plague these bastardizers of data have become on human society! They have caused untold harm already with much more to come if we follow their dishonest lead.

      • But, the CRN stations near the lake do not measure the temp of the lake water, do they?

        Ho, Michalak, and Pahlevan used 30 years of data from NASA and the U.S. Geological Survey’s Landsat 5 near-Earth satellite, which monitored the planet’s surface between 1984 and 2013 at 30 meter resolution, to reveal long-term trends in summer algal blooms in 71 large lakes in 33 countries on six continents.

        One clear finding, however, is that among the lakes that improved at any point over the 30-year period, only those that experienced the least warming were able to sustain improvements in bloom conditions.

        This suggests that climate change is likely already hampering lake recovery in some areas.

        So, they musta calculated the “lake water temperature” via the satellite data, …….. right?

      • Only on a sunny day.
        Shallow lakes with a lot of turbidity also will warm up much faster and contribute to algal blooms.

  3. Wasn’t Florida due to human farming? The red bloom? They always have to add, climate change 😐

    Likewise, the degree to which human activity –including agriculture, urban development, and “climate change” – was contributing to this problem was uncertain.

    • Aus banned all phosphates in laundry detergents many yrs ago
      they are the biggest effect o n water issues or so we were told
      hell of a lot more towns water sent to lake rivers oceans than the poor farmers fields could manage in a blue fit.
      and you have to have heavy rains to flush those paddocks anyway!

  4. Take the lakes that experienced severe `bloom` and believe it may be caused by `climate change` , look backwards at images captured 30 years ago by satellites.

    # 1 check the population change in the area
    # 2 check the change in farming in the area
    # 3 check for changes in recreational use of the lake
    # 4 check the water temperature to an accuracy commensurate with the believed climate change over that period
    # 5 check the level / size of the lake for any change
    # 6 check for cloud cover and precipitation 2 weeks prior to bloom in each area
    # 7 find the lakes that were negatively affected in `bloom` and check the water temperature

    write a separate report indicating correlation and non correlation between climate change and rate of growth of blooms

    did I get the grant money ?

  5. Uh oh! What have we here?: “One clear finding, however, is that among the lakes that improved at any point over the 30-year period, only those that experienced the least warming were able to sustain improvements in bloom conditions.“. There was obviously no clear trend of the lakes that warmed getting more algal blooms, because if there had been they would obviously have said so.

    And just how many of the lakes were involved in their “clear finding”? Well, they say: “We found that the peak intensity of summertime algal blooms increased in more than two-thirds of lakes but decreased in a statistically significant way in only six of the lakes“. So the very small part of the sample that they sort of dismiss – – is the same very small sample on which they base their one and only “clear finding”.

    I wonder how accurate their analysis of fertiliser use was. Actually, I wonder how accurate the whole thing was, and how much confirmation bias is built into it. And I’d like to know a bit more about those [lakes] that experienced the least warming – how was the lake warming measured; did they measure the lake itself or use a nearby weather station? If the former, could the algae have caused the temperature increase? If the latter, could the station’s UHE (Urban Heat Effect) have the same source as the lake’s warming? It doesn’t look like the study should have had any “clear finding”.

  6. Allow me to advance a hypothesis.
    First, data points I have noticed which suggest the hypothesis:
    Point #1
    Field ecologists who go out into the field to study ecology tend to find answers to questions which do not involve “Global Warming” or “Climate Change”.
    Point #2
    Field ecologists who select a study methodology which allows them to stay comfortably indoors, in this case analyzing archived satellite imagery, tend to invoke GW or CC to explain their findings.
    Hypothesis:
    The probability of a researcher to use GW or CC to explain results is inversely proportional to the amount of time they spend out in the field making observations and taking measurements.

    A hypothesis has been advanced, let us begin testing.
    Theory guides, Experiment decides.

  7. The lakes which warm most need to have that warming explained, those least warming ditto. It might be that lake warming is caused by pollution that has a side effect of causing plankton blooms – something that lowers albedo while increasing nutrients. Or perhaps increased nutrient and the albedo decreasing factor are a consequence of location – near sewage outfall would be one such situation.

    Sewage out falls feed plankton and smooth water surfaces.

    The researchers might usefully look at Emeliania Huxleyi blooms in the ocean. Are they changing in number and, more importantly, start date and duration.

    JF

    • They didn’t actually measure the temperature of any of the lakes. They assumed that the lake temperatures must have followed the air temperature trend of the closest recording station. Regardless of how far away from the lake that station may have been.

  8. But, but, those algae are sequestring carbon using solar energy, gobbling up carbon dioxide. What’s not to like?

    • Ed Zuiderwijk October 16, 2019 at 1:08 am

      But, but, those algae are sequestring carbon using solar energy, gobbling up carbon dioxide. What’s not to like

      “Reports of harmful algal blooms–like the ones that shut down Toledo’s water supply in 2014 or led to states of emergency being declared in Florida in 2016 and 2018–are growing. These aquatic phenomena are harmful either because of the intensity of their growth, or because they include populations of toxin-producing phytoplankton.”

      That phenomena are not to like.

  9. “One clear finding, however, is that among the lakes that improved at any point over the 30-year period, only those that experienced the least warming were able to sustain improvements in bloom conditions. This suggests that climate change is likely already hampering lake recovery in some areas.”

    What a tortuous path they take to implicate global warming!

    And they utterly ignore all of the local factors that affect their topic.

    I note also that they lump everything into a grand total.
    They fail to mention algae blooms by month.
    They fail to note weather effects.
    They fail to note whether this is a sunnier period that recent years; or whether clears skies have allowed more sun to reach placid waters.

    They ignore local wildlife populations. Even though freshwater fish, waterfowl and general wildlife populations are near maximums.

    They ignore the local drainage changes as urban/suburban land ownership spreads further into the countryside.

    Basically, these children did some somes, drew a line between these last few years and sometime in the past; whether satellite instruments were not as capable. The then attributed that calculated algae growth to global warming.

    They allege some of the lakes warmed. They’re apparently basing their warming claim on satellite capture of surface temperatures alone. A few surface millimeters, not the lake’s temperature.

    Total fail.

  10. I live near a water supply reservoir that has had this problem every summer since it was built in 1969. It is a large pumped reservoir 6 miles round, no catchment, all water pumped. Never known them close it for use, just warn the fishermen and sailing fraternity.

    So no agricultural run off to explain things it is just the way it is. My experiment finished.

  11. Lets face it, the really big DEADLY algal blooms are occurring between the ears of the CAGWarmists in general and some recent EXTREME events in the vast vacant spaces inside the heads of Extinction Rebels.

  12. Did they measure the actual temperature of the lakes? Did they get warmer? Some missing reality checks, here.

  13. Yet another “the cat had kittens – it must have been caused by global warming” piece of doggerel.

  14. Hmmmm… 71 lakes out of 117 million. I’m sure it’s fine. It’s not like we have seen a problem like this with glacier studies.

  15. Climate has had zero effect on algal blooms in Florida lakes. It is all about pollution – primarily a combination of agricultural runoff, urban development runoff, and pollution from septic systems, which are the predominant means of wasterwater treatment for most of the residences in the watershed of Lake Okeechobee.

    Florida lawmakers have refused to do anything about this pollution – either by imposing more requirements on farms, specifically the large corporate farms especially Big Sugar – which has controlled Florida politicians for many decades now – or on individual homeowners who would face big bills to fund centralized wastewater collection and treatment systems. So between Big Farming and the votes of homeowners, nobody in the Legislature or the Governor’s office has the balls to do anything about anything, except call for more money to be spent on “studies”.

  16. Another master class in snatching a bad news story from the jaws of good news.

    CO2 enrichment of the atmosphere is responsible, although needless to say it is not mentioned.

    In post modern activist led science, what could CO2 possibly have to do with plant growth? Didn’t David Attenborough already tell us that plants don’t use CO2 for photosynthesis anymore? That it is as toxin only?

  17. Since climate change effects on a local level can be quite variable, it occurred to me to see how the temperature has actually changed around Okeechobie. In searching, I came across this site from the Center for Ocean-Atmospheric Studies at Florida State University:

    https://www.coaps.fsu.edu/

    This center appears to be trying to do real science–keeping climate hype at arm’s length.

    I can’t seem to find a direct URL for this, but if you google “lake okeechobee weather station ushcn”, you should find a link to a report titled “Global Climate Change in Florida?…” Slides 15-17 seem to attribute weather changes around the lake to land use changes. Worth taking a look at, IMHO.

    • There is much to discuss when it comes to Lake O.

      Fot instance, it happens to be in a naturally phosphorous-rich area. It is shallow and receives lots of FL sun. There is lots of agriculture (away from fruit farms and now cattle instead) and development growth (i.e., greater wastewater discharges) upstream.

      The notion that climate change is the issue is just plain goofy.

  18. Anna is very cool sort of person
    it appears she has been researching algal blooms and computer models for many years , mainly lake Erie and for many years, her 2013 paper :-
    “Record-setting algal bloom in Lake Erie caused by agricultural and meteorological trends consistent with expected future conditions”, and a later paper linking blooms to Phosphorus

    I love the `consistent with the future` bit

  19. Are all fish & lake creatures carnivorous ? Kind of does not lead to a food-chain if all species feed on other species.

    I’m not a specialist but it seems that there must be something eating algae. Logically that “algae eating something” is having a party.

    Turning itself in abundant meals for the upper food-chain and so on.

    Bottom line, are algae really that bad ?

  20. 1984 to 2013. So the hiatus in latter years was evident since warming was key to non-recovery of lakes?

  21. I wonder if anyone checked the hypothesis that the algal blooms caused the lake warming, whether the water absorbed more solar energy due to greater turbidity due to the presence of algae. We have this problem with CO2 also, that nobody wants to recognize that throughout geologic history climate changes lead CO2 changes, not follow. You’d think that single uncontested historical fact would drive a stake through the heart of this AGW frenzy but this hydra just grows a new head, from nuclear winter to acid rain to ozone holes to global warming to climate change; like a Terminator robot it just keeps getting back up. Would the possibility that this was never about climate explain that?

    And, like CO2, is algae bad? We have had programs in Canada where shores of reservoirs are fertilized specifically to increase algal development in the lakes in order to prompt development of a fish culture, often Kokanee salmon, which in turn supports a population of Lake and Rainbow trout. Nobody died.

    Some algae is toxic to humans–so what? Even water is toxic to humans in too large a quantity, both by ingestion and immersion. Is the amount at all dangerous?

    I’m not scared yet. They might need more money to change that.

  22. I have a house on the Chesapeake Bay. It is a very large body of water that varies in salinity and has some exchange with the Atlantic. The largest supplier of fresh water to the Bay is the Susquehanna River draining 27,500 sq miles. Unfortunately the river carries huge amounts of nutrients from agriculture and poorly maintained septic and sewer systems that empties into the northern Bay. Additionally agricultural runoff comes from the Potomac, Rappahannock, York and James Rivers which drain almost the entire state of Virginia.

    Algae is a huge issue in the Bay and ebbs and flows with the weather. When the watershed gets a lot of rain, nutrients come in fast and the water quality changes. When the area is dry, fewer nutrients come in and the oysters and other filter feeder help clear it out to some extent. Regardless, every summer there are large areas of water that are so oxygen depleted, nothing can live in it. The creeks along the Bay are green.

    Water temperatures are pretty much the same over the course of the year. In the summer it gets very warm and in the winter the northern Bay freezes. But how much algae is dependent almost entirely on nutrient levels. Efforts to introduce oyster farming are helping somewhat in certain areas but the only way to get better water quality is to clean up the rivers feeding the system.

  23. They admit that they have no evidence that global warming is playing a part in any of these blooms, however they assume that it must be, therefore we have to do something about it.

  24. Now they need to total up all the CO2 that is being consumed by algae, phytoplankton, seaweed, trees, grass, and crops each year and compare that total to annual emissions of anthropogenic carbon. How many trees next to expressways are needed to consume all the traffic emissions?

  25. “No consistent pattern when fertilizer, temperature, rainfall etc are considered.”

    If the latter two are not correlated to the algae growth then how is this “climate” related?

    My exasperation, and my feeling of hopelessness, are DEFINITELY correlated with “climate alarmism.” it gets worse by the DAY

  26. Major pet peeve…many of these “algal” blooms are of the “blue-green alage” variety…which is a misnomer. Cyanobacteria is not algae. It happens to be one of the more infamous bloomers (in part because it can fix atmospherix nitrogen and out-compete algae), including the Lake O mess a few years ago in FL.

    Scientists misreporting cyanobacteria as algae is irreponsible and misleading to the public.

  27. Actually to permanently remove carbon from the biosphere increased algal blooms are just the thing. One of the most important mechanisms for removing carbon dioxide from the atmosphere is when phytoplankton dies and sinks to the bottom of the lake/sea. If the the bottom is anoxic the organic material collects there and ultimately gets incorporated into the sediments. Large and frequent blooms are most likely to create anoxic bottoms.

    This is the main mechanism which creates organics-rich shales and therefore ultimately (in rare cases) oil and natural gas.

  28. Since the article mentions Florida’s problems I must wade in to the fray. None of the algae problems in Florida are related to climate change. We identified the problems in some detail at least as early as the late 1970s. I helped organize conferences to review the problems and to propose solutions during the mid-1980s. There were two basic problems, the divergence of freshwater and nutrient pollution. In spite of identifying these problems in some detail little was done until there were crises. Then everyone went running around like this was some sudden emergency. Then to confuse the issue the news media and some so called scientists blamed red tide, K. brevis, on nutrient pollution in spite of the fact that red tides have been documented in the Gulf of Mexico since the time of the Spanish explorers.

    Our states problem is directly related to the extreme populations growth. In 1960 there were a bit over 3 million people in Florida the majority of those living in Jacksonville, Miami, Tampa-St. Pete, and Pensacola. Orlando was sleepy backwater where the industries were citrus and aerospace. The population would double in the winter. Interestingly no one in their right mind moving to Florida then moved to the coast because of hurricanes. Today there are over 25 million residents with an additional forty million tourists at any give time. Imagine the amount of domestic waste and stormwater due to harden services we face today.

    So what are the scientists doing, holding their hand out or demand they be given research dollars to “solve” the problem. Of course fixing the problem requires tax dollars, primarily at the local level.

    • “…red tides have been documented in the Gulf of Mexico since the time of the Spanish explorers…”

      And now people are trying to erase that from history, a la the MWP.

  29. So according to the article, the link to climate change is ‘warmer lakes dont recover as fast as cooler lakes’ . Physics is evidently not a strong point of the authors, clearly cooler lakes are going to be the larger lakes, and thus have a more diverse biome, and more water to deal with the bloom.

  30. This is “the first-ever global survey”, yet they claim to have seen an increase in algae bloom? Don’t you need a baseline before you can say there has been a change? An increase from what?

    I grew up in agricultural areas. Algae in lakes have always been associated with fertilizer runoff and sewage leakage (agricultural as well as human). If this study had wanted to look at the effects of purported warmer weather on algae in freshwater, it should have controlled for the known effects of runoff and studied only uncontaminated lakes. That is so elementary that not doing so must be deliberate. This study therefore is an insulting sham.

    • “…Ho, Michalak, and Pahlevan used 30 years of data from NASA and the U.S. Geological Survey’s Landsat 5 near-Earth satellite, which monitored the planet’s surface between 1984 and 2013 at 30 meter resolution, to reveal long-term trends in summer algal blooms in 71 large lakes in 33 countries on six continents…”

      So they used 30 yrs of data and claim to have found a trend.

      “…If this study had wanted to look at the effects of purported warmer weather on algae in freshwater, it should have controlled for the known effects of runoff and studied only uncontaminated lakes…”

      Yes, some sort of normalization would be in order for fertilizer and such. But using uncontaminated lakes makes nutrients the limiting factor, so that’s not a useful study. They seem to have been studying lakes where temperature and precipitation (i.e., runoff) may have been the limiting factors. So it was “deliberate” but appropriate in this case IMHO. An analogy would be wanting to identify the impacts of a plant-based diet on cancer patients. They aren’t saying climate change is the sole cause of blooms…they are arguing it makes them more frequent and/or worse.

      • Yes they argue that but the data does not actually support the conclusion due to the faulty methodology of the study. You do need a baseline. Lake Tahoe in California / Nevada has had zero increase in algae blooms since strict controls were put into place on runoff into the lake of sewage. The basin has seen a huge increase in population in the period in this study and zero increase in algae bloom. That would suggest the study is simply voodoo dressed up as science.

  31. Campanile Oct.16 has it correct. Its that nasty CO2 molecule yet again.

    Seriously does the water purification process remove the nasties, if not perhaps spraying the Algae is necessary.

    MJE VK5ELL

  32. As far as Lake Okeechobee goes…they found a 0.02 deg C/decade trend in temperature. So the highlight of the press release has basically been unchanged in temperature.

    Among the lakes they studied, Lake O had among the highest fertilizer trends…and rainfall trends. So they can try to blame the latter contribution partly on climate change. However, they claim this trend is 114 mm/decade, or 4.5 inches per decade(!) in Supplementary Table 1. I call bullspit. Off by a factor of 10 . I’ll have to track-down their source. The Florida Climate Center trend for Orlando, for example, is -0.28 inches per decade.

    Their source? “…Precipitation data were obtained from the combination of Climate Research Unit (CRU) Time Series 3.295 and the National Centers for Environmental Prediction (NCEP) / National Center for
    Atmospheric Research (NCAR) Reanalysis 196 products available through the North American
    Carbon Program (NACP) Multi-Scale Synthesis and Terrestrial Model Intercomparison Project
    (MsTMIP) driver data. Sub-daily values at 0.5° × 0.5° spatial resolution globally were
    Supplementary Methods 6 summed by calendar year to obtain annual total precipitation values for 1984-2010 based on data availability…”

    Actual rainfall in Lake O and upstream watersheds is readily available. Their reanalysis precipitation data is a load of crap. I understand that it may be necessary to use that for a lake in Africa, for example…but come on!

  33. It is vice versa. Not warmer climate induces the algal blooms. Algal blooms make the climate warmer.
    However, not blooms on lakes. The seas are blooming either. This is the cause of global warming.

  34. Funny how so many people here reject the conclusions of the research. Why? Why do people think they know these systems, and what has been done in the way of studying them, so much better than the researchers themselves? It’s simply not rational. If the study had found that there was no influence of climate change, the same people, I suspect, would hail the study as well-executed, knowing no more about it than they do about it now.

    • For starters, they didn’t isolate any impacts of climate change. They found no consistent pattern of cause for increases in frequency and intensity. They just linked better recovery to ponds with the least amount of warming. Sure, the point of the article and blame is climate change obviously, but I wouldn’t say their paper found an influence of climate change.

      For me in particular:
      (1) The issues raised in FL in 2016 and 2018 were because of Lake Okeechobee, which is contained in their study. The 2016 and 2018 issues there were cyanobacterial blooms, not algae as the article suggests and authors discuss. I did see mention of cyanobacteria in the paper, but the fact that the quotes from the authors still lump those in with algae shows this is about alarmism instead of science.
      (2) I saw their data concerning precipitation increases for Lake Okeechobee…at a rate of 4.5 inches per decade. It is based on reanalysis models and not actual measurements. It is off by a factor of 10 or more. There are a host of rainfall data resources that immediately indicate this as bogus.

      I’ll be digging into #2 and some other issues more this weekend. From what I saw of their methods, I’m not sure they captured the entirety of the contributory area into Lake Okeechobee. If they did, the claim of a rainfall trend of +4.5 inches/decade is even more ridiculous. I’ve got 12 yrs of engineering practice here in FL and deal with rainfall data regularly.

      If I can poke those holes into their finding of a location right down the road from me, it raises issues about their data elsewhere, particularly the rainfall data generated by reanalysis models. It also begs the question as to what happened during peer review. That rainfall trend should have jumped right out at a reviewer.

      • Michael,

        “Sure, the point of the article and blame is climate change obviously” Why is this obvious? When they started, they didn’t know what their results would be; perhaps they might have pointed to fertilizer run-off as the only significant contributor. Even if they were interested in the potential effects of climate change, what’s wrong with that?

        If there was better recovery in cooler water bodies, climate change has the potential to play a role. That doesn’t mean that in every lake algal blooms will get worse. For instance, if a lake is fed by melting mountain snow and climate change leads to greater snowfall in the watershed, it could ameliorate algal blooms. Or increased rainfall could make the lake deeper and cooler, with higher stream flow leading to greater heat exchange between surface and deep layers.

        You don’t have to conclusively demonstrate a past influence of climate change in order to discuss potential effects, which could vary based on all kinds of other factors.

        I don’t have access to the paper, so cannot evaluate your comments – except for the point about cyanobacteria, which are also known as blue-green algae because they photosynthesize. The abstract refers to phytoplankton, of which some are bacteria, some are protists, and most are plants.

        A rainfall trend of +4.5″/decade does sound implausible, especially since the time coverage is less than 3 decades; I would have to read the paper myself to see what it says. No offense. The data were not just from reanalyses (what exactly is wrong with using them?), but also from station data. “Precipitation data were obtained from the combination of Climate Research Unit (CRU) Time Series 3.2 and the National Centers for Environmental Prediction (NCEP) / National Center for Atmospheric Research (NCAR) Reanalysis 1 products available through the North American Carbon Program (NACP) Multi-Scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP) driver data” – though I don’t know how they were combined.

        I don’t see where you are getting your supplemental info. The tables I found don’t include the data you cite.

        Regardless, my point stands: people are very ready to condemn research that doesn’t accord with their beliefs, without even reading the original papers. I’ve seen this time and again. They are also ready to assume researchers are intentionally fudging data, misconstruing results, etc. in order to support AGW theory. This is symptomatic of a pervasive distrust of the scientific community – not just climate researchers, but anyone who does any research that has a potential climate change component – which seems to be more often based on their own biases than on competent assessment of the research.

    • I’ll add another…their Supplemental Information 1 includes another US lake, “Clear Lake.” There are lots of lakes with that name in the US, but the one that comes up in google searches associated with algal blooms (well, actually cyanobacteria again) is in CA, and it matches the lat and long in the SI1. SI1 says the trend in precipitation there is nearly 4.5 inches/decade as well (in an area that averages 38 inches per year). Not in my backyard and not a location I am familiar with, but I can look up enough surrounding rainfall history to see that it’s garbage. The alleged “permanent drought” in CA coinciding with this absurd increase in local rainfall should have raised a red flag with any reviewer.

      Only three locations had a decade trend in mm of 100 or more, and Clear Lake and Lake Okeechobee were two of them. Stood-out like a sore thumb. They happen to fall within 1 mm/decade of each other as well, which is an interesting coincidence. But nobody bothered to check actual instrumental data compared to the reanalysis data that was used?

    • The study is simply full of giant gaping holes, If you read the commenters on the lake in Florida and look u the actual rainfall numbers, the holes are obvious. Other commenters point out other problems in different areas with the study. Lakes are very sensitive to fertilizer inputs. The algae are mostly starving until somebody or something dumps a bunch of fertilizer in the water and the algae go on a growing spree. As others have pointed out Florida , as only one example, has had a huge population increase with a resulting increase in sewage all of which at some point flows into some body of water and boom the algae have a field day.

  35. Climate chance has nothing to do with that. Erosion, fertilizers from the fields and wastewaters causing that.

  36. The USA population has increased 60 percent from 1970, Chad increased 15 times from 1960. I suspect the increase in bloom has a whole lot to due with untreated sewage and agriculture runoff into most of those lakes. The problem from a science standpoint is the period measured is tiny compared to say the last 15000 years so whether there is an actual increase or just some cyclic increase is unknown. If you look at hurricane activity there is a different cyclic activity going on over time which may be the similar with greening and this studies findings. All these people did was take a tiny cross section of time and pretend that it has some meaning as they have zero data on actual water mineral and temperatures in any of those lakes even in the tiny time period they looked at. At best the study is interesting and at worse Voodoo used by the doom and gloomers for propaganda.

  37. If all that was required for the runaway reproduction of algae was fertiliser input, the industrial production of algae for consumption by us in various forms would not be a problem. What has been found to be a problem there was availability of sunlight, which amongst other things limited the algae’s ability to produce Carbon from Carbon Dioxide in order to reproduce. I see in this a direct parallel to experiments carried out in the sea with iron fertilisation, where I believe the mechanism at work is the oxidation of a metal removing the Oxygen from Carbon Dioxide and providing the organism with Carbon that it can acquire without expending energy in photosynthesis. Should this be correct, it may prove important in the course of major volcanic eruptions; One of the consequences is a decrease in insolation, with concommitant crop failures. If algae can be persuaded to grow in such a sunlight-limited environment, it could stave off mass famine….

  38. “Geo Rubik October 16, 2019 at 10:39 am

    When I go fishing I see algae blooms in most lakes that are river/stream fed. These lakes are fed by runoff from ag and urban areas. Most of this water is stained dark and can have silt. No algae blooms in landlocked spring fed lakes.”

    Why do eutrophic lakes have low oxygen?

    In eutrophic (more productive) lakes, hypolimnetic DO declines during the summer because it is cut-off from all sources of oxygen, while organisms continue to respire and consume oxygen. … In oligotrophic lakes, low algal biomass allows deeper light penetration and less decomposition.

    https://www.google.com/search?q=no+oxigen+in+landlocked+lakes&oq=no+oxigen+in+landlocked+lakes&aqs=chrome.

    https://www.google.com/search?q=alpes+toplitz+Lake&oq=alpes+toplitz+Lake+&aqs=chrome.

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