1. why are jellyfish a nuisance to fishermen and coastal dwellers?
2. why have jellyfish not been thoroughly studied?
3. discuss the environment inside a deep-sea submersible.
4. why is it so hard to capture and keep jellyfish alive?

1. Jellyfish cause harm to the other fish species, and it causes damage to the fisherman nets. As they have this nature, they are a nuisance to the fishermen and coastal dwellers.

2. Handling jellyfish is very difficult because of its nature. So because of this, jellyfish not been thoroughly studied.

3. There might be many types of different things in the deep-sea submersible. Among them, wastage, precious minerals, and manganese nodules are significant.

4. As jellyfish have harmful nature, it is hard to catch. And after catching, making the proper environment and providing adequate food to the jellyfish is difficult. So, it is challenging to keep it alive after picking or catching.

Explanation:

Requirement - 1:

Jellyfish is a nuisance to fishermen and coastal dwellers because fishermen and coastal dwellers are entirely dependent on fishing for their livelihood. If jellyfish present in any fishing area, it creates a problem for the fisherman. Jellyfish clog their nets and decrease the value of their fish by stinging them. Along with 600 other species which crossed the Suez, the jellyfishes are driving the native marine dwellers to extinction and taking their place. As jellyfish have a jelly-like structure, it can quickly enter and stay in the nets of the fisherman and can harm them.

Requirement - 2:

Researchers have tended to ignore or avoid jellyfish for research purposes because jellyfishes are such a nightmare to deal with. Typical nets destroy them, and collecting them intact can require fearless efforts. A marine ecologist named Shin-ichi Uye at Hiroshima University in Japan told that because some jellyfish are heavier than sumo wrestlers, marine biologists must carefully balance their small research boats to avoid inverting when recovering a single specimen.

Requirement - 3:

Researchers found many things inside a deep-sea submersible. In the environment of hydrothermal vents, there are rich mineral deposits, including silver and gold. Along with this, covering thousands of square miles of the deep-sea floor are billions of tons of so-called "manganese nodules" that are rich in cobalt, nickel, and manganese. Along with this, researchers said that approximately 70,000 tons of radioactive garbage could be stored in stainless steel cylinders, which are buried in the deep sea.

Requirement - 4:

Catching jellyfish is hard because of its nature. It can destroy the net during catching. Along with this, it has a heavyweight. For these two reasons, catching jellyfish is hard. Including this, keeping jellyfish alive is another challenge. There are many reasons behind this, but among them two are major: providing proper food to the jellyfish is not possible easily, it requires a large amount of space to keep (usually 2-20 gallons). If anyone wants to keep jellyfish alive, he/she has to make that type of environment in the tank where continuous gentle water flow is present. Along with this, jellyfish and other fish species can't be kept in the same place. If they are kept in the same place, other fish species will get harmed because of jellyfish.

As these type problems are present, catching and keeping jellyfish alive is so hard.