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"Although water temperatures at Looe Key exceeded the 30.5 °C bleaching threshold repeatedly over the 3-decade study, the three mass bleaching events occurred o

by kls 7y ago

"Although water temperatures at Looe Key exceeded the 30.5 °C bleaching threshold repeatedly over the 3-decade study, the three mass bleaching events occurred only when DIN:SRP ratios increased following heavy rainfall and increased Everglades runoff." https://link.springer.com/article/10.1007/s00227-019-3538-9 https://link.springer.com/article/10.1007/s00227-019-3538-9 "Porter, who has studied coral for 50 years, says the new research finds that coral die-offs happened long before high water temperatures reach the reef." https://www.npr.org/2019/07/16/742050975/floridas-corals-are-dying-off-but-it-s-not-all-due-to-climate-change-study-says https://www.npr.org/2019/07/16/742050975/floridas-corals-are...

CarelessExpert 7y ago
So that second quote doesn't really support the claim that temperature has no relationship to bleaching events. It only implies that bleaching can happen exclusively due to pollution. The first one is suggestive, though! At least in that specific region. Of course, that paper doesn't go so far as to make the claim you're making, only stating that "reducing the risk of coral bleaching, disease, and mortality under the current level of temperature stress". But it does indicate that pollution is an extremely important factor in bleaching events Given Australia has recently been experiencing repeated mass bleaching events over a very large area, and given you claim that that affirmatively is not associated with ocean temperature changes and is only associated with pollution, then you should be able to provide evidence that pollution levels have significantly and consistently increased near the Great Barrier in correlation with those events. Does that data exist?
- kls 7y ago
  Sorry it took so long to get back to this, while not a scientific piece it is the laymen summation of a lot of research specifically concentrated on the Great Barrier Reef: https://www.marineconservation.org.au/pollution-great-barrier-reef/ https://www.marineconservation.org.au/pollution-great-barrie... A good article on why wetlands are critical to reef systems: https://www.newscientist.com/article/2148247-plan-to-save-great-barrier-reef-from-encroaching-farm-pollution/ https://www.newscientist.com/article/2148247-plan-to-save-gr... And finally to answer the question to my knowledge this is the most comprehensive study and recommendations on the GBR. https://www.reefplan.qld.gov.au/__data/assets/pdf_file/0029/45992/2017-scientific-consensus-statement-summary.pdf https://www.reefplan.qld.gov.au/__data/assets/pdf_file/0029/... The end result is they recommend reducing waste run off as the primary driver for saving the reefs. There is an ongoing study to reproduce the claims we have seen here in the Keys but it has not concluded. The Keys and Australia (as well as Belize) are extremely similar in that all of them are barrier that exist with a fresh water outflow from wetlands. Where Florida and Australia are similar is that both use their wetlands to support industrial scale agriculture and are both in poor health. If we want to get into specifics it is actually one form of agriculture that is causing the most damage (in both Florida and Australia) and that is sugarcane farming. In the past sugarcane farming was not a cost effective endeavor in the US or Australia, with the ethanol fuel additive mandates that all changed as it increased the already high demand for sugar. Sugarcane is grown on the banks of canal systems and low lying marshes. In Florida it is grown in the everglades from Lake Okeechobee down. Given it's close proximity to the wetlands there is no time for soil containment of the high levels of nutrients used to rapidly grow the sugarcane. Specifically in Florida, historically citrus was traditionally the agricultural cash crop, citrus is grown in sandier soil with high concentrations of limestone. These is generally off of the wetlands by at least 600 yards and expands all the way inland until you get to the Florida prairies where the land is more valuable as cattle land, when only looking at it from an agricultural value standpoint. Until the introduction of sugarcane farming directly into the wetlands, Florida did not see significant coral die-offs. I have watched the reefs of Mainland Florida die off thru the last few decades ending with all of them being dead in the early 90's. This was due to diversions of flow in the everglades, done for agricultural purposes, and it killed the mainland reefs. The restoration of flow was done to restore the Everglades to it's natural and historic outflow which was traditionally out of the bottom of Florida into the gulf basin, In that exact time I have witnessed the Florida Keys reefs start to experience the same fate.
  - CarelessExpert 7y ago
    > Sorry it took so long to get back to this No worries! I appreciate the effort you're putting into your responses, even if we might disagree in our conclusions. :) Now, not to boil down your extensive post, but I'm going to highlight a key statement from that 2017 paper that you describe as the "most comprehensive study" about the GBR: > unusually warm sea temperatures in the northern Great Barrier Reef resulted in widespread coral bleaching in 2016 and 2017. This directly contradicts your claim that ocean temperature has absolutely no effect on coral survival. In fact, in multiple places that paper speaks to climate change as a key contributor to coral die-off. Here's another one (Section 5, "Condition of coastal and marine ecosystems", "Summary of evidence"): > Mid-shelf and outer shelf reefs in the southern half of the Great Barrier Reef have shown the capacity to rapidly recover from previous disturbances; however, a severe mass thermal coral bleaching event in 2016 resulted in significant coral mortality, especially north of Port Douglas. I honestly don't know what to say at this point. I'll be extremely blunt: I feel like you're cherrypicking, not just papers, but statements within papers, to support a conclusion you've already come to. Again: I absolutely agree with the conclusion that controlling coastal pollution can have a profound effect on reef health. That is unquestionably true. But the evidence is clear that climate change is also an important factor, as indicated in the very papers that you cite, and that coral will continue to die off if we don't work to solve both problems. Finally, I agree that coastal pollution management is lower hanging fruit that, if addressed, may give us more runway to address the larger issue of climate change, as these reefs may then be more resilient to increased water temperatures if pollution stressors are reduced or eliminated.
    - kls 7y ago
      So on the 2016 and 2017 bleaching there is no doubt that in the presence of higher temperatures the nitrogen (and for that matter micro-metals like zinc in sunscreen) become more deadly. Ocean temperature is only speculation as they did not measure other variables. There is an effort in Australia to reproduce the findings in the US but it has not concluded. I am trying to find that information. The prevailing though is those warming events coincided with a water quality event which make the water quality events (the true killer) even more deadly. The belief is that that link will established just as it was in Florida. The issue is though that die off has been observed in the absence of temperature and the survival has been observed over what was believed to be threshold but die-off always happened with the ratio of nitrogen to phosphates hit a threshold. I try provide the links as they are, not trying to cherry pick my opinion is based on experience with the reefs and the range of studies I have seen. There is no doubt that there is still a prevailing theme of temperature as it was long believed to be the primary driver, it takes time for the mind-shift to happen even in the research community. I am also trying to find the Cuban reef study as it sits in the same thermocline as the Florida Keys barrier reef. I will post them when I find them as I said I help out and help my daughter with her studies, I am not a researcher but I feel I have a pretty good handle on the scope of research and findings on reef destruction, I just don't have every paper at my fingertips like the researchers do. I have a query out to a few of the Mote scientist to see if they can provide me with some public accessible links to those studies.

by kls 7y ago

CarelessExpert 7y ago

So that second quote doesn't really support the claim that temperature has no relationship to bleaching events. It only implies that bleaching can happen exclusively due to pollution. The first one is suggestive, though! At least in that specific region. Of course, that paper doesn't go so far as to make the claim you're making, only stating that "reducing the risk of coral bleaching, disease, and mortality under the current level of temperature stress". But it does indicate that pollution is an extremely important factor in bleaching events Given Australia has recently been experiencing repeated mass bleaching events over a very large area, and given you claim that that affirmatively is not associated with ocean temperature changes and is only associated with pollution, then you should be able to provide evidence that pollution levels have significantly and consistently increased near the Great Barrier in correlation with those events. Does that data exist?

kls 7y ago
Sorry it took so long to get back to this, while not a scientific piece it is the laymen summation of a lot of research specifically concentrated on the Great Barrier Reef: https://www.marineconservation.org.au/pollution-great-barrier-reef/ https://www.marineconservation.org.au/pollution-great-barrie... A good article on why wetlands are critical to reef systems: https://www.newscientist.com/article/2148247-plan-to-save-great-barrier-reef-from-encroaching-farm-pollution/ https://www.newscientist.com/article/2148247-plan-to-save-gr... And finally to answer the question to my knowledge this is the most comprehensive study and recommendations on the GBR. https://www.reefplan.qld.gov.au/__data/assets/pdf_file/0029/45992/2017-scientific-consensus-statement-summary.pdf https://www.reefplan.qld.gov.au/__data/assets/pdf_file/0029/... The end result is they recommend reducing waste run off as the primary driver for saving the reefs. There is an ongoing study to reproduce the claims we have seen here in the Keys but it has not concluded. The Keys and Australia (as well as Belize) are extremely similar in that all of them are barrier that exist with a fresh water outflow from wetlands. Where Florida and Australia are similar is that both use their wetlands to support industrial scale agriculture and are both in poor health. If we want to get into specifics it is actually one form of agriculture that is causing the most damage (in both Florida and Australia) and that is sugarcane farming. In the past sugarcane farming was not a cost effective endeavor in the US or Australia, with the ethanol fuel additive mandates that all changed as it increased the already high demand for sugar. Sugarcane is grown on the banks of canal systems and low lying marshes. In Florida it is grown in the everglades from Lake Okeechobee down. Given it's close proximity to the wetlands there is no time for soil containment of the high levels of nutrients used to rapidly grow the sugarcane. Specifically in Florida, historically citrus was traditionally the agricultural cash crop, citrus is grown in sandier soil with high concentrations of limestone. These is generally off of the wetlands by at least 600 yards and expands all the way inland until you get to the Florida prairies where the land is more valuable as cattle land, when only looking at it from an agricultural value standpoint. Until the introduction of sugarcane farming directly into the wetlands, Florida did not see significant coral die-offs. I have watched the reefs of Mainland Florida die off thru the last few decades ending with all of them being dead in the early 90's. This was due to diversions of flow in the everglades, done for agricultural purposes, and it killed the mainland reefs. The restoration of flow was done to restore the Everglades to it's natural and historic outflow which was traditionally out of the bottom of Florida into the gulf basin, In that exact time I have witnessed the Florida Keys reefs start to experience the same fate.
- CarelessExpert 7y ago
  > Sorry it took so long to get back to this No worries! I appreciate the effort you're putting into your responses, even if we might disagree in our conclusions. :) Now, not to boil down your extensive post, but I'm going to highlight a key statement from that 2017 paper that you describe as the "most comprehensive study" about the GBR: > unusually warm sea temperatures in the northern Great Barrier Reef resulted in widespread coral bleaching in 2016 and 2017. This directly contradicts your claim that ocean temperature has absolutely no effect on coral survival. In fact, in multiple places that paper speaks to climate change as a key contributor to coral die-off. Here's another one (Section 5, "Condition of coastal and marine ecosystems", "Summary of evidence"): > Mid-shelf and outer shelf reefs in the southern half of the Great Barrier Reef have shown the capacity to rapidly recover from previous disturbances; however, a severe mass thermal coral bleaching event in 2016 resulted in significant coral mortality, especially north of Port Douglas. I honestly don't know what to say at this point. I'll be extremely blunt: I feel like you're cherrypicking, not just papers, but statements within papers, to support a conclusion you've already come to. Again: I absolutely agree with the conclusion that controlling coastal pollution can have a profound effect on reef health. That is unquestionably true. But the evidence is clear that climate change is also an important factor, as indicated in the very papers that you cite, and that coral will continue to die off if we don't work to solve both problems. Finally, I agree that coastal pollution management is lower hanging fruit that, if addressed, may give us more runway to address the larger issue of climate change, as these reefs may then be more resilient to increased water temperatures if pollution stressors are reduced or eliminated.
  - kls 7y ago
    So on the 2016 and 2017 bleaching there is no doubt that in the presence of higher temperatures the nitrogen (and for that matter micro-metals like zinc in sunscreen) become more deadly. Ocean temperature is only speculation as they did not measure other variables. There is an effort in Australia to reproduce the findings in the US but it has not concluded. I am trying to find that information. The prevailing though is those warming events coincided with a water quality event which make the water quality events (the true killer) even more deadly. The belief is that that link will established just as it was in Florida. The issue is though that die off has been observed in the absence of temperature and the survival has been observed over what was believed to be threshold but die-off always happened with the ratio of nitrogen to phosphates hit a threshold. I try provide the links as they are, not trying to cherry pick my opinion is based on experience with the reefs and the range of studies I have seen. There is no doubt that there is still a prevailing theme of temperature as it was long believed to be the primary driver, it takes time for the mind-shift to happen even in the research community. I am also trying to find the Cuban reef study as it sits in the same thermocline as the Florida Keys barrier reef. I will post them when I find them as I said I help out and help my daughter with her studies, I am not a researcher but I feel I have a pretty good handle on the scope of research and findings on reef destruction, I just don't have every paper at my fingertips like the researchers do. I have a query out to a few of the Mote scientist to see if they can provide me with some public accessible links to those studies.