Anton Evseyev
Read the original in Russian
Scientists managed to solve one of the
most intriguing mysteries of water. They found out how it can store
information about creatures that inhabit it. It turned out that some of
organic molecules trapped in the water can be stored in it for a long
time. This is strange, because in theory, they should immediately
disintegrate, but for some reason it does not happen.
It is traditionally believed that water medium transmits odors over long distances worse than air. The reason is that signaling molecules whose mass, strictly speaking, composes any odor, quickly disintegrate once submerged into an active solvent, even distilled water. In addition, because of the constant currents (that exist even in standing water) concentration of odor substances immediately decreases dramatically as molecules quickly spread in all directions.
It is traditionally believed that water medium transmits odors over long distances worse than air. The reason is that signaling molecules whose mass, strictly speaking, composes any odor, quickly disintegrate once submerged into an active solvent, even distilled water. In addition, because of the constant currents (that exist even in standing water) concentration of odor substances immediately decreases dramatically as molecules quickly spread in all directions.
At the same time, biologists and
chemists knew that in virtually all aquatic animals, organs of smell
were developed much better than other receptors. Apparently, their work
is very effective. It has long been known that a shark can smell its
victim at a distance of several hundred meters. And yet, it happens in
the ocean where sea water is more active than fresh water due to high
concentration of salts.
Recently, this paradox was resolved by a
study conducted by Professor Boris Koch with the Alfred Wegener
Institute of Polar Research. The scientist, using spectrometry method,
made a remarkable discovery. The accurate mass spectrometer showed that
single molecules of organic matter remain in the water after the
breakdown for a long time.
"Water has chemical "memory" that keeps
information about the organisms that were once in it as single organic
molecules. We learned to determine what part of the organisms these
molecules were and how long they were in the water," said the
researcher. According to him, the spectrometer can accurately determine
the atomic structure of the molecule, and, moreover, the proportion of
carbon, hydrogen, nitrogen, etc. Based on this, we can restore the shape
of the molecule itself, and even determine what part of the organism it
used to be.
According to Koch's study, water often
retains carbohydrates and organic acids. These substances are found in
most secretion emitted by the body surface, such as mucus in fish and
many invertebrates. Of course, the composition of mucus and other
excreta is specific to each species. Perhaps this is the reason why
sharks are able to find their victims at far distance without errors.
They simply follow the trail of organic molecules that remains in the
water for a long time, sometimes for several days. Guided by specific
odor, bloodthirsty predators immediately understand whose trail it is -
harmless tuna or not so harmless dolphins.
Furthermore, they were also able to determine that water retains information about an animal's death for a long time. Some molecules of decaying bodies can be found in a place where the animal suffered death for a very long time. Apparently, they are signals for many marine scavengers such as hagfish and crabs that have poor vision, but can easily find dead creatures immediately after their death.
Furthermore, they were also able to determine that water retains information about an animal's death for a long time. Some molecules of decaying bodies can be found in a place where the animal suffered death for a very long time. Apparently, they are signals for many marine scavengers such as hagfish and crabs that have poor vision, but can easily find dead creatures immediately after their death.
Interestingly, Koch's discovery so far
contradicts some of the laws of organic chemistry. According to them,
any organic molecule after exposure to sea water should quickly
decompose into simple components, such as carbon dioxide and water. But
in this case it does not happen. Why? Perhaps due to the fact that
excretory substances are capable of forming complex links with water
molecules resistant to any "destroyers."
How long can these stable compounds
live? The paper refers to a few days, but it is possible that this has
to do with a limited time of the experiment. Perhaps molecular
information can be stored for months or even years. This should be
tested by conducting research outside of the lab, in the ocean.
If so, then this technology can be used, for example, to track migration routes of various marine animals. In fact, members of AWI are planning to take samples of water near the colonies of southern elephant seals next summer in Antarctica to confirm this assumption. They are also going to work with sharks. Changing the concentration of organic matter in the water, they want to understand whether aquatic animals can navigate in the ocean "by smell," detecting an increased concentration of certain molecules.
Finally, this study has yet another
interesting perspective. Realizing how long water can store organic
molecules, the researchers can find the limit "capacity" of the ocean as
the largest reservoir of organic matter in the world. They will be able
to track how much CO2 is produced in the ocean, and what comes from
outside. This will help to finally get some clarity regarding the
notorious greenhouse effect. If so, then this technology can be used, for example, to track migration routes of various marine animals. In fact, members of AWI are planning to take samples of water near the colonies of southern elephant seals next summer in Antarctica to confirm this assumption. They are also going to work with sharks. Changing the concentration of organic matter in the water, they want to understand whether aquatic animals can navigate in the ocean "by smell," detecting an increased concentration of certain molecules.
