Conserve & Manage Australian Trout and climate change

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  • #862089

    micmac3701
    Participant

    Does anyone know of water temp data sets?

    MDBA has them on some of their gauges but they only go back to 2000 or there-about and only on some gauges in the catchments they are involved with.

    Kiewa data does show a temp increase trend across the period 2002 until now, but surprises me a bit that we do not have more monitoring in place.

    How hard could it be to retrofit gauge stations? Most are already set up for telemetry anyway.

    #862091

    thommo227
    Participant

    Pertinent to the thread, it is worth looking at the Bureau of Meteorology’s recently published 2019 synopsis. I’ve tried to include the direct link but doesn’t seem to work. The link to the report is at the bottom of the BoM home page under “News and events” then “Latest media releases”. Look for “Annual Climate State 2019”. There is also the “Latest Enso wrap-up” under News and events. 2019 was our hottest and driest year, marked by very hot summers at both ends. Much of this was due to a very positive Indian Ocean Dipole (IOD) combined with warm air coming up from the Antarctic due to a negative Southern Annular Mode (SAM), which caused hot dry conditions and much reduced rainfall. Yes, there’s a lot of terminology and acronyms to get you head around, but there are tutorials on the BoM website.

    In addition, the Bushfire & Natural Hazards CRC released its fire prognosis back in August 2019 forecasting a bad 2019/20 season with very high fire risks for southern WA, Eyre Peninsula, Kangaroo Island, much of the eastern seaboard from Queensland to Gippsland and east coast Tasmania. That is more-or-less what we are seeing now and coincides with the many of the mainland trout fisheries. The long-term prognosis for these regions are: further increase in temperatures, with more extremely hot days and fewer extremely cool days; decrease in cool-season rainfall across many regions of southern Australia, with more time spent in drought; increase in the number of high fire weather danger days and a longer fire season for southern and eastern Australia.

    We are very concerned with the catastrophe that is occurring now, but I am also concerned about what will happen if we have continued warming of the coolers months and we continue to experience reduced rainfall over winter in southern Australia. How will this will affect the ability of freshwater systems to recover?

    Thanks Graham

    The next few years up here in the New England will be very interesting for me (perhaps not in a good way), to see how the trout, but more importantly the cod & bass fisheries react to this current drought.

    We’ve had 100mm+ over the last 3-4 days, but I notice one of my fav. cod stream does not seem to have kicked up at all on the WaterNSW website, which is a little confusing as all other rivers/creeks have?

    On climate change, my biggest question has been how can a gas (CO2) which is such a tiny % of the atmosphere have such as big impact, but I think we have been through that issue.  And others who suggest water vapour is a bigger contributor?

    #862123

    bribri
    Participant

    The next few years up here in the New England will be very interesting for me (perhaps not in a good way), to see how the trout, but more importantly the cod & bass fisheries react to this current drought.

    Great to see some decent rain falling. Will probably lead to more fish kills this week, but I guess the good news is that there probably aren’t too many fish left to kill in some of those streams! It will be really interesting to see how they recover.

     

    #862147

    bribri
    Participant
    This reply has been marked as private.
    #862148

    DrGraham
    Participant

    My apologies for the following long post but thommo227 raised a very important and fair question yesterday.

    I understand the difficulty in understanding how an apparent “tiny” amount CO2 can have such an effect on our climate, and it’s not helped when certain TV and radio media people, with zero science credentials, attempt to trivialise the role of CO2 by saying it’s only 0.04% of the atmosphere and can’t possibly be important. The fact is, the amount of CO2 in our atmosphere is not tiny. Real numbers – there is about 3,000 billion tonnes of CO2 in our atmosphere at present. That is more than enough to act as a blanket keeping this planet warm and stopping it becoming a frozen rock. There was more than enough CO2 in the atmosphere pre-industrialisation to do that. It’s hard to imagine that amount. In relation to the equivalent tonnage of water, it would be an area the size of NSW flooded to a depth of 3.75 m. That’s probably hard to grasp too and how far it would spread around the globe. The average survival or space blanket is made of aluminised mylar, is usually just a few hundred micrometres thick (less than half a mm), and weigh about 50-75 g. Yet, its unique properties will keep you warm by trapping your body heat. CO2 has its unique properties of being transparent to incoming solar radiation/heat but opaque to infrared heat rebounding off the Earth’s surface. In rather simple terms, CO2 molecules have an ability to “absorb” the rebounding IR radiation/heat and send it back down. There’s a little bit more going on, with CO2 molecules stimulated by IR and vibrating and sending that energy back in to the system and in turn probably causing other molecules in the atmosphere to vibrate.  Nitrogen and oxygen as tightly bound double atoms don’t respond to IR directly. To really understand what’s happening with CO2, with its electron bonds, excitation of electron levels etc , is getting into the realms of quantum mechanics and I haven’t touched that stuff in decades. Suffice to say that CO2 acts as a one way blanket and like any other blanket the thicker or denser the blanket the more heat is retained, and human activity continues to add to it. 0.4% may still sound trivial but in context, ozone comprises 0.3 parts per million (ppm) in the atmosphere overall, or 10 ppm in the concentrated “ozone layer” in the stratosphere. 10 ppm is about 1/40<sup>th</sup> of the amount of CO2, or 0.0003% in the atmosphere overall or 0.001% of the stratosphere gases. That seems implausibly tiny, yet without the ozone layer blocking much of the UV radiation, the Earth’s surface would be completely sterilised. Any life would be subterranean or deep ocean where UV can’t penetrate.

    Yes, water vapour is an important greenhouse gas and its primary role is through cloud formations. Clouds act as a two-way blanket, reflecting incoming solar radiation back out, but also trapping heat that makes it to the Earth’s surface. We see the difference in heat between cloudy and cloudless days, and how quickly temperature drops on a cloudless night, usually resulting in frost in cooler months. Water vapour as clouds has a much more localised and transient effect. Clouds move constantly, and water vapour remains in the atmosphere for only days before precipitating somewhere – and there’s the problem, southern Australia is not getting adequate precipitation. Overall, water vapour various from trace amounts to 3-4% of atmospheric gases depending on location and time. It is not uniform or consistent as compared with CO2.

    In terms of trivialising the concentration and importance of key gases or elements/molecules, I can play that game too, reducing the amounts to tiny percentages and then wonder how they can be important or effective. Examples – Ketamine at 2 mg/kg of body mass, or 0.0002% is sufficient to induce anaesthesia in humans; zinc concentrations in humans is less than 0.003% but is an essential trace element necessary for an effective immune system; there’s just 3 to 14 mg selenium in the human body or 0.000004 to 0.00002% of the average adult which is essential for proper thyroid hormonal function; 18 milligrams (18 microlitres) of taipan venom will kill a human, that’s about 0.00003% of a human weighing 70kg; even 500mg of paracetamol is only 0.0007% of an average human body weight. All are tiny amounts but they have an effect.

    #862191

    thommo227
    Participant

    Thanks Graham, that is a very good explanation.  Shame the scientists don’t seem to have put it in the public arena?  Or perhaps it is that the media think it is too technical to explain?

    #862195

    Nog
    Participant

    Scientists have put it in the public arena numerous times, however it doesn’t fit in with the 10sec soundbite paradigm

     

    #862196

    MJL
    Participant

    The media won’t run it. Correcting misinformation doesn’t have the broad scale appeal mainstream media are looking for to sell product. Unfortunately the opposite is not the case.

    #862197

    Boris
    Participant

    But we are still waiting for the hotspot over the tropics that proves the amplification to the extent that the models use. There is no hot spot!

    All the models used by IPCC to make predictions have given an undue weight to the amplification. This is borne out by the fact that each model fails the replication test.

    Ice cores spanning long time frames show no sign of “runaway” warming when CO2 has risen to much much higher levels. But ice cores do show that CO2 lags the temp. So something else must be driving the temp rises.

    #862198

    Boris
    Participant

    The media won’t run it. Correcting misinformation doesn’t have the broad scale appeal mainstream media are looking for to sell product. Unfortunately the opposite is not the case.

    The media is too busy name calling and bullying public figures.

    #862199

    MJL
    Participant

    The media is too busy name calling and bullying public figures.

    Boris, we agree on something. Sky News was built on this:

    #862200

    bribri
    Participant

    Thanks Graham, that is a very good explanation.  Shame the scientists don’t seem to have put it in the public arena?  Or perhaps it is that the media think it is too technical to explain?

    You’ve hit the nail on the head I think Thommo. IMO it’s a massive problem with science in general. As far as funding agencies and employers are concerned, the most important measure of any scientist’s success is their publication record. If you don’t publish, you won’t attract funding and you won’t have a job. Unfortunately, the only publications that count are printed in scientific journals that are only read by a handful of scientists and are usually hidden behind paywalls (despite the fact that it’s often the taxpayer who funded the research in the first place!)

    The media, in general, are interested in getting clicks and advertising revenue. They don’t give a damn about printing science. Why should they? They’ll print things that sell.

    There’s plenty of good, reputable science available online. But there’s also a lot of utter bullsh*t that throws around some sciencey words and ‘expert’ opinions to make it sound believable. It can be almost impossible to tell the difference.

    Apologies, I digress.

    Anyone heard any reports on how the rain’s impacting the fire-affected trout streams on the mainland? Looks like most of eastern Vic/ southern NSW copped a fair drenching, but hopefully not enough to turn the rivers to mud?

    #862203

    DrGraham
    Participant

    Thommo227, happy to oblige. Re science and media, I spent a fair bit of my life working with an excellent media unit at the AAD trying hard to get our stories out to the public. These were stories promoting really important science relative to the Antarctic and in my area, krill, the marine ecosystem, and what was happening to them. However, we were generally dealing with reporters who didn’t care or couldn’t grasp the science in order to report it, even when we had prepared a fairly simple press release. Unless it was a cure for cancer, or the imminent collision of an asteroid with the Earth – and thus cancelling the weekend Grand Final – the media rarely gave us much air time or paragraphs other than deep in the paper. But, a star footballer getting a “hammie” injury …     I am being a tad facetious.

    #862204

    DrGraham
    Participant

    Boris, I strongly suggest you read up on some real glaciology, starting with Tas Van Ommen, glaciologist and palaeoclimate expert, and head of the Law Dome ice drilling programme at the AAD; Tim Naish, NZ ice sheet glaciologist, or Rob Massom or Sharon Stammerjohn in relation sea-ice. They are just the start of a massive glaciology network looking at current and past climatological effects.

    #862230

    Mitta
    Blocked

    . . . most of eastern Vic/ southern NSW copped a fair drenching, but hopefully not enough to turn the rivers to mud?

    Unfortunately it did turn to ‘mud’, Bribri. . . . the rivers, the landscape, everything.

    I thought that Chief may have hit town.

    Here’s the Toorongo River (near Noojee) at 6:45 Monday morning – a muddy torrent.

    It took all day today to wash the mud from everything.

    A muddied Mitta.

    88862165-4009-4F5D-A2BB-DB09966D2079-1

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