The reason is actually very simple. Like my brother, their ocean-going ships need to float at sea for 2-3 months every time they sail! Imagine what it would be like if we humans didn't wash our hair and bathe for two months. If it doesn't stink, lice and fleas will definitely grow out!
Ships also need regular cleaning, especially the bottom. The impact of sea water at high speed can't effectively solve the problem! And ocean-going ships can't sail at high speed all the time. Once they stay at sea for a long time, especially in shallow waters with many creatures, the bottom of the ship will be covered with all kinds of marine life, which makes people even feel horrible!
As we all know, many marine life in shallow water has the characteristics of attaching to other things and growing. On rocks in shallow water, on large marine animals (such as whales and turtles). Therefore, the huge underwater bottom has become another paradise for this kind of marine life to choose to parasitize.
Especially the notorious barnacle, which can secrete a strong sticky glue and stick firmly to the attachment itself. It is not afraid of seawater erosion, but also can rely on the nutrients brought by the current to maintain life! Barnacles are so attached that it is almost impossible for people to pull them out by hand. They must be cleaned with shovels or high-pressure water guns!
In addition to barnacles, there are some diatoms, barnacles, oysters, mussels and various microorganisms attached to the bottom of the ship, collectively known as "marine fouling"!
They will stick to the bottom of the boat like psoriasis. If it is not cleaned up in time, marine life at the bottom of the ship will multiply and grow in large quantities, which will greatly increase the weight of the ship, directly lead to the improvement of navigation resistance, higher fuel consumption and corresponding pollution discharge. According to the statistical analysis of scientists, marine pollution increases the global ship fuel consumption by more than 40% every year, and the economic loss is as high as 7.5 billion dollars.
The answer is actually very simple. Do you eat fleas and lice? It's disgusting to look at it, let alone eat it. So is the "seafood" at the bottom of the boat. Not only that, they may also be highly toxic!
As mentioned above, if these "marine fouling" attached to the bottom of the ship are piled up too much and not cleaned up in time, it will not only increase the load and fuel consumption of the ship and affect the normal running, but also some shellfish will secrete some acidic substances, which will corrode some important parts such as the bottom and propeller, directly affecting the service life of the ship and causing potential safety hazards.
Therefore, in order to prevent the hull from being corroded by seawater and reduce the attachment of marine fouling organisms, our shipbuilders and users should take some protective measures in advance before the ship goes into the sea, that is, painting!
According to the tonnage and displacement of the ship, it is mainly drawn below the waterline of the ship! Most of the paint painted on the bottom of the ship is red, because the workers on board have added red toxic substances such as cuprous oxide and mercury oxide to the antifouling paint! Even in the early days, the primer of many ships and warships may contain toxic compounds such as arsenic!
Cuprous oxide and mercury oxide are highly toxic to marine fouling organisms! Now, in order to protect the marine environment, a more environmentally friendly antifouling paint is used in the bottom of the ship, but it is still toxic. These toxic components are mainly aimed at barnacles, oysters, mussels and other marine parasites! Harmless to human body, little impact on marine environment!
However, you will find that painting workers in many shipyards basically wear gas masks and protective clothing for painting operations, which means that this kind of antifouling paint is less toxic and less toxic, and the gods can't save it if it is large!
Even so, after being killed, these marine pollutants will still adhere to the bottom of the ship, and some marine life will be able to resist these toxicity and survive tenaciously, and even some mutated organisms and bacteria, so these so-called seafood at the bottom of the ship is absolutely inedible!
It is worth mentioning that barnacles are the main attachments at the bottom of the ship, and they can really be eaten after drying or cooking. Some fishermen even call it "seafood from hell", which is not only rich in various amino acids necessary for human body, but also very high in protein.
However, these barnacles and other "seafood" attached to the bottom of the boat are really inedible. If you are greedy, it's not just diarrhea!
People who live by the sea, or friends who are interested in sailing and navy, should know that ships that go out to sea all the year round, from 10,000-ton ships and aircraft carriers to ordinary fishing boats and sailboats, need to clean their bottoms regularly.
No matter what kind of ship is at sea for a long time, it will attach a large number of marine life, especially various shellfish, such as oysters and barnacles, so much that there is almost no gap in the whole bottom of the ship.
Ships are not as simple as they used to be. Nowadays, the ship structure is very sophisticated, and there are keels and propellers at the bottom of the ship, which makes the ship become the attachment point of many marine life when it goes out to sea.
If you pass through shallow water, all kinds of algae and microorganisms will attach to the bottom of the ship, and barnacles, oysters, mussels and other organisms that feed on plankton will also attach to the bottom of the ship. Over time, there will be many bottoms.
A large number of bottom creatures take the bottom of the ship as their home. When a ship sails, it can open its mouth to filter the rich food in the water, so the bottom of the ship is an ideal habitat for many filter-feeding animals.
According to a rough estimate, at least17kg of marine life will attach to the bottom of seagoing ships every year. The global oil consumption caused by organisms attached to the bottom of ships will increase by more than 40% every year, and the economic loss will exceed 7 billion dollars.
For a ship, it is not a good thing to attach a lot of creatures to the bottom of the ship, because attaching too many marine creatures may not only cause damage to the ship, but also increase the difficulty of navigation and fuel consumption.
In order to reduce the loss, most ships have to clean the bottom of the ship every year. Every time they clean up, they can scrape an amazing amount of seafood from the bottom of the ship, almost all of which are oysters and barnacles, and there are few other kinds of marine life.
Oyster is a very famous seafood. Although barnacles look uncomfortable, they are also quite delicious. Oysters and barnacles are not cheap seafood on the market, but although there are many seafood at the bottom of the boat, not all of them are edible.
Because it takes time and money to clean the bottom of the ship, in order to reduce the attachment of marine life, many large ships will spray highly toxic paint on the bottom of the ship, which makes many marine life attached to the bottom of the ship contaminated by toxins and become inedible.
It may be really useful at first, but over time, many marine creatures have developed resistance to these highly toxic paints and are not afraid at all. They are still attached to life at the bottom of the ship, and people can only strengthen their toxicity and spray more toxic paint.
At present, although most coastal fishermen regularly clean the bottom of the boat, they often discard the seafood at the bottom directly. After all, the seafood attached to the bottom of the ship is dirty and may be toxic and polluted. It is better not to eat it.
I grew up in Dalian, a famous port city in northern China. Dalian's shipbuilding and ship repair industry is particularly developed, so many relatives and friends around me are engaged in shipbuilding and ship repair.
Ships will enter the dock for maintenance after sailing at sea for a period of time. One of the most important is rust-removing and antirust paint, because seawater is corrosive. Ships immersed in seawater all the year round will be eroded by seawater, and there will be many marine life parasitic on it. If it is not removed, it will affect the sailing speed and service life of the ship.
Ship derusting is a hard job, which is usually carried out in summer, because it is sunny this season and people can work more conveniently. Derusting and cleaning the bottom of the ship requires people to clean it up a little bit with a chisel, and then polish and spray paint. Cleaning the attachments at the bottom of the ship is very hard and heavy, because these attachments are smelly and smelly, so the work is dirty and tired.
First, what seafood is at the bottom of the boat?
Shellfish, such as mussels and barnacles, mainly grow in the bottom of ships. These seafood are absorbed and wound in a fixed place by secreting foot silk, and then they make a living by filtering ephemera in seawater.
During the voyage, the ship will definitely pass through many places where shellfish grow, so it is no accident that these seafood are adsorbed under the ship. Moreover, the temperature at the bottom of the ship is very suitable, and the domestic wastewater on board also provides food for these shellfish. So the longer a ship sails in the sea, the more shellfish and marine algae will grow on it.
Second, why can't the seafood at the bottom of the boat be eaten?
(1) Bottom environment: The ship relies on the power of burning diesel oil during navigation, and the waste gas and oil after burning this diesel oil are discharged into the sea, so oil flowers float on the sea around the dock where the ship stops. People generally call this "smelly oil". Seafood and marine fish polluted by smelly oil will have a bad smell and can't be eaten at all, and so will the seafood at the bottom of the ship.
2. Ship bottom structure: The ship bottom is coated with antirust paint on the outside of iron. Seafood lives on this and naturally fixes itself on rust and paint. Who dares to eat seafood grown in such a place?
(3) Seafood species growing at the bottom of the ship: Seafood growing at the bottom of the ship is basically a very fertile and common seafood species. This kind of seafood is very common at the seaside, and some people on the rocks exposed after low tide don't eat it, mainly because this kind of seafood must live in clean waters, otherwise it will do great harm to the body once it is polluted.
4. Seafood is mainly eaten fresh, especially shellfish: if the seafood at the bottom of the ship is to be put away to eat, wait until the ship enters the dock, so that the seafood at the bottom of the ship is basically dead or smelly, not to mention it smells disgusting, and naturally no one will eat it.
Eating seafood pays attention to eating fresh and clean waters. The pollution under the ship is serious, and the freshness of seafood is poor. Such seafood will not be eaten at all, so it can be said that it is not eaten at all.
Seafood at the bottom of the boat is not edible. We all know that ships are made of all kinds of steel, especially the bottom of the ship is almost made of steel. The seawater has high salinity and strong alkalinity, so seawater will corrode the hull. Because the bottom of the ship is in contact with seawater, seawater is more corrosive. In order to prevent seawater from corroding the bottom of the ship, people have come up with many ways. At present, the common method is to coat various paints on the bottom of the ship to prevent seawater corrosion, and these paints often contain a lot of heavy metals, such as commonly used mercury oxide and cuprous oxide. When marine life grows on the bottom of the ship, these heavy metals that are extremely harmful to human body will enter the bottom of the ship along the food chain, so that after a long period of accumulation, the heavy metal content of the lower seafood in the ship will seriously exceed the standard. If people eat these seafood, the harm can be imagined. In addition, at present, the power used by large ships is mainly various fuels, and a large number of harmful substances will be produced during the combustion process, and the bottom of the ship will be greatly affected by these pollutants. Moreover, large ships often enter and leave heavily polluted waters, which will also lead to the pollution of benthic organisms. Anyone who has been to the seaside knows that the coastal water is very dirty, especially the docks, and all kinds of pollutants on the land in coastal areas flow into the coast; Waste gas, waste water, leaked crude oil, etc. Entering and leaving the dock will lead to the deterioration of seawater quality in coastal areas. Therefore, ships entering and leaving the dock are bound to be affected by sewage, so benthic organisms often pass through waters with poor water quality, so it is inevitable to be polluted. Besides, many creatures living in sewage have mutated, and we must never eat these mutated creatures.
Seafood grows at the bottom of the boat? Will it be as effortless as waiting for a rabbit? The result is not like this! Even the two are not comparable. Waiting for rabbits may be delicious food, but this is not because rabbits are smarter and ensure that more rabbits will not hit trees again. The length of the bottom of the ship is the result of seafood habits.
The ocean is a treasure house of human resources. In some shallow waters, barnacles and algae attached to rocks are often seen. Similarly, when they meet a ship that can "sail the Wan Li Road" in the ocean, they can still be attached to the bottom of the water. Those barnacles, oysters, diatoms and shellfish boarded the ship and felt the pleasure of sailing comfortably.
These dependent creatures regard the bottom of the boat as a paradise, not only because they can have a pleasant ocean trip without spending a dime, but also because the constantly pounding seawater during the trip can provide them with important substances to sustain their lives.
However, even so, the seafood at the bottom of the ship is inedible.
Because once seafood is attached to the bottom of the ship, in order to survive, they will secrete a substance, which is very sticky and attached to the bottom of the ship. Even when the ship is sailing, it can't escape when it meets strong current. Otherwise, how can the old ticket of the creature get on the moving ship?
Take barnacles as an example. They are seafood that likes to adsorb on the bottom of ships. They are very fertile. A barnacle can raise thousands of offspring at a time, and a large barnacle can even raise tens of thousands of offspring. Their powerful reproductive ability will overwhelm ships, just like people walking, like carrying heavy packages on their backs, which will crush people.
The boat carrying barnacles that made them miserable not only failed to meet expectations, but also wasted fuel.
Barnacles can secrete acidic substances, so that when ships sail, their bodies will not be hit by huge currents.
However, it is the acid they secrete that poses a threat to huge ships. Acidic substances corrode the bottom of the ship, and the life of the ship will be weakened with the increase of age, which will also cause some safety hazards.
Similarly, oysters, algae and other microorganisms will take the opportunity to take a free "cruise ship" and camp, so the seafood team at the bottom of the ship is getting bigger and bigger! According to foreign statistics and analysis, the economic loss caused by the increase of fuel consumption of these seafood products to ships all over the world every year is as high as 7.5 billion US dollars.
Usually, the big ships we see are all red below the water. First, prevent the corrosion of seawater; The second is to prevent seafood from damaging the ship for a long time and high fuel consumption. The red substance is a mixture of cuprous oxide, mercury oxide and paint, and these mixtures are toxic.
It has been said that it's a shame to get these dazzling seafood as easy as blowing off dust and clean it up when the ship docks. Wouldn't it be better to have a good meal? The answer is no.
Think about it, they can live in a toxic environment for a long time, but their bodies are also attacked by toxic mixtures at the bottom of the ship. How much can they keep the nutrition of seafood? We can't treat ourselves as "guinea pigs" knowing that we are poisonous. That's too expensive.
There are also huge ships sailing, and the main power comes from oil. In the process of oil combustion, the discharged pollution directly acts on the seafood adsorbed on the bottom of the ship. Besides accumulating a lot of substances harmful to human body, what nutrition does polluted seafood have?