Arguments
Ocean Acidification Is Fatal To Fish
Posted on 22 December 2011 by Rob Painting
Fossil fuel-burning is acidifying the oceans and, up until recently, it has generally been thought that the greatest risk posed by ocean acidification was the change to seawater carbon chemistry. This is because rising levels of atmospheric carbon dioxide reduce the concentration of seawater carbonate ions, a vital building-block in the shells and skeletons of many marine life. Fish were not thought to be at direct risk from acidification, because they clearly don't build shells, and were considered to have well-developed physical mechanisms to tolerate falling pH (acidification).
Several studies published in the journal Nature Climate Change, Baumann (2011) and Frommel (2011), indicate that this might not be the case. Fish may, in fact, be seriously threatened by ocean acidification. Although adult fish seem well-equipped to deal with low pH waters, or higher levels of CO2 in seawater, their egg and larval life stages, a typically vulnerable time for all marine life, may not be so fortunate.
Baumann (2011) show that larvae survival in one fish species drops with increased levels of CO2 (figure 1). Survival rates plummeting some 75% under a scenario with 1000ppm (parts per million) of atmospheric CO2. And Frommel (2011) discovered considerable tissue damage and necrosis (dead tissue) in fish larvae of another species exposed to higher levels of CO2 than the present day. In the high CO2 experiments, this damage to internal organs was so extensive it lead to the death of afflicted larvae. Each of these studies are discussed in detail below.
Figure 1 -Survival rates of larvae with increasing CO2. Thin grey lines=error bars (95% confidence intervals). Experiment 1, red squares; experiment 2, blue down triangles; experiment 3, green diamonds; experiment 4, yellow circles; experiment 5, black up triangles. Points represent means±1 standard deviation (a spread of measurements deviating from the average).
Ocean acidity hotspots
It's important to point out that some regions of the oceans, especially coastal waters, can seasonally experience extremely acidified waters, with much lower pH than the global average. For example, due to upwelling over the warmer months, Kiel Fjord in the Western Baltic Sea (Germany) can see prolonged periods of acidification so low that it is equivalent to atmospheric CO2 levels of 2300 ppm. So this needs to be kept in mind when the reading the levels of atmospheric CO2 discussed in the following studies. High levels of ocean acidification are already occurring in some areas of the ocean where fish spawning fish takes place.
One fish, two fish, shorter fish, dead fish
The inland silverside is an ecologically important small fish native to the Atlantic coast of North America, and is found in estuaries up-and-down the coast. It can also be found in acidified freshwater environments, and humans have even successfully transplanted them into land-locked freshwater systems and lakes, so they clearly can adapt to low pH (acidified) water.
Baumann (2011) conducted a series of experiments where CO2 was bubbled into seawater containing the newly-fertilized eggs of the inland silverside. Larvae were exposed to levels of acidification representative of modern-day (390-400ppm,) right up to projected late 21st century (900-1100ppm) atmospheric CO2 levels. After a week the surviving larvae were counted and measured.
In each of the 5 experiments both the larvae body length and survival rates declined as seawater became more acidified (figure 1), and there were also more deformed larvae (figure 2).
Figure 2- Larvae with curved or curled bodies were significantly more common at increased (b,c) when compared with control (a) CO2 levels. Scale bar=1 mm.
At 1000 ppm, survival plunged some 75% and larval body length 18%. The shorter length indicates a slower rate of growth, a problem for larvae because the longer the time they spend growing in their larval stage, the higher the rate of predation by plankton-eating fish and other critters. In other words, slower growth and larval deformities will likely translate into even lower survival rates in the wild, compounding the death rate of these larvae as ocean acidification increases.
The cause of this slow growth, deformation and decline in survival rates in the experiments is not known, but given that inland silverside can grow and thrive in more acidified freshwater, this suggests something other than pH. Baumann (2011) suggest this may be related to high CO2 levels, or even the carbonate chemistry of the water.
The authors speculated that the negative response may have been related to the susceptibility of very early larval development, the egg embryo, so carried out another experiment, After growing in seawater equivalent to 410 ppm for 5 days, fertilized eggs were exposed to 780ppm once they hatched. Survival rates only slightly dropped in this treatment versus the control (at constant 410 ppm), and survival was much higher than larvae exposed to 780 ppm the entire time, suggesting that it's the eggs themselves that may be vulnerable to ocean acidification.
Acidic oceans severely damage internal organs in fish larvae
Frommel (2011) was another experiment carried out on fish larvae, this time to focus was on Atlantic cod, a fish widely distributed throughout the North Atlantic Ocean, and one listed as vulnerable on the IUCN Red List of threatened species. This is the same species that was decimated by overfishing in the late 20th century, an activity which lead to the collapse of 6 populations off the Canadian coastline.
The cod larvae for this experiment were taken from a population off Norway, and were exposed to 3 levels of seawater acidity equivalent to 380 ppm (the control), 1800 ppm (medium) and 4200 ppm (high). Although these last two scenarios may seem very high, Kiel Fjord (noted earlier) is very near to Baltic cod spawning grounds and already sees levels above the equivalent of 1800ppm, and is likely to endure acidification comparable to around 4200 ppm with a doubling of atmsopheric CO2 (560 ppm). So the experiments are directly relevant to current and near-future conditions in which Atlantic cod spawn.
Cod larvae were reared for 7 weeks in large outdoor cylinders called mesocosms. The authors did not directly test for mortality (death rate), but instead looked for changes in tissue health. They discovered that in the early stages of development, the first 25 days after hatching was a critical time. Newly-hatched larvae lack fully-functioning gills, which is the primary organ for helping regulate internal pH balance and CO2 build up in tissue. In this early development stage the larvae are essentially at the mercy of the surrounding seawater pH, and are therefore very vulnerable. In the experiment, larvae suffered extensive damage to vital organs with rising acidity, and those larvae with extreme malformations to internal organs and widespead dead tissue, obviously died from these deformities. See figure 3.
Figure 3 - histological sections (tissue samples under microscope magnification) of cod larvae liver at increasing CO2. Control=380ppm, medium=1800ppm and high=4200ppm.
The effect of the three acidity scenarios on larval tissue are is shown in figure 4. As acidity increases, so too does the amount of tissue damage.
Figure 4 - Percentage of larvae exhibiting different degrees of total damage at 32 and 46 days after hatching and three different treatment levels (control, medium and high). The damage is shown as five levels with normal as white bars, and shading increasing with increasing severity of damage. Control=380ppm, medium=1800ppm and high=4200ppm.
In the summary of their paper the authors conclude:
"Although we did not directly test for mortality rates, our data on severe tissue damage suggest that ocean acidification will negatively impact the recruitment of mass-spawning fishes because of enhanced mortality rates."
Fish flunk the acid test too
To sum up:
- The Baumann (2011) and Frommel (2011) studies are surprising in that they reveal that rather than being impervious to the effects of ocean acidification, as earlier believed, higher levels of acidification are actually fatal to fish in their early life stages (egg/larval form).
- Both the severity of tissue damage to major internal organs, and the mortality rate in fish larvae increase along with rising levels of CO2.
- The high CO2 scenarios in the experiments are representative of both current day and near-future conditions found in some regions where these fish spawn. So the results suggest ocean acidification may be having an impact on these species today.
- Further tests will be necessary to determine how widespread this egg/larval susceptibility is among fish species, but if the results of these studies are an indication of the harm ocean acidification causes to fish life in general, then along with overfishing, pollution and habitat contraction (a consequence of warming seawater and ocean acidification) we may begin to see major fish stocks collapse.
Related SkS posts: OA not OK series, Ocean Acidification: Corrosive waters arrive in the Bering Sea, Acidification:Oceans past, present & yet to come, Ocean acidification: Some Winners, Many Losers, Ocean acidification: global warming's evil twin and Great Barrier Reef Part 3: Acidification, Warming, and Past Coral Survival.
And the Honisch et al. bibliography is also a great place to go next.
"Small drop"?
Vonnegut, pH is a logarithmic scale.
A 0.1 decrease in pH represents an enormous change in the acidity of ocean waters.
From Wikipedia:
Wikipedia's sources are noted in the excerpt are:
(5) Jacobson, M. Z. (2005). "Studying ocean acidification with conservative, stable numerical schemes for nonequilibrium air-ocean exchange and ocean equilibrium chemistry". Journal of Geophysical Research – Atmospheres 110: D07302. Bibcode:2005JGRD..11007302J. doi:10.1029/2004JD005220.
(6) Hall-Spencer, J. M.; Rodolfo-Metalpa, R.; Martin, S.; et al. (July 2008). "Volcanic carbon dioxide vents show ecosystem effects of ocean acidification". Nature 454 (7200): 96–9. Bibcode:2008Natur.454...96H. doi:10.1038/nature07051. PMID 18536730.
(7) Report of the Ocean Acidification and Oxygen Working Group, International Council for Science's Scientific Committee on Ocean Research (SCOR) Biological Observatories Workshop [This is a PDF document that Wikpedia links directly to.]
Yes small drop, have you looked at how much ph changes in the sea?
It raises the question at ph7 will it still be sea water? Will the salt fall out and freeze more readily?
vonnegut wrote: "Well Dikran youre entitled to your opinion. Yes a permanent drop of 15 degrees would affect many creatures, I just dont think a small drop in ph will, thats all."
For which you provide no evidence whatsoever, and describe scientific studies that suggest otherwise as pointless. This is odd behaviour for someone who had previously stated today that they were "trying to learn thats all".
The evidence is all around us, the world didnt end, I could post studies of creatures that have been tested and survived but is that what you want?
While searching ive found it very odd that no test ive seen shows the ph of the water the fish was taken from. Almost like it wasnt significant.
[PS] Statement like "the world didnt end" constitute straw man arguements unless you can point to predictions made by climate scientists that it would. Enough of this kind of rhetoric please.
And yes, pointers to studies that support your viewpoint are precisely what is useful to a constructive discussion.
Vonnegut, if you are unable or unwilling to accept that small changes in global mean values of X (where X can be surface temperature, ocean pH, concentration of CO2 in the atmosphere, what have you) can and do have very drastic consequences, then as far as I am concerned you are wasting your time, and ours.
@57 What can I say ive seen a small change in the mean global temp and noticed no difference, Ive seen a drop of 0.3 ph in my aquarium and seen no dramatic changes.
I dare say something somewhere may be affected, I just dont think the sky is falling, if you get my meaning?
[PS] Enough of this please. The original article points to science on this subject; if you wish to dispute this, then please cite other science that supports your viewpoint (for which your fishbowl doesnt count). Unsupported assertions will be taken as sloganeering. You might also like to look "Its not bad" but please be prepared to back your position with data.
Vonnegut,
Your statements contain so many incorrect "facts" that it is difficult to know where to start.
Most fish that are kept 5C below or above the normal temperatures where they are from will stop reproducing and their immune systems will shut down. They will die in a year or two. They can survive tempory drops or increases in temperature much greater than that, but not long term.
You are simply not looking if you have not noticed any changes in flora and fauna in your area. It is difficult to find something you do not look for. Simply compare the changes in the USDA hardiness zones to see dramatic differences in temperature in just the last decade. Stone fruits do not produce fruit in many locations where they were traditionally grown. In my back yard I have over a dozen trees (includingfour jackfruit trees) that would have been killed by cold 30 years ago. Many of my neighbors have the same. The bark beatles that are killing forrests all over the country are caused by AGW. Open your eyes. Some animals and plants will survive. A few will thrive (I'm betting on the cockroaches). Most will be killed. Your trite comments about coelecanths when there are severe coral bleaching events year after year demonstrates your position. You need to provide evidence that an ecosystem will survive, not a single animal. There are myriad examples of coral reefs that are currently dying from the effects of heat and pH. While the Palau example was surprising, the overwhelming trend is down for coral worldwide. Look at the drought in the American West. Tell me where you live and I will give you examples of plants and animals that are dying off because of AGW.
You need to stop making statements like "small drop in pH" when you obviously have little knowledge of how pH works. You rarely provide evidence to support your wild claims. You claim you could post studies of creatures that would thrive, but you do not provide such evidence. When you go to look for it you will find the overwhelming majority of evidence is that things are doing worse. Read the background information so that you can understand what others are trying to tell you. Your basic science knowledge is sorely lacking.
I posted reports to support my view but was told it was just one reef , its by far one of the best outdoor labs on the planet. I cant prove all ocean creatures will adapt just the same as no one can prove they wont, time will tell.
www.pri.org/stories/2014-01-02/palau-scientists-hope-theyve-found-coral-reef-save-all-coral-reefs
www.whoi.edu/news-release/palau-corals
news.stanford.edu/news/2013/april/urchins-ocean-acidity-040813.html
http://www.int-res.com/articles/theme/m470p167.pdf
vonnegut wrote "I posted reports to support my view but was told it was just one reef"
That is a misrepresentation of the discussion. You were told that the reef in question was deeply unrepresentative of reefs in general, and the article that you referenced explained that quite clearly, and therefore didn't support your point. The article itself contained that caveat explicitly.
You will excuse me if my patience wears somewhat thin.
@61 what does it take? Imagine how many scientists are looking to find a story which disproves OA? and how hard it is to wade thru all the papers which claim it may happen?
In other words its hard to find a good news story because you have to go thru all the bad news stories first.
Vonnegut, read the article, don't ignore the caveats, don't over interpret the observations as implying that OA may be OK when the article explicitly says not to. If you need to go through lots of bad news stories (or scientific studies to give them a more accurate name) to find a good news story, that is an indication that things are not looking too good. This doesn't mean the world will end, or the sky will fall in, that is hyperbole, but it does mean that there is likely to be a substantial problem, and there is no point in ignoring that fact.
One thing that is required is that you don't downplay the objections to your arguments in the way you did at post 60.
Wading through all the papers is part of a scientists job, and there is nothing they would like more than to prove that OA is OK, it would make them famous as well as being good news.
The good news stories are also scientific its just the google search function is still lacking.
I hope you also notice I refrain from posting links from the 'other' side.
[PS] There is no problem whatsoever posting links "from the other side" - especially if what you are posting is links to published science. If you are being misled by misinformation sites, then many here will be happy to explain why you are reading is misleading.
[PS] It would help your readers if you explained how your statement of facts progresses your argument.
To put Vonnegut's discussion of Palau into perspective, the from the supplementary material of the paper, we find that site 9, the most acidic of the sites examined, has a pH of 7.84 (See Table S1). Site 9 certainly has a very healthy coral community, as shown by this picture of the site:
For perspective, however, that should be compared to the coral from Milne Bay, Papua/New Guinea discussed in Fabricius et al, 2011:
The most comparable site from Fabricius et al is site b, with a pH of 7.8-8. Although comparable in pH, clearly the Nassau site 9 is thriving far better than site b in Milne Bay (a point I will return to). However, equally, as the pH continues to fall, corals find it still harder to survive, until they die out completely. Ocean pH is projected to fall well below 7.8 by 2100 with high level emission scenarios. Consequently the fact that coral in Palau can survive at relatively low pH is little long term comfort without mitigation of emissions.
It should be noted that site 9 from Palau, like site B from Milne Bay, has no branching corals, ie, the corals most vulnerable to ocean acidification. Ocean acidity, therefore, is still having an effect in Palau. Some local feature, however, is allowing some corals to still continue to thrive, establishing the basis for a thriving marine community.
There are some further interesting nuances. Interestingly, the site at Milne Bay has the '... local traditional site name “Illi Illi Bua Bua” [which] translates to “Blowing Bubbles”' (Fabricius 2011, supplementary information). That traditional name indicates that the volcanic seep which creates the acidic conditions has existed for some time, possibly for centuries. In contrast, the unique conditions in Palau have existed for at least a few thousand of years, and potentially for as much as 8 thousand years. That difference is important. Biological organisms take time to adapt to new conditions. It is clear that in Milne Bay they have not adapted well. That is evidence that a century or two is not adequate time for an appropriate adaption. Palau indicates, on the other hand that several thousands of years are enough time for an adequate adaption (if not for branching corals). The problem is, with the rate of ocean acidification from anthropogenic emissions, corals do not have centuries within which to adapt, but mere decades. Therefore the Milne Bay example is far more likely to be informative about the probable impacts on corals globally than are the those at Palau.
Finally, the situation is grave even for the corals at Palau. That is because they are currently adapted to pH levels in the lagoons equivalent to the expected open ocean pH in a hundred years. That pH, however, is lowered (ie, more acidic) relative to the the current pH in the open ocean near Palau. Presumably, in a hundred years the pH in the lagoons will be lower than the pH in the open ocean withing 100 years as well. That means, the Palau corals will face pH levels significantly lower than those they currently face, with mere decades to adapt when many centuries, and possible more are required to adapt to that reduced pH - if it is possible.
So, Vonnegut's read on the Palau corals depends on focussing on one fact only. He does not consider the entire context, either chemically, or biologically. It is only thate very limited view of the evidence that allows him to avoid its implications.
I note that the entirety of Vonnegut's post @66 except for the last sentence is plagiarized from NOAA. Plagiarism is academic fraud. It should not be tolerated. It also appears to be a repeated practise by Vonnegut.
On the off chance that he knows no better, quotations should:
1) Always be enclosed in quotation marks;
2) If in a large block of more than one sentence, should be placed in a seperate indented paragraph (you can use the quotation symbol on the basic tab of the comments box to indent);
3) Should have any changes to the text, including any addition of emphasis clearly noted; and
4) Should have the source clearly stated, preferrably with a link.
Any time you cut and past text from any source, that is a quotation, and needs to be acknowledged as such.
I request that the moderators from now on practise zero tolerance to plagiarism from Vonnegut.
I see your text isnt in quotes like mine isnt what did I do wrong that you didnt?
Vonnegut @68, the corals of Palau are clearly adapted to unusually low pH. That adaption may mean they are more resistant to even very low relative pH levels, so that they can survive at a pH of 7.4 while other corals are dying of at 7.8. Alternatively, it may mean they have a narrower range of reduction in pH before they reach the limit of their adaptability. Which of these is true depends on:
1) How long they have been adapted to near their current levels of pH (selection under pressure reduces genetic variability, limiting the pace of future adaptions);
2) Whether or not there exists a hard biological limit in pH below which corals simply cannot adapt to no matter how long they have to do so; and
3) The extent to which they have experience lower pH than current in prior years (which may allow some level of pre-adaption).
Which of these is the case cannot be determined a priori, and indeed probably require very detailed and carefull studies to determine.
What can be known with high probability from the general situation is that coral health is not independant of pH levels, so that significantly decreased pH will decrease the health of a coral community (and a reduction of pH from 7.8 to 7.4 represents a 150% increase in Hydrogen ion activity). Further, it is known that elevated CO2 concentrations will decrease pH even within Palau's lagoons. Consequently OA is still a problem for Palau. It just may be less of a problem than for other coral communites, or possibly more depending on the factors described above.
On a side note, the discovery of the acidity resistance of the Palau corals is unquestionably good knews in one respect. While those corals may or may not be able to survive at Palau with future pH reductions, they will be able to survive if transplanted to other locations with, currently, higher pH. While this would not save all coral species, nor save the great barrier reefs it does mean coral phylum is less likely to go extinct. It probably wasn't going to in any event, but this provides a significant boost to the phylums chance of survival.
Vonnegut @69, my text, where not in quotes, is original to me. I researched the facts, formed an opinion, and then expressed that opinion in my own words. You are quite welcome to look up the supplementary material of Shamberger et al (2014) which is linked above, or that of Fabricius et al (2011) to confirm that fact. You will find the only direct quote is regarding the local name of the Milne Bay site, which I clearly indicated by single inverted commas.
While I agree with the thrust of your argument, its easy to forget there are many other creatures that live in the area by choice and are free swimming so maybe adaption to an environment like this is more instant. Such as when the tide goes out fish get stuck in tidal pools and have to put up with less alkaline even sometimes acidic water.
@71 sorry Tom I cannot see any quotes in the piece you posted on 71 Just 2 links. When I press the " button it doesnt put quotes on the text It just moves the cursor..
Vonnegut, consider your text in your post @72. If I wanted to quote it, I would first copy and paste it. I would make sure it was a seperate paragraph. I would then place quotation marks at the start and the begining of the text. Having done all that, I would then highlight the text, including the quotation marks and press the "blockquote" button on the basic dashboard of comments. The result:
If the quotation was on a different site, or a different page on this site, I would then indicate who wrote it, and where. Often I do that simply by name and with a link in the introduction to the quote. If I wanted to emphasize a particular point within the quotation, I would highlight it, but then note in brackets after the quote that the emphasis (ie, the highlighting) was mine.
Now, here is a quote from my post @66:
(Emphasis added).
You will notice that I have emphasized the quote within that quote by italicizing it. That was probably necessary to avoid confusion, given the number of double and single quotation marks in the text. As the quote from Fabricius was only of part of a sentence, I did not give it a distinct paragraph, but rather simply led into within the sentence. I made a point of noting missing text with ellipsis ( "..."); and of noting my addition to the text by enclosing it in square brackets ( "[ xxx ]"). Neither the omission nor the addition alter the meaning of the text. It is important that you never in fact alter the meaning of the text when quoting. The addition was only necessary to form a gramatically correct sentence. Of course, you can, and typically should check those claims for yourself, which is one of the reasons citing the source is necessary. I forget to include the link through pure oversight. That is, I intended to do it, but forgot that I had not yet done so when I pressed submit.
For now, as this is new to you, do not bother with quoting anything less than a full paragraph. Make sure you enclose it in quotation marks and indent it with the blockquote button, and cite the source prefferably with a link. It is too easy for inexperienced quoters to inadvertently alter the meaning of text if they try to do more than that.
"Although coral mortality was as high as 90% is some areas after the 1998 bleaching event, recovery has been tremendous. The Palau International Coral Reef Center has monitored 22 sites since 2001 and found that coral cover has increased at an annual rate of 2.9% from 2001 to 2004. The average coral cover across all monitoring sites in 2004 was 31%. Surveys from 2006-2007 show continuing recovery and increased coral cover at all sites. In addition to the Protected Areas Network Act of 2003, which supports local communities in setting up MPAs, the Micronesia Challenge is a specific initiative originally proposed by the President of the Republic of Palau that has attracted wide support"
www.reefbase.org/global_database/default.aspx?section=t4
Maybe many corals arent that old in Palau?
Vonnegut @72, it is highly unlikely that a mobile species such as fish would adapt more rapidly than corals. That is for two reasons. The first of these is that species adapt to the range of environments they typically experience. For mobile species, that is likely a far greater range than for sessile species such as corals. Second, fish are likely to have a slower rate of repreduction, which slows adaption. Corals reproduce monthly, and in bulk which allows a very fast turn over of generations, and high mutation rates - both conducive to rapid adaption. Fish are variable, but generally have fewer generations in a given period, and fewer offspring.
Consequently, while fish are probably well able to survive being caught in tide pools with aberrant pH values, that is probably primarilly because the pH is normalized within hours so that the damage, if any, is transient and quickly recovered. In contrast to that case, with OA there will be no convenient tides to flush out the water and restore the prior pH balance.
Vonnegut @75, the individual coral polyps are probably not very old at all. The coral species, however, are likely thousands of years old, and potentially 100s of thousands years old, with Palau adapted subspecies being less than about 8 thousand years old.
Wont the free swimming stage every month mean they are widely distributed?
vonnegut. you first raised the example of Palau in your post here, where you gave this link:
http://nsf.gov/news/news_summ.jsp?org=NSF&cntn_id=130129&preview=false
Do you agree that the text at that link includes the following quote:
"It doesn't mean that coral reefs around the globe are going to be fine under ocean acidification conditions. It does mean that there are some coral communities out there--and we've found one--that appear to have figured it out. But that doesn't mean that all coral reef ecosystems are going to figure it out."
If so please explain why you are ignoring this explicit caveat. Note that you are currently misrepresenting what your source of information actually says, which is every bit as much of an academic wrong-doing as plagiarism.
I suggest we ignore voneggut until he/she gives an adequate explanation of why he/she is repeatedly ignoring this caveat, even though it has been pointed out more than once.
"It doesn't mean that coral reefs around the globe are going to be fine under ocean acidification conditions. It does mean that there are some coral communities out there--and we've found one--that appear to have figured it out. But that doesn't mean that all coral reef ecosystems are going to figure it out."
So because someone said that I have to agree with it? is that how science works?
voneggut wrote "So because someone said that I have to agree with it? is that how science works?"
yes, you do have to agree with what an article says if you use that article as support for your argument, as you did. If the paper includes caveats that contradict your position, truthfullness obliges you to openly acknowledge that fact. That *is* how science works.
sorry voneggut, just going out and finding another source without acknowledging that the previous one didn't actually support your position is intellectually dishonest. What you are doing is known as "quote mining", and demonstrates that you are not looking for the truth, just conformation of your existing beliefs. That is not science.
@83 So I have to post quotes that only confirm only your beliefs? Thats intellectually dishonest.
These are not random words ive quoted they are findings of respected scientists, sorry if they dont confirm what you think.
vonnegut, any WHY do we need to protect corals from other stressors such as polution and overfishing, according to the article?
vonnegut@85 no, you have to honestly represent the sources that you use to support your argument, including relevant caveats. If you don't understand the basic need for truthfullness in science, there is no point in me continuing the discussion any further.
Does my post 84 not include a caveat?
Vonnegut @78, the free swimming stage typically lives for only a few days before forming a new colony (or dying), although they can live for up to two months. During two months they might disperse several thousand kms, but would tend to follow ocean currents so that their dispersal locations would be fairly predictable. As only a tiny number do this, their chance of forming a new colony is limited due to competition.
The fact that dispersal is limited is demonstrated by the fact that you have specialized corals adapted to local and unusual conditions in Palau. If dispersal was wide spread, such adaptability to local conditions would not be possible. On the other hand, if an area becomes coral free (and hence coral predator free), the potential for dispersal means it will be recolonized quickly (tens to hundreds of years, depending on remoteness) in suitable conditions. Of course, high acidity and high temperatures are unsuitable conditions and will limit the length of survival of planulae (the mobile form) and the probability of their succesfully forming a colony.
This does mean that for the levels of temperature rise and ocean acidification expected for this century, total extenction of corals was unlikely in that it is probable that some species will find refugia, ie, locations which due to local sea water chemistry (either due to river outflow, or nearby rocky outcrops acting as buffers), or some other favourable factor makes survival possible. Thus, total extinction of corals as a phylum is unlikely unless CO2 levels continue to rise strongly into the 22nd century. More on what that means in a later post.
Vonnegut @82 and 84, unfortunately one of the "other" stressors is high Sea Surface Temperatures, which we are not limiting under current policies. Other stressors such as soil runoff, fertilizer runoff and polution will be very hard to limit in a world with a doubling population by the mid 21st century. Finally, some biological competitors are favoured by high temperature and lower pH; so will place corals under further stress. So, you have to understand that just as some scientists are saying OA may not kill of even the majority of species if we can limit other stressors, other biologists studying the impacts of these other factors, and saying the same thing, with OA included as another stressor. Thus a glimmer of hope is not a panacea.
Specifically to 82, a major shift in reef species means the at least local extinction of many species of coral. That will significantly reduce the ability of the reef to sustain biodiversity, resulting in the at least local extinction many species of fish, crustaceans, and other reef associate species. The total loss of local biodiversity has two further knock on effects. First it reduces the total biomass sustainable by the reef (reducing its potential as a source of food); and it reduces the potential to resist other shocks to the reef. The reef become less robust, and more precarious. The loss of coverage (ie, smaller reefs) reinforces that. Smaller reefs support fewer species, and are more vulnerable to complete destruction by additional hazard.
So, this good news story with a loss of coverage, but some survival if we can exclude other stressors (which we are not doing) starts to look like a Titanic story. 'Well, there will be significant loss of life, but at least some first class passengers will get into life boats" sort of thing. It is telling of the predicament facing reefs that such essentially bad news stories if taken by themselves are regarded as signs of hope.
Further, the widespread loss of species at least locally probably means the extensive loss of some species globally. Even without other stressors, this is starting to put us into survival in refugia only scenarios. That means globaly we are looking at the extinction of a very large number of coral and associated species; with hundreds of years to restore healthy reef communities, and tens of thousands of years to restore the variety of reef species, and hence the sustainable biomass of the reefs.
I can see why you say that, You know i disagree, I think more sould be done about what we know about runoff pollutants etc because we're never going to stop producing co2 we have to mitigate the effects. Maybe while we are doing that things may adapt?
Vonnegut @91, if we are "...never going to stop producing co2..." then we are going to kill ourselves of as a species. It is that simple. Fortunately, a crashing economy and potentially a crashing global civilization will effectively our further emissions of CO2 long before that. So, almost certainly, will a limited supply of fossil fuels. Consequently, the question is not if we will stop emitting CO2, but when - and how much damage we will do to ourselves and the environment in the meantime.
If you begin on the assumption that we will not stop emitting CO2, and look only for the evidence that might suggest that could be OK in the short term, you will get a very distorted view of the science. Instead of trying to understand, you will have been merely trying to find a security blanket for your pre-established belief. There have been a lot of signs that that is indeed what you are doing.
Specifically, you have scoured the internet for one or two quotes from coral experts that indicate OA may not be totally disasterous (at least by itself). In the meantime you are ignoring far more quotes from coral scientists that indicate that OA plus SST increase by themselves may be enough to destroy the worlds major reefs. Some scientists put that possibility at 50/50 by 2050. As neither you (nor I) are experts, we have no basis to ignore any actual experts within the range of opinion. By formulating your opinions on only the more upbeat reports, you are biasing them so that they do not correspond with what the totallity of observations and analysis are showing.
Vonnegut:
At post 61 you claim that it is difficult to find scientific data about survival of species in high CO2 situation. That is exactly what everyone here is trying to tell you. We know that it is possible to search the scientific literature and find exceptional animals or plants that will survive under increased temperatures. The fact that you claim that you have to search many papers to find one that supports your argument that CO2 is not bad shows that most outcomes will be bad. If you have to search many papers to find one that supports your claim indicates that the claim is incorrect.
Think through what you have said. The fact that most papers say ecosystems will have difficulty surviving AGW indicates that is the most common result . Scientists publish everything they find. They do not look for the exceptional ecosystems that are not going to survive, they show what will happen to all ecosystems. A few will do fine for a while, but that will not do the rest any good.
My sentiments entirely , mother nature always wins in the long term.
How do you know Im ignoring other views? Im just looking at the other side of the coin.I dont rest easy knowing the oceans are polluted more each day or knowing that 'global warming did it' is being used as a get out clause and diverting money and resources away from fixing the obvious.
You say Ive scoured the internet for a few quotes, Im surprised how many coral positive reports there are from more than 2 places on the planet. Coral wont be missing off the planet anytime soon because of warming, some will, some wont. I can and have backed that up with links I can do it again if needed.
"I'm just looking at the other side of the coin." No, you're looking at the side of a coin that you like and saying "Look, how pretty!" while there is a pile of $100 bills next to it. Not impressed. The Palau study does not invalidate the overall content and conclusion of the OP at all.
@95 Done know why you think that but we all have an opinion.
Bikini atoll had 23 nuclear devices dropped on it between 1946 and 1958 there are coral there today, I think that it would be fair to say theyre persistant and resiliant, wouldnt you?
[JH] You are now skating on the thin ice of slaganeering and excessive repitition -- both of which are prohibited by the SkS Comments Policy. Please read the Comments Policy and adhere to it.
Sorry was it because I forgot the link?
Vonnegut, no, it is still excessive repetition whether the links are given or not, it is still sloganeering to ignore the content of the posts and peer reviewed litterature that contradict your assertions, whether you give the links or not. You would know this had you read the comments policy as you were directed to do by the moderator. Here are the two sections that were explicitly drawn to your attention:
No Excessive Repetition: Comments should avoid excessive repetition. Discussions which circle back on themselves and involve endless repetition of points already discussed do not help clarify relevant points. They are merely tiresome to participants and a barrier to readers. If moderators believe you are being excessively repetitive, they will advise you as such, and any further repetition will be treated as being off topic.
No sloganeering: Comments consisting of simple assertion of a myth already debunked by one of the main articles, and which contain no relevant counter argument or evidence from the peer reviewed literature constitutes trolling rather than genuine discussion. As such they will be deleted. If you think our debunking of one of those myths is in error, you are welcome to discuss that on the relevant thread, provided you give substantial reasons for believing the debunking is in error. It is asked that you do not clutter up threads by responding to comments that consist just of slogans.
Please read the comments policy and abide by it.
This maybe my last post here but I thought you may like to see this link to a yahoogroups scientists study group.
groups.yahoo.com/neo/groups/coralreef-freeforall/conversations/topics/75
And let's look at some of Goreau's other comments on that thread:
"What I take violent exception to is the claim that acidification is a major threat to tropical coral reefs NOW. It is not: corals will die of high temperaturesdecades to centuries before the dead reefs dissolve! Claiming this is a major problem is a deliberate straw man designed to avoid dealing with the immediate impacts of global warming. No wonder the US and Australian governments and their research agencies love acidification, and act like they invented it!"
"The fact is that if we solve the CO2 problem in time to save reefs from global warming, the acidification problem will automatically be taken care of. If we focus on acidification as the major threat to reefs, we guarantee their extinction."
So, Vonnegut, are you suggesting that your quote is evidence that Goreau--a recognized expert--is saying that research on ocean acidification is garbage? Is that what your quote says to you? Or do you recognize that Goreau thinks that acidification is a problem, but it's a long-term problem that pales in comparison to the problem of rapidly warming oceans (via anthropogenic global warming)?
[PS] please note that the article of this thread is not about corals but about more risk to fish and this discussion is close to offtopic.