like in lakes or rivers, and why dosen't the fishes in e water freeze to death during winter?
214272
During winter the water at the surface of lake or pond gets cooled.\n\nDue to cooling density of water increases; denser water\ngoes down, while the relatively hot water comes up. This is convection.\n\nBut water has a peculiar property that below 4 degree C it becomes less dense.\n\nTherefore when the surface temperature is 4degree and below, the water at the surface cannot go down. Hence convection of water is stopped. \n\nThe temperature increases relative to water surface.  If the temperature of the water surface reaches freezing temperature, ice is formed on the surface and the freezing takes place from top to bottom.\n\nThus lives of water living creatures are saved from freezing.
473912
Assuming it's true, then it's probably because of creatures' abilities to adapt to their environments.  Over centuries, evolution and genetic mutations and such allow different species to form, to become most suitable for their habitat.\n\nHowever, I'm a bit doubtful that a snake, a cold-blooded animal, would be able to survive in such a cold region....
371111
Because it takes a lot more energy to change the temperature of water than it does to change the air temp, since water is considerably denser.  The large body of water thus acts as a "heat-sink" holding on to heat during the day and releasing it into the air at night to keep the temperatures more moderate.\n\nBy the way, "moderate" doesn't just mean warmer in the winter, it can also mean cooler in the summer -- just less extreme all year 'round.  The same way the water holds on to heat during the winter, it stays cooler in the summer and moderates summer temps by being a constant cool source and through evaporation.
38971
Not all fish do die when taken out of water. Some fish can survive indefinitely out of water provided they are kept moist with rain or dew.\n\nOf those fish that do die the most common cause of death is suffocation. \n\nFish mainly extract oxygen form the water through their gills. The gills of fish consist of hundreds of thousands of tiny strands, almost like hair. Have you ever seen someone with long hair underwater and noticed that the hair floats out from the head? Well underwater the gill filaments behave the same way. In the water those strands float apart and the fish is able to to extract oxygen from every one of them. \n\nWhen the fish is taken out of water the gill flaments collapse.  Look at a perosn with striaght hair when they climbs out of the water and notice how the hair all sticks together in a sheet? The gills of a fish behave the same way. On dry land the gill filamens of the fish all stik togather. Instead of being able to extract oxygen from each one it can only extract oygen form the ones in the surface layer. That just can't provide the fish with enough oxygen and it suffocates.\n\nContrary to popular belive fish don't technically die because they can only extract oxygen form water. Fish could breath air just fine if the gill filaments didn't collapse. \n\nIOW fsh die on land because air can't support their bodies the way that water can.
549299
Yes, in some specific circumstances, hotter water freezes faster than colder water.  All explanations are still hypotheses and there is no fully proven explanation yet for why.  It's known as the Mpemba effect.
8626
Water gives up far more (latent) heat when cooled than soil does.  Therefore the ground around the puddle may drop to well below freezing before the water in the puddle cools and freezes solid.  This could cause the puddle to freeze at the edges first then work inward toward the middle although a thin skim of ice may cover the entire puddle.  As the freezing water advances toward the center of the puddle it pushes any excess air before it and air can collect in the middle from all sides.  This can form a hollow cavity.  Incidently, ice can freeze in large grains and since a mixture of minerals and water freezes at a lower temperature than pure water, minerals are left at the boundaries of the grains.  Later when the ice melts, the boundaries melt first and can produce weak "rotten" ice that easily breaks through when walked on.  In short, an advancing wall of freezing water or a freezing crystal can exclude foreign matter.
231650
With modern technology, it isn't possible.  When the water in our bodies freezes, it forms ice crystals that puncture cell membranes.  If the body were to be thawed, the insides would be mush.  However, many people still put themselves into deep freeze in hopes that we will be able to counteract the negative effects of deep freeze.
419338
Yes, it would be that cold. April is still very cold in those waters. The Atlantic does in fact freeze at that latitude. Open waters do not get much seasonal ice do to wave action, but bays can and do freeze up. The seals breed on seasonal ice which is drifting out to sea by the time they whelp, and a few years ago an icebreaker had to be used to keep Boston harbour open
486024
There may be certain conditions in which two beakers of water, one at a higher temperature, put into a freezer together, will freeze with the originally hotter one freezing first. It only happens under certain conditions, and is NOT generally true. Apparently the hotter one can develop stronger convection currents in the beaker due to it's initially hotter temp and increased evaporation at the surface, and the continued movement of the water due to the currents set up initially will allow faster heat transfer as it cools.\n\nIt is called the "Mpemba effect".
252451
Carp can change its gill structure by having a lack of protruding lamellae (primary site for gas exchange) for survival in anoxic (without or limited oxigen) water. Therefore, they can breath air and forget about its oxigen consumption for around a month if they want.
79057
The fact that ice always floats on water should give you a clue!  The ice is obviously not as dense.  So you can infer from this something has happened during the freezing process.\n\nThe structure of a water molecule is One atom of hydrogen to two if oxygen.  As the water freezes hydrogen bonds form between the various water molecules and these stop the molecules packing as effectively so the ice is less dense.\n\nTry the source below.
156436
The convection of heat in the water carries warm water from the bottom of the water, nearest the warm earth, to the surface and back.\nThis motion maintains enough warmth throughout the water to prevent the fish from freezing.  The bodies of the fish also enables them to survive in near freezing temperatures by moving constantly.\nConvection always occurs, in Summer and Winter.  And the pattern never changes.
490711
This is what happens if you start freezing a glass of sea water: it will start to freeze at a lower temperature than fresh water (around -4 C, but variable depending on the salinity you start with). \nImportant, the salinity of the ice formed is almost pure water (it is not salty). Some salty water may be trapped on the ice though, but the ice itself is fresh water. If you keep lowering the temperature, more ice will form and the remaining salty water gets even saltier. This process will continues until an eutectic is reached and then you will have a fast crystallization of ice, a mineral called hydrohalite. This eutectic is about -21 C, but depends on other components, like Mg, Ca that are also abundant in the composition of sea water.
355415
Lake effect snow happens because during the summer, the lake water warms up; then, during the winter, it takes this warm water longer to cool down and freeze.  As a result, there is a period of time where the weather is cold enough for snow, but the lake isn't yet frozen.  As the winds blow over the lake towards the city, it picks up water from the lake and drops it as snow on the city.\n\nBecause the lake usually does freeze, the water is relatively colder in the spring and summer, and cold water evaporates less rapidly than warm water.  So, the air picks up relatively less water from this cold water than it would if the water were warm, so the city is somewhat protected from lake effect "rain".
569645
yes.\n\nthey are mammals and do not breathe underwater.\n\nthey take in air at the surface, so it does not matter what type of water they live in.
26081
Salt will lower the freezing point of water. That is why the use in on the roads in winter.
600032
Thats pretty cold, I have swam in that temperature and I can tell you it sucks!! \n\nIf you have a group of polar bears or masoquists that like to freeze their a.. off then go ahead, just make sure you talk loud because their trembling jaws will be making a lot of noise!