Why is the sea so salty, and the fish are not so salty in it every day???

First of all, the sea water is so salty? The reason why seawater is salty is because there are about 3 5% salt in seawater, most of which is sodium chloride, and a small amount of magnesium chloride, potassium sulfate, calcium carbonate, etc. It is these salts that make the sea water bitter and astringent, difficult to consume.

So where do these salts come from? Some scientists believe that the surface water (including seawater) that has just begun to form on the earth during a long geological period is freshwater. Later, due to the erosion of the surface rocks by the current, the salt of the rocks is constantly dissolved in the water.

These streams then merge into large rivers into the sea, and as the water continues to evaporate, the salt gradually settles, and over time, the salt accumulates more and more, so that the sea becomes salty. If this reasoning is followed, then the sea water will become saltier and saltier over time. The fish are not as salty as they are in it every day???

Because it's the fish's own space, how can they feel uncomfortable in the space they breathe?

Seawater is a very complex multi-component aqueous solution, and various elements exist in certain physical and chemical forms. The existence of copper in seawater is more complex, and most of it exists in the form of organic complexes. Only a small fraction of the free ions exist in the form of divalent positive ions, and most of them occur as negative ion complexes.

So free copper ions account for only a small fraction of all dissolved copper. Sodium is extremely abundant in seawater, but its chemical form is very simple, it is almost entirely in the form of Na+ ions. Generally, the components in seawater are divided into five categories:

Main components (macro, macroelements): refers to the components in seawater with a concentration greater than 1 106mg kg. There are five kinds of cations Na+, K+, Ca2+, Mg2+ and SR2+ in this category, Cl 0 4, SO42 0 4, Br 0 4, HCO3 0 4 (CO32 0 4), F 0 4, and H3Bo3 in molecular form, the sum of which accounts for the salinity of seawater.

So it's called the main ingredient. Because the content of these components in seawater is large, the concentration ratio of each component is approximately constant, and biological activities and total salinity changes have little effect on it, so it is called a conserved element. The Si content in seawater is sometimes greater than 1 mg kg, but because its concentration is greatly affected by biological activities and its properties are unstable, it is a non-conservative element, so the main components are not included in the discussion.

Gases dissolved in seawater, such as oxygen, nitrogen and inert gases. Nutrients (nutrients, biogens): mainly related to the growth of marine plants, usually referring to N, P and Si.

The amount of these elements in seawater is often affected by plant activity, and when their levels are very low, they can limit the normal growth of plants, so these elements are important for living things. Trace elements: those that are very low in seawater, but do not belong to nutrients.

Organic substances in seawater: such as amino acids, humus, chlorophyll, etc. The concentration of seawater is similar to that of fish body fluids.

The concentration of seawater is similar to that of fish body fluids.

Remember.

If the sea is not salty, then the fish will not be delicious, hehe.

No.

This is because fish in the ocean have their own "desalinations" that remove salt from the salty water they drink. This "desalination" of bony fish and cartilaginous fish are different. Bony fishes in the ocean have a strong ability to excrete salt and have organs that specialize in rejecting salt.

Due to the efficient work of these salt-secreting cells, the salt content of marine fish is always kept low.

Cartilaginous fish have another set of skills to keep their bodies low in salt. They have a high concentration of urea in their blood, which is just right to maintain a high osmotic pressure in the body. This reduces the infiltration of salts from seawater, which accelerates the excretion of salts by the kidneys.

As a result, the meat of the fish will never become salty.

Difference Between Marine Fish and Freshwater Fish

Freshwater fish are fish that can live in freshwater with a salinity of 3 parts per thousand. Marine fish are mainly fish that live in the sea, such as hairtail, yellow croaker, etc. Freshwater fish are mostly herbivorous and omnivorous, and a small number are carnivorous. Marine fish, on the other hand, feed on a variety of flora, fauna and microorganisms in the ocean.

Another difference between marine fish and freshwater fish is that marine fish taste better than freshwater fish. This is mainly because the marine fish grow in the sea, and the swimming range and swimming force are very large, so the muscles of the sea water are more elastic and the taste is more delicious. In addition, freshwater fish mainly feed on saprophytes in the river, and the swimming range is also small, and the freshwater fish still have an earthy smell, so the taste of marine fish is better.

1. Because the salt concentration in the body tissues of saltwater fish is much lower than the salt concentration in the seawater in the surrounding environment where they live. Seawater contains a lot of salt and is dense, and the osmotic pressure of fish body fluids is lower than that of the surrounding water environment. According to the principle of osmotic pressure, the cavity-only water in the body tissues of saltwater fish will continuously seep outward from the gills and body surface.

2. In order to maintain the water balance in the body, saltwater fish must constantly swallow a large amount of seawater to make up for the loss of water in the body. However, if a large amount of seawater is swallowed, the salt content in the fish's body will increase greatly, so in addition to removing a part of the salt from the kidneys, saltwater fish mainly rely on the "chlorine cells" in the gill tissue to complete the salt excretion.

3. In addition, there are some saltwater fish, mainly cartilaginous fish, such as sharks, which store the metabolized nitride in the form of urea in the blood, so that the blood concentration is round and high, and the osmotic pressure becomes equivalent to that of seawater, so that there is no problem of water swallowing and salt discharge.

1. Fresh marine fish meat is actually not salty, because the marine fish itself has the function of desalination of seawater, and the meat is relatively light to eat. Only after making dried marine fish, it will feel salty when eaten, at this time we can soak it in light salt water to precipitate the salt inside, or soak it for a few hours before eating.

2. If you want to alleviate the saltiness of dried sea fish, then it is best to soak it in light salt water before eating, so that the two can react, analyze the salt, or soak it in water for a few hours in advance, so that its saltiness will be much lighter and the taste will be better.

<>1. Fresh marine fish meat is actually not salty, because the marine fish itself has the function of desalination of seawater in front of Wang, and the meat tastes lighter. Only after making dried marine fish, it will feel salty when eaten, at this time we can soak it in light salt water to precipitate the salt inside, or soak it for a few hours before eating.

2. If you want to relieve the saltiness of dried sea fish, it is best to soak it in light salt water before eating, let the two react, analyze the salt, or soak it in water for a few hours in advance, so that its saltiness will be much lighter and the taste will be better.