deep sea は「深海」
abyssal zone は「深海帯、無光層」
です。
日常会話では deep sea が使われていると思います。
海は sea の他に ocean、water とも言います。
"A new species of fish was discovered in the deep sea."
深海で新種の魚が見つかった。
"Creatures in the abyssal zone have unique adaptations to survive."
深海帯の生物は生き抜くための独自の適応を持っている。
Deep sea =深海
deep =深い
sea =海
海の綴りはsea、「見る」はseeなので気を付けましょう。
Depth of the sea =海の深いところ
同じいみですが、こっちの方がミステリアスに聞こえます。
The creature appeared from the depth of the sea =その生物は海の深いところから現れた
因みに深海魚はdeep sea fishやdeep sea creatureと言います。
The deep sea can be called "Deep sea or Open sea/ocean"
"Ocean" means the same as sea.
"Abyss" means very very deep. So the deep sea can be called "the abyss."
"Abyssal" means an extremely deep part of the sea.
The deepest part of the ocean is called the Challenger Deep and is located beneath the western Pacific Ocean.
I want to go deep sea fishing one day.
The ocean's deepest area is the Mariana Trench
海の最も深い部分は、the Challenger Deep（チャレンジャー海淵）と呼ばれ、西太平洋の底に位置しています。
I want to go deep sea fishing one day.（私はいつか深海での釣りに行きたいです）
海の最も深い場所は、the Mariana Trench（マリアナ海溝）です。
Deep
-extending far down from the top or surface.
Sea
-the expanse of salt water that covers most of the earth's surface and surrounds its land masses.
Layer
-a sheet, quantity, or thickness of material, typically one of several, covering a surface or body.
I hope this helps! :-)
Deep -extending far down from the top or surface.
海面からもっと深い底
Sea -地球の大部分を覆う塩水
Layer 層
参考になると幸いです。
Abyssal (adjective) denotes depths of the ocean.
Deep sea refers to the depths of the ocean.
Examples
Sam want to read about the abyssal depths of the Indian ocean.
Sam would like to go deep sea fishing next year.
Abyssal (形容詞) とは海の深さを表します。
Deep sea（深海）とは、海の深いところを指します。
例
Sam want to read about the abyssal depths of the Indian ocean.（サムはインド洋の深海について読みたい）
Sam would like to go deep sea fishing next year.（サムは来年深海に釣りに行きたい）
Often referred to simply as THE DEEP... The hadal Zone / Marianas Trench is the deepest part of the world's oceans.
In the depths of the ocean...Way way down, where the strangest sea creatures live, we find the Hadal Zone; a part of the Marianas Trench, at a depth of approximately 11,000 metres.
例：In the depths of the ocean・The deep
「海の底」「深い海」
単に"THE DEEP"で深海を表すことがあります。The hadal Zone(超深海帯)/Marianas Trench(マリアナ海溝)は世界で一番深い深海です。
海の深い深い底、ヘンテコな生き物が沢山いるところ。
私達人類はthe Hadal Zone「超深海帯」を発見しました。the Marianas Trench「マリアナ海溝」の一部で、最深部は約11,000 メーターもあります。
There are many levels to the sea
1- shallow or continental shelf
2- deep sea or Bathyal zone
3-abyss or Abyssal zone
4- Mariana's Trench or deep-sea trenches
Deep sea is the most commonly used term for water either in the ocean or sea that is not shallow . We use Abyss for water that is very deep where there is no sunlight there and the bottom of the ocean or sea is called deep-sea trenches which is where the Marianas Trench is located . When we want to describe things in the deep sea we use the term the depth of the sea. For example : In the depth of the sea we can find various sea creatures not found in the shallow part of the sea or ocean.
海は深さによって表現が沢山あります。
1-shallow or continental shelf（浅瀬または大陸棚）
2- deep sea or Bathyal zone（深海または漸深海帯）
3-abyss or Abyssal zone（深海（底）帯）
4- Mariana's Trench or deep-sea trenches（マリアナ海溝または深海の海溝）
Deep seaは一般的な表現で、浅瀬ではない海を表現します。
Abyssはとても深い深海を表す表現で、太陽光が届かないような場所を指します。
海底は deep-sea trench と呼ばれ、マリアナ海溝のようなところを指します。
深海にあるものを表現したいときには、the depth of the seaを使うことができます。
例：In the depth of the sea we can find various sea creatures not found in the shallow part of the sea or ocean.
「海の底（深海）では深海にしか生息しない沢山の生物を見られます」
深海はdeep seaと言います。そのまま翻訳しますね。
例：animals of the deep sea look like aliens. 深海の動物が宇宙人のように見える。
例：It's said that the deep sea is blacker than night. 深海は夜よりくらいと言われている。
ご参考にしていただければ幸いです。
"Deep sea," is probably the most general way to say this phrase as it uses the adjective, "Deep," to describe what part of the sea you are referring to.
"The bottom depths of the sea," describes the idea of, "the bottom depths," to talk about that it's the very bottom of the sea.
"Deep sea" がおそらく最も一般的な言い方です。形容詞の "Deep"（深い）を使って海のどの部分について言っているのか伝えています。
"The bottom depths of the sea" では、"The bottom depths" を使って「海底の底」を表しています。
Eg. 'The sea water is calm near the coast, but as soon as we get out into the open sea, it will get a little rougher.'
Eg. 'Around the bay the water is pretty shallow and warm, but when we get into the deep sea, it is much cooler.'
'Deep sea' may be used as an adjective as well as a noun.
Eg. We are going deep sea fishing in the morning.'
海の奥深いところ、「深海」のことは英語で「deep sea」「depths of the ocean」や「ocean depths」で表現します。
例文：
「深海の魚について研究しています」
→「I am doing research on fish in the deep sea」
→「I am doing research on fish in the depths of the ocean」
「深海の魚は面白いと思う」
→「I think fish in the deep sea are interesting」
→「I think fish in the ocean depths are interesting」
ご参考になれば幸いです。
To say that a part of the sea is not shallow, we can say it is 'deep'.
Deep is an adjective that means that there is a lot of space between the top of the water until the bottom of the water.
'The children are not allowed to swim in the deep sea'.
Oftentimes in popular songs or poems related to the sea you'll see the phrase 'deep blue sea', this is common and means that the sea is very deep and the color blue.
'There are many kinds of fish in the deep blue sea'.
You can also use the word 'deep' to describe other bodies of water, such as a man made swimming pool. The part of the pool that has more water is called the 'deep end' and is usually used by adults and experienced swimmers.
'My 5-year-old son can't swim in the 'deep end'.
The opposite of deep is 'shallow'.
The water here is shallow at only 10 cm!
日本 
アメリカ合衆国 
イギリス 
南アフリカ 
オーストラリア 
カナダ 
