Answer:
Hey!
The main reson why many economic activities happen and are located in the coastal areas is mainly because of 2 reasons...
One: Most of their population (and therefore the countries workforce) live in that area and would not move out because inland is an area where you cannot find work ( or work is low paid)
Two: The coastal areas mean the are locations where ports can be built. This is essential for the exportation of goods and services globally via Cargo Ships which is the most reliable source of shipping goods! And many of the countries factories are built there...
Step-by-step explanation:
HOPE THIS HELPS!!