toutyakukou ni ouzite, noritugi wo kaeru.

A natural reading is:

とうちゃくこう に おうじて、 のりつぎ を かえる。

Word by word:

• 到着港 = とうちゃくこう
• に応じて = におうじて
• 乗り継ぎ = のりつぎ
• を変える = をかえる

到着港 means arrival port or port of arrival.

It is made up of:

• 到着 = arrival
• 港 = port, harbor

So this is specifically used when the destination is a port, such as in shipping, ferries, or cargo contexts. If it were air travel, you might expect 到着空港 instead, meaning arrival airport.

に応じて means according to, depending on, or in response to.

In this sentence, it shows that the action changes based on the arrival port.

So:

• 到着港に応じて = depending on the arrival port

This pattern is common:

• N に応じて
• meaning according to N / depending on N

Examples:

• 人数に応じて、部屋を決める。
  Choose the room depending on the number of people.
• 状況に応じて、対応を変える。
  Change your response according to the situation.

The verb 応じる often takes に before the thing it matches, responds to, or depends on.

So:

• 到着港に応じて literally has the sense of
• responding to / in accordance with the arrival port

This is just the standard grammar for this expression. It is not the destination に here; it belongs to the pattern N に応じて.

乗り継ぎ means a transfer, connection, or changing from one vehicle to another.

It comes from the verb 乗り継ぐ, which means to transfer between rides or to continue a journey by changing vehicles.

Depending on context, 乗り継ぎ could refer to:

• a connecting flight
• a transfer between trains
• a transfer between ships or ferries
• a transit route in general

In this sentence, it likely means the transfer/connecting route is being changed depending on the arrival port.

Because 乗り継ぎ is the direct object of 変える.

• 変える = to change something
• X を変える = change X

So:

• 乗り継ぎを変える = change the transfer/connection

Even though 乗り継ぎ can sound like an action in English, in Japanese it can function as a noun here, so it takes を like any other object.

This is an important pair:

• 変える = to change something (transitive)
• 変わる = to change / to be changed (intransitive)

This sentence uses 変える because someone is actively changing the transfer arrangement.

• 乗り継ぎを変える。
  Change the transfer.

If it were 変わる, the transfer itself would be the thing changing:

• 乗り継ぎが変わる。
  The transfer changes.

So を + 変える tells you there is some decision-maker or operator changing it.

Japanese often leaves out the subject when it is understood from context.

So 到着港に応じて、乗り継ぎを変える。 could mean:

• We change the transfer depending on the arrival port.
• You should change the transfer depending on the arrival port.
• The company changes the transfer depending on the arrival port.

The missing subject would be supplied by the situation:

• a manual
• an announcement
• a set of instructions
• a business procedure

This kind of omission is very normal in Japanese.

The comma marks a pause and separates the condition or basis from the main action.

Structure:

• 到着港に応じて、 = depending on the arrival port,
• 乗り継ぎを変える。 = change the transfer.

The comma is helpful because に応じて introduces a phrase that modifies the whole rest of the sentence. In short sentences, the comma may sometimes be omitted, but using it here makes the sentence easier to read.

Yes. The best English translation depends on context.

Possible translations:

• depending on the arrival port
• according to the arrival port
• based on the arrival port
• in accordance with the arrival port

All of these capture the general meaning.
Depending on is often the most natural in everyday English, while according to or in accordance with can sound more formal.

Yes, it is natural, especially in formal, procedural, or transport-related contexts.

It has a concise, instruction-like style:

• 到着港に応じて、乗り継ぎを変える。

In more casual speech, a speaker might say something longer or more explicit depending on the situation, but this short style is very common in:

• manuals
• schedules
• operations documents
• travel instructions
• logistics contexts

It is broader than connecting flight.

乗り継ぎ basically means a transfer/connection during travel, so the exact English word depends on the kind of transportation involved.

For example:

• with planes: connection / connecting flight
• with trains: transfer
• with buses: transfer
• with ships or ferries: transfer / connecting service

Because the sentence uses 到着港 rather than 到着空港, this probably is not specifically about air travel. So transfer or connection is a safer general translation than connecting flight.